JP2005030329A - Scroll type compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll type compressor capable of reducing the upsetting moment generated when a movable scroll is revolved irrespective of the size of the tooth depth. <P>SOLUTION: The scroll type compressor comprises a fixed scroll 250 having a substantially spiral tooth part 252, a movable scroll 240 having a substantially spiral tooth part 242 and assembled so as to be engaged with the fixed scroll 250 in an offset manner, a rotary shaft 211, a bush 213 having an offset hole 213a in which a drive pin 212 provided on an end part of the rotary shaft 211 is rotatably inserted, and a working chamber 256 in which the volume to be demarcated between the substantially spiral tooth part 252 and the substantially spiral tooth part 242 by an offset crank mechanism 210 comprising the rotary shaft 211 and a bush 213 is reduced from the outer circumferential side of the substantially spiral tooth part to a substantially center side. The offset hole 213a has a thickness-reduced portion 213b in which the inner circumference on the end part side of the rotary shaft 211 is reduced in thickness out of the inner circumference 213a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a scroll compressor, for example, a scroll compressor suitable for application to a supercritical refrigeration cycle using CO ₂ as a refrigerant.

  As a scroll type compressor, a spiral tooth portion formed on each end plate of a fixed scroll and a movable scroll is combined, and a movable fluid such as a refrigerant is sucked and compressed by revolving the movable scroll. Is known (see Patent Document 1). In Patent Document 1, the tooth height of at least one of the teeth of the fixed scroll is slightly higher than the tooth height of the movable scroll. A technique for suppressing a rollover moment that a movable scroll receives due to an influence of a compression reaction force or the like is disclosed. Since the tooth tip of the fixed scroll always comes into contact with the end plate of the movable scroll, the tooth tip of the movable scroll is prevented from coming into contact with the end plate of the fixed scroll.

  In addition, when the tooth height of the tooth | gear part of a movable scroll and the tooth | gear part of a fixed scroll is substantially the same, there exists a possibility that the tooth | gear tip of a movable scroll and a fixed scroll may contact. When these contact, a pressing force is generated between the tooth tip of the movable scroll and the end plate of the fixed scroll. Therefore, the action point of the rollover moment is extended by the tooth height, and the rollover moment is increased.

  The tooth height difference between the tooth part of the movable scroll and the tooth part of the fixed scroll, that is, the tooth tip clearance, forms a leakage clearance of the compression working chamber that is partitioned by both tooth parts when the movable scroll revolves.

Of the fixed scroll teeth, as a method of increasing the tooth height of at least one circle from the outermost circumference, generally the tooth height of the spiral center side excluding at least one circle from the outermost circumference is cut. It is conceivable to form it smaller.
JP-A-7-35057

  However, in the prior art, there is a problem in that leakage loss increases because the tip clearance becomes larger toward the spiral center of the tooth portion.

In addition, when a CO ₂ refrigerant that has been attracting attention in recent years due to environmental problems is applied, the capacity is generally smaller than that of chlorofluorocarbon. Therefore, the tooth length is about 1/8 to 1 compared with the case of using chlorofluorocarbon. / 10. For this reason, the effect of suppressing the rollover moment according to the tooth height in the prior art tends to be small. That is, in the prior art, consideration for positively reducing the rollover moment is not sufficient.

  The present invention has been made in consideration of such circumstances, and an object of the present invention is to reduce the rollover moment that occurs during the revolution of the movable scroll regardless of the size of the tooth height.

  Another object is to provide a scroll compressor capable of reducing the overturning moment generated during the revolution of the movable scroll regardless of the height of the tooth and reducing the leakage loss.

  According to claim 1 of the present invention, it has a fixed scroll member having a first substantially spiral tooth portion formed on the end plate, and a second substantially spiral tooth portion formed on the end plate, A movable scroll member incorporated so as to be eccentrically engaged with the fixed scroll member, a rotating shaft that rotates by receiving a driving force, and an eccentric hole into which a driving pin provided at the end of the rotating shaft is rotatably inserted. A volume divided between the first substantially spiral tooth portion and the second substantially spiral tooth portion by the rotational drive of the eccentric crank mechanism including the bushing having the rotation shaft and the bush. A working chamber that decreases from the outer peripheral side toward the substantially central side, and the inner periphery of the eccentric hole supports the drive pin in a rotatable manner, and the inner periphery on the rotating shaft end side of the inner periphery is removed. It is characterized in that a thinned portion is provided.

  In general, the drive pin is slightly deformed by the influence of the compression reaction force and receives a load corresponding to the input load at the base portion of the drive pin. Therefore, in the conventional configuration, the point of action of the input load due to the driving force is at the position of the root portion of the driving pin.

  On the other hand, in the scroll compressor according to claim 1 of the present invention, the eccentric hole in the bush that rotatably supports the drive pin has an inner periphery on the rotating shaft end side of the inner periphery. Since the thinned portion is removed, it is possible to prevent the drive pin from coming into contact with the thinned portion. As a result, the action point of the input load can be moved to the inner circumference on the rotating shaft end side excluding the wall removal part, and the distance between the action points can be shortened. Therefore, it is possible to reduce the rollover moment that occurs when the movable scroll member revolves.

  Furthermore, in the scroll compressor according to claim 1 of the present invention, it is possible to reduce the rollover moment generated when the movable scroll member revolves regardless of the size of the tooth height.

  According to claim 2 of the present invention, it is preferable that the thinning portion has a predetermined length from the end surface of the bush on the rotating shaft end side toward the extending direction of the inner periphery such as the axial direction of the rotating shaft. . Thereby, the distance between action points can be shortened by a predetermined length.

  According to claim 3 of the present invention, of the gap between the inner periphery and the drive pin, the avoidance gap portion between the thinning portion and the drive pin is formed in a size that the thinning portion does not contact the outer periphery of the drive pin. Has been.

  As a result, the avoidance gap between the thinning portion and the drive pin is limited to a size that prevents the thinning portion from coming into contact with the outer periphery of the drive pin, so that the overturning moment can be reduced, and the thinning amount at the thinning portion And the bush rigidity can be secured.

  According to claim 4 of the present invention, the fixed scroll member having the first substantially spiral tooth portion formed on the end plate, and the second substantially spiral tooth portion formed on the end plate, A movable scroll member incorporated so as to be eccentrically engaged with the fixed scroll member, a rotating shaft that rotates by receiving a driving force, and an eccentric hole into which a driving pin provided at the end of the rotating shaft is rotatably inserted. A volume divided between the first substantially spiral tooth portion and the second substantially spiral tooth portion by the rotational drive of the eccentric crank mechanism including the bushing having the rotation shaft and the bush. And a drive pin that is rotatably supported on the inner periphery of the eccentric hole and from the rotating shaft end side toward the open end of the inner periphery. It is characterized by being provided with a substantially tapered part that increases the outer circumference. That.

  In the scroll compressor according to claim 4, as a technique for reducing the overturning moment that occurs when the movable scroll member revolves, a substantially tapered portion that is thinned, for example, on the drive pin side instead of the thinned portion in the eccentric hole on the bush side. May be provided. As a result, the portion of the drive pin that comes into contact with the inner periphery of the eccentric hole of the bush in the open end direction that approaches the size of the inner circumference from the rotating shaft end side toward the inner end of the open end. As a result, the distance between the operating points can be shortened.

  According to the fifth aspect of the present invention, the substantially tapered portion can be formed from the substantially root of the drive pin to the central portion of the length in the extending direction of the inner periphery.

  According to claim 6 of the present invention, of the gap between the inner circumference and the drive pin, the avoidance gap between the inner circumference and the substantially tapered portion is in contact with the inner circumference as the outer circumference of the substantially tapered portion is in the anti-open end direction. It is formed in a size that does not.

  As a result, the avoidance gap between the inner periphery and the substantially tapered portion is limited to a size such that the outer periphery of the substantially tapered portion is in the anti-opening end direction and does not contact the inner periphery, thereby reducing the overturning moment. For example, the thickness of the drive pin can be reduced at the substantially tapered portion, and the rigidity of the drive pin can be ensured.

  According to the seventh aspect of the present invention, the tooth height difference between the tooth height of the first substantially spiral tooth portion and the tooth height of the second substantially spiral tooth portion is approximately the center from the outer peripheral side of the substantially spiral tooth portion. It is suitable for application to a scroll type compressor having a predetermined difference in tooth height toward the side. In the scroll compressor according to the seventh aspect, as a method of reducing the overturning moment generated when the movable scroll member revolves, it can be reduced regardless of the size of the tooth height. It can be set to a predetermined constant value. Accordingly, the leakage clearance of the working chamber can be reduced as compared with the conventional method of reducing the overturning moment, so that the leakage loss can be reduced.

  Hereinafter, embodiments in which the scroll compressor of the present invention is embodied will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view showing the configuration of the scroll compressor according to the present embodiment. FIG. 2 is a cross-sectional view showing the drive pins and bushes in FIG. FIG. 3 is a schematic diagram showing a balance relationship of loads in the compression mechanism portion in FIG. FIG. 4 is a schematic cross-sectional view showing a meshed state of the movable scroll member and the fixed scroll member in FIG.

As shown in FIG. 1, a scroll compressor (hereinafter referred to as a compressor) 100 includes a compression mechanism unit 200 that sucks and compresses a working fluid (hereinafter referred to as a fluid) such as a CO ₂ refrigerant, and a compression mechanism unit. And an electric motor unit (electric motor) 300 that generates a driving force for driving the motor 200. The compressor 100 is a so-called electric compressor in which an electric motor unit 300 is integrally provided in the compression mechanism unit 200 and the compression mechanism unit 200 is operated by the electric motor unit 300. The compression mechanism unit 200 and the electric motor unit 300 are accommodated in a pressure-resistant container 101 having a main body casing 101a, an upper casing 101b, and a lower casing 101c.

As the fluid compressor 100 compresses, Freon, a gas such as CO ₂ refrigerant gas, may be any of the liquid. Hereinafter, the fluid described in the present embodiment is CO ₂ refrigerant gas.

  As shown in FIG. 1, the electric motor unit 300 includes a rotor 310 fixed to a rotating shaft (main shaft) (hereinafter referred to as a shaft) 211, and a stator disposed on the outer peripheral side facing the rotor 310. 320. Note that the stator 320 is shrink-fitted and fixed to the inner wall of the main body casing 101a. When electric power is supplied to the motor unit 300 from an external power source (battery) (not shown), the rotor 310 is excited and rotates. Then, the shaft 211 on which the rotor 310 is fixed is driven to rotate.

  As shown in FIG. 1, the compression mechanism unit 200 includes a shaft 211, a bush 213 that rotatably supports the shaft 211, a movable scroll member (hereinafter referred to as a movable scroll) 240 that supports the bush 313, and a movable scroll. It is configured to include a fixed scroll member (hereinafter referred to as a fixed scroll) 250 incorporated so as to be eccentrically engaged with the member 240.

  As shown in FIG. 1, the shaft 211 has one end side (the motor unit 300 side shown in FIG. 1) fixed to the rotor 310, and the other end (hereinafter referred to as an end) side compared to the one end side. The main receiving part 211a is formed with a relatively large outer diameter. The main receiving portion 211a is integrally provided with a drive pin 212 that is eccentric by a predetermined amount with respect to the axis of the shaft 211. Since the end portion has a main receiving portion 211a formed with a relatively large outer diameter, the degree of freedom of setting a predetermined amount of eccentricity in the drive pin 212 provided at the end portion can be improved. Further, a bearing member (hereinafter referred to as a main bearing) 215 is disposed in the middle housing 220 provided in the main body casing 101a. The main bearing 215 rotatably supports the end portion (specifically, the main receiving portion 211a) of the shaft 211. Since the main bearing 215 has an eccentric crank mechanism 210 described later on the end portion side of the shaft 211, a bearing is used. The holder 230 having the opening 231 is provided with a sub-bearing 216, and rotatably supports one end side of the shaft 211.

  The shape of the drive pin 212 may be a substantially cylindrical shape that can be inserted into the eccentric hole 213a of the bush 213. Hereinafter, the shape of the drive pin 212 described in the present embodiment will be described as a cylindrical shape. The outer periphery 212a of the drive pin 212 has an outer diameter of φa, for example.

  The bush 213 is a substantially cylindrical body having an eccentric hole 213a, and a drive pin 212 is rotatably inserted into the eccentric hole 213a. Note that a C-shaped snap ring 214 is fitted to the tip of the drive pin 212, and this snap ring 214 prevents the bush 213 from coming off.

  The shaft 211 and the bush 213 configured as described above are rotatably mounted in a state where the bush 213 is eccentric with respect to the axis of the shaft 211. Further, when the shaft 211 rotates, the bush 213 is allowed to rotate (swing) with respect to the drive pin 212, and the bush 213 revolves around the axis of the shaft 211.

  Further, as shown in FIGS. 1 and 2, the drive pin 212 is rotatably supported on the inner periphery of the eccentric hole 213a in the bush 213, and the inner end of the shaft 211 on the end side of the shaft 211 is supported. A thinning part 213b whose thickness has been thinned is provided. As shown in FIG. 1, the inner periphery 213c that has been thinned in the thinned portion 213b has an inner diameter of φB and is relatively larger than the inner diameter φA of the inner periphery 213a (φB> φA).

  Furthermore, in this embodiment, as shown in FIG. 1, the thinning portion 213b is formed on the inner periphery 213c having a predetermined length Lb1 in the axial direction toward the direction in which the drive pin 212 extends. The thinning portion 213b is not limited to the one in which the inner periphery 213c having the predetermined length Lb1 is formed in the axial direction, and may be, for example, in the axial direction as long as the inner periphery 213a rotatably supports the drive pin 212. On the other hand, an inner circumference 213c having a predetermined length Lb1 may be formed in the extending direction of the inner circumference 213a such as an inner circumference slightly inclined.

  Furthermore, in this embodiment, as shown in FIGS. 2 and 3, the gap between the thinning portion 213b (specifically, the inner circumference 213c) and the drive pin φa is the inner circumference 213a. It is preferable that the inner periphery 213c be formed in a size that does not contact the outer periphery 212a of the drive pin 212 that is supported and can be tilted. Accordingly, the size of the avoidance gap is limited to such a size that the inner periphery 213c is not in contact with the outer periphery 212a of the drive pin 212 that is supported by the inner periphery 213a and can be tilted. Since the amount of thinning to be performed can be reduced, the rigidity of the bush 213 can be ensured.

  Here, the shaft 211 and the bush 213 constitute an eccentric crank mechanism 210. The eccentric crank mechanism 210 has a structure in which the amount of eccentricity of the bush 213 with respect to the axis of the shaft 211 changes as the bush 213 rotates (swings) with respect to the drive pin 212. As shown in FIG. 1, a balancer 217 is fixed to the bush 213 by press-fitting, caulking, shrink fitting, welding, or the like. The balancer 217 cancels or reduces dynamic imbalance that occurs when the shaft 211 rotates (specifically, the operation of the eccentric crank mechanism 210). A movable scroll 240 is connected to the bush 213 constituting the eccentric crank mechanism 210.

  As shown in FIG. 1, the movable scroll 240 includes an end plate 241 and a substantially spiral body (hereinafter referred to as a second substantially spiral tooth portion) 242 formed on the end plate 241. ing.

  As shown in FIG. 1, the end plate 241 is a substantially disk-like body, and a holding portion (hereinafter referred to as a boss portion) 243 capable of supporting the bush 213 is provided on the eccentric crank mechanism 210 side. Yes. The boss portion 243 is provided with a bearing member (hereinafter referred to as a movable scroll bearing) 245 that rotatably supports the outer periphery of the bush 213. The movable scroll bearing 245 is fixed to the boss portion by pressure or the like. Yes.

  Here, the boss portion 243 and the movable scroll bearing 245 constitute holding means for rotatably supporting the bush 213 constituting the eccentric crank mechanism 210.

  As shown in the drawing, the second substantially spiral tooth portion 242 is provided on the end surface of the end plate 241 on the side of the anti-eccentric crank mechanism 210, and is a wall plate portion (for example, formed in a spiral shape having an involute curve) ( Hereinafter referred to as a tooth portion).

  As shown in FIG. 1, the end plate 241 is sandwiched between the axial direction of a bearing member (hereinafter referred to as a thrust bearing) 246 fixed to the middle housing 220 and the fixed scroll 251, and the thrust plate 246 Supported in the axial direction. The thrust bearing 246 allows the revolving operation of the movable scroll 240 that revolves through the bush 213 when the shaft 211 rotates. Further, the thrust bearing 246 plays a role of receiving a thrust load applied to the movable scroll 240 by a compression reaction force in the thrust direction when a fluid in a working chamber 256 described later is compressed.

  As shown in FIG. 1, an anti-rotation hole 244 is provided on the outer peripheral side of the end plate 241, and an anti-rotation pin 254 provided on the fixed scroll 250 is inserted to prevent the movable scroll 240 from rotating. I am doing so. Here, the rotation prevention hole 244 and the rotation prevention pin 254 constitute movable scroll rotation prevention means for preventing the rotation of the movable scroll 240.

  As shown in FIG. 1, the fixed scroll 250 includes an end plate 251 and a substantially spiral body (hereinafter, referred to as a first substantially spiral tooth portion) 252 formed on the end plate 251. ing.

  As shown in FIG. 1, the end plate 251 is a substantially disk-like body, and is fixed to the middle housing 220 by a fixing means such as a bolt (not shown).

  As shown in FIG. 1, the first substantially spiral tooth portion 252 is provided on the end face of the end plate 252 facing the first substantially spiral tooth portion 242, and the second substantially spiral tooth portion 242 It consists of a tooth portion formed in a spiral shape corresponding to the shape.

  Here, the axial heights of the tooth portions in the second substantially spiral tooth portion 242 and the first substantially spiral tooth portion 252 are referred to as tooth height, and the tip of the tooth portion is referred to as a tooth tip. .

  The tooth height H0 (see FIG. 3) of the second substantially spiral tooth portion 242 and the tooth height H1 (see FIG. 3) of the first substantially spiral tooth portion 252 are substantially the same. To form. Of the tooth height H1, the tooth height H2 (see FIG. 6 of the comparative example) on the substantially central side may be formed small (H1> H2). In addition, since the 2nd substantially spiral tooth part 242 and the 1st substantially spiral tooth part 252 demonstrated in this embodiment below are demonstrated compared with a comparative example, tooth height H0 and tooth height H1 are substantially the same. Suppose that In order to ensure reliability, such as an increase in the temperature of the fluid that compresses the fluid in the working chamber 256, the tip clearance is actually provided in the range of 10 to 20 μm (H0 <H1).

  The movable scroll 240 and the fixed scroll 250 configured in this way are incorporated into each other so that the second substantially spiral tooth portion 242 and the first substantially spiral tooth portion 252 are fitted in the longitudinal direction of the shaft 211. As a result, a working chamber 256 for sucking and compressing fluid is formed. The working chamber 256 includes a second substantially spiral tooth portion 242, a first substantially spiral tooth portion 252, an end surface of the end plate 241 on which the second substantially spiral tooth portion 242 is formed, and a first substantially spiral portion. It is a fluid compression space defined by the end face of the end plate 251 in which the tooth-like portion 252 is formed. This fluid compression space is moved from the outer peripheral side of these substantially spiral tooth portions 242 and 252 toward the substantially central side in accordance with the revolution operation of the movable scroll 240 by the rotational drive of the eccentric crank mechanism 210, and the second substantially spiral tooth. The volume defined by the portion 242 and the first substantially spiral tooth portion 252 is reduced. The fluid in the working chamber 252 is increased in pressure toward the substantially central side.

  Here, the eccentric crank mechanism 210 constitutes a revolving means that rotates by receiving a driving force and revolves the movable scroll 240 by the rotational driving. Further, the eccentric crank mechanism 210 has an operation chamber 252 defined by the second substantially spiral tooth portion 242 and the first substantially spiral tooth portion 252 in accordance with the revolution operation of the movable scroll 240. The compression means is configured to move from the outer peripheral side of the 242 and 252 toward the substantially central side to reduce the volume of the working chamber 252.

  Further, as shown in FIG. 1, a stepped portion 255 is formed on the side of the fixed scroll 250 opposite to the first substantially spiral tooth portion 252, and a discharge hole 253 is provided in the central portion (specifically, the central portion). It has been. The opening side of the stepped portion 255 is closed by the rear plate 260, and a discharge chamber 257 is formed as an internal space. The shape of the stepped portion 255 may be any shape such as a bottomed hole, a concave shape, a groove shape, or a step shape as long as it has a volume capable of storing a high-pressure fluid inside. .

  Furthermore, the discharge hole 253 is provided with a discharge valve 270 that opens to the discharge chamber 257 side and a stopper 271 that restricts the maximum opening of the discharge valve 270, and is fixed to the fixed scroll 250 by bolts 272.

  Furthermore, as shown in FIG. 1, the middle housing 220 is provided with a fluid passage (hereinafter referred to as a refrigerant passage) 221 and a suction chamber 222, and the motor unit 300 is accommodated mainly as a fluid flow path. The refrigerant passage 221, the outer portion of the boss 243, and the thrust bearing 246 communicate with the suction chamber 222 from the space formed. Further, the suction chamber 222 and the working chamber 256 communicate with each other through a fluid passage provided in the fixed scroll 250 (not shown).

  The upper housing 101b is provided with a suction pipe 281 communicating with the inside of the main casing 101a, and low-pressure fluid from the outside is accommodated in the motor unit 300 via the suction pipe 281 and the opening 231. Led to the space to be.

  Further, the fixed scroll 250 is provided with a discharge pipe 282 communicating with the inside of the discharge chamber 257, and the fluid stored in the discharge chamber 257 at a predetermined fluid pressure by the discharge valve 270 passes through the discharge pipe to drive external fluid. Guided to an external device such as a device.

The operation of the compressor 100 having the above-described configuration will be described with reference to FIG. When electric power is supplied from the external power source to the motor unit 300, the electromagnetic unit 300 generates a driving force. The shaft 211 is rotated by receiving the driving force generated through the rotor 310. A bushing 213 rotatably mounted on a drive pin 212 provided at the end of the shaft 211 rotates in a circular orbit that is eccentric by a predetermined amount with respect to the shaft center of the shaft 211, that is, revolves around the shaft 211. The eccentric crank mechanism 210 including the shaft 211 and the bush 213 revolves the movable scroll 240 that supports the bush 213 via the boss portion 243. When the movable scroll 240 revolves, the movable scroll 240 and the fixed scroll 250 that are incorporated so as to be eccentrically engaged with each other and the fixed scroll 250 (specifically, the second substantially spiral tooth portion 242 and the second spiral tooth portion 252). The partitioned working chamber 256 sucks and compresses fluid (CO ₂ refrigerant) while decreasing in volume from the outer peripheral side toward the substantially central side.

At this time, the CO ₂ refrigerant guided from the evaporator outlet side of the refrigeration cycle such as an automobile air conditioner (not shown) is sucked into the suction chamber 222 of the compression mechanism unit 200 through the suction pipe 281. Then, the working chamber 256 is confined in the outermost working chamber portion, and is gradually compressed to the substantially central side by the revolving operation of the movable scroll accompanying the rotation of the shaft 211, and finally the discharge valve 270 is discharged from the discharge hole 253. The CO ₂ refrigerant whose pressure is increased to a predetermined pressure is introduced into the discharge chamber 257 by opening the valve. Then, the CO ₂ refrigerant compressed at high pressure from the discharge chamber 257 is sent to the condenser inlet side of the refrigeration cycle (not shown) via the discharge pipe 282.

Here, the operation | movement regarding revolution of the movable scroll which comprises the compression mechanism part 200 is demonstrated according to FIG. When the above-described fluid (CO ₂ refrigerant) is sucked and compressed, the movable scroll 240 performs a revolving motion while maintaining a predetermined radius with respect to the fixed scroll 250. The movable scroll 240 is restricted from rotating about the center of the boss portion 13 by the movable scroll rotation preventing means 244 and 254. A thrust load F3 received by the movable stroke 240 due to the influence of the thrust direction component F1 of the compression reaction force is supported by the thrust bearing 246. The radial component F4 of the compression reaction force acts on the second substantially spiral tooth portion 242 and the first substantially spiral tooth portion 252 that compress the fluid in the working chamber 256. An input load F6 corresponding to a driving force (input torque) for driving the shaft 211 is applied to a portion where the driving pin 212 and the bush 213 are in contact with each other. For example, when the rotational speed of the shaft 211 increases, the input load F6 increases because the fluid compression force in the working chamber 256 increases. When the input load F <b> 6 increases, the overturning moment M that acts to incline the movable scroll 240 with respect to the fixed scroll 250 increases due to a balance related to the overturning moment M described later. When the tilting moment M becomes large and cannot be supported by the thrust bearing 246, the movable scroll 240 is actually tilted with respect to the fixed scroll 250. Then, the tooth tip of one of the substantially spiral tooth portions (242 or 252) of the movable scroll 240 and the fixed scroll 250 and the end face facing the tooth tip of the other end plate (251 or 241) are provided. May come into contact. When the tooth tip and the end surface come into contact, a pressing force F2 is generated between the tooth tip and the end surface, and a frictional force F5 is generated by the pressing force F2.

  Here, the balance relationship between the loads F1, F2, F3, F4, F5, and F6 applied to the movable scroll 240 is as follows. As shown in FIG. 3, the thrust direction component F1 of the compression reaction force and one substantially spiral tooth portion. The thrust force F2 generated between the tooth tip of (242 or 252) and the end face of the other end plate (251 or 241) is balanced with the thrust load F3 by the support of the thrust bearing. Further, the radial direction component F4 of the compression reaction force, the frictional force F5 corresponding to the pressing force F2, and the input load (load acting on the boss portion 243) F4 received at the contact portion between the drive pin 211 and the bush 213 are balanced. Yes.

  Further, the overturning moment M includes various loads acting as the overturning moment M, including a radial component F4 of the compression reaction force, a frictional force F5, and an input load (load acting on the boss portion 243) F4. The action point acting as the overturning moment M is that the radial direction component F4 and the frictional force F5 of the compression reaction force are in the thrust direction position where the tooth tip of the second substantially spiral tooth portion 242 and the end face of the end plate 251 are in contact (hereinafter referred to as the thrust force). The input load F6 is a thrust direction position where the drive pin 211 and the bushing 213 are in contact (hereinafter referred to as a second action point position). The rollover moment M is approximately proportional to the distance L1 between the first action point position and the second action point position.

  According to the present embodiment described above, the eccentric hole 212a in the bushing 213 that rotatably supports the drive pin 212 has a thinned portion 212b in which the inner periphery on the shaft 211 end side of the inner periphery 212a is thinned. Therefore, the thinning portion 212b (specifically, the inner periphery 212c) can be prevented from coming into contact with the outer periphery 212a of the drive pin 212. As a result, the second operating point to which the input load F6 is applied can be moved to the inner periphery on the rotating shaft end side excluding the wall removal portion 212b, and the distance L1 between the operating points can be shortened. Therefore, the overturning moment M generated when the movable scroll 240 revolves can be reduced. For example, under the condition that the rotation speed of the shaft 211 is the same, that is, the driving force is the same, the distance L1 between the operating points can be shortened, so that the overturning moment M generated when the movable scroll 240 revolves can be reduced.

Furthermore, according to the present embodiment described above, it is possible to reduce the overturning moment M generated when the movable scroll 240 revolves regardless of the size of the tooth height. In the conventional method of reducing the rollover moment, the pressing force F2 and the friction force F5 are generated between the end surface of the end plate 241 of the movable scroll 240 and the tooth tip of the first substantially spiral tooth portion 252 of the fixed scroll 250. To shorten the distance between the operating points by the tooth height H1 (see FIGS. 7 and 8 of the comparative example), the tooth heights H1 and H0 required from the volume required by applying to the CO ₂ refrigerant are originally In some cases, the effect of reducing the rollover moment M cannot be expected. On the other hand, in the present embodiment, the rollover moment M generated when the movable scroll 240 revolves can be reduced even if the required specification of any tooth height is small.

  In the comparative example shown in FIG. 8, out of the tooth heights of the first substantially spiral tooth portion 252 of the fixed scroll 250, the tooth height H1 for at least one round from the outermost circumference is excluded from the tooth height H1 for one round. This is a conventional technique for reducing the rollover moment by forming the tooth height H2 on the spiral center side small (H1> H2). Further, in the comparative example, unlike the present embodiment, the inner periphery of the eccentric hole 213a of the bush 213 is formed of φA and does not have a thinned portion. The tooth tip clearance is in the range of 10 to 20 μm on the tooth height H1 side and 40 to 60 μm on the tooth height H2 side.

  Furthermore, according to the present embodiment described above, the thinned portion 213b is formed on the inner circumference 213c of the predetermined length Lb1 in the axial direction toward the direction in which the drive pin 212 extends. The second action point can be brought closer to the first action point side by the length Lb1, and the distance between the action points can be shortened.

  The thinning portion 213b is not limited to the one in which the inner periphery 213c having the predetermined length Lb1 is formed in the axial direction, and may be, for example, in the axial direction as long as the inner periphery 213a rotatably supports the drive pin 212. On the other hand, an inner circumference 213c having a predetermined length Lb1 may be formed in the extending direction of the inner circumference 213a such as an inner circumference slightly inclined. It is possible to shorten the distance between the operating points by a predetermined length in the direction in which the inner periphery 213a extends in the thickness removing portion 213b.

  Furthermore, according to the present embodiment described above, the avoidance gap between the thinning portion 213b (specifically, the inner periphery 213c) and the drive pin φa is supported by the inner periphery 213a and can be tilted by the outer periphery 212a of the drive pin 212. In addition, it is preferable that the inner circumference 213c be formed in such a size that it does not contact. Thereby, the avoidance clearance between the thinning portion 213b and the drive pin 212 is limited to a size that the inner periphery 212c is not in contact with the outer periphery 212a of the drive pin 212 that is supported and tilted in the inner periphery 213a. The rollover moment M can be reduced, and the amount of thinning at the thinning portion 213b can be suppressed to ensure the rigidity of the bush 231.

  Furthermore, the driving force, that is, the input load F6 is substantially proportional to the thrust direction component F4 of the compression reaction force, and the drive pin 212 is slightly deformed by the influence of the thrust direction component F4 of the compression reaction force. Since the drive pin 212 is cantilevered by the shaft 211, the micro deformation pattern is bent in the direction of the counter-input load F6 from the root portion of the drive pin 212 (see FIG. 3). In the state where the drive pin 212 is inclined in consideration of the amount of bending, the avoidance gap portion is preferably sized so that the inner periphery 212 c does not contact the outer periphery 212 a of the drive pin 212. Thereby, the reduction of the overturning moment M and the securing of the rigidity of the bush 231 can be achieved at the same time.

(Second Embodiment)
Hereinafter, other embodiments to which the present invention is applied will be described. In the following embodiments, the same or equivalent components as those in the first embodiment are denoted by the same reference numerals, and description thereof will not be repeated.

  In the second embodiment, the shape of the drive pin 212 is changed to the cylindrical shape described in the first embodiment, and as shown in FIG. . FIG. 5 is a cross-sectional view showing a drive pin and a bush according to the present embodiment. FIG. 6 is a schematic diagram showing a balance relationship of loads in the compression mechanism portion according to the present embodiment. In addition, the inner periphery 213a of the bush 213 is cylindrical. The inner diameter of the inner periphery 212a is φA.

  As shown in FIG. 5, the drive pin 212 is rotatably supported by the inner periphery 213a of the bush 213, and the outer periphery 212c increases from the end of the shaft 211 toward the open end of the inner periphery 212a. A tapered portion 212b is provided.

  Even with such a configuration, the same effects as those of the first embodiment can be obtained (see FIG. 6). As shown in FIG. 5, it is preferable that an R chamfer 212d is provided on the connection portion between the end portion of the shaft 211 and the substantially tapered portion 212b on the base side of the drive pin 212. As a result, the root portion of the drive pin 212 is a portion where stress concentrates easily due to the bending of the drive pin 212, so that stress relaxation at the root portion of the drive pin 212 can be achieved.

  Furthermore, in this embodiment, as shown in FIG. 5, the substantially tapered portion 212 b is formed beyond the root portion of the drive pin 212 beyond the central portion of the length in the extending direction (length in the longitudinal direction) of the inner periphery 213 a. ing. The inner circumferential position (hereinafter referred to as the inner circumferential position at the substantially tapered end) Lb2 facing the end of the substantially tapered portion 212b shown in FIG. 5 is Lb2> 1/2 with respect to the entire length Lb of the bush 213. × Lb. A portion where the drive pin 212 is bent and contacts the inner periphery 212a can be moved from the root portion of the conventional drive pin to the tip side as shown in FIG. A portion where the drive pin 212 bends and contacts the inner periphery 212a, that is, the second action point, is formed in the vicinity of the inner periphery position Lb at the substantially tapered end. Accordingly, the distance between the operating points can be shortened as the end of the substantially tapered portion 212b is extended to the tip side and the inner peripheral position Lb2 at the end of the substantially tapered portion is extended.

  Furthermore, in the present embodiment, the avoidance gap between the inner periphery 213a and the substantially tapered portion 212b is located closer to the inner periphery 212a as the outer periphery 212c of the substantially tapered portion 212b faces in the anti-open end direction (upward direction in FIG. 5). It is formed in the size which does not contact.

  As a result, the avoidance gap portion is limited to a size such that the outer periphery 212c of the substantially tapered portion 212b is in contact with the inner periphery 213a as the outer periphery toward the anti-open end direction reduces the rollover moment M generated when the movable scroll 240 revolves. In addition, it is possible to suppress the thickness of the drive pin 212 that is thinned by the substantially tapered portion 212b and to secure the rigidity of the drive pin 212.

  According to the first and second embodiments described above, the rollover moment can be reduced, so that the mechanical loss of the compression mechanism unit 200 can be reduced, and thus the compressor efficiency can be improved.

  Furthermore, according to the first and second embodiments described above, the tooth height H0 of the second substantially spiral tooth portion 242 and the tooth height H1 of the first substantially spiral tooth portion 252 are substantially the same, Since the tooth height difference H1−H0 is 10 to 20 μm as the tooth tip clearance, the leakage clearance of the working chamber 256 can be made smaller than that by the conventional method of reducing the rollover moment. In particular, in the case of applying the conventional overturning moment reduction method (see FIG. 8 of the comparative example), the tooth tip clearance, that is, the leakage clearance becomes larger toward the substantially central side where the fluid pressure in the working chamber 256 is increased. As compared with the above, the leakage clearance can be reduced to a range of 10 to 20 μm {δ1 (see FIGS. 3 and 6) <δ2 (see FIG. 7)}. Therefore, it is possible to reduce the overturning moment M generated during the revolution of the movable scroll 240 and to reduce the leakage loss.

In the present embodiment described above, the scroll compressor 100 using the CO ₂ refrigerant as the working fluid has been described. However, the scroll compressor 100 is not limited to the one using the CO ₂ refrigerant, and both the substantially spiral teeth of the movable scroll 240 and the fixed scroll 250 are used. If the tooth heights H0 and H1 of the parts 242 and 252 are relatively small, the present invention can be suitably applied.

  In the above-described embodiment, the scroll compressor 100 has been described as an electric compressor in which the compression mechanism unit 200 is operated by the electric motor unit 300. However, for example, the scroll compressor 100 is operated by an external prime mover such as an internal combustion engine mounted on a vehicle. It may be actuated.

Although described as being suitable for supercritical refrigeration cycle using CO ₂ as the refrigerant, may be applied to conventional refrigeration cycles using Freon is not limited thereto.

It is sectional drawing which shows the structure of the scroll compressor of the 1st Embodiment of this invention. It is sectional drawing which shows the drive pin and bush in FIG. It is a schematic diagram which shows the balance relationship of the load in the compression mechanism part in FIG. It is typical sectional drawing which shows the balance state of the movable scroll member and fixed scroll member in FIG. It is sectional drawing which shows the drive pin and bush concerning 2nd Embodiment. It is a schematic diagram which shows the balance relationship of the load in the compression mechanism part concerning 2nd Embodiment. It is a schematic diagram which shows the balance relationship of the load in the compression mechanism part of a comparative example. It is typical sectional drawing which shows the meshing state of the movable scroll member and fixed scroll member in FIG.

Explanation of symbols

100 Compressor (Scroll type compressor)
200 Compression Mechanism Section 210 Eccentric Crank Mechanism 211 Shaft (Rotating shaft)
212 driving pin 212a outer periphery 213 bush 213a inner periphery 213b thinning portion 213c inner periphery in the thinning portion 213 240 movable scroll (movable scroll member)
241 End plate 242 Second substantially spiral tooth portion 243 Boss portion (holding portion)
250 Fixed scroll (fixed scroll member)
251 End plate 252 First substantially spiral tooth portion 256 Working chamber 300 Electric motor portion Lb1 Length in the axial direction of the thinning portion 213b H0 Tooth height of the second substantially spiral tooth portion 242 H1 First substantially spiral tooth portion 252 tooth length

Claims (7)

A fixed scroll member having a first substantially spiral tooth portion formed on the end plate;
A movable scroll member having a second substantially spiral tooth portion formed on the end plate, and being incorporated so as to be eccentrically engaged with the fixed scroll member;
A rotating shaft that rotates upon receiving a driving force;
A bush having an eccentric hole into which a drive pin provided at the end of the rotary shaft is rotatably inserted;
The volume divided between the first substantially spiral tooth portion and the second substantially spiral tooth portion by the rotational drive of the eccentric crank mechanism comprising the rotating shaft and the bush is the substantially spiral tooth portion. A working chamber that decreases from the outer peripheral side toward the substantially central side,
The inner periphery of the eccentric hole supports the drive pin rotatably,
A scroll compressor characterized in that a thinning portion is provided by thinning the inner circumference on the rotary shaft end portion side among the inner circumference. 2. The scroll compressor according to claim 1, wherein the thinning portion has a predetermined length from an end surface of the bush on the rotating shaft end portion side in a direction in which the inner circumference extends. Of the gap between the inner periphery and the drive pin, the avoidance gap portion between the thinning portion and the drive pin is formed in a size such that the thinning portion does not contact the outer periphery of the drive pin. The scroll compressor according to claim 1 or 2, characterized by the above. A fixed scroll member having a first substantially spiral tooth portion formed on the end plate;
A movable scroll member having a second substantially spiral tooth portion formed on the end plate, and being incorporated so as to be eccentrically engaged with the fixed scroll member;
A rotating shaft that rotates upon receiving a driving force;
A bush having an eccentric hole into which a drive pin provided at the end of the rotary shaft is rotatably inserted;
The volume divided between the first substantially spiral tooth portion and the second substantially spiral tooth portion by the rotational drive of the eccentric crank mechanism including the drive shaft and the bush is the substantially spiral tooth portion. A working chamber that decreases from the outer peripheral side toward the substantially central side,
The drive pin is rotatably supported on the inner periphery of the eccentric hole,
A scroll type compressor, wherein a substantially tapered portion having an outer periphery that increases from an end of the rotating shaft toward an open end of the inner periphery is provided. 5. The scroll compressor according to claim 4, wherein the substantially tapered portion is formed so as to extend from a substantially root of the drive pin to a central portion of a length in the extending direction of the inner periphery. Of the gap between the inner circumference and the drive pin, the avoidance gap between the inner circumference and the substantially tapered portion is formed in such a size that the outer circumference of the substantially tapered portion is not in contact with the inner circumference as the outer circumference is directed toward the anti-open end direction. The scroll compressor according to claim 4 or 5, wherein the scroll compressor is provided. The tooth height difference between the tooth height of the first substantially spiral tooth portion and the tooth height of the second substantially spiral tooth portion is approximately from the outer peripheral side of the substantially spiral tooth portion toward the substantially central side. The scroll compressor according to any one of claims 1 to 6, wherein the difference is a predetermined tooth height difference.

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