JP2019127828A - Shoe - Google Patents

Abstract

To provide a shoe of which size can be made small while keeping high durability.SOLUTION: A shoe 30 comprises a bottom part 32 having a contact surface 138 abutted against a swash plate 5; an apex 31 having a band part 131 abutted against a recess 13; and intermediate parts 136, 137 arranged between the apex 31 and the bottom part 32. The intermediate parts 136, 137 comprise a first intermediate part 136 of which diameter becomes small in a direction as they are faced from the apex 31 toward the bottom part 32 and a second intermediate part 137 of which diameter becomes large in a direction from the apex 31 toward the bottom part 32.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a shoe provided between a swash plate and a piston.

  The swash plate type compressor is provided in a housing, a housing, a rotating shaft that rotates, and a swash plate that is provided at an angle around the periphery of the rotating shaft, and swash plate rotates with the rotating shaft. It has a piston that reciprocates in the direction of the rotation axis as the swash plate rotates, and a shoe provided between the swash plate and the piston. The shoe has a flat surface that contacts the swash plate and a spherical surface that is held pivotably in a recess provided in the piston.

  In order to reduce the weight of the shoe, it is known that the hollow surface is formed, and the thickness of the flat surface is approximately the same thickness, and the thickness of the spherical surface is gradually reduced toward the top. (See Patent Document 1).

  However, if the hollow shape is changed as shown in Patent Document 1 in order to make the film thickness uniform, the strength of the shoe is reduced, and with a miniaturized shoe, the durability is poor and it is difficult to put it into practical use. It is.

JP 2002-39058 A

  The present invention has been made in consideration of such points, and provides a shoe that can be reduced in size while maintaining high durability.

The shoe according to the present invention is
A shoe provided between a rotating swash plate and a piston having a piston recess,
A bottom portion having a contact surface abutting on the swash plate;
A top portion having a band portion in contact with the piston recess;
An intermediate portion provided between the top and the bottom;
With
The intermediate part may include a first intermediate part that decreases in diameter in a direction from the top part toward the bottom part, and a second intermediate part that increases in diameter in a direction from the top part toward the bottom part.

In the shoe according to the invention
In the cross section, the first intermediate portion has a linearly smaller diameter in a direction from the top to the bottom,
The second intermediate portion may have a diameter that increases linearly in a direction from the top to the bottom in the cross section.

In the shoe according to the invention
The diameter at the boundary between the first intermediate part and the second intermediate part may be smaller than the diameter of the second intermediate part and the diameter of the band part.

In the shoe according to the invention
The height of the first intermediate portion and the height of the second intermediate portion may be substantially the same.

In the shoe according to the invention
The height of the second intermediate portion may be equal to or higher than the height of the first intermediate portion.

In the shoe according to the invention
The diameter in the in-plane direction of the first intermediate portion and the diameter of the contact surface of the bottom portion may be substantially the same.

  In the present invention, when the intermediate portion has a mode having a first intermediate portion whose diameter decreases in the direction from the top to the bottom and a second intermediate portion whose diameter increases in the direction from the top to the bottom The lubricating oil can be taken in smoothly in the direction from the top to the bottom in the first middle part, and the lubricating oil can be taken in smoothly in the direction from the bottom to the top in the second middle part as well. Therefore, the flow of lubricating oil between the top and the bottom can be smoothed, and the friction generated between the top of the shoe and the recess and the friction generated between the bottom of the shoe and the swash plate The force can be reduced.

Sectional drawing which shows the operating method of the swash plate type compressor by embodiment of this invention. The side view which shows the relationship between the shoe for swash plate type compressors and the swash plate by the embodiment of the present invention. The side view which shows the shoe for swash plate type compressors by embodiment of this invention. FIG. 2 is a side view showing the relationship between a swash plate compressor shoe and a virtual spherical surface according to the embodiment of the present invention. The side view which shows the shoe for swash plate type compressors by the modification of embodiment of this invention. The side view which shows the conventional shoe for swash plate type compressors.

Embodiment < Configuration>
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a swash plate compressor and a swash plate compressor shoe 30 (hereinafter referred to as “shoe 30”) according to the present invention will be described below with reference to the drawings. The shoe 30 according to the present embodiment can be used for an air compressor of an automobile, for example. In the present embodiment, the direction from the bottom 32 to the top 31 of the shoe 30 and the direction from the top 31 to the bottom 32 (vertical direction in FIG. 3) are referred to as the thickness direction of the shoe 30, and the surface is normal to the thickness direction. The inward direction (the horizontal direction in FIG. 3 and the front and back direction of the paper surface) is referred to as “in-plane direction”.

  As shown in FIG. 1, the swash plate type compressor is provided in the housing 20 and the housing 20, and is provided so as to be inclined to the rotary shaft 2 rotating in the direction of arrow C in FIG. The swash plate 5 that rotates together with the rotary shaft 2, the piston 7 that sandwiches the swash plate 5 in the vicinity of the outer peripheral edge and reciprocates in the direction in which the rotary shaft 2 extends by rotating the swash plate 5, The shoe 30 is provided between the piston 7 and the shoe 7. The shoe 30 in FIG. 1 is schematically shown.

  Among these, as shown in FIG. 1, the housing 20 includes a pair of cylinder blocks 1a and 1b covering the piston 7 from the peripheral edge, a front cover 9 connected to one end of the cylinder blocks 1a and 1b, and the cylinder blocks 1a and 1b. And a rear cover 11 connected to the other end of the rear cover 11. A first valve plate 8a is provided between the cylinder blocks 1a, 1b and the front cover 9, and a second valve plate 8b is provided between the cylinder blocks 1a, 1b and the rear cover 11. . The pair of cylinder blocks 1a and 1b are connected by bolts (not shown).

  As shown in FIG. 1, the first valve plate 8a is supplied with a first discharge valve 21a connected to a discharge pipe (not shown) for discharging a frozen refrigerant (for example, fluorocarbon gas etc.), and the frozen refrigerant. There is provided a first suction valve 22a connected to a suction pipe (not shown). Further, the second valve plate 8b is connected to a second discharge valve 21b connected to a discharge pipe (not shown) for discharging the frozen refrigerant, and a second pipe connected to a suction pipe (not shown) to which the frozen refrigerant is supplied. A suction valve 22b is provided. The refrigeration refrigerant contains a small amount of mist-like lubricating oil. The lubricating oil is supplied between the swash plate 5 and the shoe 30 and between the shoe 30 and the piston 7.

  Moreover, as shown in FIG. 1, the rotating shaft 2 is rotatably held by the cylinder blocks 1a and 1b via bearings 3 and 4. The rotating shaft 2 is connected to a drive unit (not shown) that drives the rotating shaft 2.

  Further, as shown in FIG. 1, the piston 7 that reciprocates in the direction of the rotary shaft 2 is housed by the pair of cylinder blocks 1a and 1b, the first valve plate 8a, the second valve plate 8b, and the rotary shaft 2. The compression chamber 6 is formed.

  As shown in FIG. 2, the shoe 30 provided between the swash plate 5 and the piston 7 includes a bottom portion 32 that contacts the swash plate 5 and a top portion 31 that contacts the piston 7.

  As shown in FIG. 2, the piston 7 is provided with a recess 13, and the shoe 30 is held swingably in the recess 13 of the piston 7. Specifically, as shown in FIGS. 1A and 1B, the top 31 of the shoe 30 is held swingably in the recess 13 of the piston 7. In FIG. 1, the shoe 30 is shown in a schematic shape.

  Further, as shown in FIG. 3, the top 31 of the shoe 30 has a band 131 having a contact surface 131 a that contacts the recess 13 of the piston 7 in a stationary state where the swash plate type compressor is not driven. And a non-contact portion 132 having a non-contact surface 132a that does not contact the recess 13 in a stationary state where the machine is not driven. The top 31 may be truncated and the upper surface of the band 131 may have a flat surface 133. By adopting such an aspect, not only the weight of the shoe 30 can be reduced, but also lubricating oil can be efficiently taken in between the recess 13 and the shoe 30 on the top 31 side. In FIGS. 3 and 4, the band portion 131 is pseudo-hatched, but has the same form as the other portions. However, the present invention is not limited to this, and the shape of the band portion 131 may be made different from that of the other portions, such as providing a groove in the band portion 131 or providing unevenness. The peripheral edge of the flat surface 133 may be chamfered, but the peripheral edge of the flat surface 133 may not be chamfered so as to maximize the contact area with the recess 13.

  As shown in FIG. 3, the outer peripheral edge of the bottom 32 of the shoe 30 may be inclined toward the top 31. When this embodiment is adopted, the bottom portion 32 has a contact surface 138 which contacts the swash plate 5 in a stationary state where the swash plate type compressor is not driven, and a swash plate in a stationary state where the swash plate type compressor is not driven. 5 and a non-contact surface 139 that does not contact 5.

  As shown in FIG. 4, the shoe 30 has a shape that fits in a virtual spherical surface having a radius R that matches the inner peripheral surface of the recess 13. More specifically, the outer peripheral surface of the band portion 131 conforms to the virtual spherical surface, and the other portion is positioned inward of the virtual spherical surface.

  As shown in FIG. 3, the shoe 30 may have intermediate portions 136 and 137 provided between the top portion 31 and the bottom portion 32. The middle portions 136 and 137 have a first middle portion 136 whose diameter decreases continuously in the direction from the top 31 to the bottom 32, and a second middle portion whose diameter increases continuously in the direction from the top 31 to the bottom 32 137.

  The first intermediate portion 136 may have a diameter that decreases linearly in the direction from the top 31 to the bottom 32 in the cross section. The second intermediate portion 137 may have a diameter that increases linearly in the direction from the top 31 to the bottom 32 in the cross section.

  The minimum diameter d2 at the boundary between the first middle portion 136 and the second middle portion 137 may be smaller than the diameter d3 of the second middle portion 137 and the diameter d1 of the band portion 131. As shown in FIG. 3, the diameter d3 of the second intermediate part 137 may be larger than the diameter d1 of the band part 131, and the diameter d3 of the second intermediate part 137 is smaller than the diameter d1 of the band part 131. May be. Further, as shown in FIG. 3, the diameter d5 of the first intermediate portion 136 may be smaller than the diameter d4 of the contact surface 138 of the bottom portion 32, but as shown in FIG. d5 may be larger than the diameter d4 of the contact surface 138 of the bottom 32.

  As shown in FIG. 4, the height H1 of the first middle portion 136 and the height H2 of the second middle portion 137 may be substantially the same. In the present embodiment, “substantially the same” means that the difference between the two is within 10% of the larger value. Therefore, assuming that the height H1 of the first intermediate portion 136 is equal to or greater than the height H2 of the second intermediate portion 137, the height H1 of the first intermediate portion 136 and the height H2 of the second intermediate portion 137 are “Substantially the same” means that H1−H2 ≦ H1 × 0.1.

  The height H2 of the second intermediate portion 137 may be equal to or higher than the height H1 of the first intermediate portion 136 (see FIGS. 4 and 5). However, the present invention is not limited to this, and the height H1 of the first middle portion 136 may be larger than the height H2 of the second middle portion 137.

  The intermediate portions 136 and 137 of the present embodiment are formed by, for example, a side diaphragm shape in which the outer peripheral portion of the shoe 30 as shown in FIG. . The shoe 30 as shown in FIG. 6 is manufactured by pressing using a spherical material, grinding, and polishing sequentially. On the other hand, in the shoe 30 according to the present embodiment, it is important to use a wire instead of a spherical material as a material. As an example, the shoe 30 according to the present embodiment forms a cylindrical material by cutting a wire, forms the material shape by forging the cylindrical material, and then performs pressing, grinding, and polishing. Manufactured sequentially.

"effect"
Next, effects of the present embodiment having such a configuration will be described.

  First, a driving unit (not shown) such as a motor connected to the rotating shaft 2 rotationally drives the rotating shaft 2 (in the direction of the arrow C in FIG. 1A). Thus, when the rotating shaft 2 is rotationally driven, the swash plate 5 provided to be inclined with respect to the rotating shaft 2 rotates (see FIG. 1A). At this time, the swash plate 5 rotates while being in contact with the bottom portion 32 of the shoe 30 provided in the recess 13 of the piston 7 (see FIG. 1A).

Also, by this manner is the swash plate 5 rotates, the piston 7 moves linearly in the rotation axis in two directions in one direction (arrow M ₁ direction in FIG. 1 (a)) (see Figure 1 (a)). At this time, the top 31 of the shoe 30 disposed in the recess 13 of the piston 7 swings in the recess 13 of the piston 7 in the direction of the arrow C _{1 in} FIG. 1A (see FIG. 1A).

  Thus, when the piston 7 linearly moves in one direction along the rotation axis 2, the pressure of the refrigeration refrigerant compressed between the piston 7 and the second valve plate 8b is connected to the second valve plate 8b. When the pressure is higher than the pressure of the refrigerant in the discharge pipe (not shown), the refrigerant in the compression chamber 6 is discharged to the discharge pipe via the second discharge valve 21b (see FIG. 1A). Further, the refrigerant refrigerant containing a mist-like lubricating oil is drawn into the compression chamber 6 from a suction pipe (not shown) through the first suction valve 22a provided at one end of the compression chamber 6 (FIG. 1) (See (a)). At this time, the first discharge valve 21a provided on the first valve plate 8a and the second suction valve 22b provided on the second valve plate 8b are closed (see FIG. 1A).

  Next, when the drive unit connected to the rotation shaft 2 further rotates the rotation shaft 2 (in the direction of the arrow C in FIG. 1B), the swash plate 5 provided to be inclined to the rotation shaft 2 further rotates (See FIG. 1 (b)). At this time, the swash plate 5 rotates while contacting the bottom 32 of the shoe 30 provided in the recess 13 of the piston 7 (see FIG. 1B).

Furthermore, by rotating this way is the swash plate 5 further piston 7 moves linearly in the opposite direction (arrow M ₂ direction in FIG. 1 (b)) from the above a rotation axis in two directions (FIG. 1 (b)). At this time, the top portion 31 of the shoe 30 disposed in the concave portion 13 of the piston 7 swings in the concave portion 13 of the piston 7 in the direction of arrow C ₂ (see FIG. 1B).

  Thus, when the piston 7 linearly moves in the other direction along the rotational axis 2, the pressure of the refrigerant refrigerant compressed between the piston 7 and the first valve plate 8a is connected to the first valve plate 8a. When the pressure exceeds the pressure of the refrigerant in the discharge pipe, the refrigerant in the compression chamber 6 is discharged to the discharge pipe via the first discharge valve 21a (see FIG. 1 (b)). In addition, the refrigerant refrigerant containing mist-like lubricating oil is drawn into the compression chamber 6 from the suction pipe through the second suction valve 22b provided at the other end of the compression chamber 6 (see FIG. 1 (b)) ). At this time, the second discharge valve 21b provided on the second valve plate 8b and the first suction valve 22a provided on the first valve plate 8a are closed (see FIG. 1 (b)).

  After that, the above-described steps are sequentially repeated. As described above, when the rotating shaft 2 is rotated by the drive unit, the swash plate 5 is rotated, and the piston 7 can be reciprocated. For this reason, the swash plate type compressor can compress and discharge the frozen refrigerant in the compression chamber 6 and can suck the cooling refrigerant into the compression chamber 6 from the suction pipe.

  While the piston 7 is reciprocated as described above, lubricating oil is supplied between the intermediate portions 136 and 137 and the recess 13. A mode in which the intermediate portions 136 and 137 have a first intermediate portion 136 whose diameter decreases in the direction from the top 31 to the bottom 32 and a second intermediate portion 137 whose diameter increases in the direction from the top 31 to the bottom 32 When employed, the lubricating oil can be smoothly taken in the direction from the top 31 to the bottom 32 in the first intermediate portion 136, and similarly, in the second intermediate portion 137, the lubricant is lubricated in the direction from the bottom 32 to the top 31. Oil can be taken in smoothly. Therefore, the flow of lubricating oil between the top 31 and the bottom 32 can be smoothed, and the friction generated between the top 31 of the shoe 30 and the recess 13 and the bottom 32 of the shoe 30 and the swash plate The frictional force generated between them and 5 can be reduced.

  From the viewpoint of obtaining such an effect, the diameter of the first intermediate portion 136 decreases continuously in the direction from the top 31 to the bottom 32, and the diameter of the second intermediate portion 137 in the direction from the top 31 to the bottom 32 It is beneficial to adopt a continuously growing aspect. The mode in which the diameter is continuously reduced includes a mode in which the diameter is reduced in a curvilinear manner and a mode in which the diameter is gradually reduced in addition to a mode in which the diameter is linearly decreased. The aspect in which the diameter is continuously increased includes the aspect in which the diameter is increased in a curved shape and the aspect in which the diameter is gradually increased in addition to the aspect in which the diameter is linearly increased.

  By providing the intermediate portions 136 and 137 formed of the outer periphery removing portion of the conventional shoe 30 to secure the space in the recess 13 of the piston 7, the lubricating oil retention capability is enhanced and a lubricating effect can be expected. As a result, it is possible to prevent the top 31 and the recess 13 from being burned in, and to prevent the bottom 32 and the swash plate 5 from being baked.

  Although it is conceivable to adopt an aspect in which a cylindrical portion having a cylindrical shape is provided between the top portion 31 and the bottom portion 32, as compared with the aspect having such a cylindrical portion, as in the present embodiment. In the case of adopting an embodiment having such intermediate portions 136 and 137, the weight of the shoe 30 can be significantly reduced, and the holding ability of the lubricating oil can be remarkably increased.

  Further, as shown in FIGS. 3 to 5, the diameter of the first intermediate portion 136 decreases linearly in the direction from the top 31 to the bottom 32 in the cross section, and the second intermediate portion 137 has the cross section from the top 31 to the bottom 32 in the cross section. If a mode is adopted in which the diameter is increased linearly in the direction toward the top, the convection by the lubricating oil is effectively generated at the boundary between the first middle part 136 and the second middle part 137. It can also be expected that the flow of lubricating oil between the and the bottom 32 can be made smoother.

  In the case where the minimum diameter d2 at the boundary between the first intermediate portion 136 and the second intermediate portion 137 is smaller than the diameter d3 of the second intermediate portion 137 and the diameter d1 of the band portion 131, the shoe 30 Is beneficial in that it can reduce the weight of

  The minimum diameter d2 at the boundary between the first intermediate portion 136 and the second intermediate portion 137 may be 70% or more of the diameter d5 in the in-plane direction of the first intermediate portion 136. From the viewpoint of retaining the lubricating oil, it is conceivable to make the minimum diameter d2 at the boundary between the first intermediate portion 136 and the second intermediate portion 137 smaller, but the first intermediate portion 136 and the second intermediate portion 137 If the minimum diameter d2 at the boundary between the two is too small, the shoe 30 can not withstand the force (compression load in the thickness direction of the shoe 30) received from the swash plate 5 and the piston 7. By setting the minimum diameter d2 at the boundary between the first intermediate portion 136 and the second intermediate portion 137 to 70% or more of the diameter d5 in the in-plane direction of the first intermediate portion 136, the swash plate 5 and the piston 7 It is possible to provide the shoe 30 which can be reliably resisted by the force received from the seat.

  If the height H1 of the first intermediate portion 136 is substantially the same as the height H2 of the second intermediate portion 137, the flow of the lubricating oil from the top 31 side and the lubricating oil from the bottom 32 side Flow is caused to collide at an intermediate position in the thickness direction (vertical direction in FIG. 4) of the shoe 30, thereby effectively causing convection by the lubricating oil at the boundary between the first intermediate portion 136 and the second intermediate portion 137. It can be expected to make the flow of lubricating oil between the top 31 and the bottom 32 smoother.

  The diameter d5 in the in-plane direction of the first intermediate portion 136 and the diameter d4 of the contact surface 138 of the bottom portion 32 may be substantially the same. When such an embodiment is adopted, the end position on the top 31 side of the first intermediate portion 136 where the lubricant easily flows in on the top 31 side, and the contact surface 138 where the lubricant easily flows in on the bottom 32 side The outermost position can be matched. Assuming that the diameter d4 of the contact surface 138 of the bottom 32 is equal to or greater than the diameter d5 in the in-plane direction of the first intermediate portion 136, the contact surface of the diameter d5 of the first intermediate portion 136 in the in-plane direction and the bottom 32 The fact that the diameter d4 of 138 is substantially the same means that d4−d5 ≦ d4 × 0.1.

  The area of the contact surface 131a of the top 31 and the area of the contact surface 138 of the bottom 32 may be substantially the same. When this embodiment is employed, the pressing force per unit area working between the recess 13 and the top 31 can be made approximately equal to the pressing force per unit area working between the bottom 32 and the swash plate 5. As a result, the swing of the shoe 3031 can be performed in a balanced manner. Assuming that the area S1 of the contact surface 131a of the top 31 is equal to or larger than the area S2 of the contact surface 138 of the bottom 32, the area S1 of the contact surface 131a of the top 31 and the area S2 of the contact surface 138 of the bottom 32 are approximately The same means that S1−S2 ≦ S1 × 0.1. The area of the contact surface 131a of the top part 31 can be adjusted by the height of the band part 131, for example.

  In the case of adopting the aspect of manufacturing the shoe 30 using the process of forging using a wire, the fiber flow of a material that was random by using a spherical material in the past can be forged from the wire. Can be aligned in the same direction. For this reason, the abrasion resistance of the manufactured shoe 30 can be made uniform. Moreover, in the aspect which uses the conventional spherical raw material, since it is a special raw material, the raw material procurement cost was on its own, but the cost can be reduced.

  The description of each embodiment and the disclosure of the drawings described above are merely examples for explaining the invention described in the claims, and are described in the claims by the description of the above-described embodiments or the disclosure of the drawings. The invention is not limited. The description of the claims at the beginning of the application is merely an example, and the description of the claims can be appropriately changed based on the description, drawings, and the like.

5 Swash plate 7 Piston 13 Concave portion 30 Shoe 31 Top portion 32 Bottom portion 131 Band portion 136 First intermediate portion (intermediate portion)
137 Second middle part (middle part)

Claims (6)

A shoe provided between a rotating swash plate and a piston having a piston recess,
A bottom portion having a contact surface that contacts the swash plate;
A top portion having a band portion in contact with the piston recess,
An intermediate portion provided between the top and the bottom;
With
The intermediate portion includes a first intermediate portion that decreases in diameter in a direction from the top portion toward the bottom portion, and a second intermediate portion that increases in diameter in a direction from the top portion toward the bottom portion. Shoe. In the cross section, the first intermediate portion has a linearly smaller diameter in a direction from the top to the bottom,
2. The shoe according to claim 1, wherein the second intermediate portion has a diameter that increases linearly in a direction from the top to the bottom in the cross section.   The diameter at the boundary between the first intermediate portion and the second intermediate portion is smaller than the diameter of the second intermediate portion and the diameter of the band portion. The listed shoe.   The shoe according to any one of claims 1 to 3, wherein the height of the first intermediate portion and the height of the second intermediate portion are substantially the same.   The shoe according to any one of claims 1 to 4, wherein a height of the second middle part is equal to or more than a height of the first middle part.   The shoe according to any one of claims 1 to 5, wherein a diameter of the first intermediate portion in the in-plane direction and a diameter of the contact surface of the bottom portion are substantially the same.