JPS61167178A - Swash plate type compressor - Google Patents

Abstract

PURPOSE:To enhance the anti-seizure of a shoe in a swash plate type compressor, which has a contact surface formed thereinwith a hole, and as well to enhance the durability of the swash plate type compressor, by forming the contact surface of the shoe in a convex arcuate shape having a large curvature and formed therein with a hole. CONSTITUTION:A bottomed hole 5 is formed in the center of a shoe 1 in a swash plate type compressor, and the outer surface of the shoe 1 is formed in a convex arcuate shape having a large curvature. The top 2a of the arcuate shape is positioned at the center thereof or at a position slight inward from the latter between the hole 2 and the outer edge of the slide contact surface. The connecting sections between the arcuate shape section and the hole 5 and between the arcuate shape section and the outer peripheral surface of the shoe are in smooth curve shapes. Therefore, the vacuum on an oil film formed on the rear side of the top, is restricted to be effected in the inside of the top 2a as viewed in the direction of movement of the shoe, and therefore, the area of the oil film where no oil film is effected may be reduced, and it is possible to improve the anti-seizure of the shoe.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a shoe for a swash plate type compressor, and more particularly to a shoe having holes formed in the sliding surface that slides on the swash plate.

"Prior Art" A swash plate compressor is equipped with a swash plate that is rotated by a rotating shaft within a cylinder block and a piston that is fitted within the cylinder block, and the piston can be reciprocated by the rotation of the swash plate. It is. Conventionally, a shoe and a pawl have been used to interlock the swash plate and the piston as described in 1. One end surface of the shoe is brought into sliding contact with the swash plate, and a spherical concave portion is formed on the other end surface of the shoe. The swash plate and the piston are interlocked by interposing a pole between the swash plate and the spherical recess formed in the piston. Other known pistons include those in which the other end surface is formed into a hemispherical shape and the hemispherical shape is brought into direct sliding contact with the spherical concave portion of the piston.
Furthermore, it is known that a recessed hole with a bottom or a through hole penetrating to the other end surface is formed on the surface of the shoe that comes into sliding contact with the stripping plate.

"Problems to be Solved by the Invention" Conventionally known compressors have not caused any particular problems in general use, but as the compression ratio of swash plate compressors has increased in recent years, they have become more difficult than before. Shoes with excellent seizure resistance have become desirable.

In view of such circumstances, the present invention provides a shoe for a swash plate type compressor in which holes are formed in the sliding surface that slides on the swash plate. The sliding surface between the outer circumferential portion and the top surface is formed into a convex curved surface consisting of a top surface and a surface lower than the top that smoothly continues on both sides of the top, and the top of the convex curved surface is formed between the hole and the shoe. It is set approximately at the center in the radial direction of the sliding surface between the outer circumferential portion or inside the sliding surface.

"Operation" According to such a configuration, when the shoe moves relative to the swash plate, the wedge effect caused by the gap between the sliding surface and the swash plate on the forward side in the direction of movement from the top causes the lubricating oil to flow out. It can be well introduced between the sliding surface and the swash plate to generate high positive oil film pressure.

Negative pressure is generated in the gap between the sliding surface and the swash plate on the rear side in the direction of travel from the top of L.
1-The apex is set at a position that almost coincides with the center in the radial direction, or inside it to keep the negative pressure generation area small, and the negative pressure is at most 1 atm. Since it is only a pressure, it can be made much smaller than a series of positive oil film pressures, and therefore -
1- It is possible to improve the seizure resistance by making the riverside conditions between the shoe and the swash plate favorable.

``Embodiment'' The present invention will be described below with reference to the illustrated embodiment. In FIG. 1, the shell is formed in a hemispherical shape as a whole,
The sliding contact surface 2 on the bottom end surface is brought into sliding contact with the swash plate 3, and the hemispherical sliding contact surface 4 on the opposite side of the sliding contact surface 2 is brought into sliding contact with the spherical recessed part of the screw (not shown). That's what I do. A bottomed hole 5 is formed in the center of the sliding contact surface 2.

The sliding surface 2 between the hole 5 and the outer periphery of the shoe 1 is
It consists of a surface of the top 2a, a surface 2b lower than the top that smoothly continues from the top surface to the hole 5 side, and a surface 2C lower than the top that smoothly continues from the top 2a to the other side. It is formed into a convex curved surface, and the apex 2a of the convex curved surface is located at a position that substantially coincides with the radial center portion 6 of the sliding surface between the hole 5 and the outer circumferential portion of the shoe 1, or on the inner side thereof. It is set so that

The above convex curved surface has the same shape in the circumferential direction,
Therefore, the top portion 2a is continuous in the circumferential direction and has a circular shape on the swash plate 3.
It comes into sliding contact with. The sliding surface 2 and the inner circumferential surface of the hole 5 of the hole 5, that is, the surface 2b located on one side of the apex 2a and the inner circumferential surface of the hole 5 are continuous in a smooth arc, and the apex The continuous portion between the surface 2C located on the other side of 2a and the outer circumferential surface of the shell is also continuous with a smooth circular arc so that no corners are formed.

According to the above configuration, the sliding surface 2 of the shoe l and the swash plate 3 come into sliding contact at the top portion 2a described below, and therefore, as shown in FIG. and the swash plate 3 come into sliding contact at two apexes 2a. When the screen 1 is moved relative to the swash plate 3 in the direction of the arrow in FIG. Due to the wedge effect of 8, the lubricating oil is well introduced between the sliding surface 2 and the slope &3, and a high positive oil pressure 11 is generated. l become angry.

On the other hand, negative pressure is generated in the gap 9 between the sliding surface 2 and the swash plate 3 on the rear side in the traveling direction from the In part 2a, but -1- The negative pressure generation area is maintained at a position approximately equal to 6 or inside of 5 to maintain the negative pressure generation area.
In addition, since the negative pressure is 1 atm at maximum, which is usually much smaller than the positive oil film pressure, the shoe 1 can smoothly slide on the slope 4i1 due to the large oil film pressure as a whole.

Furthermore, among the two gaps 7.8 between the sliding surface 2 and the swash plate 3 located on the forward side in the traveling direction from each top portion 2a in h.
Since the oil film pressure is larger in the gap 7 on the forward side in the traveling direction where the lubricating oil supply condition is good, 1 = the top portion 2a is placed as far inward as possible from the center portion 6 in the radial direction of the shaft, that is, the shaft , 1 is preferably formed on the central portion side.

However, if the top 2a is formed too close to the hole 5 of the shoe 1, the surface 2a located between the top 2a and the hole 5
The radius of curvature of b becomes smaller, and as a result, the top portion 2a bites the swash plate 3, which in turn impairs the seizure resistance.

FIG. 2 is an explanatory diagram for explaining the innermost position of the top portion 2a, and shows the bottom shape of the shoe 1 at vertical magnification (axial magnification).
is displayed at 100 times the horizontal magnification (radial magnification) (vertical magnification: horizontal magnification = 1000:10). In the figure, a line 20 is a line connecting the top 2a of the sliding surface 2, and a line 21 is parallel to the line 20 and 20 points from the line 20.
A line drawn 0 pm away from the shoe 1 side, line 22 is a line drawn perpendicular to line 20 from the intersection 23 of line 21 and the inner peripheral surface of hole 5, and rough line 24 is line 20 and 22. Intersection with 2
It is a line drawn at an angle of 45 degrees from point 26, which is the required distance from 5, 4 g for one Jt weight, and more than m. Then, draw an arc 27 with a radius of curvature that is tangent to this line 24 and the -I- marking line 20 and continues smoothly on the inner peripheral surface of the hole 5, and the point where the arc 27 touches the line 20 is located at the innermost point. The position is at the top 2d.

Next, the effects of the present invention will be explained based on the test results shown in FIG. This test was to measure the seizure resistance of ordinary steel. ■Ma1300~1500) 10~15
Slide the pLm-treated shoe 1 into contact with the refrigeration oil and light oil.
:40Kg with lubricating oil mixed at a ratio of 9
The test was started from the state ylB in which the shutter was pressed against the swash plate 3 with a load of , and the load was increased by 20 kg for each required time, and the load at which seizure occurred was measured. The relative sliding speed between the shutter and the swash plate 3 at this time was 15 m/s.

In FIG. 3, A and B are shoes according to the present invention,
A has the top 2a aligned with the center part 6, and B has the top 2a inside the center 6 at a position of approximately 115 points from the distance between the hole 5 and the outer peripheral surface of the shell. It is something.

In addition, C-F indicates a comparative material, and C has a convex sliding surface as in the present invention, but the top part 2a is located outside the center part 6 and is between the hole 5 and the outer circumferential surface of the shell. Approximately 1/4 of the distance of
It is formed at the position of . Furthermore, D has the entire sliding surface formed flat, and the continuous portion between the sliding surface and the hole and the continuous portion between the sliding surface and the outer circumferential surface are corners. The continuous part between the contact surface and the hole and the continuous part between the sliding contact surface and the outer circumferential surface are continuous in a circular arc. The continuous portion and the continuous portion between the sliding surface and the outer circumferential surface are continuous in an arc.

As can be understood from the test results shown in FIG. 3, the products A and B of the present invention yielded better results than the comparative materials C-F.

Furthermore, FIG. 4 is a diagram showing test results regarding the innermost position of the top portion 2a, in which changes in seizing resistance were measured when the distance mentioned above was varied variously. The test conditions at this time were the same as those in FIG.

In Fig. 4, the continuous part between the sliding surface and the outer peripheral surface of the shoe is formed in advance with a large radius of curvature, and the dimension of -2 distance in the continuous part between the sliding surface and the inner peripheral surface of the hole is We made various changes and observed the effects on seizure resistance.

As can be understood from the figure, the seizure resistance of the comparative material with a flat sliding surface decreases by -1 as the recording distance increases, but from 5 pm onwards, the seizure resistance decreases by -1. 12 is not recognized, and as a result, very high seizure resistance cannot be obtained. On the other hand, with the product of the present invention, by setting the recording distance #L to 4 pLm, it is possible to ensure seizure resistance that is at least equivalent to the best seizure resistance of the above-mentioned comparative materials, and even further improves the distance. By increasing the size, even greater seizure resistance can be obtained.

In addition, although the above embodiment described a hemispherical shoe,
Of course, the present invention can also be applied to shoes using conventional poles.

"Effects of the Invention" As described above, according to the present invention, it is possible to obtain the effect that the seizure resistance of the shoe can be improved compared to the conventional method.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention and a diagram showing the distribution of hydraulic pressure generated when the shul moves in the direction of the arrow, and FIG. An explanatory diagram for explaining the inner position, FIG. 3, and FIG. 4 are diagrams showing test results regarding seizure resistance, respectively. l...Shu 2...Sliding surface 2a...Top 2b, 2C...Surface lower than the top 3...Swash plate 5...Hole 6...Radially central portion 7N opening ff6l -167178(6)4 figure

Claims (3)

[Claims] (1) In a swash plate compressor shoe in which a hole is formed in the sliding surface that slides on the swash plate, the sliding surface between the hole and the outer periphery of the shoe should be smooth on the top surface and both sides of the top. and a surface lower than the top of the convex curved surface, and the top of the convex curved surface is set at approximately the center in the radial direction of the sliding surface between the hole and the outer periphery of the shoe, or the inside thereof. A shoe for swash plate type compressors that is characterized by: (2) The shoe for a swash plate compressor according to claim 1, wherein the convex curved surface and the inner circumferential surface of the hole are continuous in a smooth circular arc. (3) The shoe for a swash plate compressor according to claim 1, wherein the convex curved surface and the outer peripheral surface of the shoe are continuous in a smooth arc.