JP2010180734A - Shoe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent seizure of a swash plate and abrasion of the swash plate by a shortage of an oil film, by maximally checking an end surface part from assuming a center recessed state. <P>SOLUTION: This shoe 5 arranged in a swash plate type compressor 1 has a spherical surface part 11 slidingly contacting with a semispherical recessed sliding surface 4a formed in a piston 4, and a flat end surface part 12 slidingly contacting with the swash plate 3. The spherical surface part 11 and the end surface part 12 are integrally formed, and an inside space S is formed by forming the spherical surface part 11 and the end surface part 12 in a thin shape. A flange part 13 slidingly contacting with the swash plate 3 is also formed so as to surround a boundary part between the spherical surface part 11 and the end surface part 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a shoe, and more particularly, to a shoe having an inner space while being provided with a spherical surface portion that is in sliding contact with a hemispherical concave sliding surface of a piston and a flat end surface portion that is in sliding contact with a swash plate.

Conventionally, a swash plate compressor includes a swash plate that rotates about a rotation axis, a piston that moves forward and backward as the swash plate rotates, and a substantially hemispherical shoe provided between the swash plate and the piston. And are provided.
As such a shoe, a spherical surface portion that is in sliding contact with a hemispherical concave sliding surface formed on the piston and a flat end surface portion that is in sliding contact with a swash plate are formed, and the spherical surface portion and the end surface portion are integrally formed. In addition, a shoe is known in which the spherical surface portion and the end surface portion are formed thin to form an internal space (Patent Document 1).

JP 2002-39058 A

As shown in the experimental results shown in FIG. 3, the shoe having the inner space as described above deformed toward the inner space when the load is applied to the piston by the operation of the swash plate compressor. It becomes indented.
When the end surface portion is in a concave state in this way, the central portion of the end surface portion is separated from the swash plate, and only the outer peripheral portion of the end surface portion comes into sliding contact with the swash plate, and seizure or slanting due to oil film cutting of the lubricating oil occurs. Problems such as plate wear occur.
In view of such a problem, the present invention provides a shoe having an inner space in which a spherical surface portion and an end surface portion are integrally formed, and prevents the end surface portion from being depressed as much as possible to prevent burning due to oil film breakage. The present invention provides a shoe capable of preventing sticking and swash plate wear.

In other words, the shoe according to the first aspect of the present invention includes a spherical portion that is in sliding contact with the hemispherical concave sliding surface formed on the piston, and a flat end surface portion that is in sliding contact with the swash plate, and the spherical portion and the end surface portion. In the shoe in which the spherical portion and the end face portion are formed in a thin shape to form an internal space,
A flange portion that slidably contacts the swash plate is formed surrounding a boundary portion between the spherical surface portion and the end surface portion.

  According to the invention, by forming the flange portion, even if a load is applied to the spherical surface portion of the shoe, a part of the load can be received by the flange portion, and an indented state of the end surface portion is allowed. It is possible to prevent as much as possible, and to prevent seizure and swash plate wear due to oil film breakage.

Sectional drawing of a swash plate type compressor. Sectional drawing of the shoes concerning a present Example. The table | surface which shows the experimental result about the shoes (test product 1) in which the internal space was formed, and the shoes (test product 2) which are not formed. The figure which shows the simulation result about the shoe (invention product) in which the flange part was formed, and the shoe (test product) in which it is not formed.

FIG. 1 shows the internal structure of a swash plate compressor 1. FIG. 1 shows an internal structure of a swash plate compressor 1, a rotating shaft 2 supported by a housing (not shown), a swash plate 3 fixed to the rotating shaft 2, and an illustration of the housing. A plurality of pistons 4 that move forward and backward in the cylinder bores that do not perform, and a plurality of shoes 5 that are provided so as to face the inside of each piston 4 and sandwich the swash plate 3 are shown.
The swash plate 3 is fixed obliquely with respect to the rotary shaft 2 or can change the inclination angle of the swash plate 3, and is sandwiched by two shoes 5 for each piston 4. . The portion of the swash plate 3 that is in sliding contact with the shoe 5 is coated with a required sprayed layer, a plating layer, a resin coating, or the like.
The piston 4 is formed with a hemispherical concave sliding surface 4a so as to face each other, and the shoe 5 swings with respect to the sliding surface 4a, while rotating the swash plate 3 to rotate the piston 4. It is supposed to convert to advance and retreat.
In addition, the swash plate type compressor 1 having such a configuration is conventionally known, and further detailed description thereof is omitted.

The shoe 5 will be described below. FIG. 2 shows a cross-sectional view of the shoe 5, and the shoe 5 is formed into a thin-walled spherical portion 11 that swings with respect to the sliding surface 4 a of the piston 4 and the swash plate 3. An end surface portion 12 formed in a thin-wall shape in sliding contact with the flange portion 13 and surrounding the boundary portion between the spherical surface portion 11 and the end surface portion 12 and in sliding contact with the swash plate 3. An internal space S is formed inside the end surface portion 12.
The shoe 5 can be manufactured from sintered materials, resin materials, etc. in addition to iron-based, copper-based, and aluminum-based materials. However, from the viewpoint of simultaneously achieving weight reduction and ensuring rigidity and springiness, SUJ2 It is preferable to be manufactured. The spherical surface portion 11 and the end surface portion 12 are manufactured to have a constant thickness, and the thickness is preferably 0.1 to 2 mm, and more preferably 0.2 to 1.5 mm. .
A through hole 11 a is formed at the top of the spherical surface portion 11. Lubricating oil enters and exits the internal space S through the through hole 11 a and traps foreign matter in the internal space S, whereby the spherical surface portion 11 of the shoe 5. And the sliding surface 4a of the piston 4 are kept in good lubrication. Note that the through hole 11 a may be formed in the end surface portion 12.
The slidable contact surface with the swash plate 3 in the end surface portion 12 and the flange portion 13 is smoothly connected. Although not shown, the center of the slidable contact surface bulges slightly toward the swash plate 3 side. As a result, the lubricating oil is drawn between the end surface portion 12 and the swash plate 3.
An escape portion 13a that does not slidably contact with the swash plate 3 is formed on the slidable contact surface side with the swash plate 3 at the outer peripheral end of the flange portion 13, and the slidable contact portion between the shoe 5 and the swash plate 3 from the escape portion 13a. The swash plate 3 is prevented from being damaged by the outer peripheral end of the flange portion 13.

FIG. 3 illustrates experimental results relating to the deformation of the end face portion of the shoe 5 (test product 1) in which the internal space S is not formed and the shoe 5 (test product 2) in which the internal space S is formed.
The shoe 5 used in this experiment is not provided with the flange portion 13 in the above embodiment, and the dimensions of the spherical surface portion 11 and the end surface portion 12 are the same except for the presence or absence of the internal space S. The plate thickness of the spherical surface portion 11 and the end surface portion 12 is 1 mm.
In FIG. 3A, the test products 1 and 2 are compressed by a pressurizer (autograph), respectively, and at this time, pressure-sensitive paper is inserted between the endface portion 12 and the pressurizer, thereby contacting the endface portion 12. The state is measured.
As shown in FIG. 3A, the test product 1 in which the internal space S is not formed does not show a change in the contact state of the end face 12 even when the load is increased, whereas the internal space S is formed. It can be seen that the contact state of the center portion of the end surface portion 12 of the test product 2 decreased as the load increased.
As described above, in the shoe 5 in which the internal space S is formed, a moment toward the internal space S is generated in the central portion of the end surface portion 12 due to the load, whereby the central portion of the end surface portion 12 is deformed into the internal space S. Presumed to be in a concave state.

Thus, since the end surface portion 12 of the shoe 5 in which the internal space S is formed becomes indented by a load, when this shoe 5 is actually used in the swash plate compressor 1, only the outer peripheral portion of the end surface portion 12 is present. Sliding with the swash plate 3, the surface pressure of the outer peripheral portion of the end surface portion 12 is increased.
As a result, the lubricating oil between the end surface portion 12 and the swash plate 3 causes the oil film to break and causes seizure, or the coating formed on the surface of the swash plate 3 wears and the shoes 5 and the swash plate 3 There arises a problem that the clearance increases and the posture of the shoe 5 becomes unstable.
For such a problem, by using the shoe 5 provided with the flange portion 13 in the above embodiment, the end surface portion 12 is prevented from being in a concave state as much as possible, and seizure or slanting due to oil film breakage occurs. It is possible to suppress wear of the coating on the plate 3.

FIG. 4 shows a simulation result of the shoe 5 according to the present invention in which the flange portion 13 is formed (invention product: FIG. 4A) and the shoe 5 in which the flange portion 13 is not formed (test product: FIG. 4B). Is shown.
The spherical surface portion 11 and the end surface portion 12 in the invention product and the test product have the same dimensions, respectively, the internal space S is formed, and the plate thickness of the spherical surface portion 11 and the end surface portion 12 is the same. .
4 (a) and 4 (b) show the magnitude of the displacement amount to the inner space side at the center of the end surface portion 12 by applying a load to the spherical surface portion 11, and the displacement amount of the invention product is the test product's displacement amount. It was about 1/4 compared with the amount of displacement.

Thus, according to the shoe 5 according to the present invention, the rigidity of the end surface portion 12 can be improved by forming the flange portion 13, and the central portion of the end surface portion 12 is deformed to the internal space S side. It is possible to prevent as much as possible the indented state.
As a result, only the outer peripheral portion of the end surface portion 12 can be in sliding contact with the swash plate 3 to prevent seizure due to the oil film running out of the lubricating oil, and the wear of the coating on the swash plate 3 can be reduced.
In addition, the shoe 5 is formed integrally with the spherical surface portion 11 and the end surface portion 12 and is formed into a thin shape so as to form the internal space S, whereby the entire shoe 5 can be reduced in weight.
As a result, the impact between the shoe 5 and the swash plate 3 due to the striking load acting on the shoe 5 due to the reciprocating movement of the piston 4 is mitigated, and the wear of the coating on the swash plate 3 can be reduced. It is possible to prevent the posture of the shoe 5 from becoming unstable due to an increase in the clearance with the swash plate 3. In some cases, the cost can be reduced by omitting the coating of the swash plate 3.
Furthermore, the weight reduction of the shoe 5 whole can be maintained by making the plate | board thickness of the spherical surface part 11 and the end surface part 12 constant. That is, it is conceivable to increase the plate thickness of the end surface portion 12 as a means for preventing the indented state of the end surface portion 12, but in this case, the weight of the shoe 5 increases, so that the weight reduction as described above is possible. The effect due to will be reduced.
Although it is conceivable that the spherical surface portion 11 and the end surface portion 12 are separated and the end surface portion 12 is made of a highly rigid material, there are problems in terms of weight increase and manufacturing cost.

DESCRIPTION OF SYMBOLS 1 Swash plate type compressor 3 Swash plate 4 Piston 4a Sliding surface 5 Shoe 11 Spherical surface part 12 End surface part 13 Flange part S Internal space

Claims (2)

A spherical portion slidably contacting the hemispherical concave sliding surface formed on the piston, and a flat end surface portion slidably contacting the swash plate, and the spherical portion and the end surface portion are integrally formed, and the spherical portion and In the shoe where the inner space is formed by forming the end face part thinly,
A shoe characterized in that a flange portion is formed to slidably contact the swash plate surrounding a boundary portion between the spherical surface portion and the end surface portion.   The shoe according to claim 1, wherein the spherical surface portion and the end surface portion have a constant thickness.