JP4425289B2 - Piston type compressor - Google Patents

Description

  The present invention relates to a piston type compressor such as a swash plate type or a swash plate type compressor that can sufficiently lubricate a shaft seal device.

  Conventionally, as this kind of compressor, a swash plate type compressor as shown in Patent Document 1 is known. As shown in FIG. 12, the swash plate compressor 11 has a bottomed cylindrical housing 13, and a drive shaft 17 is supported on the housing 13 via a bearing 15. In addition, a shaft seal device 19 that hermetically seals the housing 13 and the drive shaft 17 is provided at the fitting portion between the housing 13 and the drive shaft 17. The drive shaft 17 is provided with a swash plate 21 having a variable tilt angle. On the other hand, a cylinder block 23 is provided in the opening of the housing 13. A plurality of cylinder bores 25 are formed in the cylinder block 23 so as to be separated from each other in the circumferential direction, and a piston 27 is inserted into the cylinder bore 25 so as to be reciprocally movable. A substantially spherical shoe 29 is swingably attached to the piston 27, and the outer peripheral portion of the swash plate 21 is slidably engaged with the shoe 29 in the circumferential direction. When the swash plate 21 is rotated by the drive shaft 17, the piston 27 reciprocates in the cylinder bore 25 via the shoe 29 engaged with the outer peripheral portion of the swash plate 21. In addition, lubricating oil for lubricating each sliding portion is supplied into the housing 13, and this lubricating oil is stirred in the housing 13 as the swash plate 21 and the like rotate.

  As shown in FIG. 13, a pair of recesses 31 is formed on the outer periphery of the bottom surface 13 a of the housing 13, and an oil guide wall 33 is provided between the pair of recesses 31. The recess 31 is formed with an oil guide groove 35 connected thereto. A conduction hole 37 is connected to the oil guide groove 35, and the oil guide hole 37 communicates with the shaft seal device 19. The lubricating oil that is rotationally stirred in the housing 13 is collected in the recess 31 by the resistance of the oil guide wall 33 and supplied to the shaft seal device 19 through the oil guide hole 35.

  However, the turning force of the lubricating oil agitated by the drive shaft 17 is strong, and the capture of the lubricating oil may be insufficient only by the resistance of the oil guide wall 33 formed between the recesses 31. In particular, the shaft seal device This tendency is strong during high-speed rotation, where 19 requires a large amount of lubricating oil. Further, the oil swirling in the housing 13 is not necessarily swung at the bottom of the housing 13 in which the recess 31 is formed, and is often swung on the side of the swash plate 21 separated from the bottom, In some cases, the swash plate 21 may escape. For this reason, the supply of lubricating oil may be insufficient.

  Moreover, in patent document 2, as shown in FIG. 14, the housing 43 is provided with the housing | casing 43 along the inner peripheral wall 13b from the bottom part 13a in the housing 13, The recessed part 45 is provided in this housing | casing 43 vicinity in the bottom part 13a, The oil guide groove 47 and the oil guide hole 49 are connected. Then, the lubricating oil swirling in the housing 13 is captured by the housing 43 and guided to the recess 45, and supplied to the shaft seal device through the oil guide groove 47 and the oil guide hole 49. However, the lubricating oil in the housing 13 swirls violently, and this tendency is particularly strong at high revolutions. Accordingly, the lubricating oil actually collides with the housing 43 and scatters, and there is a problem that it is difficult to capture these and guide them to the oil guiding groove.

JP 2005-171851 A JP 9-242667 A

  An object of the present invention is to provide a piston type compressor that can effectively lubricate a shaft seal device provided on a drive shaft that penetrates the bottom of a housing.

In order to solve the above-mentioned problem, a part of the inner peripheral surface (53b, 123a, 183a) of the housing (53, 123, 183) that contacts the bottom (53a, 123b, 183b) of the housing (53, 123, 183) An annular concave groove (111, 173, 185) having a larger inner radius than the inner peripheral surface (53b, 123a, 183a) of the housing (53, 123, 183) is formed, and the concave groove (111, 173, 185) is formed. And step (111b, 173b, 185b) are formed between the inner peripheral surface (53b, 123a) of the housing (53, 123, 183), and the recess (113, 175) is formed in the bottom (53a, 123b, 183b). , 187) is formed, and the recesses (113, 175, 187) are formed on the bottoms (53a, 123b, 18) of the housing (53, 123, 183). b) and communicates with the shaft sealing member (69,132A) provided on the shaft seal chamber (65,132) between the drive shaft (63,129), an opening of the housing (183) than the step portion (185b) It is possible to adopt means in which a flange-like convex shape (191) extending in the axial direction of the housing (183) is formed on the inner peripheral surface (183a) of the housing (183) on the side .

According to this means, the swirling lubricating oil can be confined in the stepped portion, and the lubricating oil can be prevented from escaping from the bottom of the housing or deviating in the direction of the cylinder block. Therefore, the front side shaft seal device and the bearing can be effectively lubricated.
In addition to supplying oil to the shaft seal member, radial bearing, etc. by the stepped portion, oil is also supplied to the sliding portion in the crank chamber by the bowl-shaped convex shape, so that sufficient oil can be supplied to both. it can.

  Moreover, in order to solve the said subject, the inner peripheral surface (123a) of a housing (123) can employ | adopt the means by which the draft which expands as it goes to the opening part from the bottom part (123b) is formed. . Therefore, even if the lubricating oil swirling in the housing moves toward the opening, it can be held and held by the stepped portion, and the oil can be sufficiently supplied to the shaft seal member and the bearing on the front side. it can.

  Moreover, in order to solve the said subject, the axis | shaft of a drive shaft (63,129) can employ | adopt the means which has faced the horizontal direction.

  In addition, the code | symbol in the parenthesis attached | subjected to each said means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

  Hereinafter, a swash plate type or swing swash plate type compressor according to an embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 1 shows the swash plate compressor according to the first embodiment in a motion state that provides the maximum discharge capacity (100% capacity), and FIG. 2 shows the minimum discharge capacity (0% capacity) of the compressor of FIG. Indicates the driving condition that will result.

  In these drawings, reference numeral 51 denotes a swash plate compressor, and this swash plate compressor 51 has a bottomed cylindrical front housing 53. A cylinder block 55 is provided at the opening of the bottomed cylindrical front housing 53 so as to close the opening, and a rear housing 57 is provided at the cylinder block 55. Radial bearings 59 and 61 are provided at the center of the bottom wall 53 a of the front housing 53 and the center of the cylinder block 55, respectively. A shaft 63 is pivotally supported between the radial bearings 59 and 61. Further, a shaft sealing chamber 65 is provided between the shaft 63 and the bottom wall 53 a on the bottom wall 53 a of the front housing 53 on the front side of the radial bearing 59. A sealing member 69 is fixed. The shaft seal member 69 is in sliding contact with the inner peripheral wall 65a of the shaft seal chamber 65 and the outer peripheral surface of the shaft 63, thereby isolating the swash plate chamber 71 in the front housing 53 from the outside, and maintaining airtightness. Yes.

  On the bottom wall 53a of the front housing 53, a disc-shaped lug plate 73 fixed to the shaft 63 is provided. A thrust bearing 75 is interposed between the lug plate 73 and the bottom wall 53a, and receives an axial load due to a piston compression reaction force.

  A swash plate 77 is provided between the lug plate 73 of the shaft 63 and the cylinder block 55 so as to be rotatable with respect to the axial direction of the shaft 63. The swash plate 77 and the lug plate 73 are coupled so as to be tiltable by a link mechanism 79 provided on the lug plate 73 and a pin 81 provided on the swash plate 77, and the rotation of the lug plate 73 is inclined. This is transmitted to the plate 77.

  Cylinder bores 83 are formed in the cylinder block 55 at regular intervals in the circumferential direction. The cylinder bore 83 is disposed parallel to the axis of the shaft 63, and a piston 85 is inserted therein so as to be able to reciprocate.

  The piston 85 is provided with a spherical bearing 87. The spherical bearing 87 is engaged with a pair of shoes 89 holding the outer peripheral portion of the swash plate 77 so as to be slidable in the circumferential direction.

  A valve plate 91 is interposed between the cylinder block 55 and the rear housing 57, and a suction valve 93 is provided between the valve plate 91 and the cylinder block 55 to seal the suction port. It is like that.

  A suction chamber 95 and a discharge chamber 97 are provided inside the rear housing 57. In a discharge chamber 97 on the rear housing 57 side of the valve plate 91, a discharge valve 99 and a retainer 101 that regulates the valve lift amount are fastened to the valve plate 91 by bolts or the like.

  The rear housing 57 is provided with a control valve 103, and a control gas is introduced into the swash plate chamber 71 to adjust the inclination angle of the swash plate and set the discharge capacity. A passage for introducing control gas from the control valve 103 to the swash plate chamber 71 is formed in the cylinder block 55, the rear housing 57, the valve plate 91, etc., but is not shown here.

  Here, FIG. 1 shows the case of the maximum capacity, which is regulated by the swash plate 77 coming into contact with the lug plate 73. FIG. 2 shows the minimum capacity, and the swash plate 77 connected to the link mechanism 79 and the pin 81 is substantially perpendicular to the shaft 63, and the stroke of the piston is minimized.

  When the shaft 63 is rotated by an external driving force (for example, a vehicle engine), the lug plate 73 fixed to the shaft 63 rotates, and the swash plate 77 connected by the pin 81 and the link mechanism 79 rotates. Here, the outer peripheral portion of the swash plate 77 is gripped by a shoe 89 so as to be slidable in the circumferential direction, and the shoe 89 is slidably engaged with a spherical bearing of the piston 85. Accordingly, the rotational swing motion of the swash plate 77 is converted into the reciprocating motion of the piston 85, and the fluid in the cylinder is discharged and sucked.

  In such a swash plate compressor, an inner radius R2 larger than the inner radius R1 of the inner peripheral surface 53b is formed in a portion of the inner peripheral surface 53b (inner radius R1) of the front housing 53 that is in contact with the bottom wall portion 53a. An annular concave groove portion 111 is formed. A stepped portion 111 b is formed between the inner peripheral surface 111 a of the recessed groove portion 111 and the inner peripheral surface 53 b of the front housing 53.

  Further, as shown in FIG. 3, three recesses 113 are formed in the bottom wall 53 a of the front housing 53. The recess 113 is formed in the upper half of the bottom wall 53a, and an oil guide groove 115 is connected to the recess 113. The oil guide groove 115 communicates with the shaft seal chamber 65 through the oil extraction passage 117, and supplies lubricating oil to the shaft seal member 69. The number of recesses 113 is not limited to three, and the shape of the recess 113 is not limited to that shown in FIG.

  As described above, in the swash plate compressor 51, the inner radius R2 larger than the inner radius R1 is formed in a portion of the inner peripheral surface 53b (inner radius R1) of the front housing 53 in contact with the bottom wall portion 53a. An annular concave groove portion 111 is formed. A stepped portion 111 b is formed between the inner peripheral surface 111 a of the recessed groove portion 111 and the inner peripheral surface 53 b of the front housing 53.

  Therefore, conventionally, as shown in FIG. 4, the swirling oil D sometimes escapes from the bottom wall portion 53 a or escapes toward the cylinder block 55. In the swash plate compressor 51, As shown in FIG. 5, the oil C swirling on the bottom wall portion 53a of the front housing 53 can be confined in the concave groove portion 111, and oil can be prevented from escaping to the cylinder block 55 side. The amount of oil to be held in the recess 113 on the wall 53a can be secured.

  Further, of the oil turning on the inner peripheral surface 53b of the front housing 53, the oil escaping to the bottom can be captured and confined by the step portion 111b. Accordingly, it is possible to ensure the amount of oil to be captured in the recess 113 stably and constantly to the swivel portion near the bottom wall portion 53a.

  Furthermore, as shown in FIG. 6, when the swirling oil collides with the stepped portion of the groove 111, the swirling force of the oil is weakened and disturbed, thereby increasing the amount of oil E that can be captured in the recess 113. it can.

  FIG. 7 shows the swing swash plate compressor 121 of the second embodiment, and shows a motion state that provides the maximum discharge capacity (100% capacity).

  In these drawings, the swing swash plate compressor 121 has a bottomed cylindrical front housing 123.

  In the swash plate compressor 51 shown in FIG. 1, the inner peripheral surface 53b of the front housing 53 is used as a non-rotating sliding surface for the piston 85, and therefore the inner peripheral surface 53b is smooth and has the same diameter in the axial direction. Has been made. On the other hand, in the swing swash plate compressor 121 according to the present embodiment, since this is not necessary, the inner peripheral surface 123a is generally left as a cast surface, and is directed from the bottom to the opening. Accordingly, a draft that gradually increases in diameter in a tapered shape is formed.

  A cylinder block 125 is provided at an opening of the bottomed cylindrical front housing 123 so as to close the opening, and a rear housing 127 is provided at the cylinder block 125.

  A front shaft 129 is pivotally supported by a radial bearing 131 at the center of the bottom wall 123 b of the front housing 123. A shaft sealing chamber 132 is formed on the cylinder block 125 side of the radial bearing 131, and a shaft sealing member 132a is interposed. A disc portion 133 is provided on the rear end side of the front shaft 129 so as to be supported by a radial bearing 135 and a thrust bearing 137.

  On the other hand, a rear shaft 139 is planted in the central portion of the cylinder block 125, and a front end portion 139 a of the rear shaft is inserted into a concave portion 133 a formed in the central portion of the disc portion 133 via a radial bearing 141. It is pivotally supported.

  A constant velocity joint 143 is mounted between the disc portion 133 of the rear shaft 139 and the cylinder block 125. This constant velocity joint 143 has a structure in which a ball bearing 143b is interposed between an inner ring 143a and an outer ring 143c. The inner ring 143a is attached to the rear shaft 139 so as not to rotate and to be movable in the axial direction, and the outer ring 143c can be swung back and forth with respect to the inner ring 143a via a ball bearing 143b. An annular wobble plate 145 is fitted and fixed to the outer ring 143c of the constant velocity joint 143. Therefore, the wobble plate 145 can move in the axial direction and cannot rotate in the circumferential direction with respect to the rear shaft 139. And it is arranged so as to be swingable in the front-rear direction.

  An annular drive plate 151 is mounted on the wobble plate 145 via a thrust bearing 147 and a radial bearing 149. The drive plate 151 can rotate in the circumferential direction relative to the wobble plate 145. Has been made.

  The drive plate 151 and the disk part 133 are coupled to each other by a link mechanism part 153 provided on the drive plate 151 and a pin 155 provided on the disk part 133 so as to be inclined. The rotation is transmitted to the drive plate 151.

  A plurality of cylinder bores 157 are formed in the cylinder block 125 so as to be spaced apart in the circumferential direction and drilled in the axial direction. In the cylinder bores 157, pistons 159 are slidably arranged in the axial direction. .

  A spherical bearing 161 is formed on a portion of the wobble plate 145 facing the cylinder bore 157, and a connecting rod 165 is connected to the spherical bearing 163 formed on the piston 159.

  A valve plate 167 is interposed between the cylinder block 125 and the rear housing 127, and a control valve 169 is provided in the rear housing 127. This control valve 169 adjusts the inclination angle of the swash plate by introducing control gas into the swash plate chamber 171 and sets the suction / discharge capacity.

  When the shaft 129 is rotated by an external driving force (for example, a vehicle engine), the disk portion 133 fixed to the shaft 129 rotates, and the drive plate 151 connected by the pin 155 and the link mechanism 153 rotates. Here, the drive plate 151 is rotatable in the circumferential direction with respect to the wobble plate 145, and the wobble plate 145 is attached to the rear shaft 139 so as to be swingable in the front-rear direction but not in the circumferential direction. . Therefore, the rotational motion of the drive plate 151 is converted to the wobble plate 153 as a swing motion. Then, the swinging motion of the wobble plate 153 is converted into the reciprocating motion of the piston via the connecting rod 165, and the fluid in the cylinder is discharged and sucked.

  In such a swing swash plate compressor 121, a portion of the inner peripheral surface 123a (inner radius R1) of the front housing 123 that is in contact with the bottom wall portion 123b has an inner radius R2 that is larger than the inner radius R1. An annular concave groove 173 is formed. A step 173 b is formed between the inner peripheral surface 173 a of the recessed groove 173 and the inner peripheral surface 123 a of the front housing 123.

  A recess 175 is formed in the bottom wall 123 b of the front housing 123. The recess 175 is formed in the upper half of the bottom wall 123b, and an oil guide groove 177 is connected to the recess 175. The oil guide groove 177 communicates with the shaft seal member 132a and the radial bearing 135 so as to supply oil.

  As described above, in the swing swash plate compressor 121, the inner radius of the inner peripheral surface 123 a of the front housing 123 is formed in a portion of the inner peripheral surface 123 a of the front housing 123 that is in contact with the bottom wall portion 123 b. An annular concave groove 173 having a larger inner radius is formed. A step 173 b is formed between the inner peripheral surface 173 a of the recessed groove 173 and the inner peripheral surface 123 a of the front housing 123. Therefore, even if the inner peripheral surface 123a is left as a cast surface and a gradient gradually increasing in taper from the bottom toward the opening is formed, the oil swirling on the inner peripheral surface 123a remains in the cylinder block 125. The oil does not flow to the side, and the oil can be retained by the stepped portion 173b and retained in the recessed groove portion 173. Therefore, the oil can be sufficiently supplied to the front shaft sealing member 132a, the radial bearing 135, and the like through the recess 175 and the oil guide groove 177 formed in the bottom wall portion 123b.

  FIG. 11 is a diagram illustrating an example of the oil supply effect of the swing swash plate compressor. In the figure, the horizontal axis indicates the amount of oil stored in the crank chamber, and the vertical axis indicates the amount of oil supplied to the lip chamber. From this figure, it can be seen that the amount of oil supply has increased significantly compared to the prior art.

  8 and 9 show the swing swash plate compressor according to the third embodiment, and show a motion state that provides the maximum discharge capacity (100% capacity). In these drawings, the same components as those in the second embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The swing swash plate compressor 181 has a front housing 183. An annular groove 185 having an inner radius R2 larger than the inner radius R1 of the inner peripheral surface 183a is formed in a portion of the front housing 183 that contacts the bottom wall portion 183b of the inner peripheral surface 183a. A stepped portion 185b is formed between the inner peripheral surface 185a of the recessed groove portion 185 and the inner peripheral surface 183a of the front housing 183.

  A recess 187 is formed in the bottom wall portion 183b of the front housing 183. The recess 187 is formed in the upper half of the bottom wall portion 183b, and an oil guide groove 189 is formed in the recess 187. The oil guide groove 189 communicates with the shaft seal member 132a and the radial bearing 135 so as to supply oil.

  A flange shape 191 is formed in the portion of the inner surface 183a of the front housing 183 where the concave groove 185 is not formed, extending in the axial direction along the upper end portion of the inner surface 183a.

  The ridge shape 191 is formed as shown in FIG. That is, the inner peripheral surface is formed as a normal inner peripheral surface 183a having an inner radius R1 in the left part of the figure with the vicinity of the upper end portion of the inner peripheral surface as a boundary. On the other hand, the portion on the right side in the drawing with the vicinity of the upper end portion of the inner peripheral surface as the boundary is substantially equal to the inner radius R1 of the normal inner peripheral surface 183a, and S An inner peripheral surface 183c having a center at a position offset by a distance is formed. And the collar shape 191 is formed between this inner peripheral surface 183a and the inner peripheral surface 183c. Therefore, the bowl shape 191 can disturb the swirling flow of the oil by the oil rotating in the R direction on the inner peripheral surface colliding with the bowl shape 191, and can direct the oil inward.

  Conventionally, in a compressor 201 as shown in FIG. 10, for example, the flange shape 203 is formed in the entire region from the bottom wall portion to the opening portion of the bottomed cylindrical front housing 205. The flange shape 203 has an inner peripheral surface with an inner radius R4 and an inner radius equivalent to the inner radius R4, and the center is centered at a position offset by F above the center of the inner peripheral surface with the inner radius R4. It is formed between the inner peripheral surface and the oil that has rotated in the U direction along the inner peripheral surface is directed inward. In such a compressor 201, although there is an advantage that the oil colliding with the bowl shape 203 is scattered in the crank chamber and the oil is spread over the sliding portion, the oil is scattered, so it is formed on the bottom wall portion. There is a problem that the oil does not easily reach the recessed portion and the amount of oil reaching the shaft seal chamber is reduced.

  On the other hand, the swash plate type compressor 181 has an inner radius R2 larger than the inner radius R1 of the inner peripheral surface 183a at a portion in contact with the bottom wall portion 183b of the inner peripheral surface 183a of the front housing 183. An annular concave groove portion 185 is formed, and a step portion 185 b is formed between the inner peripheral surface 185 a of the concave groove portion 185 and the inner peripheral surface 183 a of the front housing 183. In addition, a flange shape 191 is formed in the portion of the inner surface 183a of the front housing 183 where the concave groove 185 is not formed, extending in the axial direction along the upper end portion of the inner surface 183a.

  Therefore, oil is supplied to the shaft seal member 132a, the radial bearing 135, etc. by the concave groove portion 185, and oil is supplied to the sliding portion in the crank chamber by the flange shape 191 so that sufficient oil is supplied to both. Can do.

The longitudinal cross-sectional view which shows the time of 100% capacity | capacitance of the swash plate type compressor of the 1st Embodiment of this invention. The longitudinal cross-sectional view which shows the time of the minimum capacity | capacitance of the swash plate type compressor shown in FIG. Sectional drawing which follows the XX line of the housing of the swash plate type compressor shown in FIG. The longitudinal cross-sectional view which shows the flow of the lubricating oil in the conventional swash plate type compressor. The longitudinal cross-sectional view which shows the flow of the lubricating oil in the swash plate type compressor shown in FIG. Sectional drawing which shows the flow of lubricating oil about the housing shown in FIG. The longitudinal cross-sectional view which shows the time of 100% capacity | capacitance of the swing swash plate type compressor of the 2nd Embodiment of this invention. The longitudinal cross-sectional view which shows the time of 100% capacity | capacitance of the swing swash plate type compressor of the 3rd Embodiment of this invention. Sectional drawing which follows the YY line of the housing of the rocking swash plate type compressor shown in FIG. The figure which shows the axial cross section of the conventional rocking | fluctuation swash plate type compressor. The figure which shows the oil supply effect of a rocking swash plate type compressor. The longitudinal cross-sectional view which shows the conventional swash plate type compressor. Sectional drawing which follows the ZZ line of the housing of the swash plate type compressor shown in FIG. The figure which shows the bottom part of the housing of the conventional swash plate type compressor.

Explanation of symbols

51 Swash plate compressor 53 Front housing 53a Bottom wall 53b Inner peripheral surface 55 Cylinder block 63 Shaft 77 Swash plate 83 Cylinder bore 85 Piston 89 Shoe 111 Recessed groove 111b Stepped portion 121 Swing swash plate compressor 123 Front housing 123a Inside Peripheral surface 123b Bottom wall 125 Cylinder block 129 Front shaft 143 Constant velocity joint 145 Wobble plate 151 Drive plate 157 Cylinder bore 159 Piston 165 Connecting rod 173 Concave groove 173b Stepped portion 181 Swing swash plate compressor 183 Front housing 183a Inner circumference Surface 183b Bottom wall portion 185 Concave groove portion 185b Step portion

Claims (3)

A bottomed cylindrical housing (53, 123, 183);
A drive shaft (63, 129) disposed in the axial direction of the housing (53, 123, 183) and pivotally supported on the bottom of the housing (53, 123, 183) via a bearing;
Housed in the housing (53, 123, 183), connected to the drive shaft (63, 129), rotated by the drive shaft (63, 129) and inclined with respect to the drive shaft (63, 129). A swivel plate (77, 151) variably provided;
A plurality of cylinder bores (83, 157) which cover the opening of the housing (53, 123, 183) and which are bored in the axial direction of the housing (53, 123, 183) are formed apart from each other in the circumferential direction. Cylinder block (55, 125);
Pistons (85, 159) disposed in the cylinder bores (83, 157) so as to reciprocate;
The outer periphery of the swivel plate (77, 151) is connected to the outer periphery of the swirl plate (77, 151) so as to be slidable in the circumferential direction, and is connected to the piston (85, 159) disposed opposite to the outer periphery of the swirl plate (77, 151). Motion transmission mechanisms (89, 143, 145, 165) for transmitting the axial movement of the outer peripheral portion of the swivel plate (77, 151) to the pistons (85, 159) disposed opposite to the outer peripheral portion, respectively. When,
With
By changing the pressure in the housing (53, 123, 183) relative to the pressure in the cylinder bore (83, 157), the inclination angle with respect to the axis of the swivel plate (77, 151) is changed, and the piston In the piston type compressor that changes the discharge amount by changing the stroke of (85, 159),
Of the inner peripheral surfaces (53b, 123a, 183a) of the housing (53, 123, 183), the portions of the housing (53, 123, 183) that are in contact with the bottom (53a, 123b, 183b) 123, 183) to form an annular groove (111, 173, 185) having a larger inner radius than the inner peripheral surface (53b, 123a, 183a) of the other part,
Step portions (111b, 173b, 185b) are formed between the recessed groove portions (111, 173, 185) and the inner peripheral surfaces (53b, 123a) of the housing (53, 123, 183),
Concave portions (113, 175, 187) are formed in the bottom portions (53a, 123b, 183b),
The recesses (113, 175, 187) are provided in the shaft sealing chamber (65, 132) between the bottom (53a, 123b, 183b) of the housing (53, 123, 183) and the drive shaft (63, 129). Communicating with the shaft sealing member (69, 132a) provided in the
A flange-like convex shape (191) extending in the axial direction of the housing (183) on the inner peripheral surface (183a) of the housing (183) on the opening side of the housing (183) from the stepped portion (185b). ) Is formed , a piston type compressor.   2. The piston type compressor according to claim 1, wherein the inner peripheral surface (123 a) of the housing (123) is formed with a draft increasing in diameter from the bottom (123 b) toward the opening. . Axis of the drive shaft (63,129) is a piston-type compressor according to claim 1 or 2, wherein the facing horizontally.

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