JP2015200353A - Rotary machine with torque limiter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate a torque limiter of a solenoid clutch 20 when its component is not dropped and an acting torque becomes more than a prescribed torque.SOLUTION: A solenoid clutch 20 comprises: an inner hub 70 rotated by receiving a rotating driving force from an engine 10; a rotary shaft 2a having a male thread part 2b fastened by thread to a female thread part 73; and a holding member 80 arranged at an outside in a radial direction in respect to the rotary shaft 2a to give a resilient force at an inside in a radial direction in respect to the rotary shaft 2a. When a torque transmitted from an engine 10 to the rotary shaft 2a through the inner hub 70 becomes more than a prescribed value and a thread fastening between the female thread part 73 and the male thread part 2b is loosened due to occurrence of slip between the holding member 80 and the rotary shaft 2a, the holding member 80 holds the rotary shaft 2a with its resilient force.

Description

  The present invention relates to a rotating device with a torque limiter.

  Conventionally, in a compressor for a vehicle air conditioner that compresses and operates by obtaining driving force from a traveling engine via a belt (V-belt), transmission of driving force from the traveling engine to the compressor and driving force transmission are stopped. In general, the control to be performed is performed by turning on and off the electromagnetic clutch.

  The electromagnetic clutch is an electromagnet that generates a pulley that rotates by a rotational driving force output from a traveling engine, an armature that rotates by being connected to the pulley, and an electromagnetic force that connects the pulley and the armature by being energized. And have. The armature is connected to the rotating shaft of the compressor via a hub. When the armature is attracted by the electromagnetic force of the electromagnet and connected to the pulley, the rotating shaft of the compressor is rotated to operate the compressor.

  In such a configuration, when the compressor is seized for some reason and the compressor is locked (that is, the movable part in the compressor is seized and fixed to the fixed part), an electromagnetic clutch is used to protect the belt. There is a compressor or a pulley provided with a torque limiter that turns off and interrupts transmission of driving force (see, for example, Patent Documents 1 and 2).

  The torque limiter of Patent Document 2 is provided with a breaking portion that is broken by an axial force generated along with tightening when a tightening torque of a predetermined value or more is applied to the threaded portion of the pulley and the shaft.

  The torque limiter of Patent Document 3 is a screw type torque limiter configured such that when an excessive torque is applied, a screw portion that fastens between the rotating shaft and the hub is loosened. In this screw type torque limiter, when the threaded portion is loosened, power transmission is cut off by expanding the air gap to a distance that the pulley cannot attract the armature by electromagnetic force. The air gap is a gap between the armature and the pulley.

JP-A-10-009122 JP 2004-340158 A JP 2008-82388 A

  In the invention described in Patent Document 2, as described above, when a tightening torque of a predetermined value or more is applied to the screw coupling portion, the fracture portion is broken by the axial force generated along with the tightening. If the torque to be applied is greater than or equal to a predetermined torque, there is an advantage that power transmission can be reliably interrupted, but there is a risk that the broken part will drop off and the dropped broken part will cause a secondary disaster to the vehicle.

  On the other hand, in the screw-type torque limiter disclosed in Patent Document 3, when the electromagnetic clutch is off, vibrations transmitted from the outside may loosen the threaded portion and expand the air gap, and the hub may fall off. There is.

  Furthermore, the deterioration of the screw surface material over time, external vibrations, or the microscopic (microscopic) contact state between the male screw thread and the female screw valley changes, so that there is a change between the male screw and the female screw. The frictional force that occurs at the time gradually decreases. For this reason, the loosening torque of the screw becomes unstable. The screw loosening torque is an operating torque at which the fastening of the male screw and the female screw starts to loosen.

  In view of the above points, the present invention is provided with a torque limiter that stabilizes the operating torque that operates the torque limiter while operating the torque limiter without the parts falling off when the applied torque exceeds a predetermined torque. The purpose is to provide rotating equipment.

In order to achieve the above object, according to the first aspect of the present invention, a hollow portion (75) and a female screw portion (73) formed on the inner surface of the hollow portion are provided, and power is supplied from a drive source (10). An inner hub (70) that rotates in response to
A rotating shaft (2a) having a male screw part (2b) screwed to the female screw part of the inner hub;
A holding member (80, 80A) that is disposed in the hollow portion of the inner hub and that is disposed radially outward with respect to the rotating shaft, and that contacts the rotating shaft; torque transmitted from the drive source to the rotating shaft through the inner hub Is less than a predetermined value, the holding member and the rotating shaft rotate together by friction between the holding member and the rotating shaft, and power is transmitted from the inner hub to the rotating shaft through the holding member.
When the torque transmitted from the drive source to the rotating shaft through the inner hub exceeds a predetermined value, slip occurs between the holding member and the rotating shaft, and the screw fastening between the female screw portion and the male screw portion is loosened. The rotating shaft is held by an elastic force.

  According to the first aspect of the present invention, the screw fastening between the inner hub and the rotating shaft can be loosened without the inner hub falling off from the rotating shaft. For this reason, it is possible to operate the torque limiter that stops the transmission of power from the inner hub through the holding member to the rotating shaft without the parts falling off.

  In addition, according to the first aspect of the present invention, the holding member and the rotating shaft rotate together by friction between the holding member and the rotating shaft. For this reason, it is possible to make it difficult for the operating torque at which slipping between the holding member and the rotating shaft starts to be affected by vibrations transmitted from the outside and aging deterioration. Therefore, the operation torque for operating the torque limiter can be stabilized.

  As described above, it is possible to provide a rotating device with a torque limiter that stabilizes the operating torque that operates the torque limiter while operating the torque limiter without causing the components to drop off when the applied torque exceeds the predetermined torque.

In the invention according to claim 8, the inner hub (75) includes a hollow portion (75) and a female screw portion (73) formed on the inner surface of the hollow portion, and rotates by receiving power from the drive source (10). 70)
A rotating shaft (2a) having a male screw part (2b) screwed to the female screw part of the inner hub;
A holding member (80, 80A) disposed in the hollow portion of the inner hub and disposed radially outside the rotation axis to contact the inner hub,
When the torque transmitted from the drive source through the inner hub to the rotating shaft is less than a predetermined value, the friction between the holding member and the inner hub causes the inner hub and the rotating shaft to rotate together, and power is transmitted from the inner hub to the rotating shaft through the holding member. ,
When the torque transmitted from the drive source to the rotating shaft through the inner hub exceeds a predetermined value, slip occurs between the holding member and the inner hub, the screw fastening between the female screw part and the male screw part is loosened, and the holding member is elastic. The inner hub is held by force.

  According to the eighth aspect of the present invention, when the applied torque is equal to or greater than the predetermined torque, the screw fastening between the inner hub and the rotating shaft can be loosened without the inner hub falling off from the rotating shaft. For this reason, it is possible to operate the torque limiter that stops the transmission of power from the inner hub through the holding member to the rotating shaft without the parts falling off.

  In addition, according to the eighth aspect of the present invention, the holding member and the rotating shaft rotate together by friction between the holding member and the inner hub. For this reason, it is possible to make it difficult for the operating torque at which the slip starts between the inner hub and the holding member to be affected by vibrations transmitted from the outside and aging deterioration. That is, the operating torque for operating the torque limiter can be stabilized.

  As described above, it is possible to provide a rotating device with a torque limiter that stabilizes the operating torque that operates the torque limiter while operating the torque limiter without causing the components to drop off when the applied torque exceeds the predetermined torque.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a whole lineblock diagram of the refrigerating cycle device of the air-conditioner for vehicles to which the electromagnetic clutch of a 1st embodiment of the present invention was applied. It is sectional drawing of the electromagnetic clutch of 1st Embodiment. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is sectional drawing which shows the action | operation of the electromagnetic clutch of 1st Embodiment. It is sectional drawing of the electromagnetic clutch of 2nd Embodiment of this invention. It is sectional drawing which shows the action | operation of the electromagnetic clutch of 2nd Embodiment. It is sectional drawing of the electromagnetic clutch of the modification of 1st, 2nd embodiment. It is a perspective view of the tolerance ring of 3rd Embodiment of this invention. It is sectional drawing of the tolerance ring of 3rd Embodiment. It is sectional drawing of the inner hub, tolerance ring, and rotating shaft of 3rd Embodiment. It is a half sectional view of an inner hub, a tolerance ring, and a rotating shaft of a 3rd embodiment. It is sectional drawing of the inner hub of 4th Embodiment of this invention, and a rotating shaft. It is sectional drawing of the inner hub and tolerance ring of 4th Embodiment. It is a half sectional view of the inner hub, tolerance ring, and rotating shaft of a 4th embodiment. It is sectional drawing of the inner hub of 5th Embodiment of this invention, and a rotating shaft. It is XVI-XVI sectional drawing in FIG. It is XVII-XVII sectional drawing in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are given the same reference numerals in the drawings in order to simplify the description.

(First embodiment)
(First embodiment)
FIG. 1 is an overall configuration diagram of a first embodiment of a refrigeration cycle apparatus 1 to which a rotating device with a torque limiter of the present invention is applied.

  The refrigeration cycle apparatus 1 is configured by connecting a compressor 2, a radiator 3, an expansion valve 4, and an evaporator 5. The compressor 2 sucks and compresses the refrigerant. The radiator 3 radiates the refrigerant discharged from the compressor 2. The expansion valve 4 decompresses and expands the refrigerant flowing out of the radiator 3. The evaporator 5 evaporates the refrigerant depressurized by the expansion valve 4 and exhibits an endothermic effect.

  The compressor 2 is installed in the engine room of the vehicle. The compressor 2 sucks the refrigerant from the evaporator 5 and compresses it by driving the compression mechanism by the rotational driving force applied from the engine 10 as the driving source for driving through the electromagnetic clutch 20.

  As the compression mechanism, either a fixed displacement compression mechanism with a fixed discharge capacity or a variable displacement compression mechanism configured to be able to adjust the discharge capacity by an external control signal may be employed.

  The electromagnetic clutch 20 of this embodiment constitutes a rotating device with a torque limiter, and is a pulley-integrated electromagnetic clutch connected to the compressor 2. The electromagnetic clutch 20 transmits the rotational driving force of the engine 10 given from the engine side pulley 11 via the V belt 12 to the compressor 2. The engine-side pulley 11 is connected to the rotational drive shaft of the engine 10.

The electromagnetic clutch 20 includes a pulley 30 and a hub 40. The pulley 30 is rotated by a rotational driving force applied from the engine 10 via the V belt 12.
The hub 40 constitutes a driven side rotating body connected to the rotating shaft 2 a of the compressor 2. The electromagnetic clutch 20 is configured to intermittently transmit the rotational driving force from the engine 10 to the compressor 2 by connecting or separating between the pulley 30 and the hub 40.

  That is, when the electromagnetic clutch 20 connects the pulley 30 and the hub 40, the rotational driving force of the engine 10 is transmitted to the compressor 2 and the refrigeration cycle apparatus 1 is operated. On the other hand, when the electromagnetic clutch 20 separates the pulley 30 and the hub 40, the rotational driving force of the engine 10 is not transmitted to the compressor 2, and the refrigeration cycle apparatus 1 does not operate.

  Next, the detailed structure of the electromagnetic clutch 20 of this embodiment is demonstrated using FIG.

  FIG. 2 is an axial sectional view of the electromagnetic clutch 20. This axial sectional view is a sectional view including the axis of the rotary shaft 2a of the compressor 2 in the electromagnetic clutch 20 and along the axis. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 2 illustrates a state where the pulley 30 and the hub 40 are separated.

  As shown in FIG. 2, the electromagnetic clutch 20 includes a pulley 30 and a hub 40.

  First, the pulley 30 has an outer cylindrical portion 31, an inner cylindrical portion 32, and an end surface portion 33. The outer cylindrical portion 31 is formed in a cylindrical shape having the axis of the rotation shaft 2a of the compressor 2 (the chain line in FIG. 2) as the center line. The outer cylindrical portion 31 is formed of a magnetic material (for example, iron). A V groove (specifically, a poly V groove) on which the V belt 12 is hung is formed on the outer peripheral side of the outer cylindrical portion 31.

  The inner cylindrical portion 32 is disposed on the inner peripheral side of the outer cylindrical portion 31 and is formed in a cylindrical shape whose axis is the axis of the rotation shaft 2 a of the compressor 2. The inner cylindrical portion 32 is made of a magnetic material (for example, iron).

  The outer cylindrical portion 31 and the end surface portion 33 are connected by a connecting portion (not shown). The inner cylindrical portion 32 and the end surface portion 33 are connected by a connecting portion (not shown).

  An outer ring 34 a of a ball bearing 34 is fixed to the inner peripheral side of the inner cylindrical portion 32. The ball bearing 34 fixes the pulley 30 to the housing forming the outer shell of the compressor 2 so that the pulley 30 is rotatable about the axis of the rotary shaft 2a. Therefore, the inner ring 34 b of the ball bearing 34 is fixed to the housing of the compressor 2 by a snap ring or the like.

  The end surface portion 33 is formed between one end side in the rotation axis direction of the outer cylindrical portion 31 and one end side in the rotation axis direction of the inner cylindrical portion 32. The end surface portion 33 is formed in a ring shape centered on the axis of the rotation shaft 2a.

  Here, a nonmagnetic portion 33 a is disposed between the end surface portion 33 and the outer cylindrical portion 31. A nonmagnetic portion 33 b is disposed between the end surface portion 33 and the inner cylindrical portion 32. The nonmagnetic portions 33a and 33b are each formed in a ring shape centered on the axis of the rotating shaft 2a.

  In addition, the nonmagnetic parts 33a and 33b of this embodiment are each comprised by the space. Or you may comprise the nonmagnetic parts 33a and 33b with nonmagnetic metal materials, such as SUS304 (stainless steel) or copper.

  The other end side surface of the end surface portion 33 forms a friction surface that comes into contact with the hub 40 when the pulley 30 and the hub 40 are connected. Therefore, in the present embodiment, the friction member 35 for increasing the friction coefficient of the end surface portion 33 is disposed on the surface side of the nonmagnetic portion 33a of the end surface portion 33. The friction member 35 is formed in a ring shape centered on the axis of the rotary shaft 2a. The friction member 35 is made of a nonmagnetic material. Specifically, a material obtained by solidifying alumina with a resin or a sintered material of metal powder (for example, aluminum powder) can be used.

  The hub 40 is disposed on one end side in the axial direction with respect to the end surface portion 33 of the pulley 30. Specifically, the hub 40 includes an armature 50, a spring member 60, and an inner hub 70.

  The armature 50 is a disk-shaped member that extends in a direction perpendicular to the axis of the rotating shaft 2a and has a through hole that penetrates through the front and back at the center. The rotation center of the armature 50 coincides with the axis of the rotation shaft 2a.

  As shown in FIG. 2, the armature 50 includes ring members 52 and 53. The ring members 52 and 53 are formed in a ring shape centering on the axis of the rotating shaft 2a. The ring members 52 and 53 are arranged offset in the radial direction of the rotary shaft 2a. The ring member 52 of this embodiment is disposed on the outer peripheral side with respect to the ring member 53. The ring members 52 and 53 are each formed of a magnetic material (for example, iron). The ring members 52 and 53 are connected by a connecting portion (not shown).

  A nonmagnetic portion 54 made of a nonmagnetic metal material is disposed between the ring members 52 and 53. The nonmagnetic portion 54 is formed in a ring shape centered on the axis of the rotating shaft 2a. The nonmagnetic portion 54 of the present embodiment is constituted by a void. The nonmagnetic portion 54 may be made of a nonmagnetic metal material such as SUS304 (stainless steel) or copper.

  Here, the surface of the armature 50 that faces the end surface portion 33 of the pulley 30 forms a friction surface that contacts the pulley 30 when the pulley 30 and the hub 40 are connected.

  The spring member 60 is a metal leaf spring that applies an elastic force in a direction in which the armature 50 moves away from the pulley 30. The spring member 60 is connected to a plane of the armature 50 opposite to the pulley 30 by a plurality of rivets 41 (one rivet 41 is shown in FIG. 1). The spring member 60 is disposed so as to be orthogonal to the axis of the rotating shaft 2a. When the armature 50 and the pulley 30 are separated from each other by the elastic force of the spring member 60, a predetermined gap G1 is formed between the armature 50 and the pulley 30.

  The inner hub 70 constitutes a connecting member that connects the armature 50 and the rotating shaft 2 a of the compressor 2. The inner hub 70 includes a cylindrical portion 71 and a flange portion 72.

  The cylindrical portion 71 is formed in a cylindrical shape centered on the axis of the rotation shaft 2a. The flange portion 72 is formed so as to extend radially outward from one axial end side of the cylindrical portion 71. The cylindrical portion 71 and the flange portion 72 are formed with a hollow portion 75 formed so as to extend in the axial direction of the rotary shaft 2a. The flange portion 72 and the spring member 60 are connected by a plurality of rivets 42 (one rivet 42 is shown in FIG. 1).

  A female threaded portion 73 is provided in the middle portion in the axial direction of the hollow portion 75 of the cylindrical portion 71. The female screw portion 73 is screwed to the male screw portion 2b of the rotating shaft 2a. The inner hub 70 is made of a metal material such as aluminum.

  Here, when the inner hub 70 rotates in the same direction as the pulley 30, the screw fastening between the female screw portion 73 of the inner hub 70 and the male screw portion 2b of the rotating shaft 2a is loosened. On the other hand, when the inner hub 70 rotates in the opposite direction to the pulley 30, the female screw portion 73 and the male screw portion 2b are configured so that the screw fastening between the female screw portion 73 and the male screw portion 2b is tightened.

  A holding member 80 is disposed on the other axial end side of the hollow portion 75 of the cylindrical portion 71 of the present embodiment. That is, the holding member 80 is disposed on the radially inner side with respect to the cylindrical portion 71. The holding member 80 is disposed radially outside the rotation shaft 2a. Specifically, the holding member 80 is formed in a cylindrical shape having a hollow portion with the axis of the rotating shaft 2a as the axis. The inner peripheral surface of the holding member 80 gives an elastic force radially inward with respect to the outer peripheral surface of the rotating shaft 2a.

  Here, before the holding member 80 is fitted into the hollow portion 75 of the cylindrical portion 71, the outer dimension of the holding member 80 is larger than the inner diameter size of the hollow portion 75 of the cylindrical portion 71. The holding member 80 is fitted into the hollow portion 75 of the cylindrical portion 71 by press fitting. In addition, as a material of the holding member 80, metal materials, such as iron and aluminum, can be used.

  In this embodiment, the outer peripheral surface which contacts the holding member 80 among the rotating shafts 2a is formed in the cross-sectional arc shape over the whole circumferential direction centering on the axial center of the rotating shaft 2a. The inner peripheral surface of the holding member 80 that is in contact with the rotating shaft 2a is formed in a circular arc shape in the entire circumferential direction around the axis of the rotating shaft 2a. Thereby, the inner peripheral surface of the holding member 80 and the outer peripheral surface of the rotating shaft 2a come into contact with each other, and the holding member 80 and the rotating shaft 2a are rotated by friction between the holding member 80 and the rotating shaft 2a. Yes. The inner peripheral surface of the holding member 80 and the outer peripheral surface of the rotary shaft 2a are set so that the friction torque acting by the friction between the holding member 80 and the rotary shaft 2a is 7 Nm or more and 185 Nm or less.

  Note that 7 Nm is the minimum value of torque that acts when a general vehicular compressor is compressed. 185 Nm is a torque that acts on the compressor at the timing when the V-belt 12 starts to slide with respect to the pulley 30.

  In the present embodiment, an electromagnetic coil 90 is disposed on the outer cylindrical portion 31 and the inner cylindrical portion 32 of the pulley 30. The electromagnetic coil 90 is formed in a ring shape centered on the axis of the rotating shaft 2a. The electromagnetic coil 90 of the present embodiment is configured by winding a wire made of copper, aluminum or the like around a resin spool in a double row / multiple layer. The electromagnetic coil 90 of the present embodiment is fixed to the housing of the compressor 2 by fitting and fastening.

  Moreover, the control apparatus 6 of FIG. 1 controls the electricity supply to the electromagnetic coil 90 based on the control signal output from air-conditioner ECU (electronic control apparatus).

  Next, assembly of the electromagnetic clutch 20 of the present embodiment will be described.

  First, the compressor 2, the pulley 30, the ball bearing 34, the armature 50, the spring member 60, the inner hub 70, the holding member 80, and the electromagnetic coil 90 are prepared separately.

  First, the outer ring 34a of the ball bearing 34 is fixed to the pulley 30 by press fitting or the like.

  Thereafter, the hub 40 is assembled using the inner hub 70, the spring member 60, the armature 50, and the like. Specifically, the inner hub 70 and the spring member 60 are fixed by a plurality of rivets 42. The space between the armature 50 and the spring member 60 is fixed by a plurality of rivets 41.

  Next, the electromagnetic coil 90 is fixed to the housing of the compressor 2. Next, the inner ring 34 b of the ball bearing 34 is fixed to the housing of the compressor 2.

  Next, one end of the rotating shaft 2 a in the axial direction is inserted into the hollow portion of the holding member 80. And the holding member 80 is moved to the axial direction other end side with respect to the external thread part 2b. At this time, the holding member 80 is elastically deformed radially outward by the rotating shaft 2a, and the hollow portion of the holding member 80 expands. As a result, the holding member 80 has a spring property that generates an elastic force acting on the rotating shaft 2a side. For this reason, the holding member 80 is attached to the rotating shaft 2a due to its springiness.

  Here, the mounted state is a state in which the elastic force of the holding member 80 is applied to the rotating shaft 2a, and the rotating shaft 2a and the holding member 80 are rotated below a certain friction torque. The above is the fitting that causes the sliding between the rotating shaft 2a and the holding member 80. The friction torque is a friction torque generated between the rotating shaft 2a and the holding member 80.

  Next, the rotating shaft 2 a is inserted into the hollow portion 75 of the inner hub 70 from the other end side in the axial direction. Along with this, the holding member 80 is press-fitted into the hollow portion 75 of the inner hub 70. At this time, the holding member 80 contracts due to elastic deformation. As a result, the holding member 80 is press-fitted into and fitted into the inner hub 70.

  Next, the rotary shaft 2 a is rotated with respect to the inner hub 70, and the male screw portion 2 b of the rotary shaft 2 a is screwed to the female screw portion 73 of the inner hub 70. Thereby, the rotating shaft 2a is fitted to the inner hub 70 from the other end side in the axial direction. At this time, the holding member 80 is pressed by the rotating shaft 2a and contracts due to elastic deformation. Accordingly, an elastic force is applied from the holding member 80 to the inside in the radial direction with respect to the rotating shaft 2a. Thereby, the rotating shaft 2a is fixed to the hub 40.

  Next, the operation of the electromagnetic clutch 20 of this embodiment will be described.

  First, when the control device 6 is not energizing the electromagnetic coil 90, a gap M1 is formed between the armature 50 and the pulley 30 by the elastic force of the spring member 60 as shown in FIG. . That is, the electromagnetic clutch 20 is in an OFF state.

  Next, the control device 6 starts energizing the electromagnetic coil 90. At this time, the magnetic circuit M through which the magnetic flux passes through the outer cylindrical portion 31, the armature 50, the end surface portion 33, the armature 50, the inner cylindrical portion 32, and the electromagnetic coil 90 is formed.

  Here, the magnetic force generated by the magnetic circuit M is an attractive magnetic force that connects the pulley 30 and the armature 50. The attractive magnetic force of the magnetic circuit M is larger than the elastic force of the spring member 60. For this reason, the pulley 30 and the armature 50 can be connected by the magnetic force generated from the magnetic circuit M. That is, the electromagnetic clutch 20 is turned on.

  Here, when the torque transmitted from the engine 10 to the rotary shaft 2a side through the inner hub 70 and the holding member 80 is less than a predetermined value, the rotary shaft 2a and the holding member 80 are caused by friction between the holding member 80 and the rotary shaft 2a. Will go around. That is, the pulley 30, the armature 50, the inner hub 70, the holding member 80, and the rotating shaft 2a rotate in the same direction.

  Accordingly, the rotational driving force from the engine 10 is transmitted in the order of the pulley 30 → the armature 50 of the hub 40 → the inner hub 70 → the holding member 80 → the rotating shaft 2a. For this reason, the rotational driving force from the engine 10 can be transmitted to the compressor 2 by the electromagnetic clutch 20. Therefore, the compressor 2 starts the compression operation by the rotational driving force from the engine 10.

  Next, the compressor is locked (that is, the movable part in the compressor is seized and fixed to the fixed part), and the torque transmitted from the engine 10 to the rotating shaft 2a side through the inner hub 70 and the holding member 80 is a predetermined value. That's it. At this time, slip occurs between the holding member 80 and the rotary shaft 2a, and the screw fastening between the female screw portion 73 of the inner hub 70 and the male screw portion 2b of the rotary shaft 2a is loosened. That is, the screw fastening between the female screw portion 73 and the male screw portion 2b is loosened by the rotation of the inner hub 70 with respect to the rotating shaft 2a. Thereby, the inner hub 70 and the holding member 80 move to the axial direction one end side with respect to the rotating shaft 2a. For this reason, the clearance gap between the armature 50 and the pulley 30 spreads.

  Thereby, the magnetic force generated by the magnetic circuit M is reduced, and the attractive magnetic force for connecting the pulley 30 and the armature 50 is smaller than the elastic force of the spring member 60. Accordingly, the connection between the pulley 30 and the armature 50 is released. That is, the torque limiter that stops transmission of the rotational driving force from the inner hub 70 to the rotary shaft 2a through the holding member 80 is activated. At this time, the elastic force from the holding member 80 acts radially inward with respect to the rotating shaft 2a. At this time, in a state where the holding member 80 is press-fitted into and fitted to the inner hub 70, the holding member 80 holds the rotating shaft 2a by its elastic force (see FIG. 4).

  According to the present embodiment described above, the electromagnetic clutch 20 includes the internal thread portion 73 and is rotated by receiving the rotational driving force from the engine 10 and the external thread that is screwed to the internal thread portion 73 of the inner hub 70. The rotating shaft 2a provided with the part 2b, and the holding member 80 which is arrange | positioned radially outside with respect to the rotating shaft 2a and contacts the rotating shaft 2a is provided. The elastic force of the holding member 80 acts on the outer peripheral surface of the rotating shaft 2a over the entire circumference. When the torque transmitted from the engine 10 to the rotary shaft 2a through the inner hub 70 is less than a predetermined value, the holding member 80 and the rotary shaft 2a rotate together by friction between the holding member 80 and the rotary shaft 2a. On the other hand, the torque transmitted from the engine 10 to the rotary shaft 2a through the inner hub 70 becomes a predetermined value or more, and slip occurs between the holding member 80 and the rotary shaft 2a, so that the screw fastening between the female screw portion 73 and the male screw portion 2b is performed. When loosened, the holding member 80 holds the rotary shaft 2a by its elastic force in a state where the holding member 80 is press-fitted into and fitted to the inner hub 70.

  According to the above, when the torque acting on the rotating shaft 2a side from the engine 10 through the inner hub 70 becomes a predetermined torque or more, the holding member 80 holds the rotating shaft 2a by its elastic force. For this reason, the screw fastening between the inner hub 70 and the rotating shaft 2a can be loosened without the inner hub 70 falling off from the rotating shaft 2a. Therefore, when the applied torque becomes equal to or higher than the predetermined torque without the parts falling off, the torque limiter is operated to stop the rotation driving force from being transmitted from the inner hub 70 to the rotating shaft 2a side through the holding member 80. . As a result, it is possible to avoid a risk that a secondary disaster will occur due to parts falling off with the operation of the torque limiter.

  In addition, according to the present embodiment, the inner peripheral surface of the holding member 80 that contacts the rotating shaft 2a is formed in a circular arc shape with the axis of the rotating shaft 2a as the center. The outer peripheral surface which contacts the holding member 80 among the rotating shafts 2a is formed in the cross-sectional arc shape centering on the axis line of the rotating shaft 2a. And the holding member 80 and the rotating shaft 2a rotate together by the friction between the holding member 80 and the rotating shaft 2a. For this reason, the operating torque at which sliding starts between the holding member 80 and the rotating shaft 2a is not easily affected by vibrations transmitted from the outside or aging deterioration. That is, it is possible to stabilize the operating torque of the torque limiter that stops the rotation driving force from being transmitted from the inner hub 70 to the rotating shaft 2a through the holding member 80.

  In the present embodiment, the holding member 80 is disposed opposite to the opening 74 of the inner hub 70 with respect to the male screw portion 2 b and the female screw portion 73. For this reason, the distance between the opening 74 of the inner hub 70 and the holding member 80 can be secured. Therefore, it is possible to prevent water that has entered from the opening 74 of the inner hub 70 from entering the holding member 80.

  Here, when water enters between the holding member 80 and the rotating shaft 2a, the friction acting between the holding member 80 and the rotating shaft 2a becomes unstable. For this reason, in the torque limiter, the operating torque at which the slip starts between the holding member 80 and the rotating shaft 2a becomes unstable.

  On the other hand, in this embodiment, as described above, water that has entered from the opening 74 of the inner hub 70 can be prevented from entering between the holding member 80 and the rotating shaft 2a. Thereby, the friction which acts between the holding member 80 and the rotating shaft 2a can be stabilized, and the operating torque which starts a slip between the holding member 80 and the rotating shaft 2a can be stabilized.

  In the present embodiment, the operating torque of the torque limiter is determined by the frictional force between the holding member 80 and the rotating shaft 2a. For this reason, in order to stabilize the operating torque of the torque limiter, it is necessary to stabilize the friction coefficient of the holding member 80 and the friction coefficient of the rotating shaft 2a.

  Therefore, in the present embodiment, in order to stabilize the respective friction coefficients of the holding member 80 and the rotating shaft 2a with desired values, surface treatment or corrosion that stabilizes the friction coefficient on at least one of the holding member 80 and the rotating shaft 2a. An anticorrosion treatment may be performed to prevent a change in the friction coefficient due to.

(Second Embodiment)
In the first embodiment, the example in which the holding member 80 is arranged on the other end side in the axial direction of the rotary shaft 2a with respect to the male screw portion 2b and the female screw portion 73 has been described. 5, the example which has arrange | positioned the holding member 80 in the axial direction one end side of the rotating shaft 2a with respect to the external thread part 2b and the internal thread part 73 is demonstrated.

  In FIG. 5, since the configuration other than the arrangement of the holding member 80 with respect to the male screw portion 2 b and the female screw portion 73 is the same as that in FIG. 2, the description of the other configurations is omitted.

In the first and second embodiments, when friction is generated between the holding member 80 and the rotary shaft 2a and the torque transmitted from the engine 10 becomes equal to or greater than a predetermined value, the gap between the holding member 80 and the rotary shaft 2a. However, instead of this, the following (a) and (b) may be used.
(A) When friction is generated between the holding member 80 and the inner hub 70 and the torque transmitted from the engine 10 to the rotary shaft 2a through the inner hub 70 and the holding member 80 becomes a predetermined value or more, the gap between the holding member 80 and the inner hub 70 is reached. To start sliding. In this case, the elastic force of the holding member 80 acts on the inner peripheral surface of the inner hub 70 over the entire circumference. As shown in FIG. 6, the holding member 80 holds the inner hub 70 by its elastic force. For this reason, when the applied torque exceeds a predetermined torque, the inner hub 70 does not fall off the rotating shaft 2a, and the torque limiter is operated, so that the rotational driving force is transmitted from the inner hub 70 to the rotating shaft 2a side through the holding member 80. Can be stopped.

  In this modification, the outer surface of the holding member 80 and the inner surface of the inner hub 70 are set so that the friction torque acting by the friction between the holding member 80 and the inner hub 70 is 7 Nm or more and 185 Nm or less. In this case, the rotating shaft 2a is press-fitted into the hollow portion of the holding member 80 and fitted.

  In this modification, the operating torque of the torque limiter is determined by the frictional force between the holding member 80 and the inner hub 70. For this reason, in order to stabilize the operating torque of the torque limiter, it is necessary to stabilize the friction coefficient of the holding member 80 and the friction coefficient of the inner hub 70, respectively.

Therefore, in this modification, in order to stabilize the respective friction coefficients of the holding member 80 and the inner hub 70 at desired values, at least one of the holding member 80 and the inner hub 70 is subjected to surface treatment or friction due to corrosion. An anticorrosion treatment may be performed to prevent the coefficient from changing.
(B) Friction is generated between the holding member 80 and the rotating shaft 2a, and friction is generated between the holding member 80 and the inner hub 70. In this case, the holding member 80 holds either the inner hub 70 or the rotating shaft 2a by its elastic force. For this reason, when the acting torque becomes equal to or higher than the predetermined torque, the inner hub 70 can be operated without the inner hub 70 falling off the rotating shaft 2a.

  In this modification, the added value obtained by adding the friction torque acting by the friction between the holding member 80 and the rotating shaft 2a and the friction torque acting by the friction between the holding member 80 and the inner hub 70 is 7 Nm or more. The outer surface of the rotating shaft 2a, the inner surface of the holding member 80, the outer surface, and the inner surface of the inner hub 70 are set so as to be 185 Nm or less.

  Further, in the first embodiment, the rotation preventing portion 100 may be provided on the holding member 80 and the inner hub 70.

  For example, as shown in FIG. 7, the rotation stopper 100 is composed of a protrusion 80a and a recess 70a. The protrusion 80a is a protrusion that is formed on the holding member 80 and protrudes radially outward. The anti-rotation portion 70a is formed in the inner hub 70 so as to be recessed radially outward so that the protrusion 80a fits.

  Similarly, in the second embodiment, the holding member 80 and the rotation shaft 2a may be provided with a rotation preventing portion.

(Third embodiment)
In the third embodiment, an example in which the tolerance ring 80A is used as a holding member in the electromagnetic clutch 20 of the first embodiment will be described with reference to FIGS.

  As shown in FIG. 8, the tolerance ring 80 </ b> A includes a ring member 81 and a space 82. In the ring member 81, a thin plate member is formed in a ring shape around the axis of the rotation shaft 2a. The void 82 is disposed between one end side 81 b and the other end side 81 c in the circumferential direction of the ring member 81. The ring member 81 is provided with a plurality of protrusions 81a. The plurality of protrusions 81a are arranged at intervals in the circumferential direction around the axis of the rotation shaft 2a. Each of the plurality of protrusions 81a is formed such that the front surface and the back surface of the ring member 81 are convex outward in the radial direction. The surface is a radially outer surface of the ring member 81. The back surface is a radially inner surface of the ring member 81. As the tolerance ring 80A, a known ring described in JP-A-2005-1114025 or the like can be used.

  As shown in FIG. 9, in the tolerance ring 80 </ b> A, the plurality of protrusions 81 a are fitted in the corresponding recesses 84 among the plurality of recesses 84 of the inner hub 70. The plurality of recesses 84 are formed so as to be recessed radially outward on the inner peripheral surface of the inner hub 70. The plurality of recesses 84 are arranged on the inner peripheral surface of the inner hub 70 in the circumferential direction around the axis of the rotation shaft 2a.

  The rotating shaft 2a is fitted into the hollow portion of the tolerance ring 80A. As shown in FIG. 10, the tolerance ring 80A is disposed on the other end side in the axial direction with respect to the male screw portion 2b of the rotating shaft 2a. A support portion 85 that supports the tolerance ring 80A from the axial direction is provided on the other end side in the axial direction with respect to the tolerance ring 80A in the rotating shaft 2a.

  Of the inner peripheral surface of the tolerance ring 80A, a portion 86 (see FIG. 9) other than the plurality of protrusions 81a is formed in a cross-sectional arc shape centering on the axis of the rotating shaft 2a. The other portion 86 of the inner peripheral surface of the tolerance ring 80A is in contact with the outer peripheral surface of the rotating shaft 2a. Of the outer peripheral surface of the rotating shaft 2a, a portion that contacts the other portion 86 of the inner peripheral surface of the tolerance ring 80A is formed in a circular arc shape with the axis of the rotating shaft 2a as the center. As a result, the other portion 86 of the inner peripheral surface of the tolerance ring 80A comes into contact with the outer peripheral surface of the rotary shaft 2a, and the other portion 86 of the inner peripheral surface of the tolerance ring 80A and the outer peripheral surface of the rotary shaft 2a. There will be friction between the two.

  In the electromagnetic clutch 20 of the present embodiment, the configuration other than the tolerance ring 80A and the rotating shaft 2a is the same as that of the electromagnetic clutch 20 of the first embodiment, and a description thereof will be omitted.

  Next, assembly of the tolerance ring 80A, the inner hub 70, and the rotating shaft 2a in the electromagnetic clutch 20 of the present embodiment will be described.

  First, the rotating shaft 2a is fitted into the hollow portion of the tolerance ring 80A. At this time, the tolerance ring 80A expands radially outward due to elastic deformation, and the interval between the circumferential one end side 81b and the other end side 81c increases.

  Next, as shown in FIG. 10, the front end portion of the rotating shaft 2a is opposed to the hollow portion 75 of the inner hub 70, and the rotating shaft 2a is inserted into the hollow portion 75 of the inner hub 70 (see FIG. 11). In addition, the rotary shaft 2 a is rotated with respect to the inner hub 70, and the male screw portion 2 b is screwed to the female screw portion 73.

  At this time, in the tolerance ring 80A, the plurality of protrusions 81a are supported by the support portion 85 of the rotating shaft 2a, and the inner peripheral surface of the inner hub 70 is scraped off, while the hollow portion 75 of the inner hub 70 is moved to one end in the axial direction. move on. For this reason, in the tolerance ring 80 </ b> A, the plurality of protrusions 81 a form the plurality of recesses 84 on the inner peripheral surface of the inner hub 70. Accordingly, the tolerance ring 80A is press-fitted between the inner hub 70 and the rotating shaft 2a.

  Thereafter, the plurality of protrusions 81 a of the tolerance ring 80 </ b> A are fitted in the corresponding recesses 84 among the plurality of recesses 84 on the inner peripheral surface of the inner hub 70. At this time, the plurality of projecting portions 81a are pressed by the inner hub 70 and the rotating shaft 2a and contract by elastic deformation. Along with this, an elastic force is generated in the plurality of protrusions 81a of the tolerance ring 80A. Thereby, an elastic force acts on the rotating shaft 2a from the portion 86 other than the plurality of protrusions 81a on the inner peripheral surface of the tolerance ring 80A. Thus, the assembly of the electromagnetic clutch 20 is completed.

  Next, the operation of the electromagnetic clutch 20 of this embodiment will be described.

  First, when the control device 6 starts energizing the electromagnetic coil 90, the magnetic circuit M is formed as in the first embodiment. The magnetic force generated by the magnetic circuit M can connect the pulley 30 and the armature 50. That is, the electromagnetic clutch 20 is turned on. Accordingly, the rotational driving force from the engine 10 is transmitted in the order of the pulley 30 → the hub 40 → the tolerance ring 80A.

  When the torque transmitted from the engine 10 to the rotary shaft 2a through the inner hub 70 and the tolerance ring 80A is less than a predetermined value, the other portion 86 other than the plurality of protrusions 81a on the inner peripheral surface of the tolerance ring 80A, and the rotary shaft The rotating shaft 2a and the tolerance ring 80A are rotated by friction with the outer peripheral surface of 2a. Accordingly, the rotational driving force from the engine 10 is transmitted in the order of the pulley 30 → the armature 50 of the hub 40 → the inner hub 70 → the tolerance ring 80A → the rotating shaft 2a. For this reason, the rotational driving force from the engine 10 can be transmitted to the compressor 2 by the electromagnetic clutch 20. Therefore, the compressor 2 starts the compression operation by the rotational driving force from the engine 10.

  Next, the compressor is locked, and the torque transmitted from the engine 10 to the rotary shaft 2a through the inner hub 70 and the tolerance ring 80A becomes a predetermined value or more.

  Then, slip occurs between the tolerance ring 80A and the rotary shaft 2a, and the screw fastening between the female screw portion 73 of the inner hub 70 and the male screw portion 2b of the rotary shaft 2a is loosened. Along with this, the inner hub 70 moves toward one end in the axial direction with respect to the rotating shaft 2a. For this reason, the clearance gap between the armature 50 and the pulley 30 spreads.

  Thereby, the magnetic force generated by the magnetic circuit M is reduced, and the attractive magnetic force for connecting the pulley 30 and the armature 50 is smaller than the elastic force of the spring member 60. Accordingly, the connection between the pulley 30 and the armature 50 is released. That is, the torque limiter that stops transmission of the rotational driving force from the inner hub 70 to the rotating shaft 2a through the tolerance ring 80A is activated.

  At this time, the elastic force from the plurality of protrusions 81a of the tolerance ring 80A acts on the rotation shaft 2a inward in the radial direction. At this time, the tolerance ring 80A holds the rotating shaft 2a by its elastic force.

  According to the present embodiment described above, as in the first embodiment, when the torque acting on the rotary shaft 2a from the engine 10 through the inner hub 70 becomes a predetermined torque or more, the inner hub 70 does not fall off the rotary shaft 2a. The screw fastening between the inner hub 70 and the rotating shaft 2a can be loosened. Therefore, the torque limiter can be operated when the applied torque becomes equal to or greater than the predetermined torque without the parts falling off.

  In addition to this, according to the present embodiment, of the inner peripheral surface of the tolerance ring 80A, the other portion 86 other than the plurality of protrusions 81a is formed in a cross-sectional arc shape centering on the axis of the rotating shaft 2a. Thus, it is in contact with the outer peripheral surface of the rotating shaft 2a. A portion of the outer peripheral surface of the rotating shaft 2a that contacts the other portion 86 of the tolerance ring 80A is formed in a circular arc shape with the axis of the rotating shaft 2a as the center. And the tolerance ring 80A and the rotating shaft 2a rotate together by the friction between the tolerance ring 80A and the rotating shaft 2a. For this reason, the operating torque at which sliding starts between the tolerance ring 80A and the rotating shaft 2a is not easily affected by vibrations transmitted from the outside or aging deterioration. That is, the operating torque for operating the torque limiter can be stabilized.

  In the present embodiment, the inner peripheral surface of the inner hub 70 is provided with a plurality of recesses 84 in which the plurality of protrusions 81a of the tolerance ring 80A are disposed. For this reason, the rotation of the tolerance ring 80A with respect to the inner hub 70 can be stopped.

  In particular, the plurality of recesses 84 are formed by cutting the inner peripheral surface of the inner hub 70 when the tolerance ring 80 </ b> A is fitted into the hollow portion 75 of the inner hub 70. For this reason, it is not necessary to form the plurality of recesses 84 in the inner hub 70 in advance.

  In the present embodiment, the tolerance ring 80 </ b> A is disposed opposite to the opening 74 of the inner hub 70 with respect to the male screw portion 2 b and the female screw portion 73. For this reason, the distance between the opening 74 of the inner hub 70 and the tolerance ring 80A can be secured. Therefore, it is possible to prevent water that has entered from the opening 74 of the inner hub 70 from entering the tolerance ring 80A side. Thereby, the friction which acts between the tolerance ring 80A and the rotating shaft 2a can be stabilized, and the operating torque at which the slip starts between the tolerance ring 80A and the rotating shaft 2a can be stabilized.

  In the present embodiment, the tolerance ring 80 </ b> A needs to form a detent by scraping the inner surface of the inner hub 70. For this reason, when the material of the inner hub 70 is carbon steel having a hardness of 150 to 240 HV, a hard metal of 240 HV or more is used as the material of the tolerance ring 80A.

(Fourth embodiment)
In the third embodiment, the example in which the tolerance ring 80A is arranged on the other end side in the axial direction of the rotating shaft 2a with respect to the male screw portion 2b and the female screw portion 73 has been described, but instead of this, in this embodiment, the male screw An example in which the tolerance ring 80A is arranged on one end side in the axial direction of the rotating shaft 2a with respect to the portion 2b and the female screw portion 73 will be described with reference to FIGS.

  In the present embodiment, as shown in FIG. 12, a portion 2c where the tolerance ring 80A is disposed is set on the distal end side at one axial end side of the rotating shaft 2a. A male screw portion 2b is disposed on the other end side in the axial direction with respect to the portion 2c of the rotating shaft 2a. Of the rotating shaft 2a, the male screw portion 2b is formed radially outward with respect to the portion 2c. As shown in FIG. 13, a support portion 85 for supporting the tolerance ring 80A is provided on one end side in the axial direction with respect to the male screw portion 2b of the rotating shaft 2a.

  In this embodiment configured as described above, the rotary shaft 2 a is inserted into the hollow portion 75 of the inner hub 70, and the male screw portion 2 b of the rotary shaft 2 a is screwed to the female screw portion 73 of the inner hub 70. At this time, as shown in FIG. 14, the tolerance ring 80 </ b> A is supported by the support portion 85 of the rotating shaft 2 a and advances into the hollow portion 75 of the inner hub 70 while cutting the inner peripheral surface of the inner hub 70. For this reason, the male threaded portion 2b of the rotary shaft 2a is screwed to the female threaded portion 73 of the inner hub 70 while the protrusion 81a of the tolerance ring 80A forms a plurality of recesses 84 on the inner peripheral surface of the inner hub 70.

  Thereafter, in a state where the plurality of protrusions 81a of the tolerance ring 80A are fitted into the corresponding recesses 84 among the plurality of recesses 84 on the inner peripheral surface of the inner hub 70, the internal thread portion 73 of the inner hub 70 and the external thread portion 2b of the rotary shaft 2a. Screw fastening is completed. At this time, the plurality of projecting portions 81a are pressed by the inner hub 70 and the rotating shaft 2a and contract by elastic deformation. Along with this, an elastic force is generated in the plurality of protrusions 81a of the tolerance ring 80A. Thereby, an elastic force acts on the rotating shaft 2a from the portion 86 other than the plurality of protrusions 81a on the inner peripheral surface of the tolerance ring 80A. Thus, the assembly of the electromagnetic clutch 20 is completed.

  According to the present embodiment described above, as in the third embodiment, the torque limiter can be operated when the applied torque is equal to or greater than the predetermined torque without the components falling off. In addition to this, the tolerance ring 80A and the rotating shaft 2a rotate together by friction between the tolerance ring 80A and the rotating shaft 2a as in the third embodiment. For this reason, the operating torque for operating the torque limiter can be stabilized.

(Fifth embodiment)
In the fifth embodiment, in the third embodiment, a plurality of guide grooves 87a for guiding the plurality of protrusions 81a when the plurality of protrusions 81a of the tolerance ring 80A advance in the hollow portion 75 of the inner hub 70. An example in which is provided will be described with reference to FIGS. 15, 16, and 17. FIG.

  FIG. 15 is a cross-sectional view of the inner hub 70, the tolerance ring 80A, and the rotating shaft 2a. 16 and 17 are cross-sectional views of the inner hub 70 on the other end side in the axial direction with respect to the female threaded portion 73.

  The plurality of guide grooves 87a of the present embodiment are formed so as to correspond to the recesses 84, respectively. The plurality of guide grooves 87 a are formed on the other end side in the axial direction with respect to the female screw portion 73 on the inner peripheral surface of the inner hub 70.

  As shown in FIGS. 15 and 17, the plurality of guide grooves 87 a are formed to be recessed outward in the radial direction on the inner peripheral surface of the inner hub 70. The plurality of guide grooves 87a are arranged on the inner peripheral surface of the inner hub 70 at intervals in the circumferential direction. The plurality of guide grooves 87 a are formed in the axial direction on the other axial end side with respect to the annular stepped portion 87 b on the inner peripheral surface of the inner hub 70. The annular step portion 87 b is convex on the radially inner side of the bottom portion of the guide groove 87 a on the other end side in the axial direction with respect to the female screw portion 73 on the inner peripheral surface of the inner hub 70. The annular step 87b supports the plurality of protrusions 81a of the tolerance ring 80A from one end in the axial direction.

  Here, the cross-sectional area in the direction orthogonal to the axial direction of the plurality of guide grooves 87a is smaller than the cross-sectional area in the direction orthogonal to the axial direction of the protrusion 81a.

  In the present embodiment configured as described above, the rotary shaft 2 a is inserted into the hollow portion 75 of the inner hub 70, and the rotary shaft 2 a is rotated with respect to the inner hub 70. Accordingly, the male screw portion 2b of the rotating shaft 2a is screwed to the female screw portion 73 of the inner hub 70. At this time, the tolerance ring 80A is supported by the support portion 85 of the rotating shaft 2a, and the plurality of protrusions 81a are arranged in the hollow portion 75 of the inner hub 70 along the corresponding guide grooves 87a among the plurality of guide grooves 87a. To one end in the axial direction.

  Accordingly, the plurality of protrusions 81 a form the plurality of recesses 84 while cutting the groove forming portion 87 that forms the guide groove 87 a in the inner hub 70. That is, the plurality of projecting portions 81 a advance toward the one end in the axial direction through the hollow portion 75 of the inner hub 70 while cutting the inner peripheral surface of the inner hub 70.

  Thereafter, the screw fastening of the male threaded portion 2b of the rotating shaft 2a to the female threaded portion 73 of the inner hub 70 is completed, and the plurality of protrusions 81a of the tolerance ring 80A correspond to the corresponding recesses among the plurality of recessed portions 84 on the inner peripheral surface of the inner hub 70. It will be in the state fitted in 84. At this time, the plurality of projecting portions 81a are pressed by the inner hub 70 and the rotating shaft 2a and contract by elastic deformation. Along with this, an elastic force is generated in the plurality of protrusions 81a of the tolerance ring 80A. Thereby, an elastic force acts on the rotating shaft 2a from the portion 86 other than the plurality of protrusions 81a on the inner peripheral surface of the tolerance ring 80A. Thus, the assembly of the electromagnetic clutch 20 is completed.

  According to the present embodiment described above, the torque limiter can be operated and the operating torque for operating the torque limiter can be stabilized as in the fourth embodiment.

  In the present embodiment, a plurality of guide grooves 87a are provided for guiding the plurality of protrusions 81a when the plurality of protrusions 81a of the tolerance ring 80A advance in the hollow portion 75 of the inner hub 70. For this reason, the plurality of recesses 84 can be easily formed on the inner peripheral surface of the inner hub 70.

(Other embodiments)
In the third, fourth, and fifth embodiments, in the tolerance ring 80A, the example in which the plurality of protrusions 81a are formed to protrude radially outward has been described. However, the plurality of protrusions are radially inward. You may form so that it may become convex.

  In this case, when the torque transmitted from the engine 10 to the rotary shaft 2a side through the inner hub 70 is less than a predetermined value, the inner hub 70 and the tolerance ring 80A rotate together due to friction between the tolerance ring 80A and the inner hub 70, A rotational driving force is transmitted from the inner hub 70 to the rotating shaft 2a through the tolerance ring 80A.

  On the other hand, when the torque transmitted from the engine 10 to the rotary shaft 2a side through the inner hub 70 becomes a predetermined value or more, slip occurs between the tolerance ring 80A and the inner hub 70, and the screw fastening between the female screw portion 73 and the male screw portion 2b occurs. Loosens. At this time, the elastic force acts on the inner peripheral surface of the inner hub 70 from the outer peripheral surface of the tolerance ring 80A other than the plurality of convex portions. For this reason, the tolerance ring 80A holds the inner hub 70 by its elastic force.

  In this case, when the tolerance ring 80A and the rotating shaft 2a are fitted into the hollow portion 75 of the inner hub 70, the plurality of convex portions of the tolerance ring 80A scrape the outer peripheral surface of the rotating shaft 2a to form a detent. . For this reason, it is necessary for the tolerance ring 80A to have a higher hardness than the rotating shaft 2a.

  Specifically, the tolerance ring 80A is formed in a ring shape centering on the axis of the rotating shaft 2a, and a plurality of protruding portions protruding radially inward are arranged in the circumferential direction. The plurality of protrusions are fitted into the corresponding recesses among the plurality of recesses on the outer surface of the rotation shaft 2a, whereby the rotation shaft 2a is coupled to the tolerance ring 80A.

  The plurality of concave portions of the rotating shaft 2a are formed by being cut by the plurality of protrusions when the rotating shaft 2a is fitted into the hollow portion of the tolerance ring 80A.

  Furthermore, a plurality of guide grooves corresponding to the plurality of recesses may be formed in the rotating shaft 2a. The plurality of recesses are formed by scraping the rotating shaft 2a while the plurality of protrusions proceed along the corresponding guide groove among the plurality of guide grooves when the rotating shaft 2a is fitted into the hollow portion of the tolerance ring 80A. Is.

  Here, a tolerance ring 80A may be disposed on the opposite side of the opening 74 of the inner hub 70 with respect to the female screw portion 73 and the male screw portion 2b in the axial direction of the rotating shaft 2a. Alternatively, the tolerance ring 80A may be disposed on the opening 74 side of the inner hub 70 with respect to the female screw portion 73 and the male screw portion 2b.

  In the first to fifth embodiments, the example in which the rotating device with the torque limiter is applied to the in-vehicle electromagnetic clutch 20 has been described. However, the present invention is not limited to this, and the rotating device with the torque limiter is used in devices other than the in-vehicle device. You may apply.

  In addition, this invention is not limited to above-described embodiment, In the range described in the claim, it can change suitably. The first to fifth embodiments are not irrelevant to each other, and can be combined as appropriate unless the combination is clearly impossible.

DESCRIPTION OF SYMBOLS 1 Refrigeration cycle apparatus 2 Compressor 2a Rotating shaft 2b Male thread part 10 Engine 11 Engine side pulley 12 V belt (belt)
20 Electromagnetic clutch 30 Pulley 34 Ball bearing 40 Hub 50 Armature 70 Inner hub 71 Cylindrical part 72 Flange part 73 Female thread part 75 Hollow part 80 Holding member 90 Electromagnetic coil

Claims (16)

An inner hub (70) comprising a hollow portion (75) and a female screw portion (73) formed on the inner surface of the hollow portion, and rotating by receiving power from a drive source (10);
A rotating shaft (2a) having a male screw portion (2b) screwed to the female screw portion of the inner hub;
A holding member (80, 80A) disposed in a hollow portion of the inner hub and disposed radially outside the rotating shaft and contacting the rotating shaft; and the rotating shaft from the driving source through the inner hub When the torque transmitted to the side is less than a predetermined value, the holding member and the rotary shaft rotate together by friction between the holding member and the rotary shaft, and power is transmitted from the inner hub to the rotary shaft through the holding member. Is transmitted,
When the torque transmitted from the drive source to the rotary shaft side through the inner hub becomes a predetermined value or more, slip occurs between the holding member and the rotary shaft, and screw fastening between the female screw portion and the male screw portion is performed. A rotating device with a torque limiter, wherein the holding member holds the rotating shaft by its elastic force. The surface of the rotating shaft that contacts the holding member is formed in a circular arc shape with the axis of the rotating shaft as the center.
2. The rotating device with a torque limiter according to claim 1, wherein a surface of the holding member that is in contact with the rotation shaft is formed in a cross-sectional arc shape centering on an axis of the rotation shaft.   The rotary device with a torque limiter according to claim 1 or 2, wherein the holding member is press-fitted into and fitted into a hollow portion of the inner hub. The holding member is formed in a ring shape around the axis of the rotating shaft, and a plurality of projecting portions (81a) projecting radially outward are arranged in the circumferential direction,
The torque limiter according to any one of claims 1 to 3, wherein the plurality of protrusions are disposed in corresponding recesses among the plurality of recesses (84) on the inner surface of the inner hub. Rotating equipment.   5. The rotation with a torque limiter according to claim 4, wherein the plurality of recesses are formed by being cut by the plurality of protrusions when the holding member is fitted into the hollow portion of the inner hub. machine. A plurality of guide grooves (87a) corresponding to the plurality of recesses are formed in the inner hub, respectively.
The plurality of recesses are formed by scraping the inner hub while the plurality of protrusions proceed along the corresponding guide grooves among the plurality of guide grooves when the holding member is fitted into the hollow portion of the inner hub. The rotating device with a torque limiter according to claim 5, wherein the rotating device has a torque limiter.   When the power is transmitted from the drive source to the rotating shaft through the inner hub, the holding member and the holding member and the rotating member so that the friction torque generated by the friction between the holding member and the rotating shaft is 7 Nm or more and 185 Nm or less. The rotating device with a torque limiter according to any one of claims 1 to 6, wherein a rotating shaft is set. An inner hub (70) comprising a hollow portion (75) and a female screw portion (73) formed on the inner surface of the hollow portion, and rotating by receiving power from a drive source (10);
A rotating shaft (2a) having a male screw portion (2b) screwed to the female screw portion of the inner hub;
A holding member (80, 80A) disposed in the hollow portion of the inner hub and disposed radially outside the rotating shaft and contacting the inner hub,
When the torque transmitted from the drive source to the rotating shaft through the inner hub is less than a predetermined value, the inner hub and the rotating shaft rotate together by the friction between the holding member and the inner hub, and the holding from the inner hub. Power is transmitted to the rotating shaft through the member,
When the torque transmitted from the drive source to the rotary shaft side through the inner hub becomes a predetermined value or more, slip occurs between the holding member and the inner hub, and screw fastening between the female screw portion and the male screw portion is performed. A rotating device with a torque limiter, wherein the rotating member is loosened and the holding member holds the inner hub by its elastic force. The surface of the inner hub that contacts the holding member is formed in a circular arc shape with the axis of the rotation shaft as the center,
The rotating device with a torque limiter according to claim 8, wherein a surface of the holding member that contacts the inner hub is formed in a circular arc shape with the axis of the rotating shaft as a center.   The rotary device with a torque limiter according to claim 8 or 9, wherein the rotary shaft is press-fitted into and fitted into a hollow portion of the holding member. The holding member is formed in a ring shape centering on the axis of the rotating shaft, and a plurality of protruding portions protruding radially inward are arranged in the circumferential direction,
The rotation with a torque limiter according to any one of claims 8 to 10, wherein the plurality of protrusions are disposed in corresponding recesses among the plurality of recesses on the outer surface of the rotation shaft. machine.   12. The torque limiter according to claim 11, wherein the plurality of recesses are formed by being cut by the plurality of protrusions when the rotating shaft is fitted into the hollow portion of the holding member. Rotating equipment. A plurality of guide grooves corresponding to the plurality of recesses are formed on the rotation shaft,
The plurality of recesses scrape the rotation shaft while the plurality of protrusions advance along the corresponding guide grooves among the plurality of guide grooves when the rotation shaft is fitted into the hollow portion of the holding member. The rotating device with a torque limiter according to claim 12, wherein the rotating device has a torque limiter.   When the power is transmitted from the drive source to the rotating shaft through the inner hub, the holding member and the rotation are set such that a friction torque generated by friction between the inner hub and the holding member is 7 Nm or more and 185 Nm or less. The rotating device with a torque limiter according to any one of claims 8 to 13, wherein a shaft is set. A pulley (30) that is rotated by transmitting power from the drive source via a belt (12);
The inner hub receives power from the drive source via the pulley,
The screw fastening is loosened when the inner hub rotates in the same direction as the pulley, and the screw fastening is tightened when the inner hub rotates in the opposite direction to the pulley. A rotating device with a torque limiter according to claim 1. The hollow portion of the inner hub includes an opening (75) that opens to one end side in the axial direction of the rotating shaft,
The rotating shaft is fitted from the other end side in the axial direction with respect to the hollow portion of the inner hub,
The rotary device with a torque limiter according to any one of claims 1 to 15, wherein the holding member is located on the opposite side of the opening with respect to the female screw portion and the male screw portion.

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