JP2006304558A - Hypocycloid speed reducer built in motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hypocycloid speed reducer built in a motor wherein the influence of runout and deflection in an output shaft on a speed reducing mechanism can be reduced and the engagement of the speed reducing mechanism can be kept in favorable state. <P>SOLUTION: Ball bearings 13 and 14 are respectively provided on opposite walls of a case member 10 (first and second cases 11 and 12). The output shaft 15 is supported in the bearings 13 and 14 across the opposite walls of the case member 10. The load drive 15x of the output shaft 15 is established on one side in the direction of the axis of the speed reducer. The portion (output plate 15a) of the output shaft 15 coupled with the speed reducing mechanism G is established on the other side in the axial direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a motor-equipped hypocycloid speed reducer in which an electric motor and a speed reduction mechanism are integrated on the same axis.

  Conventionally, there have been various types of configurations in which a reduction mechanism is attached to an electric motor for the purpose of obtaining a high torque at a low speed. In many of these cases, the assembly of the speed reduction mechanism and the assembly of the electric motor are separately manufactured, and are then assembled together by being connected together. There is a hypocycloid mechanism as one of the reduction mechanisms, and a reduction gear using this hypocycloid mechanism has been proposed (see Patent Document 1).

In this hypocycloid reduction mechanism, first, a rotor of an electric motor (electric drive unit) is rotatably provided on the outer periphery of the output shaft, and a stator is disposed on the outer periphery of the rotor. The rotor rotates an eccentric shaft portion (eccentric body) offset with respect to the rotation axis of the rotor, and a planetary gear (planetary external gear) provided via the eccentric shaft portion and a bearing is fixed to the case. Revolves along the ring gear (fixed sun internal gear). At the same time, since the revolving planetary gear rotates by meshing with the ring gear, the rotation of the planetary gear is transmitted to the output shaft via the output panel, so that a deceleration output can be obtained from the output shaft.
JP 2000-120810 A

  By the way, in a speed reducer using such a hypocycloid speed reduction mechanism, the planetary gear is eccentrically rotated, and therefore, a meshing failure that causes abnormal noise or the like is likely to occur in the speed reduction mechanism, and the meshing becomes severe. There is a need.

  Therefore, it is required to stably support the output shaft that is drivingly connected to the planetary gear and to reduce the deflection of the output shaft. Further, for example, when a load is applied to the output shaft in the radial direction, the output shaft is bent, and this bending deteriorates the meshing state of the speed reduction mechanism. Therefore, it is also required to reduce the influence on the speed reduction mechanism caused by the deflection of the output shaft.

  An object of the present invention is to provide a hypocycloid speed reducer with a built-in motor that can reduce the influence on the speed reduction mechanism due to deflection or deflection of the output shaft and can maintain the meshing state of the speed reduction mechanism satisfactorily.

  According to the first aspect of the present invention, a case member, a motor unit that is disposed in the case member and rotationally drives the rotor, and cannot move on the same axis as the central axis of the rotor in the case member. A hypocycloidal speed reduction comprising: a ring gear provided; and a planetary gear that is arranged eccentrically with respect to the central axis inside the ring gear, revolves based on rotation of the rotor, and rotates by meshing with the ring gear. A mechanism and an output shaft that is supported by the case member so as to be rotatable coaxially with the central axis, rotates with the rotation of the planetary gear by connection with the planetary gear, and drives a load by the rotation; A hypocycloid speed reducer with a built-in motor, wherein bearing members are provided on opposing wall portions of the case member, and the output shaft is connected to the casing by each bearing member. The load drive portion of the output shaft is set on one side in the axial direction of the speed reducer, and the connecting portion of the output shaft to the speed reduction mechanism is connected to the shaft of the speed reducer. The gist is that it is set in the other direction.

  According to a second aspect of the present invention, in the motor built-in hypocycloid speed reducer according to the first aspect, one side of the output shaft in the axial direction protrudes from the case member, and the protruding portion is used as the load driving unit. Is the gist.

  According to a third aspect of the present invention, in the hypocycloid speed reducer with a built-in motor according to the first or second aspect, the rotor is provided so that the output shaft passes therethrough. The gist of the invention is that it is rotatably supported via a bearing member.

  According to a fourth aspect of the present invention, in the hypocycloid speed reducer with a built-in motor according to the third aspect, at least one of the bearing members that support the output shaft and a bearing member that supports the rotor are ball bearings. The gist of this is

  According to a fifth aspect of the present invention, in the motor built-in hypocycloid speed reducer according to any one of the first to fourth aspects, the rotor is provided with an eccentric portion that is eccentric with respect to the central axis. The gist is that the planetary gear is attached to the eccentric portion via a bearing member.

  The gist of a sixth aspect of the present invention is that, in the hypocycloid speed reducer with a built-in motor according to the fifth aspect, the bearing member that supports the planetary gear is configured by a ball bearing.

(Function)
According to the first aspect of the present invention, the bearing members are respectively provided on the opposing wall portions of the case member of the speed reducer, and the output shaft is bridged and supported between the opposing wall portions of the case member by each bearing member. . Therefore, since the output shaft is supported by the two bearing members separated as much as possible in the case member, the output shaft is stably supported, and the deflection of the output shaft is small. Further, the load drive portion of the output shaft is set on one side in the axial direction of the speed reducer, and the connection portion of the output shaft with the speed reduction mechanism is set on the other side in the axial direction. Therefore, even if a load is applied to the load drive portion of the output shaft, for example, in the radial direction and the output shaft is bent, the speed reduction mechanism is disposed on the opposite side of the output shaft in the axial direction and is separated from each other. The influence of the bending is kept small. As described above, since the influence on the speed reduction mechanism due to the deflection or deflection of the output shaft is suppressed, a hypocycloid speed reduction mechanism that requires severe engagement with the speed reduction mechanism is used. It can be maintained, and it is possible to suppress the occurrence of abnormal noise.

  According to the second aspect of the present invention, since one side of the output shaft in the axial direction protrudes from the case member and the protruding portion serves as the load driving portion, the load driving portion and the speed reduction mechanism are separated as much as possible, and the output shaft The influence on the speed reduction mechanism when bending occurs is smaller. In addition, since the load driving unit is located outside the bearing member, this also reduces the influence of the deflection of the output shaft on the speed reduction mechanism.

  According to the invention described in claim 3, since the output shaft is supported across the opposing wall portions of the case member, the rotor is provided so that the output shaft passes therethrough. The rotor is supported rotatably with respect to the output shaft via a bearing member. Therefore, there is no need to specially configure a means for rotatably supporting the rotor, and for example, an effect that it can contribute to space saving of the reduction gear is obtained.

  According to the fourth aspect of the invention, at least one of the bearing members that support the output shaft and the bearing member that supports the rotor are constituted by ball bearings. That is, since the ball bearing can not only support the radial direction but also regulate the movement in the axial direction, there is no need to specially configure means for regulating the movement of the output shaft and the rotor in the axial direction. Can be obtained.

  According to the fifth aspect of the present invention, the rotor is provided with the eccentric portion that is eccentric with respect to the central axis, and the planetary gear is attached to the eccentric portion via the bearing member. That is, the planetary gear can be easily arranged eccentrically only by attaching the planetary gear to the eccentric portion. Further, since the eccentric portion is provided integrally with the rotor, the number of parts is not increased. Incidentally, if this eccentric part is a recess capable of accommodating a part of the bearing member or the planetary gear, it is possible to reduce the axial size.

  According to the sixth aspect of the present invention, the bearing member that supports the planetary gear is constituted by a ball bearing that is capable of restricting movement in the axial direction in addition to support in the radial direction, so that the planetary gear can be moved in the axial direction. There is no need to specially configure the restricting means, and for example, the effect of reducing the number of parts can be obtained.

  According to the present invention, it is possible to provide a hypocycloid speed reducer with a built-in motor capable of reducing the influence on the speed reduction mechanism due to the deflection and deflection of the output shaft and maintaining the meshing state of the speed reduction mechanism satisfactorily.

DESCRIPTION OF EXEMPLARY EMBODIMENTS An embodiment of the invention will be described below with reference to the drawings.
FIG. 1 shows a hypocycloid reducer with a built-in motor in the present embodiment. In FIG. 1, a case member 10 is composed of a first case 11 and a second case 12, both of which are substantially bowl-shaped, and forms a space for housing a component therein. A ball bearing 13 is provided in the central portion of the first case 11, and a ball bearing 14 is provided in the central portion of the second case 12, and both end portions of the output shaft 15 of the speed reducer are formed by both bearings 13, 14. Is rotatably supported. That is, the output shaft 15 is supported by being spanned between the opposing wall portions of the cases 11 and 12.

  In the first case 11, a motor unit M including a permanent magnet 16 that forms a stator, a rotor core 17 and a winding 18 that form a rotor, and a rectifying mechanism 19 that includes a brush and a commutator is formed. ing. A plurality of permanent magnets 16 are fixed to the inner peripheral surface of the first case 11. An annular rotor core 17 around which a winding 18 is wound is rotatably supported on the output shaft 15 via a ball bearing 20 inside the permanent magnet 16. A rectifying mechanism 19 is disposed in a space provided on one side in the axial direction of the rotor core 17 (on the ball bearing 13 side), and the rectifying mechanism 19 supplies an external power to the winding 18.

  On the other side in the axial direction of the rotor core 17 (the side opposite to the rectifying mechanism 19), an eccentric portion 17a that is recessed in the axial direction is provided on the inner side of the portion around which the winding 18 is wound. The eccentric portion 17a has an eccentric axis L2 that is eccentric with respect to the central axis L1 of the output shaft 15 as its central axis. A ball bearing 21 is fitted into the eccentric portion 17a, and the planetary gear 25 is rotatably supported by the ball bearing 21. That is, the planetary gear 25 is arranged eccentrically with respect to the output shaft 15 by the eccentric portion 17a.

  The planetary gear 25 is provided with a mounting portion 25c that protrudes in a cylindrical shape from the center to one axial direction. The mounting portion 25c is fitted inside the ball bearing 21 and allows the output shaft 15 to pass therethrough. The planetary gear 25 includes a first gear portion (external gear) 25a and a second gear portion (external gear) 25b having a smaller diameter than the first gear portion 25a on the other side in the axial direction. These first and second gear portions 25a and 25b are provided on a coaxial line and coincide with the eccentric axis L2.

  The first gear portion 25 a is meshed with a ring gear (internal gear) 26 that is fixed to the inner peripheral surface of the second case 12. The ring gear 26 is provided such that its center axis coincides with the center axis L 1 of the output shaft 15. The ring gear 26 has a larger diameter than the first gear portion 25a (in this case, the radius of the ring gear 26 is a value obtained by adding the eccentric distance of the gear portion 25a to the radius of the first gear portion 25a).

  The second gear portion 25 b is meshed with a ring gear portion (internal gear) 15 b of an output board 15 a provided on the output shaft 15. The ring gear portion 15 b is provided so that its center axis coincides with the center axis L 1 of the output shaft 15. The ring gear portion 15b has a larger diameter than the second gear portion 25b (in this case, the radius of the ring gear portion 15b is a value obtained by adding the eccentric distance of the gear portion 25b to the radius of the second gear portion 25b). . In addition to the ring gear portion 15b, the planetary gear 25 and the ring gear 26 constitute a hypocycloid reduction mechanism G.

  The output shaft 15 is provided with the output panel 15 a on the other side in the axial direction, and one side in the axial direction protrudes from the first case 11 to the outside. A portion projecting to the outside of the output shaft 15 is a load driving unit 15x, and the load driving unit 15x is connected to a load and transmits a driving force.

  In the above configuration, when the motor unit M is energized, a current corresponding to the rotational position flows through the winding 18 via the rectifying mechanism 19, the rotor core 17 is magnetized, and the permanent magnet 16 is attracted or repelled. In response, the rotor core 17 (rotor) rotates about the output shaft 15.

  At this time, the planetary gear 25 supported by the eccentric portion 17a via the ball bearing 21 revolves around the center axis L1 of the output shaft 15. Further, since the first gear portion 25a of the planetary gear 25 meshes with the ring gear 26, the planetary gear 25 rotates while revolving, and the trajectory of the planetary gear 25 becomes a hypocycloid. Similarly, the second gear portion 25b of the planetary gear 25 draws a hypocycloid locus. Since the second gear portion 25b meshes with the ring gear portion 15b of the output shaft 15 (output board 15a), the output shaft 15 rotates as the second gear portion 25b rotates. The rotation of the output shaft 15 at this time is a rotation decelerated with respect to the rotation of the rotor core 17 (rotor) because the diameter of the second gear portion 25b is smaller than the diameter of the first gear portion 25a. . And the deceleration output of this output shaft 15 is transmitted to the load side from the load drive part 15x provided in the opposite side to the side connected with the deceleration mechanism G. As shown in FIG.

Next, effects obtained in the present embodiment will be described below.
(1) Ball bearings 13 and 14 are provided on opposing wall portions of the case member 10 (first and second cases 11 and 12), and the output shaft 15 is the opposing wall of the case member 10 at each bearing 13 and 14. It is supported across the clubs. Therefore, since the output shaft 15 is supported by the two bearings 13 and 14 separated as much as possible in the case member 10, the output shaft 15 can be stably supported and the deflection of the output shaft 15 is reduced. be able to. In addition, the load drive unit 15x of the output shaft 15 is set on one side in the axial direction of the speed reducer, and the connecting portion (the output panel 15a) of the output shaft 15 with the speed reduction mechanism G is set on the other side in the axial direction. Therefore, even if a load is applied to the load driving portion 15x of the output shaft 15 in the radial direction, for example, and the output shaft 15 bends, the speed reduction mechanism G is disposed on the opposite side of the output shaft 15 in the axial direction. Since it is spaced apart, the influence of the bending can be suppressed small. As described above, since the influence on the speed reduction mechanism G due to the deflection or deflection of the output shaft 15 can be suppressed, a hypocycloid speed reduction mechanism that needs to be engaged with the speed reduction mechanism G as in the present embodiment is used. However, the meshing of the speed reduction mechanism G can be maintained satisfactorily, and the occurrence of abnormal noise can be suppressed.

  (2) Since the output shaft 15 projects from the case member 10 on one side in the axial direction as the load driving portion 15x, the load driving portion 15x and the speed reduction mechanism G are separated as much as possible, and the output shaft 15 is bent. When this occurs, the influence on the speed reduction mechanism G can be further reduced. In addition, since the load driving unit 15x is located outside the ball bearing 13, the influence of the deflection of the output shaft 15 on the speed reduction mechanism can be further reduced.

  (3) Since the output shaft 15 is supported across the opposing wall portions of the case member 10, the rotor core 17 (rotor) is provided so that the output shaft 15 penetrates. The rotor core 17 is rotatably supported with respect to the output shaft 15 via a ball bearing 20. Therefore, it is not necessary to specially configure a means for rotatably supporting the rotor core 17, and it is possible to obtain an effect that, for example, it can contribute to space saving of the reduction gear.

  (4) The two bearings 13 and 14 that support the output shaft 15 and the bearing 20 that supports the rotor core 17 are constituted by ball bearings. That is, since these ball bearings 13, 14, and 20 can not only support in the radial direction but also regulate the movement in the axial direction, a means for regulating the movement of the output shaft 15 and the rotor core 17 in the axial direction is specially configured. There is no need, and for example, the effect of reducing the number of parts can be obtained.

  (5) The rotor core 17 is provided with an eccentric portion 17a that is eccentric with respect to the central axis L1, and a planetary gear 25 is attached to the eccentric portion 17a via a ball bearing 21. That is, the planetary gear 25 can be easily arranged eccentrically only by attaching the planetary gear 25 to the eccentric portion 17a. Moreover, since the eccentric part 17a is provided integrally with the rotor core 17, the number of parts does not increase. Further, since the eccentric portion 17a is a concave portion that can accommodate a part of the bearing 21 and the planetary gear 25, the axial size can be reduced.

  (6) Since the bearing 21 for supporting the planetary gear 25 is constituted by a ball bearing capable of restricting movement in the axial direction in addition to supporting in the radial direction, a means for restricting movement of the planetary gear 25 in the axial direction is specially provided. There is no need to configure, and for example, an effect that the number of parts can be reduced can be obtained.

The embodiment of the present invention may be modified as follows.
In the above embodiment, the portion of the output shaft 15 that protrudes from the case member 10 is the load driving portion 15x. However, for example, the output shaft 15 may be hollow or recessed and the load driving portion may be set inside. Also in the load driving unit in this case, the speed reduction mechanism G is set on the opposite side in the axial direction.

In the above embodiment, the bearings 13, 14, 20, and 21 are all ball bearings. However, the bearings are not limited to ball bearings, and for example, sliding bearings may be used.
In the above embodiment, the rotor core 17 is supported by the bearing 20 with respect to the output shaft 15. However, for example, a support portion that supports the rotor core 17 is provided on the case member 10, and the rotor core 17 is supported by the support portion. It may be.

  In the above embodiment, the rotor core 17 is provided with the concave eccentric portion 17a and the planetary gear 25 is assembled. However, the eccentric portion may be convex. Alternatively, the eccentric portion may be configured by a separate member and assembled to the rotor core 17.

  In the above embodiment, the motor unit M having the configuration using the rectifying mechanism 19 that mechanically rectifies with a brush and a commutator is incorporated, but a so-called brushless motor that electrically performs the rectifying mechanism 19 may be incorporated.

It is sectional drawing which shows the hypocycloid reduction gear of this Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Case member, 13 ... Ball bearing as a bearing member, 14 ... Ball bearing as a bearing member, 15 ... Output shaft, 15a ... Output board equivalent to the connection part of a reduction mechanism, 15x ... Load drive part, 17 ... Rotation Rotor core constituting the child, 17a ... eccentric part, 20 ... ball bearing as bearing member, 21 ... ball bearing as bearing member, 25 ... planetary gear, 26 ... ring gear, G ... hypocycloid reduction mechanism, M ... motor part, L1 is the central axis.

Claims (6)

A case member;
A motor unit that is disposed in the case member and rotationally drives the rotor;
A ring gear provided coaxially with the central axis of the rotor in the case member so as to be immovable, and arranged eccentrically with respect to the central axis inside the ring gear, and revolved based on the rotation of the rotor. And a hypocycloid reduction mechanism having a planetary gear that rotates by meshing with the ring gear;
An output shaft that is supported by the case member so as to be rotatable coaxially with the central axis, rotates with the rotation of the planetary gear by connection with the planetary gear, and drives a load by the rotation;
A hypocycloid speed reducer with a built-in motor,
A bearing member is provided on each of the opposing wall portions of the case member, and the output shaft is spanned and supported between the opposing wall portions of the case member by each bearing member, and
The motor built-in hypocycloid characterized in that the load drive part of the output shaft is set on one side in the axial direction of the reduction gear, and the connecting portion of the output shaft with the speed reduction mechanism is set on the other side in the axial direction of the reduction gear Decelerator. In the hypocycloid reducer with a built-in motor according to claim 1,
A hypocycloid reducer with a built-in motor, wherein one side of the output shaft in the axial direction protrudes from the case member, and the protruding portion serves as the load drive unit. In the motor built-in hypocycloid reducer according to claim 1 or 2,
The rotor is provided so that the output shaft passes therethrough, and is supported so as to be rotatable with respect to the output shaft via a bearing member. In the motor-equipped hypocycloid reducer according to claim 3,
A hypocycloid reducer with a built-in motor, wherein at least one of the bearing members that support the output shaft and the bearing member that supports the rotor are configured by ball bearings. In the motor built-in hypocycloid reducer according to any one of claims 1 to 4,
A hypocycloid reducer with a built-in motor, wherein the rotor is provided with an eccentric portion eccentric to the central axis, and the planetary gear is attached to the eccentric portion via a bearing member. In the motor built-in hypocycloid reducer according to claim 5,
A hypocycloid speed reducer with a built-in motor, wherein the bearing member that supports the planetary gear is configured by a ball bearing.

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