JPH0223827Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a swash plate compressor used for refrigerant compression, etc. In particular, the swash plate has a variable inclination angle with respect to the drive shaft, and the inclination angle This invention relates to a variable capacity swash plate compressor that can change the compression capacity by changing the .

[Conventional technology]

An example of this type of variable capacity swash plate compressor is one proposed in Japanese Patent Application Laid-open No. 135680/1983. This will be explained with reference to FIG.

In FIG. 3, a crank chamber 14 is formed adjacent to the cylinder block 12 in a compressor housing 13 having a cylinder block 12 at one end having a cylinder 11 therein. Note that 15 is a front end plate that closes the other end of the housing 13.

A drive shaft 16 introduced from the outside of the housing 13 extends inside the crank chamber 14 .
The drive shaft 16 is supported by the front end plate 15 via a radial bearing 17, and its inner end is also rotatably supported by the cylinder block 12. That is, a center bore 18 is formed in the cylinder block 12, and the tip of the drive shaft 16 is supported within the center bore 18 by a radial bearing 19.

Inside the crank chamber 14, a rotor 20 is attached to the drive shaft 16, and this rotor 20 is
It is thrust supported on the inner surface of the front end plate 15 via a thrust bearing 21 .

An adjustment screw 22 is screwed into the center bore 18, and by rotating and adjusting the adjustment screw 22, the axial position of the drive shaft 16 is adjusted. That is, the axial clearance of the thrust bearing 21 portion is adjusted. Note that a thrust bearing 23 is arranged between the distal end surface of the drive shaft 16 and the adjustment screw 22.

A swash plate 25 is hinged to the rotor 20 through a pin 24 . Because of this hinge connection, the swash plate 2
5 has a variable inclination angle with respect to the drive shaft.

A swing plate 26 is rotatably supported on the swash plate 25. A rotation prevention mechanism 27 is provided at the lower part of the outer circumference of the swing plate 26. As the plate 25 rotates, it performs a rocking motion without rotating.

A piston 28 is slidably fitted into the cylinder 11 and is spherically connected to the rocker plate 26 by a piston rod 29.

On the outer end surface of the cylinder block 12 is a valve plate 3.
A cylinder head 31 is provided on both sides of the cylinder. A suction chamber 32 and a discharge chamber 33 are formed within the cylinder head 31.
2 and the discharge chamber 33 are connected to a suction hole 34 provided in the valve plate.
and are connected to the cylinder 11 through discharge holes 35, respectively. Note that the suction hole 34 and the discharge hole 35 are provided with a suction valve and a discharge valve (not shown), respectively.

A communication hole 36 communicating the crank chamber 14 and the suction chamber 32 is formed through the cylinder block 12 and the valve plate 30. A solenoid valve 37 for opening and closing the communication hole 36 is provided in the suction chamber 32 .

In this configuration, when the drive shaft 16 rotates,
The rotor 20 and the swash plate 25 rotate, thereby causing the swing plate 26 to swing. As a result, the piston 28 reciprocates within the cylinder 11, thereby sucking fluid into the cylinder 11 through the suction chamber 32, compressing it, and discharging it into the discharge chamber 33. ).

When the fluid is compressed by the reciprocating movement of the piston 28, fluid gas blows through the gap between the inner wall of the cylinder 11 and the piston 28 into the crank chamber 14 as so-called blow-by gas, and the internal pressure of the crank chamber 14 increases. This increases the back pressure of the piston 28, and limits the distance the piston 28 moves toward the bottom dead center. This reduces the angle of inclination of the swash plate 25, reduces the stroke of the piston 28, and reduces compression capacity.

When the solenoid valve 37 is operated to open the communication hole 36, the crank chamber 14 is communicated with the suction chamber 32, whereby the pressure within the crank chamber 14 is reduced to the suction pressure. As a result, the angle of inclination of the swash plate 25 becomes maximum again, and the compression capacity of the piston 28 increases.

[Problems to be solved with the idea]

In the conventional variable capacity swash plate compressor, the drive shaft 16 is supported on both sides by radial bearings 17 and 19 press-fitted into the front end plate 15 and cylinder block 12, respectively. These radial bearings 17, 19 may break down due to various factors and may require replacement. However, when these radial bearings are press-fitted, a bearing stopper is usually provided to position them in the axial direction and to prevent their movement in the axial direction.
However, when such a bearing stopper is provided, it becomes difficult to disassemble and separate the cylinder block 12 from the center bore 18 in order to replace the radial bearing 19. For this reason, even though only the radial bearing 19 has failed, the cylinder block 12 must also be replaced, resulting in a high-cost product.

An object of the present invention is to provide a variable capacity swash plate compressor having a structure in which a radial bearing can be easily disassembled and taken out from a cylinder block using a simple jig.

[Means for solving problems]

In order to solve the above problems, a cylinder block having a plurality of cylinders and a center bore, and a radial bearing that extends into the crank chamber adjacent to the cylinder block and has one end press-fitted into the center bore are rotatably supported. an adjustment screw screwed into the center bore for adjusting the axial position of the drive shaft; and an adjustment screw screwed into the center bore for adjusting the axial position of the drive shaft; and a swash plate connected to the swash plate, which is relatively rotatably installed on the inclined surface of the swash plate, and performs a rocking motion when the swash plate rotates due to the rotation of the drive shaft, causing the piston to reciprocate within the cylinder. a cylinder head that is attached to the end face of the cylinder block via a valve plate and has a suction chamber and a discharge chamber for fluid; It has a communication passage for communicating the crank chamber and the suction chamber in order to adjust the pressure, and a control valve for controlling opening and closing of the communication passage. In a variable capacity swash plate compressor, the inclination angle of the piston is controlled, and the stroke of the piston changes as the inclination angle changes, thereby changing the compression capacity.
The relationship between the radial size of the radial bearing that supports the drive shaft within the center bore and the adjustment screw for adjusting the axial position of the drive shaft is such that the root diameter of the female thread inside the center bore that the adjustment screw screws into is outside the radial bearing. This is characterized in that the thread diameter of the female thread is larger than the outer diameter of the drive shaft.

〔Example〕

Fig. 1 is a sectional view of a variable capacity swash plate compressor showing one embodiment of the present invention, and since it has basically the same configuration as Fig. 3, corresponding parts are given the same numbers. However, a detailed explanation will be omitted, and the different parts will be explained below.

In FIG. 1, one end of the drive shaft 16 is rotatably supported by a radial bearing 19 press-fitted into a center bore 18 formed in the cylinder block 12. As shown in FIG. The center bore 18 has a large diameter opening 18a at the boundary with the crank chamber 14, and the radial bearing 19 is press-fitted into the center bore 18 through the large diameter opening 18a. That is, the needles constituting the radial bearing 19 are supported by an outer race 19a, and this outer race 19a is supported by the center bore 18.
It is fitted in such a way that it does not easily move in the axial direction. The radial bearing 1 of the center bore 18
There is a female thread 4 on the inner wall of the part adjacent to the press-fit position 9.
0 is formed, and the adjustment screw 22 is screwed into this female thread 40. This adjustment screw is for adjusting the axial position of the drive shaft 16 as explained in the conventional example. Note that a thrust bearing shown in FIG. 3 may be provided between the adjusting screw 22 and the end face of the drive shaft 16, but it is omitted to simplify the explanation. The female thread 40 into which the adjustment screw 22 is threaded is connected to the adjacent radial bearing 19 and the drive shaft 1.
6 is configured to have the following relationship. That is, (i) the root diameter _l1 of the female thread 40 is smaller than the radial bearing outer diameter _l3 (outer diameter of the outer race 19a).

(ii) The thread diameter l ₂ of the female thread 40 is larger than the outer diameter l ₄ of the drive shaft 16.

FIG. 2 is a diagram showing the structure of a jig used for replacing the radial bearing 19, in which A is a side view and B is a front view. The jig 50 is composed of a cylindrical main body 52 having a female thread 51 formed on its surface, and a screw head 53 fixed to the upper surface of the main body. The male thread 51 has the same dimensions as the adjustment screw 22, and is configured to be screwed into the female thread 40 in the center bore 18.

In FIG. 1, the communication hole connecting the suction chamber 32 and the crank chamber 14 is a communication hole 45 formed in the valve plate 30.
A communication hole 43 is formed in the cylinder block 12 in parallel with the valve plate 30, and the communication hole 43 communicates with the center bore 18.

[Effect]

Since the basic operation of the compressor of the present invention constructed as described above is the same as that of the conventional apparatus shown in FIG. 3, a detailed explanation of the operation will be omitted. A method for replacing the radial bearing 19 will be explained below.

First, the front end plate 15 is removed and the drive shaft 16 is removed from the center bore 18. Next, after removing the cylinder head 31 and valve plate 30, the adjusting screw 22 is removed from the center bore 18 toward the cylinder head 31 side, and instead, the jig 50 is screwed onto the female thread 40 from the cylinder head 31 side. By rotating the screw head 53 of the jig 50 from the cylinder head 31 side with a nut driver, the jig 50 advances inside the center bore 18 to the left in the figure.
Its lower surface 54 contacts the right end surface of the radial bearing 19. When the jig 50 is further rotated and moved leftward in the center bore 18, the press-fitted radial bearing 19 is pushed out from the center bore 18 into the crank chamber 14 through the large diameter opening 18a.

In this way, the radial bearing 19 is disassembled and separated from the center bore 18 of the press-fitted cylinder block 12 by the jig 50. For this purpose, the axial length L of the jig 50 pushes the radial bearing 19 out of the center bore 18. It is desirable that the length is sufficient for Furthermore, jig 5
In order to properly press the end surface of the radial bearing 19 with the lower surface 54 of 0, the thread root diameter of the female thread 40 into which the jig 50 is screwed must be the outer diameter l ₃ of the radial bearing 19, and the relationship as described above should be established. It is important that the If l ₁ > l ₃ , the shaft 50 is restricted from moving to the left beyond a certain range within the center bore 18, and cannot push out the radial bearing 19. Also, l ₂ > l ₄ is necessary to prevent interference between the female thread 40 in the center bore and the drive shaft 16 in the assembled state, and in order to prevent the above interference with the relationship l ₂ < l ₄ , the drive shaft, It is necessary to strictly control the axial dimensional tolerances of the cylinder block and other parts.

[Effect of idea]

According to the variable capacity swash plate compressor of the present invention as described above, if any problem occurs with the radial bearing, the jig can be screwed into the center bore after disassembling the cylinder block and radial bearing assembly. This thrust force can push out the radial bearing, making maintenance extremely easy, and at the same time providing an economical compressor that allows large tolerances in the axial dimensions of several parts, including the drive shaft.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the variable capacity swash plate compressor of the present invention, Fig. 2 is a side view and front view showing the configuration of the jig used in the invention, and Fig. 3 is a diagram of a conventional device. FIG. 3 is a sectional view showing the configuration. 11...Cylinder, 12...Cylinder block, 13...Housing, 14...Crank chamber,
15... Front end plate, 16... Drive shaft, 17... Radial bearing, 18... Center bore, 19... Radial bearing, 20...
Rotor, 21... Thrust bearing, 22... Adjustment screw, 25... Swash plate, 26... Rocking plate, 27... Rotation prevention mechanism, 28... Piston, 29... Piston rod, 30... Valve plate, 31... Cylinder head, 32... Suction chamber, 33... Discharge chamber, 40...
Female thread, 50... jig.

Claims (1)

[Scope of utility model registration request] a cylinder block having a plurality of cylinders and a center bore; a drive shaft extending into a crank chamber adjacent to the cylinder block and rotatably supported by a radial bearing having one end press-fitted into the center bore; an adjustment screw screwed together to adjust the axial position of the drive shaft; a swash plate connected to the drive shaft such that its inclination angle with respect to the drive shaft is variable and rotates together with the drive shaft; a oscillating plate that is relatively rotatably installed on an inclined surface of the plate and performs an oscillating motion when the swash plate rotates due to the rotation of the drive shaft, causing the piston to reciprocate within the cylinder; and the cylinder block. a cylinder head mounted on an end face of the cylinder via a valve plate and provided with a fluid suction chamber and a fluid discharge chamber; It has a communication passage for communicating with the suction chamber, and a control valve that controls opening and closing of the communication passage, and controls the inclination angle of the swash plate by controlling the opening and closing of the communication passage. A variable capacity swash plate compressor in which the compression capacity is changed by changing the stroke of the piston as the angle changes, includes a radial needle bearing disposed in the center bore to support the drive shaft; The relationship between the adjustment screws is characterized in that the root diameter of the center bore internal female thread into which the adjustment screw is screwed is smaller than the outer diameter of the radial needle bearing, and the thread diameter of the female thread is larger than the drive shaft outer diameter. Variable capacity swash plate compressor.