JPS6338552B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to a cylinder block having a rotating shaft, a plurality of cylinder bores provided parallel to the rotating shaft, a swash plate rotated by the rotating shaft, and a swash plate arranged in the cylinder bore. The present invention relates to a swash plate type compressor comprising a slidably fitted piston and a shoe interposed between the piston and the swash plate to cause the piston to reciprocate as the swash plate rotates.

Prior Art In a swash plate type compressor, large loads and sliding speeds act on the sliding surface between the swash plate part of the swash plate and the shoe, so the thickness accuracy of the swash plate part and the smoothness accuracy of the sliding surface are especially critical. It was managed. As a result, gaps are less likely to form between the sliding surface and the shoe.
There was a problem in that oil film formation was inhibited and the sliding surfaces of the swash plate and shoe were susceptible to seizing. This phenomenon has the problem that seizure is particularly likely to occur under severe sliding conditions, such as when there is no return oil at startup or when the load during sliding is large.

As a countermeasure for this, the swash plate part has been devised by changing the material of the shoe, especially the material of the surface portion that forms the sliding surface, and by devising the shape of the sliding surface of the shoe.

OBJECTS OF THE INVENTION An object of the present invention is to solve the above problem and provide a swash plate type compressor with excellent seizure resistance by improving the shape of the sliding surface of the swash plate portion.

Structure of the Invention In a swash plate type compressor, the swash plate portion of the swash plate is inclined with respect to a vertical plane perpendicular to the drive shaft axis, at least on the sliding trajectory of the swash plate portion with respect to the shoe. The curved surface shape has a deviation in the surface height so that the contact area with the shoe is the highest when the plate is tilted in the maximum slope direction, and the contact area is the lowest when the plate is in the minimum slope direction. During rotation of the swash plate, a wedge-shaped gap is formed between the shoe peripheral portion and the sliding surface of the swash plate.

The swash plate type compressor of the present invention includes a swash plate, a swash plate,
It is sufficient to have the components of a piston, a drive shaft, and a cylinder block, and the shapes of these components may be the same as those of a conventional swash plate type compressor except for the shape of the sliding surface of the swash plate.

In the swash plate type compressor of the present invention, the swash plate means a member that is rotated and oscillated by a drive shaft in opposition to the bore of the cylinder block.

The shoe means something that slides on the sliding surface of the swash plate and causes the piston to reciprocate as the swash plate rotates. Therefore, the shoe may be a hemispherical shoe, a flat shoe, or other shapes.

Effects of the Invention In the swash plate type compressor of the present invention, the sliding surface of the swash plate part of the swash plate is the contact area with the shoe when the swash plate is tilted in the maximum slope direction and when the swash plate is tilted in the minimum slope direction. Since the curved surface has a height difference in surface height, a wedge-shaped gap is always formed between the swash plate part and the shoe peripheral part. Therefore, when the swash plate and shoe slide relative to each other, lubricating oil is drawn between them through this wedge-shaped gap.
More lubricating oil is present on the sliding surfaces between the swash plate and the shoe, promoting oil film formation.

Therefore, the area where the swash plate portion and the shoe come into direct surface contact is correspondingly reduced, and the seizure caused by direct contact between the swash plate portion and the shoe is also reduced accordingly. In addition, by making the thickness of the swash plate the thickest at the part of the swash plate that makes contact with the shoe when the swash plate is tilted in the direction of maximum inclination (at top dead center), it is possible to The clearance between the swash plate and the swash plate is small, reducing impact force and reducing impact noise.

Embodiment In FIG. 1, which shows a cross-sectional view of the main parts of a swash plate type compressor, 1 is a drive shaft, which is rotatably mounted in a cylinder block 2.
A boss portion 3a of the swash plate 3 is connected and fixed, which is composed of a boss portion 3a having a boss hole and a swash plate portion 3b integrally formed diagonally with respect to the boss portion 3a.

A plurality of cylinder bores 21 are formed in the cylinder block 2 at positions parallel to the drive shaft 1 and at equal radial intervals, and the head 4a of the double-headed piston 4 is slidably inside each bore 21. It is fitted.

A concave portion 4b is formed in the center portion of the piston 4 to receive the outer peripheral portion of the swash plate portion 3b of the swash plate 3, and spherical concave portions 4c are formed on axially opposing surfaces of the concave portion 4b. A shoe 5 is brought into sliding contact with both side surfaces, that is, a sliding surface, of the swash plate portion 3b of the swash plate 3, and converts the rotation of the swash plate 3 into a reciprocating motion via the double-headed piston 4 via the ball 6. It is designed to communicate. The above structure is basically the same as that of a conventional swash plate compressor, except for the shape of the sliding surface of the swash plate portion 3b.

In this embodiment, the shape of the sliding surface of the swash plate portion 3b is different from that of the conventional one. That is, the shape of the sliding surface of the swash plate 3 in the swash plate portion 3b of the swash plate 3 with respect to the shoe 5 according to this embodiment is at least on the sliding locus of the shoe 5 with respect to the sliding surface as shown by the imaginary line in FIG. , from the contact portions B and D with the shoe 5 when the swash plate portion 3b is tilted in the direction of the minimum inclination with respect to the vertical plane perpendicular to the 1st axis of the drive shaft, and with respect to the shoe 5 when it is in the direction of the maximum inclination. A curved surface shape with a height difference that gradually rises as it reaches the contact points A and C, that is, the swash plate portion 3
As shown in FIG. 6, the sliding surface b forms a continuous, gently undulating curved surface that gradually slopes downward from point A to point B and gradually slopes upward from point B to point C. Therefore, the plate thickness W of the swash plate portion 3b is varied so that the plate thicknesses W1 and W3 at the points A and C are the thickest, and the plate thicknesses W2 and W4 at the points B and D are the thinnest. Note that the plate thickness W is W
1=W3, W2=W4, and the maximum deviation between W1 and W2 is preferably 5μ to 50μ.

By making the sliding surface of the swash plate portion 3b with the shoe 5 curved with a height difference, the shoe 5 moves in a direction perpendicular to the sliding surface when the swash plate 3 rotates. (undulating motion in the vertical direction), and a wedge-shaped gap is always formed between the peripheral edge of the shoe 5 and the sliding surface of the swash plate 3b, so that, for example, the contact portion with the shoe 5 moves from point B to point A. When the swash plate moves, the lubricating oil adhering to the sliding surface of the swash plate follows the rotational force of the swash plate and is easily introduced into the wedge-shaped gap, thereby promoting the formation of an oil film between the two.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the main parts of a swash plate compressor, Figure 2 is a front view of the swash plate, Figure 3 is a cross-sectional view taken along line A in Figure 2, and Figure 4 is a cross-sectional view showing the main parts of the swash plate compressor. The sectional view and FIG. 5 are developed views of the sliding surface of the swash plate portion. DESCRIPTION OF SYMBOLS 1... Drive shaft, 3... Swash plate, 3b... Swash plate part, 5... Sew, A, C... Contact part with Sew at the time of the swash plate's maximum inclination, B, D... Swash at the time of the swash plate's minimum inclination. Contact area, W... Swash plate thickness.

Claims (1)

[Scope of Claims] 1. A drive shaft, a cylinder block having a plurality of cylinder bores provided parallel to the drive shaft, a swash plate rotated by the drive shaft, and a cylinder block slidably fitted into the cylinder bore. A compressor comprising a combined piston, and a shoe that is slidably interposed between the piston and the swash plate and causes the piston to reciprocate by rotation of the swash plate, wherein the swash plate of the swash plate is 1. A swash plate type compressor, wherein at least a sliding locus surface between the shoe and the shoe is formed into a smoothly curved surface so as to form a wedge-shaped gap between the shoe and the shoe peripheral portion during rotation of the swash plate. 2 The surface height of the curved swash plate part on the sliding trajectory with the shoe is the height of the surface of the swash plate part when it comes into contact with the shoe when the swash plate part is in the direction of minimum inclination with respect to the vertical plane orthogonal to the drive shaft axis. The swash plate type compressor according to claim 1, wherein the swash plate type compressor has a height difference that gradually rises from the part to the part that contacts the shoe when tilted in the direction of maximum inclination.