JP2007218162A - Reciprocating type fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reciprocating type fluid machine improving the durability of a thrust bearing while reducing manufacturing cost. <P>SOLUTION: This machine is provided with a rotor 36 stored in a crank chamber 16 and rotating as one body with a rotary shaft to reciprocate a piston 50, link mechanisms 42, 44 connecting the rotor and a swash plate 40, and a reciprocating unit 35 provided with the thrust bearing 38 provided between the rotor and an inner end surface 13 of a housing. The thrust bearing includes a raceway ring 70 provided with a bearing seat 76 butting on the inner end surface of the housing and a raceway surface 78 on which a rolling element 80 having rotation shaft line toward a width direction of the bearing rolls. The inner end surface of the housing includes an apex 66 butting on the bearing seat in a formed range of the raceway surface and is formed in a rotary around an axis of the rotary shaft. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a reciprocating fluid machine, and more particularly, to a reciprocating fluid machine suitable for use with a refrigerant having a high working pressure.

  A fluid machine of this type, for example, a reciprocating compressor, includes a compression unit in a housing that performs a series of refrigerant suction, compression, and discharge processes, and the compression unit reciprocates linearly in its axial direction. It is driven by a reciprocating unit that converts to The reciprocating unit includes a rotor that can rotate integrally with a shaft, and a thrust bearing disposed between the inner end surface of the housing and the rotor.

  A high pressure space is formed in the compression unit. This pressure acts as a thrust load on the front side of the bearing ring of the thrust bearing, more specifically, on the raceway surface on which the rolling elements roll, and on the rear side of the raceway, more specifically, on the opposite side of the raceway surface. The bearing seat positioned is urged in a direction to abut against the inner end surface of the housing. On the other hand, the bearing seat is supported on the inner end surface of the housing. That is, a bearing support reaction force against the thrust load acts on the bearing seat, and urges the bearing seat in a direction in which the bearing seat is separated from the inner end surface of the housing.

Here, the cross-sectional shape of the inner end face of the housing is separated from the bearing seat at a constant rate toward the outer side in the width direction of the bearing starting from a contact point between the inner end face and the inner peripheral end of the bearing seat. There is disclosed a compressor in which a substantially wedge-shaped gap having an inward end formed between the bearing and the bearing seat (see, for example, Patent Document 1). The cross-sectional shape is the shape when the rotor is unloaded, and considering that the thrust load is composed of the compression reaction force from the piston, the outer side in the width direction of the bearing bends when the rotor is loaded, and the inner end surface of the housing The object is to bring the bearing seat into contact with each other so that the thrust load is evenly applied to the raceway surface.
JP 2004-316252 A

  By the way, the thrust load is affected by the internal pressure of the housing in addition to the compression reaction force described above, and the thrust load can fluctuate. Specifically, the above-described compression reaction force can be easily changed by a thermal load or the like, and the internal pressure of the housing can also be changed by a crank chamber as a pressure source in a variable displacement compressor, for example. It is. In other words, the amount of deformation of the housing cannot necessarily be determined uniquely as long as the thrust load can vary, but the size of the above-mentioned substantially wedge-shaped gap is determined, and the inner end surface and the track of the housing are determined. There is concern that it will be difficult to form the ring.

  It should also be noted that the inner and outer edge portions of the rolling elements that contact the raceway surface are crowned. Specifically, the relationship between the thrust load and the bearing support reaction force when the outside in the width direction of the bearing is deflected when the rotor is loaded is that the thrust load becomes a concentrated load at the inner crowning position of the rolling element. The bearing support reaction force becomes a concentrated load at the contact point with the inner peripheral end of the bearing seat, and the application point of the thrust load and the application point of the bearing support reaction force are not located on the same line. For this reason, the bearing ring has a problem that only the bearing ring is bent and a couple force (biased load) acting in a direction separating the raceway surface and the rolling element is generated, and the durability of the thrust bearing is lowered. . The problem becomes particularly prominent when a refrigerant having a high working pressure is used. Although it is conceivable to select a bearing having a large allowable load as a measure for solving this problem, this is not necessarily an appropriate measure because it causes an increase in the manufacturing cost of the compressor. As described above, the above-described conventional technology still has a problem regarding the durability of the thrust bearing.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a reciprocating fluid machine that can improve the durability of a thrust bearing while reducing the manufacturing cost.

  In order to achieve the above object, a reciprocating fluid machine according to claim 1 is provided in a housing, a crank chamber including a swash plate formed in the housing and rotating integrally with the rotating shaft, and the housing. A cylinder block having a piston that reciprocates with the rotation of the swash plate therein, a rotor housed in the crank chamber, and a rotor that rotates together with the rotary shaft to perform the reciprocating motion of the piston, the rotor and the swash plate A reciprocating unit having a thrust bearing disposed between the rotor and the inner end surface of the housing, the thrust bearing having a bearing seat abutting against the inner end surface of the housing; A bearing ring having a raceway surface that rolls on a rolling element having its axis of rotation in the width direction of the bearing, and the inner end surface of the housing is in contact with the bearing seat within the formation range of the raceway surface. Having an apex that is characterized by being formed on the rotating body with respect to the axis of the rotating shaft.

  According to a second aspect of the present invention, the apex is an intersection of two straight lines that intersect at an obtuse angle that is convex toward the bearing seat in a sectional view of the housing. In the invention, the apex is formed on an arc that is convex toward the bearing seat in a cross-sectional view of the housing. Furthermore, in the invention according to claim 4, the apex is formed on the housing. In a cross-sectional view, it is convex toward the bearing seat, and is formed in a straight line that is separated from the bearing seat toward the inside in the width direction of the bearing. The apex is formed on a line connecting a plurality of fillets that are convex toward the bearing seat in a sectional view of the housing.

Furthermore, the invention according to claim 6 is characterized in that the fluid machine is inserted in a circulation path of a refrigeration circuit using CO ₂ refrigerant.

  Therefore, according to the reciprocating fluid machine of the first aspect of the present invention, the raceway ring includes a bearing seat that comes into contact with the inner end surface of the housing and a raceway surface that rolls on the rolling element. The inner end surface has an apex that contacts the bearing seat within the raceway surface formation range, and the point of action of the bearing support reaction force from the inner end surface of the housing toward the rolling element is the length in the width direction of this rolling element. It exists in the range. Therefore, when the rotor is loaded, no couple force is generated to separate the raceway surface and the rolling element, and the rolling element is reliably rolled on the raceway surface, and the thrust load from the rolling element toward the inner end surface of the housing is concentrated load. It is not a distributed load. As a result, separation and wear of the bearing seat and raceway surface of the bearing ring are prevented, which contributes to the improvement of the durability of the thrust bearing.

Further, it becomes unnecessary to select a thrust bearing having a large allowable load, and an inexpensive compressor can be provided.
According to the second to fifth aspects of the present invention, the inner end surface of the housing has an apex that abuts against the bearing seat within the range of the length in the width direction of the rolling element, and this apex is the bearing seat. Formed at the intersection of two straight lines intersecting at an obtuse angle that forms a convex shape, or formed on a circular arc that forms a convex shape toward the bearing seat, or formed convex toward the bearing seat, on the inner side in the width direction of the bearing Because it is formed in a straight line that is away from this bearing seat or between multiple fillets that are convex toward the bearing seat, the bearing support reaction force is reduced, and peeling and wear of the bearing seat Can be further prevented. Further, according to the invention described in claim 4, it can be easily installed as compared with the above-described forming of two straight lines or arcs intersecting at an obtuse angle.

Furthermore, according to the invention described in claim 6, the durability of the thrust bearing is improved even when a CO ₂ refrigerant having a high operating pressure is used, and the use of the CO ₂ refrigerant greatly reduces the environmental load. To contribute.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the present embodiment is applied to a swash plate type variable displacement compressor (reciprocating fluid machine) 4 using a CO ₂ refrigerant, and the compressor 4 is a vehicle air conditioner. The refrigeration circuit 2 is configured as one device. Specifically, a compressor 4, a gas cooler 6, an expansion valve 8 and an evaporator 10 are sequentially inserted in the refrigeration circuit 2.

The compressor 4 includes an aluminum front housing (housing) 12, and a cylinder head 14 is joined to the rear side of the front housing 12. The front housing 12 and the cylinder head 14 are connected to a bolt hole 63. They are connected by a plurality of inserted bolts 64.
More specifically, the front housing 12 has a cylindrical shape with a large diameter toward the cylinder head 14 and has both open ends. A cylinder block 46 is disposed in the front housing 12. . The cylinder block 46 may be integrally formed with the front housing 12.

  A crank chamber 16 is formed between the back side of the cylinder block 46 and the front side of the housing inner end surface (inner end surface) 13, and a shaft (rotating shaft) 18 is disposed in the crank chamber 16. The shaft 18 does not have a stepped shape, one end thereof protrudes from the front housing 12, and a driving disk 20 is attached to the protruding end via a nut 22. Specifically, the drive disk 20 is disposed so as to be connectable to a drive pulley 26 via an electromagnetic clutch 24, and the drive pulley 26 is rotatably supported by the front housing 12 via a bearing 28.

  When the electromagnetic clutch 24 is turned ON, the electromagnetic clutch 24 integrally connects the drive pulley 26 and the drive disk 20 and rotates the shaft 18 together with the drive pulley 26 in one direction. On the other hand, when the electromagnetic clutch 24 is turned off, the electromagnetic clutch 24 releases the connection between the drive pulley 26 and the drive disk 20 and cuts off the transmission of power from the drive pulley 26 to the shaft 18.

  The shaft 18 is rotatably supported in the front housing 12 via bearings 30 and 32. Further, in the front housing 12, a lip seal 34 is disposed between one end side of the shaft 18 and the bearing 30, and the lip seal 34 partitions the crank chamber 16 in an airtight manner. Further, the shaft 18 is provided with a reciprocating unit 35 that converts the rotation of the shaft 18 into a reciprocating linear motion in the axial direction thereof.

  Specifically, the reciprocating unit 35 has a disk-shaped rotor 36 fixed to the shaft 18, and a thrust bearing 38 is disposed on the back side of the rotor 36. Further, an arm (link mechanism) 42 for transmitting the rotation of the shaft 18 to the swash plate 40 is fixed to the shaft 18, and the rotor 36 and the arm 42 are connected via a hinge (link mechanism) 44. ing. The swash plate 40 described above is configured to be tiltable with respect to a virtual plane orthogonal to the rotation axis of the shaft 18, and the swash plate 40 swings outside the shaft 18.

  On the other hand, the cylinder block 46 is provided with a plurality of cylinder bores 48 at predetermined intervals in the circumferential direction around the shaft 18, and a piston 50 is accommodated in each cylinder bore 48. The piston 50 has a tail protruding from the cylinder bore 48, and a pair of shoes 52 sandwiching the outer peripheral edge of the swash plate 40 are held by the tail. The swash plate 40 is in sliding contact with the inner surface of the shoe 52 when rotating. Thereby, when the rotation of the drive pulley 26 is transmitted to the shaft 18, the shaft 18 rotates the swash plate 40 via the arm 42. The rotational movement of the swash plate 40 is converted into the reciprocating motion of the piston 50 via the shoe 52. When the inclination angle of the swash plate 40 is changed, the stroke amount of the piston 50 is changed, and consequently the discharge capacity of the compressor 4 is adjusted.

  The cylinder head 14 has a cup shape opened toward the front housing 12, and the opening end thereof is airtightly connected to the cylinder block 46 via the valve plate 54. A refrigerant suction chamber 56 and a discharge chamber 58 are formed in the cylinder head 14, and the suction chamber 56 is disposed around the discharge chamber 58. The suction chamber 56 can communicate with each cylinder bore 48 through a suction hole of the valve plate 54, and the suction hole is opened and closed by a suction reed valve (not shown) that is opened and closed from the cylinder bore 48 side. The crank chamber 16 and the suction chamber 56 are always in communication with each other through a passage 60 formed in the valve plate 54 and the cylinder block 46. The passage 60 has a fixed throttle in the middle, and can gradually release the pressure in the crank chamber 16 toward the suction chamber 56 side.

  On the other hand, the discharge chamber 58 communicates with each cylinder bore 48 via a discharge hole of the valve plate 54, and this discharge hole is opened and closed by a discharge reed valve (not shown). The discharge reed valve is attached to the discharge chamber 58 side by a bolt together with the valve presser 62. The discharge chamber 58 and the crank chamber 16 communicate with each other via a passage (not shown), and this passage is configured to be opened and closed by an electromagnetic control valve (not shown). Thereby, the said discharge capacity is adjusted and the blowing temperature from the evaporator 10 is controlled uniformly.

  A suction port (not shown) is formed at an appropriate position on the peripheral wall of the cylinder head 14. The suction port communicates with the suction chamber 56 and is connected to the evaporator 10 via the circulation path 11. Yes. On the other hand, a discharge port (not shown) is formed at an appropriate position on the end wall of the cylinder head 14. The discharge port communicates with the discharge chamber 58 and is connected to the gas cooler 6 through the circulation path 5. The gas cooler 6 is connected to an expansion valve 8 via a circulation path 7, and the expansion valve 8 is connected to an evaporator 10 via a circulation path 9.

  Here, as the thrust bearing 38 of this embodiment, a thrust roller bearing is shown as an example. As shown in FIG. 2, the thrust bearing 38 includes an annular housing side race plate (orbital ring) 70 that abuts against the housing inner end surface 13, and an annular rotor side race plate 90 that abuts against the rotor 36. The lace plate 70 is composed of a cylindrical roller (rolling element) 80 disposed between the lace plates 70 and 90, and the rotor side lace plate 90 passes through the cylindrical roller 80 and the housing side lace plate 70 as the rotor 36 rotates. It is comprised so that rotation is possible.

Specifically, the housing-side race plate 70 is made of steel, and has a housing washer 72 arranged in the width direction of the bearing. A shaft washer 74 extending in the vertical direction is provided. The shaft washer 74 may be provided at the inner peripheral end of the rotor-side race plate 90.
A bearing seat 76 is formed on the rear side of the housing washer 72, and the bearing seat 76 is opposed to the inner end surface 13 of the housing so as to be in contact therewith. On the other hand, a raceway surface 78 is formed on the front side of the housing washer 72, and this raceway surface 78 is opposed to be able to contact the outer peripheral surface 82 of the cylindrical roller 80, and the cylindrical roller 80 rolls.

  The rotor-side race plate 90 has a rotor washer 92 disposed in the bearing width direction, and a raceway surface 94 and a bearing seat 96 are formed on the back side and the front side of the rotor washer 92, respectively. The cylindrical roller 80 is opposed to the outer peripheral surface 82 and the back side of the rotor 36 so as to be in contact with each other. In addition, although this cylindrical roller 80 is hold | maintained by the holder | retainer, it is not necessarily limited to this form.

By the way, the housing inner end surface 13 of the present embodiment is formed in the range of formation of the raceway surface 78 of the housing washer 72 as viewed in the width direction of the bearing, specifically, the range of the outer peripheral surface 82 which is the length in the width direction of the cylindrical roller 80. It has a contact apex (vertex) 66 that contacts the bearing seat 76 of the housing washer 72.
More specifically, as shown in FIG. 1, the housing inner end surface 13 is formed as a rotating body with respect to the shaft center of the shaft 18, and is formed symmetrically with respect to the shaft center of the shaft 18 in a sectional view of the housing 12. ing. As shown in FIG. 2A corresponding to the state in which the thrust bearing 38 is assembled to the housing inner end surface 13, the housing inner end surface 13 is formed in a convex shape toward the bearing seat 76. The abutment vertex 66 in the convex shape is formed as an intersection of two straight lines that intersect at an obtuse angle θ within the formation range of the raceway surface 78 that abuts on the outer peripheral surface 82. This obtuse angle θ is as close as possible to 180 °. As a result, the housing inner end face 13 and the bearing seat 76 are spaced apart from the bearing seat 76 at a constant rate from the contact apex 66 toward the outer side and the inner side in the width direction of the bearing. Between the bearing seats 76, there are two substantially wedge-shaped gaps, specifically, an approximately wedge-shaped inward gap 68 whose tip is inward, and an approximately wedge-shaped outward gap 69 whose tip is outward. And are formed respectively.

  According to the compressor 4 described above, when the electromagnetic clutch 24 is turned off, the shaft 18 does not rotate, and the compression reaction force of the piston 50 does not act on the rotor 36. Therefore, as shown in FIG. 2A, the thrust load w corresponds to the pressure in the crank chamber 16, and the bearing seat 76 is applied to the housing inner end face 13 in a range where the raceway surface 78 contacts the outer peripheral surface 82. Energize in the direction of contact. On the other hand, the bearing support reaction force f acts on the contact apex 66 that is a contact point between the housing inner end face 13 and the bearing seat 76, and urges the bearing seat 76 in the direction of separating from the housing inner end face 13. Here, since the contact vertex 66 is located in a range where the contact surface 66 contacts the outer peripheral surface 82 of the raceway surface 78, the thrust load w becomes a distributed load, and the raceway surface 78 and the outer periphery surface 82 are not separated from each other.

  More specifically, in the contact between the aluminum front housing 12 and the steel housing side race plate 70, the front housing 12 is plastically deformed in units of several microns (μm) by the thrust load w, and the inner end surface 13 of the housing As a result of the further expansion of the contact range with the bearing seat 76, a contact surface that substantially covers the width of the outer peripheral surface 82 of the cylindrical roller 80 is formed on the raceway surface 78.

  On the other hand, when the electromagnetic clutch 24 is turned on, the shaft 18 is rotated by the external power transmitted through the electromagnetic clutch 24. The rotation of the shaft 18 is converted into a reciprocating motion of the piston 50 via the rotor 36 and the swash plate 40. The reciprocating motion of each piston 50 includes a suction process in which the refrigerant in the suction chamber 56 is sucked into the cylinder bore 48, A series of processes including a compression process in which the refrigerant is compressed in 48 and a discharge process in which the compressed refrigerant is discharged into the discharge chamber 58 is performed. The refrigerant discharge capacity is adjusted by controlling the pressure in the crank chamber 16 by opening / closing the electromagnetic control valve and increasing / decreasing the stroke length of the piston 50.

  As shown in FIG. 4B, the thrust load W corresponds to a force obtained by adding a compression reaction force from the piston 50 to the pressure in the crank chamber 16, and the range in which the raceway surface 78 abuts the outer peripheral surface 82. The bearing seat 76 is urged in the direction in which it abuts against the inner end face 13 of the housing. In this case, a force in a direction in which the crank chamber 16 is further expanded acts on the inner end face 13 of the housing, so that the inward gap 68 is widened while the outward gap 69 is narrowed.

However, since the bearing support reaction force F acts on the contact apex 66 located within the range of contact with the outer peripheral surface 82 of the raceway surface 78, only the housing washer 72 is loaded even when the rotor 36 is loaded. In this case, the thrust load W is also a distributed load, and the raceway surface 78 and the outer peripheral surface 82 are not separated from each other.
The present invention is not limited to the first embodiment described above, and various modifications are possible. The compressors of the second to fourth embodiments will be described below with reference to FIGS. In the description of the second to fourth embodiments, members and parts similar to those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 3 shows a second embodiment. The housing inner end face 13A is formed in a convex shape toward the bearing seat 76, and the contact vertex (vertex) 66A in the convex shape is the outer periphery. It is formed on an arc having a radius r within the formation range of the raceway surface 78 in contact with the surface 82. Also in this case, between the housing inner end face 13A and the bearing seat 76, two substantially wedge-shaped inward gaps 68A and outward gaps 69A starting from the contact apex 66A are formed.

  As shown in FIG. 5A, when the rotor 36 is not loaded, the abutment vertex 66A is located within a range where it abuts on the outer peripheral surface 82 of the raceway surface 78. Therefore, the thrust load w is a distributed load. Thus, the raceway surface 78 and the outer peripheral surface 82 are not separated from each other. On the other hand, as shown in FIG. 5B, when the rotor 36 is loaded, the inward gap 68A is wide, the outward gap 69A is narrow, and the contact vertex 66A that is the point of action of the bearing support reaction force F is the inner side. However, even when the rotor 36 is loaded, a couple force that only deflects the housing washer 72 is obtained because the abutment vertex 66A is still in a range where it abuts on the outer peripheral surface 82 of the raceway surface 78. Does not occur. Therefore, the thrust load W in this case is also a distributed load, and the raceway surface 78 and the outer peripheral surface 82 are not separated from each other.

  Next, FIG. 4 shows a third embodiment. The housing inner end surface 13B is also formed in a convex shape toward the bearing seat 76, and the contact vertex (vertex) 66B in the convex shape is the formation range of the raceway surface 78 in which the outer peripheral surface 82 is contacted. Inside, it forms in the straight line spaced apart from the bearing seat 76 at a fixed ratio toward the inner side in the width direction of the bearing. Also in this case, between the housing inner end face 13B and the bearing seat 76, two substantially wedge-shaped inward gaps 68B and outward gaps 69B starting from the contact apex 66B are formed. Further, the periphery of the convex portion of the housing inner end surface 13B is formed as a retracting portion that is not brought into contact with the bearing seat 76.

  Then, as shown in FIG. 6A, when the rotor 36 is not loaded, the inward gap 68B disappears and only the outward gap 69B is formed, and the contact vertex 66B is formed on the outer peripheral surface 82 of the raceway surface 78. Since the thrust load w is a distributed load because it is located within the abutting range, the raceway surface 78 and the outer peripheral surface 82 are not separated from each other. Further, as shown in FIG. 5B, when the rotor 36 is loaded, the inward gap 68B is formed and the outward gap 69B disappears, and the point of action of the bearing support reaction force F moves inward. However, since the abutment vertex 66B is also located within the range where it abuts against the outer peripheral surface 82 of the raceway surface 78, no couple force is generated to bend only the housing raceway 72, and the thrust load W in this case is also the same. Further, the load 78 is distributed and the raceway surface 78 and the outer peripheral surface 82 are not separated from each other.

Further, FIG. 5 shows a fourth embodiment, wherein the housing inner end face 13C is formed in a convex shape toward the bearing seat 76, and the contact vertex (vertex) 66C in the convex shape is the outer periphery. It is formed on a line connecting a plurality of fillets θ <b> 1 and θ <b> 2 within the formation range of the raceway surface 78 in contact with the surface 82.
The fillets θ1 and θ2 are obtained as follows. First, for simplification, a force F [N / mm] per unit width is applied to a soft fixed cylinder (corresponding to the housing inner end face 13C) having a radius R [mm] and a hard flat surface (corresponding to the housing washer 72). ] Is pressed.

Here, the Young's modulus E of the housing end face 13C [N / ^mm 2], and Poisson's ratio [nu, Young's modulus E'housing washer 72 [N / ^mm 2], when the Poisson's ratio Nyu', contact theory Hertz The band width a [mm] of the rectangular contact surface due to contact between the cylinder and the plane is expressed by the following formula (1).
a = √ (16 DFR / 3π) (1)
However, this D [mm ² / N] is a coefficient, and is represented by Expression (2).

^{D = (1-ν 2 /} E + 1-ν'2 / E') × 3/4 ··· (2)
Next, assuming that the band width a is equal to the width b of the outer peripheral surface 82 of the cylindrical roller 80, the fillet R [mm] is expressed by the following equation (3).
R = 3πb ² / 16DF (3)
Then, the angles θ1 and θ2 formed on the inner end face 13C of the housing are obtained from this R. In the housing inner end face 13C, angles θ1 and θ2 are provided in two straight lines that intersect at an obtuse angle θ, and the obtuse angle θ has a relationship of θ1 + θ2-π.

Also in the present embodiment, two substantially wedge-shaped inward gaps 68C and outward gaps 69C starting from the contact apex 66C are formed between the housing inner end face 13C and the bearing seat 76, respectively. Is done.
When the illustrated rotor 36 is not loaded, the abutment vertex 66C is located within a range where it abuts on the outer circumferential surface 82 of the raceway surface 78. Therefore, the thrust load w becomes a distributed load. And are not separated. Further, when the rotor 36 is loaded, the inward gap 68C is widened and the outward gap 69C is narrowed. However, the bearing support reaction force is applied to the outer peripheral surface 82 of the raceway surface 78 as in the first embodiment. Since it acts on the abutting vertex 66C located within the abutting range, no couple force is generated to bend only the housing washer 72, and the thrust load in this case also becomes a distributed load, and the raceway surface 78 and the outer periphery The surface 82 is not separated.

Although the fourth embodiment is a combination of two straight lines intersecting at an obtuse angle θ and a plurality of fillets θ1, θ2, the contact vertex 66C may be formed by only the plurality of fillets θ1, θ2, It is also possible to combine Examples 1-4 mentioned above suitably.
As described above, in the conventional structure, when the rotor is loaded, only the housing-side race plate is bent, not the entire bearing, and a couple is generated that acts in the direction of separating the raceway surface and the cylindrical roller.

  However, in the present invention, the bearing washer 76 in which the housing washer 72 of the housing-side race plate 70 is brought into contact with the housing inner end face 13 (13A, 13B, 13C), and the raceway surface 78 rolled on the cylindrical roller 80, The inner end surface 13 of the housing has a contact vertex 66 (66A, 66B, 66C) that contacts the bearing seat 76 within the formation range of the raceway surface 78, and even when the rotor 36 is loaded, The point of action of the bearing support reaction force F acting on the bearing seat 76 from the inner end face 13 (13A, 13B, 13C) of the housing toward the cylindrical roller 80 is within the range of the length of the cylindrical roller 80 in the width direction. Therefore, no couple is generated to bend only the housing washer 72 when the rotor 36 is loaded, and the cylindrical roller 80 is reliably rolled on the raceway surface 78. The thrust load W acting on the raceway surface 78 from the cylindrical roller 80 toward the housing inner end face 13 (13A, 13B, 13C) is not a concentrated load but a distributed load. As a result, contact of the bearing seat 76 and the raceway surface 78 of the housing washer 72 is avoided, and peeling and wear of the bearing seat 76 and raceway surface 78 are prevented, thereby contributing to improvement in the durability of the thrust bearing.

Further, it becomes unnecessary to select a thrust bearing having a large allowable load, and an inexpensive compressor can be provided.
Further, according to the first to fourth embodiments described above, the contact apex 66 (66A, 66B, 66C) is formed at the intersection of two straight lines that intersect at an obtuse angle θ that is convex toward the bearing seat 76. Formed on a circular arc with a radius r that is convex toward the bearing, formed convex toward the bearing seat 76, formed in a straight line spaced from the bearing seat 76 toward the inside in the width direction of the bearing, or formed on the bearing seat 76 Since it is formed between the plurality of fillets θ1 and θ2 that are convex toward each other, the bearing support reaction force F is reduced, and peeling and wear of the bearing seat 76 can be further prevented.

Furthermore, according to the third embodiment, it can be easily installed as compared with the above-described forming of the two straight lines intersecting at the obtuse angle θ, the arc having the radius r, and the fillets θ1, θ2.
Furthermore, even if a CO ₂ refrigerant having a high operating pressure is used, the durability of the thrust bearing is improved, and if a CO ₂ refrigerant is used, it greatly contributes to reducing the environmental load.
The description of one embodiment of the present invention is finished above, but the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the description has been given of the example embodied in the thrust bearing 38 having one cylindrical roller 80. However, the present invention is not necessarily limited to this configuration, and the cylindrical roller may be combined in the width direction of the bearing. The present invention can also be applied to the case of a lined thrust bearing. In this case, the above-described formation range of the raceway surface corresponds to the length between the inner peripheral end of the cylindrical roller located on the inner side and the outer peripheral end of the cylindrical roller located on the outer side, and this length in the width direction. The contact apex that is the point of action of the bearing support reaction force may be disposed within the range.

  Further, the reciprocating fluid machine of the present invention can be applied not only to a fixed capacity type swash plate compressor but also to a oscillating compressor. It is also applicable to the machine.

1 is a longitudinal sectional view of a reciprocating fluid machine according to a first embodiment of the present invention. It is a principal part enlarged view in the fluid machine of FIG. 1, (a) is a figure which shows the thrust bearing when a rotor is unloaded, (b) is a figure which shows the thrust bearing when a rotor is loaded. It is a principal part enlarged view in the fluid machine of 2nd Example, (a) is a figure which shows the thrust bearing when a rotor is unloaded, (b) is a figure which shows the thrust bearing when a rotor is loaded. It is a principal part enlarged view in the fluid machine of 3rd Example, (a) is a figure which shows the thrust bearing at the time of no load of a rotor, (b) is a figure which shows the thrust bearing at the time of the load of a rotor. It is a principal part enlarged view in the fluid machine of 4th Example, and is a figure which shows the thrust bearing at the time of no load of a rotor.

Explanation of symbols

2 Refrigerating circuit 4 Variable capacity compressor (reciprocating fluid machine)
12 Front housing (housing)
13, 13A, 13B, 13C Housing inner end face (inner end face)
16 Crank chamber 18 Shaft (Rotating shaft)
35 Reciprocating unit 36 Rotor 38 Thrust bearing 40 Swash plate 42 Arm (link mechanism)
44 Hinge (link mechanism)
46 Cylinder block 50 Piston 66, 66A, 66B, 66C Contact vertex (vertex)
70 Housing-side race plate (Raceway)
76 Bearing seat 78 Raceway surface 80 Cylindrical roller (rolling element)

Claims (6)

A housing, a crank chamber having a swash plate formed in the housing and rotating integrally with a rotation shaft, and a piston disposed in the housing and reciprocatingly moved with the rotation of the swash plate are provided therein. A cylinder block; a rotor housed in the crank chamber and reciprocatingly moving the piston; and a rotary mechanism integrally rotating with the rotary shaft; a link mechanism connecting the rotor and the swash plate; the rotor and the housing A reciprocating unit including a thrust bearing disposed between the inner end surface of
The thrust bearing includes a bearing ring including a bearing seat that is in contact with the inner end surface of the housing, and a raceway surface that rolls on a rolling element having a rotation axis in the width direction of the bearing,
The inner end surface of the housing has a vertex abutting on the bearing seat within the formation range of the raceway surface, and is formed in a rotating body with respect to the axis of the rotating shaft. Type fluid machine.   The reciprocating fluid machine according to claim 1, wherein the vertex is an intersection of two straight lines that intersect at an obtuse angle that is convex toward the bearing seat in a sectional view of the housing.   The reciprocating fluid machine according to claim 1, wherein the apex is formed on an arc that is convex toward the bearing seat in a cross-sectional view of the housing.   The apex is formed in a straight line that protrudes toward the bearing seat in a cross-sectional view of the housing and is separated from the bearing seat toward the inner side in the width direction of the bearing. The reciprocating fluid machine according to claim 1.   2. The reciprocating fluid machine according to claim 1, wherein the apex is formed on a line connecting a plurality of fillets projecting toward the bearing seat in a sectional view of the housing. . The reciprocating fluid machine according to claim 1, wherein the fluid machine is inserted in a circulation path of a refrigeration circuit using CO ₂ refrigerant.

Images