JPH07293466A - Compressor - Google Patents

Abstract

PURPOSE:To prevent starting shock as well as to miniaturize a compressor to be used for an air conditioner without using any electromagnetic clutch and to reduce its cost. CONSTITUTION:A diving shaft 5 of a scroll-type compressor 1 is always driven rotated through a pulley 7. When a solenoid valve 23 provided on an inlet passage 24 is opened, pressure in an inlet pressure chamber 32 becomes higher than that in an atmospheric pressure chamber 31 by refrigerant to be supplied, thereby, an annular piston 28 is moved leftward, and the clearance between the conical tip part 27a of a taper pin 27 and a conical inner surface 26a of a taper sleeve 26 is increased. The revolution radius of a movable scroll member 12 is increased, and seal parts on both ends of a crescent-shaped fluid compression pocket 13 are brought into contact with each other, and effective compression work is performed. When the solenoid valve 23 is closed, pressure in the inlet pressure chamber 32 is lowered, the taper pin 27 is moved rightward, and the revolution radius is decreased, and a clearance is formed between the seal parts, thereby, refrigerant is not compressed, and a compressor 1 is brought into the idling state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a scroll type compressor used as a refrigerant compressor of an air conditioner,
A positive displacement compressor that compresses fluid by rotationally driving a driven part such as a movable scroll member that is only allowed to revolve while being prevented from rotating by a crank mechanism connected to a drive shaft. In particular, by constantly rotating the drive shaft and the driven part without interrupting the rotation of the drive shaft with an electromagnetic clutch or the like, the fluid can be generated without a shock accompanying the switching of the operating state such as start / stop. The present invention relates to a compressor capable of interrupting the compression action of.

[0002]

2. Description of the Related Art In an air conditioner mounted on a vehicle such as an automobile, normally, in order to protect a refrigerant compressor for compressing a refrigerant in a refrigeration cycle or other auxiliary equipment or to control a cooling capacity, The drive shaft of the refrigerant compressor is rotationally driven from the crankshaft of the internal combustion engine for traveling through a belt transmission mechanism and an electromagnetic clutch formed inside a pulley on the compressor side that constitutes a part of the belt transmission mechanism. When the air conditioner switch is turned on automatically or manually, the electromagnetic clutch is connected and the refrigerant compressor is activated and compressed regardless of the operating state of the internal combustion engine. When the refrigerant is discharged and circulates to the refrigeration cycle and the temperature in the vehicle interior drops to the target value and the air conditioner switch is turned off automatically or manually, the electromagnetic clutch Connection state is operation of the refrigerant compressor is stopped is the release, so as to also stop the circulation of refrigerant in the refrigeration cycle.

In this type of electromagnetic clutch, parts such as an electromagnetic coil, a friction plate, and a spring are used, and these parts are housed inside the pulley. Therefore, it is not possible to make the outer diameter of the pulley too small. Can not. Therefore, even if the body of the refrigerant compressor can be downsized while maintaining the same discharge capacity by increasing the rotation speed, it is difficult to downsize the electromagnetic clutch directly attached to it. Therefore, there is a limit to downsizing the entire refrigerant compressor including the electromagnetic clutch. Further, since the pulley incorporating the electromagnetic clutch has a complicated structure, it is much more expensive than a mere belt pulley, and occupies a considerable part of the cost of the air conditioner.

Further, since the load torque of the engine fluctuates when the refrigerant compressor is started or stopped by the electromagnetic clutch, the occupant may feel temporary fluctuations in vehicle speed or shock depending on the operating state of the engine. . In particular, the torque fluctuation that occurs when the refrigerant compressor starts up is called a startup shock of the refrigerant compressor.Since the startup shock slightly impairs the occupant's riding comfort, the comfort of vehicles such as automobiles is reduced. It has become a problem to be solved in pursuing sex.

Various means for reducing the starting shock of a scroll type compressor are disclosed in, for example, Japanese Patent Publication No. 1-525.
No. 92, Japanese Patent Publication No. 6-5069, and JP-A-6-6
No. 1-72889. However, all of these means are for preventing only the starting shock, and an electromagnetic clutch provided on the drive shaft for intermittently operating the refrigerant compressor to change the discharge amount is used. It is not an unnecessary technology. Therefore,
It is still inadequate in view of demands for downsizing and cost reduction of the refrigerant compressor.

[0006]

SUMMARY OF THE INVENTION The present invention does not use an electromagnetic clutch for intermittently driving a drive shaft of a compressor, but always connects the compressor to a driving internal combustion engine or the like. This makes it possible to fundamentally prevent sudden changes in the load torque of the drive engine due to the discontinuity of the electromagnetic clutch, and start shocks, etc. that occur, and it is a compressor that is constantly driven by the prime mover. However, it is an object of the present invention to provide a compressor capable of controlling discharge of a compressed fluid according to demand and reducing wear of moving parts and power loss.

[0007]

As a means for solving the above problems, the present invention provides a drive shaft which is constantly rotated by a prime mover, and the drive shaft which is eccentrically supported with respect to the axis of the drive shaft. A driven portion that revolves to compress a fluid between a fixed portion and a driven portion driven by a drive mechanism; a rotation prevention mechanism that prevents rotation of the driven portion and allows revolution and revolution radius change; A crank mechanism for transmitting torque by connecting a shaft and the driven portion and valve means for opening and closing a fluid suction passage are provided, and the driven portion is opened by the valve means. Sometimes the radius of revolution increases and the fluid effectively compresses,
Provided is a positive displacement compressor in which, when the valve means is closed, the revolution radius is reduced and the fluid compression effect is nullified.

[0008]

In the positive displacement compressor of the present invention, the drive shaft thereof is connected to the prime mover and is constantly rotated without being driven by a power connecting / disconnecting means such as an electromagnetic clutch. It is driven so that it always revolves around. However, rotation of the driven portion is prevented by the rotation prevention mechanism. When the valve means provided in the suction passage is opened in this state, the revolution radius of the driven part increases within the range allowed by the rotation prevention mechanism, and part of the driven part contacts part of the fixed part. The space that compresses the fluid is sealed,
The effective compression action of the fluid is initiated. Further, when the valve means provided in the suction passage is closed, the revolution radius of the driven portion is reduced within the range allowed by the rotation prevention mechanism, and one portion of the driven portion that is in contact with a part of the fixed portion is reduced. Since a gap is created between the compressed fluid and the portion, the compressed fluid leaks to the low-pressure side from the gap, so that the compression action of the fluid due to the revolution of the driven portion becomes ineffective, and the compressor simply idles.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIG. 1 and FIG. 2 of a positive displacement compressor according to the present invention.
The whole structure of the scroll type compressor 1 which is an example is shown.
The cross section is shown in FIG. The compressor of the illustrated embodiment is
Both are described as being used as a refrigerant compressor of an air conditioner mounted on a vehicle. Therefore, the fluid compressed by the compressor of these examples is a gaseous refrigerant. Incidentally, the scroll compressor 1 of the first embodiment
Is mainly equipped with no electromagnetic clutch, is instead equipped with an electromagnetic valve on the suction side, and has a different structure of a so-called anti-rotation mechanism as described in detail later. It has the same structure as the scroll type compressor.

The housing 2 is a center housing 2a,
It is composed of three parts, a front housing 2b and a rear housing 2c, and a fixed scroll member 3 is integrally formed inside the center housing 2a. These three parts forming the housing 2 are integrated by several through bolts.

A drive shaft 5 extends in the front housing 2b so as to pass through it. Expanding part 5 of drive shaft 5
a is a bearing 6 mounted in the front housing 2b
Is rotatably supported by a pulley 7 having a simple structure in which rotational power transmitted from a prime mover (which may be a hydraulic motor or an electric motor) such as an internal combustion engine (not shown) is attached to the front end of the drive shaft 5. Therefore, it is always introduced into the scroll compressor 1. Since the pulley 7 is supported by the bearing 8 on the front end of the front housing 2b, the bearing 8 pivotally supports the front end of the drive shaft 5 via the pulley 7. In addition, 9 shown in FIG. 1 is a shaft sealing device. An eccentric pin 5b is formed in the axial direction at the rear end of the drive shaft 5, and a circular bush 10 is attached to the eccentric pin 5b. Furthermore, bush 1
0 to the movable scroll member 1 via a needle bearing 11.
Two are rotatably connected.

The fixed scroll member 3 and the movable scroll member 12 are provided with spiral-shaped vanes 3a and 12a having substantially the same shape, and they have the same length (width) in the axial direction. And, when they are viewed in the axial direction for compressing the fluid between the blades by being supported so that they are relatively out of phase and are eccentrically combined and engaged with each other. Two or more fluid compression pockets 13 each having a crescent shape are formed.

The fluid compression pocket 13 takes in low-pressure fluid when it opens in the low-pressure chamber 14 formed in the center housing 2a at the outer periphery of the spiral blades 3a and 12a, and revolves around the orbiting scroll member 12. Along with this, the fluid is compressed while moving toward the central portion, and when it is opened in the central high-pressure chamber 15, the compressed fluid is discharged to the high-pressure chamber 15. High pressure chamber 15
Can communicate with a discharge chamber 18 formed in the housing 2 through a discharge port 16 formed in the end plate 3b of the fixed scroll member 3 and a discharge valve 17 as a check valve made of a reed-like elastic metal piece. Has become. In addition, 19 in the figure
Is a discharge port, and 20 is a stopper that limits the opening of the discharge valve 17.

Reference numeral 21 denotes the eccentric pin 5b which is eccentric with respect to the drive shaft 5, the bush 10, the movable scroll member 12, and the like. The attached balance weights are shown. One of the features of the scroll compressor of the embodiment of the present invention is that the suction chamber 22 connected to the low pressure chamber 14 has a suction passage communicating with an unillustrated evaporator in an air conditioner of a vehicle via a solenoid valve 23. 24 is connected, and the solenoid valve 23 can be opened and closed by manually or automatically operating a switch (not shown) of the air conditioner. When the valve is opened, the fluid to be compressed is in the suction chamber. It is possible to cut off the flow of fluid to be introduced into the low pressure chamber 14 when the valve is closed while being introduced into the low pressure chamber 14 via 22.

A scroll type compressor 1 as a first embodiment.
As the greatest feature of the above, the rotation preventing mechanism 25 that regulates the revolution radius of the movable scroll member 12 has the following structure. First, on the rear surface side of the end plate 12b of the movable scroll member 12, there are several tapered sleeves 26 having a conical inner surface.
, Are fitted and fixed at positions at substantially even intervals on the circumference of the virtual circle. On the conical inner surface 26a, there are taper pins 27 supported in parallel with the axial direction of the drive shaft 5, respectively.
The conical tip end portion 27a of is in contact. Several taper pins 27 are integrated with a common annular piston 28, and the annular piston 28 is fitted in an annular groove 29 formed in the front housing 2b. It is not necessary when the fitting condition between the annular groove 29 and the annular piston 28 is highly airtight, but when there is a slight gap, the bellows 30 is provided in the annular groove 29 to maintain the airtightness. As a result, an atmospheric pressure chamber 31 communicating with the atmosphere is formed on the left side of the annular piston 28 in the drawing, and a suction pressure chamber 32 communicating with the suction chamber 22 is formed on the right side.

In the annular piston 28, the tip end portion 27a of the taper pin 27 has a conical inner surface 26 of the taper sleeve 26.
The spring 33 constantly presses and urges in the direction of entering the inside a. The bellows 30 and the spring 3
3 may both be large annular ones along the annular piston 28, or one or both of them may be several small ones which are arranged substantially evenly in the annular groove 29. Good. If several small bellows 30 are used, it is necessary to individually provide holes for introducing atmospheric pressure inside each. A partition wall 34 for limiting the movable range of the annular piston 28 is provided between the suction pressure chamber 32 and the suction chamber 22, and the taper pin 27 is inserted into the hole of the partition wall 34. Needless to say, a hole is formed in the partition wall 34 to connect the suction pressure chamber 32 and the suction chamber 22. Reference numeral 35 denotes an axial load receiving portion that supports an axial thrust acting on the movable scroll member 12.

Since the scroll compressor 1 of the first embodiment is constructed in this way, the operation switch (not shown) of the air conditioner is not turned on, that is, the solenoid valve 23 is closed and the scroll type compressor 1 is used. Even when the refrigerant is not supplied from the suction passage 24 to the suction chamber 22 of the compressor 1, the drive shaft 5 of the scroll compressor 1 is constantly driven to rotate by an external prime mover such as an internal combustion engine via the pulley 7. There is. Since the bush 10 attached to the eccentric pin 5b of the drive shaft 5 rotates eccentrically with respect to the drive shaft 5, the movable scroll member 12 engaged with it via the needle bearing 11 also rotates. However, since the taper pin 27 of the rotation preventing mechanism 25 is engaged with the taper sleeve 26, the rotation of the movable scroll member 12 is prevented and only the revolving motion is performed.

As a result, like the conventional scroll compressor, the spiral blade 3a of the fixed scroll member 3 is formed.
The fluid compression pocket 13 formed between the spiral scroll blade 12a of the orbiting scroll member 12 and the axial direction has a substantially crescent shape as viewed in the axial direction. In the non-operating state of the air conditioner in which the solenoid valve 23 is closed but moves to the high pressure chamber 15, the scroll compressor 1 is closed on the suction side like the vacuum pump, so that the fluid compression pocket 13 is In order to move the refrigerant remaining in the low pressure chamber 14 toward the center, the suction chamber 22 and the low pressure chamber 14 and the suction pressure chamber 32 communicating with them become lower than atmospheric pressure.

Therefore, the bellows 30 and the annular piston 28 are moved in the right direction as shown in FIG. 2 due to the bias of the spring 33 in addition to the pressure difference between the suction pressure chamber 32 and the atmospheric pressure chamber 31. , The conical tip portion 27 of the taper pin 27
The a penetrates deeply inside the taper sleeve 26. Since the taper sleeve 26 is attached to the back surface of the end plate 12b of the movable scroll member 12 and does not move in the axial direction,
The conical inner surface 26a of the taper sleeve 26 and the taper pin 2
The gap between the conical tip portion 27a of No. 7 and the movable scroll member 12 with respect to the fixed scroll member 3 changes slightly at the same time, and the revolution radius of the movable scroll member 12 decreases. As a result, the contact point between the spiral blade 3a of the fixed scroll member 3 and the spiral blade 12a of the movable scroll member 12, that is, the crescent shape of the fluid compression pocket 13 formed between the spiral blades 3a and 12a. Since a gap 36 corresponding to the reduction of the revolution radius is generated at the seal portion that closes both ends of the refrigerant, even if the refrigerant is compressed in the fluid compression pocket 13, the refrigerant should immediately leak to the outside low pressure side. Therefore, the refrigerant is substantially not compressed in the scroll compressor 1.

As described above, in the non-operating state of the air conditioner in which the solenoid valve 23 is closed, the scroll compressor 1 cannot compress the refrigerant, and the scroll compressor 1
Causes a large power loss, even if the drive shaft 5 is not disconnected from the output shaft of the prime mover by using a large and expensive electromagnetic clutch or the like because the engine idles substantially without load. There is no fear of causing wear to the moving parts.

When operating the air conditioner, the solenoid valve 23 is opened by manually or automatically turning on the operation switch of the air conditioner. Since the pressure of the return refrigerant from the evaporator of the refrigeration cycle supplied from the suction passage 24 to the suction chamber 22 is generally higher than atmospheric pressure, the suction pressure chamber 32
Becomes higher than the pressure in the atmospheric pressure chamber 31, and the pressure difference pushes the bellows 30 and the annular piston 28 to the left against the bias of the spring 33, as shown in FIG.
The taper pin 27 moves in the axial direction in the direction of coming out of the taper sleeve 26. As a result, the gap between the conical inner surface 26a of the taper sleeve 26 and the conical tip portion 27a of the taper pin 27 increases, and the orbiting radius of the movable scroll member 12 increases accordingly.
The size of the revolution radius is such that the fixed scroll member 3 and the spiral blades 3a and 12a of the movable scroll member 12 come into contact with each other at the sealing points at both ends of the crescent shape of the fluid compression pocket 13 to eliminate the gap 36 shown in FIG. The maximum value is reached when the fluid compression pocket 13 is made into a closed space.

In such an operating state, the scroll compressor 1 has the fluid compression pocket 13 in the low pressure chamber 14 at the outer peripheral edges of the fixed scroll member 3 and the movable scroll member 12, as in the conventional scroll compressor. When it is opened toward, the low-pressure return refrigerant is taken into the inside thereof, and the orbiting of the movable scroll member 12 whose rotation is prevented by the rotation preventing mechanism 25 causes the fluid compression pocket 13 to become a closed space and shrink. When the fluid compression pocket 13 is opened toward the high pressure chamber 15 at the center by compressing the refrigerant while continuously moving toward the center, the compressed refrigerant is discharged from the discharge port 16 by pushing the discharge valve 17 open. It will be pushed into the chamber 18. The pressurized refrigerant is sent from the discharge port 19 to a refrigerant condenser (not shown).

Further, like the conventional scroll type compressor, at the portions where the axial end edges of the spiral blades 3a and 12a of the scroll members 3 and 12 are in sliding contact with the opposite end plates 12b and 3b, Grooves 3c and 12c, respectively, are formed in which the tip seals 37 and 38 are formed.
When the scroll compressor 1 is in the working state as shown in FIG. 1 by opening the solenoid valve 23 in this way, as shown in FIG. 3, the spiral blades 3a or The pressure difference between the two surfaces of 12a pushes the tip seals 37 and 38 against the mating end plates 12b and 3b to enhance the sealing at the axial edges of the spiral vanes 3a and 12a.

On the other hand, in the idling state of the scroll compressor 1 as shown in FIG. 2, the spiral blade 3a is used.
Or, since there is almost no pressure difference between both surfaces of 12a, the tip seals 37 and 38 are in a floating state as shown in FIG. 4 and are not pressed against the end plates 12b and 3b of the other side, so that heat generation and wear are prevented. The accompanying large sliding friction does not occur, and the power loss called mechanical loss is negligible. Therefore, the need for special lubrication and cooling for the no-load operation of the scroll compressor 1, that is, for the idling is eliminated. As described above, in the case of the scroll compressor 1 of the first embodiment (invention) in which the air conditioner is in the idling state when the air conditioner is not in operation, the tip seals 37 and 38 function differently from those of the conventional scroll compressor. Will be done.

As described above, in the scroll compressor 1 according to the first embodiment (the present invention), it is not necessary to stop the drive shaft 5 because it is rotationally driven not only during actual operation but also under no-load operation. In general, it is not necessary to provide a power connection / disconnection means such as an electromagnetic clutch, which is generally expensive and tends to increase the size of the compressor. Instead, a solenoid valve 23 having a simple structure and a small size is used. It is easy to rotate the scroll compressor 1 at high speed,
As a result, it is possible to realize a small-sized refrigerant compressor having a large discharge capacity at low cost.

Further, the scroll type compressor 1 is constantly driven to rotate, and the electromagnetic valve 23 is opened by turning on the operation switch of the air conditioner again to make the scroll type compressor 1 from the idling state to the actual operating state. Even when shifting to, the axial movement of the annular piston 28 and the taper pin 27 and the increase of the revolution radius of the movable scroll member 12 occur gently, so that the load torque of the drive shaft 5 and the drive engine does not suddenly increase. It gradually increases without. Therefore, a sudden change in load torque or a shock such as a start shock cannot occur, so that the riding comfort of the vehicle is improved.

Next, FIG. 6 shows a second embodiment of the positive displacement compressor of the present invention.
1 shows the entire structure of a scroll compressor 39 as an example. Scroll compressor 39 of the second embodiment
Has a common structure in many respects with the scroll compressor 1 of the first embodiment, and therefore, common points are designated by the same reference numerals, and redundant description will be omitted.

The scroll type compressor 39 of the second embodiment is
At the eccentric position of the enlarged diameter portion 5a of the drive shaft 5, a bottomed hole 40 having a cross section close to a rectangle is formed in the axial direction, and a communication hole 41 communicating with the suction chamber 22 is formed at the bottom of the hole 40. Perforated. In addition, a base portion 42a of a separate drive pin 42, which is entirely bent in a V shape, is fitted in the hole 40 so as to be slidable in the axial direction while maintaining an airtight state. The inclined portion 42b at the tip of the inclined hole 4 is formed so as to penetrate the bush 10 in accordance therewith.
3 is slidably fitted in an airtight state. The structure of these portions is shown in FIG. 7 as an exploded perspective view. Inside the bottomed hole 40, the spring 4
4 is inserted and urges the drive pin 42 so as to constantly press it toward the bush 10.

In this way, the base portion 42 of the drive pin 42 is
A suction pressure chamber 45 is formed in the bottomed hole 40 on the end surface on the a side. On the other hand, the end surface of the tip of the drive pin 42 on the side of the inclined portion 42b is exposed to the discharge pressure chamber 46 formed between the bush 10 and the back surface of the end plate 12b of the movable scroll member 12, and is defined by the communication hole 47. High pressure room 1
It receives the pressure of the refrigerant in 5. 48
Is a seal member provided to enhance the sealing property of the discharge pressure chamber 46. In the case of the second embodiment, the axial load receiving portion 4 that supports the thrust acting on the movable scroll member 12.
The rotation preventing mechanism 50 that allows the orbiting of the movable scroll member 12 and prevents rotation thereof may be the same as that used in the conventional scroll compressor.

Since the scroll type compressor 39 of the second embodiment is constructed in this way, the drive shaft 5 is always directly connected to the pulley 7 regardless of whether or not the operation switch of the air conditioner (not shown) is turned on. Are driven to rotate, and the high pressure chamber 15 at the center of the fixed scroll member 3 and the movable scroll member 12 is operated by the same operation as a normal scroll compressor as described in the description of the first embodiment.
There is a refrigerant whose pressure is slightly higher than that of the low pressure chamber 14 and the suction chamber 22.

When the operation switch of the air conditioner is turned on to open the solenoid valve 23 and the return refrigerant supplied to the low pressure chamber 14 is compressed in the fluid compression pocket 13, the pressure in the high pressure chamber 15 is further increased. The pressure of the discharge pressure chamber 46 that receives the pressure of the high pressure chamber 15 through the communication hole 47 becomes high, and the pressure difference between the pressure of the suction pressure chamber 45 and the suction pressure chamber 45 that receives the pressure of the suction chamber 22 becomes large. As a result, the drive pin 42 is pressed to the left as shown in FIG.
4 is compressed and moved in the axial direction. When the drive pin 42 moves to the left in the axial direction, the bush 10 that cannot move in the axial direction engages with the portion of the inclined portion 42b of the drive pin 42 that is closer to the tip, so that the drive shaft 5 of The amount of eccentricity of the bush 10 with respect to the axis increases, and the revolution radius of the movable scroll member 12 axially supported by the bush 10 via the needle bearing 11 also increases accordingly.

As a result, the sealing points on both ends of the crescent-shaped fluid compression pocket 13 formed between the spiral blades 3a and 12a of the two scroll members come into contact with each other, and thereafter the same as in the case of the first embodiment. Fluid compression pocket 13
In the above, effective compression of the refrigerant is performed to increase the pressure in the high pressure chamber 15, and the compressed refrigerant pushes the discharge valve 17 open and is discharged to the discharge chamber 18. After the solenoid valve 23 is opened, the pressure in the high pressure chamber 15 is increased, the drive pin 42 is moved leftward in the axial direction, and the revolution radius of the movable scroll member 12 is increased accordingly. The increase in the load torque acting on the drive engine via 5 is gentle, and the phenomenon such as the start shock that is seen when the conventional refrigerant compressor is started does not occur.

When the air conditioner is deactivated, the operation switch of the air conditioner (not shown) is manually or automatically turned off to close the solenoid valve 23 and return the refrigerant to the suction chamber 22. Shut off the supply. In this state, the scroll compressor 39 is temporarily brought into an operating state similar to that of a vacuum pump. Therefore, the refrigerant pressure in the low pressure chamber 14 and the suction chamber 22, and hence the suction pressure chamber 45 on the side of the base 42a of the drive pin 42 is reduced. However, the width of the pressure drop of the discharge pressure chamber 46 formed at the tip of the high pressure chamber 15, that is, the end of the drive pin 42 on the inclined portion 42b side is larger than the width of the pressure drop, and The differential pressure will be reduced.

As a result, the drive pin 42 has the spring 44
Is pushed to move to the right in the axial direction and the operating state shown in FIG. 8 is reached. By moving the drive pin 42 to the right in the axial direction,
Since the bush 10 engages with the portion of the inclined portion 42b of the drive pin 42 near the base portion 42a, the eccentric amount of the bush 10 and the revolution radius of the movable scroll member 12 supported by the bush 10 are reduced. A gap 36 is generated between the two spiral blades 3a and 12a, increasing the amount of refrigerant leaking from the fluid compression pocket 13. Therefore, the scroll-type compressor 39 cannot substantially compress the refrigerant to push and open the discharge valve 17 to discharge the refrigerant to the discharge chamber 18, resulting in a so-called idling state. Figure 8
The operating state shown in FIG. 2 is the same as that shown in FIG.
As described in FIG. 4, the sliding friction of the tip seals 37 and 38 is also small, and the movable portion of the scroll compressor 39 rotates with almost no power consumption. The same effect as in the case of can be obtained.

In both cases of the first and second embodiments, the electromagnetic valve 23 is closed and the scroll type compressor 1 is used.
Alternatively, when 39 is put into the idling state, a gap 36 is generated at the sealing position between the two spiral blades 3a and 12a to leak the refrigerant, but the maximum value of the gap 36 is several mm or less. In addition, the ratio of the centrifugal force due to the revolution that acts on the movable scroll member 12 having a large revolution radius in the actual operation state to the centrifugal force that acts on the balance weight 21 is, for example, 100: 84, and the solenoid valve 23 is closed. In the idling state, the orbiting radius of the movable scroll member 12 is reduced by, for example, 0.65 mm, so that the centrifugal force ratio is set to 100: 100, and the movable scroll member 12 is set so that the centrifugal force does not act on it. You can also

In this case, the spiral blades 3a and 12a
The size of the gap 36 at the sealing point between the two is 0.65
However, when the solenoid valve 23 is opened and the refrigerant is supplied to the low pressure chamber 14, the compression work in the fluid compression pocket 13 is not zero even if there is such a gap 36.
A slight discharge pressure is generated in the high pressure chamber 15. Therefore, due to this discharge pressure, the drive pin 42 can start moving to the left in the axial direction in FIG.
The radius of revolution of the circle expands and gradually approaches the state shown in FIG.

When the electromagnetic valve 23 is closed and the scroll type compressor 39 of the second embodiment is temporarily brought into an operating state like a vacuum pump, the compression reaction force of the refrigerant pushes the movable scroll member 12 in the radial direction. Force and movable scroll member 12
Since the centrifugal force acting on is also small, it is not necessary to increase the mounting load of the spring 44, and the scroll compressor 39 can easily shift to the idling state.

In each of the first and second embodiments, the case where the present invention is applied to the scroll type compressor has been described, but the present invention is not only applicable to the scroll type compressor, As will be apparent to those skilled in the art, such as rolling piston compressors,
It is also applicable to other types of positive displacement compressors having a crank mechanism similar to that of scroll compressors.

[0039]

In the positive displacement compressor of the present invention, it is not necessary to use a large and expensive electromagnetic clutch, and a sudden change in the load torque of the drive engine due to the discontinuity of the clutch causes a change. It is possible to fundamentally prevent a starting shock or the like that occurs, and the entire compressor can be made inexpensive and small. Further, even though the drive shaft is constantly driven by the prime mover, the discharge of the compressed fluid can be controlled according to demand, as in the case where the drive shaft is intermittently driven by the electromagnetic clutch or the like. Moreover,
Wear and power loss of moving parts can be reduced to the extent that there is no problem

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional front view showing the overall configuration of a scroll type compressor as a first embodiment of the present invention in an operating state.

FIG. 2 is a vertical cross-sectional front view showing the overall configuration of the scroll compressor of the first embodiment in an idling state.

FIG. 3 is an enlarged cross-sectional view showing a state of a tip seal in an actual operation state.

FIG. 4 is an enlarged cross-sectional view showing the state of the tip seal in the idling state.

FIG. 5 is a transverse side view showing a transverse section of the scroll compressor of the first embodiment.

FIG. 6 is a vertical cross-sectional front view showing the overall configuration of a scroll type compressor according to a second embodiment of the present invention in an operating state.

FIG. 7 is an exploded perspective view showing a main part of the second embodiment.

FIG. 8 is a vertical cross-sectional front view showing the overall configuration of a scroll type compressor of a second embodiment in an idling state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Scroll compressor (1st Example) 2 ... Housing 3 ... Fixed scroll member 3a ... Spiral blade 5 ... Drive shaft 7 ... Pulley 10 ... Bushing 12 ... Movable scroll member 12a ... Spiral blade 12c ... Boss Portion 13 ... Fluid compression pocket 14 ... Low pressure chamber 15 ... High pressure chamber 17 ... Discharge valve 21 ... Balance weight 22 ... Suction chamber 23 ... Electromagnetic valve 24 ... Suction passage 25 ... Rotation preventing mechanism (first embodiment) 26 ... Tapered sleeve 26a ... Conical inner surface 27 ... Taper pin 28 ... Annular piston 29 ... Annular groove 30 ... Bellows 31 ... Atmospheric pressure chamber 32 ... Suction pressure chamber 36 ... Gap 37, 38 ... Tip seal 39 ... Scroll type compressor (second embodiment) 40 ... Bottom hole 42 ... Drive pin 42a ... Base 42b ... Inclined part 43 ... Inclined hole 45 ... Suction pressure chamber 46 ... Discharge pressure chamber 50 ... Rotation prevention Stop mechanism

Claims (4)

[Claims] 1. A fluid is compressed between a drive shaft that is constantly driven to rotate by a prime mover, and revolves by being driven eccentrically with respect to the axis of the drive shaft and driven by the drive shaft, and a fixed portion. A driven portion, a rotation preventing mechanism that prevents rotation of the driven portion and allows a revolution and a revolution radius to change, and a crank mechanism that connects the drive shaft and the driven portion to transmit torque. And a valve means capable of opening and closing a fluid suction passage, wherein the driven portion has an increased revolution radius when the valve means is opened to effectively compress the fluid. A positive displacement compressor characterized in that, when the means is closed, the revolution radius is reduced and the fluid is put in an idle state in which the compression action of the fluid is invalidated. 2. The positive displacement compressor according to claim 1, wherein the fixed portion is a fixed scroll member, and the driven portion is a movable scroll member. 3. A taper pin at least in which the rotation preventing mechanism moves in the axial direction by a pressure difference between suction pressure and atmospheric pressure, and a conical inner surface formed on an end plate of the movable scroll member and engaged with the taper pin. 3. The revolution radius of the movable scroll member changes according to the degree of penetration of the taper pin into the conical inner surface.
The positive displacement compressor described. 4. At least the crank mechanism comprises a bent drive pin that can slide in an axial hole formed in a part of the drive shaft, and a slidable portion on the tip side of the drive pin. And a bush having an inclined hole for dynamic engagement, wherein the drive pin moves in the axial direction by a differential pressure between suction pressure and discharge pressure acting on both ends of the drive pin, thereby causing the eccentricity of the bush and the movement of the bush. The positive displacement compressor according to claim 2, wherein the revolution radius of the scroll member changes.