JP3203887B2 - Reciprocating compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor suitable for use in vehicle air conditioning, and more particularly, to a multi-cylinder reciprocating compressor having a single-headed piston.

[0002]

2. Description of the Related Art Conventionally, as a compressor of this type, a rotating swash plate is moored to a single-headed piston via a shoe, or a swinging plate whose rotation is restricted is connected to a single-headed piston via a connecting rod. A known type of compressor is known. These compressors include a cylinder block having a plurality of bores arranged side by side, and a housing for forming a crank chamber therein to close a front end of the cylinder block and rotatably supporting a drive shaft in cooperation with the cylinder block. The drive shaft provided with a swash plate element that rotates in the crank chamber is supported by radial bearings fitted in respective central shaft holes of the housing and the cylinder block.

[0003] Compressors used for vehicle air conditioning are:
Aluminum-based metal is used for the cylinder block due to the strong demand for weight reduction, and the radial bearing of iron-based metal structure fitted to this cylinder block is likely to loosen due to the difference in thermal expansion due to the temperature rise of the compressor. At present, it is press-fitted with a margin.

[0004]

However, the cylinder block is provided with a plurality of bores around the central shaft hole for accommodating the radial bearing, and expands the central shaft hole when the radial bearing is press-fitted. The force applied in the direction causes subtle plastic deformation in each bore. Therefore, the deformation is naturally taken into account in the setting of the clearance between the bore and the piston, and there is a problem that the influence on the performance of the compressor cannot be neglected.

An object of the present invention is to completely eliminate the influence on the bore caused by press fitting of a radial bearing.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method in which one radial bearing supporting a drive shaft is inserted into a crank chamber so as to avoid coexistence with a bore in a plane perpendicular to the drive shaft center. It adopts a new structure that it is press-fitted inside the boss of the protruding cylinder block.

[0007]

[Function] When a radial bearing is press-fitted, even if a force is applied in the direction of expanding the central shaft hole, all the functions of the molecular force are absorbed in the boss, and the effect is exerted on each bore having a phase difference in the axial direction. Since it does not extend at all, it is possible to properly select the fitting play gap between the bore and the single-headed piston without any consideration.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to FIG. In the figure, a housing 2 is connected to a front end of a cylinder block 1 constituting a part of an outer shell of a compressor, and a cylinder head 3 having a suction chamber 5 and a discharge chamber 6 formed at the rear end thereof serves as a valve plate 4. Are coupled through. A drive shaft 8 connected to a power source is inserted into a crank chamber 7 formed in the housing 2. The drive shaft 8 is rotatable through the cylinder block 1 and the housing 2 via radial bearings 20 and 21, respectively. It is supported by A rotary swash plate 9 is fixed on a drive shaft 8 in the crank chamber 7,
A swing plate 10 is supported on the rear surface side of the rotary swash plate 9 so as to be relatively rotatable, and a guide portion 10 a provided on an outer edge portion is engaged with a through bolt 11 to restrict rotation, and a cylinder block. A single-headed piston 13 in a bore 12 penetrating through 1 and the swinging plate 10 are connected by a connecting rod 14. Therefore, the rotational motion of the drive shaft 8 is converted into the forward and backward swing of the swing plate 10 via the rotary swash plate 9, and the single-headed piston 13 reciprocates in the bore 12, and moves from the suction chamber 5 into the bore 12. The sucked refrigerant gas is discharged to the discharge chamber 6 while being compressed.

Next, the drive shaft support structure on the cylinder block 1 side which is the most characteristic of the present invention will be described. As is apparent from the figure, a boss 1a protruding into the crank chamber 7 is formed in the axial center portion of the cylinder block 1, and the radial bearing 20 is housed in a central shaft hole formed in the boss 1a. It is press-fitted. That is, the radial bearing 2
0 is shifted (phase difference) in the axial direction so as not to coexist with each of the bores 12 in a plane orthogonal to the drive axis. The rear end of the drive shaft 8 supported by the radial bearing 20 is supported by a thrust trace 22 and a disc spring 23 housed in the center shaft hole, and the urging force of the disc spring 23 is It is received by a thrust bearing 24 interposed between the housing 2 and the rotary swash plate 9 fixed to 8.

Therefore, when the radial bearing 20 is press-fitted,
Even if a force is applied in the direction of expanding the central shaft hole, the function of the molecular force is absorbed in the boss portion 1a and does not affect the bores 12 having a phase difference in the axial direction. The clearance between the bore 12 and the single-headed piston 13 can be properly selected without any consideration.

[0011]

As described above in detail, according to the present invention, one of the radial bearings supporting the drive shaft is internally press-fitted into the boss portion of the cylinder block projecting into the crank chamber. Is free from the influence of the deformability derived at the time of press-fitting of the radial bearing, and it is possible to always select the optimal value for the play clearance with the piston. Performance can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the entire configuration of a compressor according to an embodiment of the present invention.

[Explanation of symbols]

1 is a cylinder block, 1a is a boss, 7 is a crankcase, 8 is a drive shaft, and 20 and 21 are radial bearings.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F04B 27/08

Claims (1)

(57) [Claims] 1. A cylinder block having a plurality of bores arranged side by side, and a housing for forming a crank chamber therein to close a front end of the cylinder block and rotatably supporting a drive shaft in cooperation with the cylinder block. A reciprocating compressor having a single-headed piston that linearly moves in the bore in cooperation with a swash plate element fixed to the drive shaft in the crank chamber, one of the radial bearings that supports the drive shaft is In order to avoid coexistence with the bore in a plane perpendicular to the drive axis,
A reciprocating compressor characterized by being internally press-fitted into a boss portion of the cylinder block protruding into a crank chamber.