JPS63235674A - Bearing structure of solid cam type reciprocating type compressor - Google Patents

Abstract

PURPOSE:To shorten each length in the crosswise directions of a cylinder block by installing a flange part at the rear edge part extending into the rear housing of a rotary shaft and arranging a thrust bearing between the flange part and the inner wall of the rear housing. CONSTITUTION:When a solid cam 6 is turned by a rotary shaft 2, a piston 8 is moved in reciprocation. Therefore, the coolant gas in a cam chamber 5 is introduced into a suction chamber 15 from a suction passage 20, and after introduced into a compression chamber 17 through a suction valve mechanism 18, said coolant gas is supplied into a discharge chamber 16 from a discharge valve mechanism 19. In this case, flange part 21a is installed onto the rotary shaft 2 extending into a rear housing 14, and thrust bearings 23 and 24 are arranged between the flange part 21a and the inner wall of the rear housing 14. Therefore a cylinder bore 7 is set close to the rotary shaft 2 sides, and the side wall surfaces of the solid cam 6 and the cam chamber 5 are set close, and each length in the radial and thrust directions of the cylinder block 1 is shortened.

Description

[Detailed Description of the Invention] Object of the Invention (Field of Industrial Application) The present invention relates to a double-headed piston type three-dimensional cam type reciprocating compressor suitable for vehicle air conditioning, and more specifically relates to a three-dimensional cam type reciprocating compressor suitable for vehicle air conditioning. This invention relates to a bearing structure for a rotating shaft for support.

(Prior Art) A conventional three-dimensional cam type reciprocating compressor has a cam chamber 5 at the joint of a pair of left and right cylinder blocks 1, 1, as shown in Fig. 4.
The rotating shaft 2 is supported at the center of both cylinder blocks 1.1 via a radial ball bearing 31 (hereinafter simply referred to as a radial bearing) which also has the function of receiving thrust in the thrust direction. A three-dimensional cam 6 that is fitted and fixed to the rotating shaft 2 is disposed within the cylinder block 1.1 through a shoe 9.10.
A piston 8 fitted reciprocally into the cylinder bore 7 of
When the three-dimensional cam 5 is rotated, the piston 8 is reciprocated and a compression operation is performed. (Refer to Japanese Unexamined Patent Publication No. 56-23583.) Furthermore, as a conventional compressor, the applicant of the present application has developed a system in which the cylinder block 1 is rotated by radial needle bearings 3 and 4 (hereinafter simply referred to as radial bearings), as shown in FIG. While supporting the shaft 2, the inner wall surface 5 of the cam chamber 5
We have proposed a thrust needle bearing 32 (hereinafter simply referred to as a thrust bearing) interposed between the three-dimensional cam 6 and the three-dimensional cam 6, which exclusively receives thrust in the thrust direction.

(Refer to Utility Application No. 61-184667) (Problem to be solved by the invention) However, the former three-dimensional cam type reciprocating compressor uses a radial bearing 31 which also has the function of receiving thrust in the thrust direction. Therefore, there was a problem in that a force in the thrust direction, which is a mechanical weakness, was applied to the radial bearing 31, resulting in a decrease in durability. That is, since thrust in the thrust direction is repeatedly applied to the rotating shaft 2 during the ON-OFF operation and compression operation of the electromagnetic clutch, play is likely to occur in the radial bearing 31, and this play accelerates the wear of the radial bearing 31. This reduces durability.

Furthermore, the width of the cam chamber 5 in the thrust direction can be shortened by bringing it closer to the three-dimensional cam 6, thereby making the compressor more compact, but ball bearings 31 are conveniently used in the radial direction. First, it was difficult to shorten the distance R from the center axis 0 of the rotating shaft 2 to the cylinder bore 7, which was an obstacle to downsizing the compressor.

On the other hand, since the latter compressor has a thrust bearing interposed between the three-dimensional cam and the side wall surface of the cam chamber, it is difficult to downsize the compressor. That is, the outer diameter of the thrust bearing 32 is large in thickness because it receives a large compression reaction force, and the outer diameter is larger than the inscribed circle of the plurality of cylinder bores 7.
In other words, when trying to approach the rotating shaft 2 side, in order to avoid interference between the outer circumferential surface of the thrust bearing 32 and the piston 8, it is necessary to cut out the outer circumference of the piston 8 on the thrust bearing 32 side, and therefore, There is a limit to miniaturization in the radial direction. Furthermore, if an attempt is made to downsize the cylinder block 1 by shortening it in the thrust direction, the sliding distance in the thrust direction between the inner peripheral surface of the cylinder bore 7 and the outer peripheral surface of the piston 8 will become shorter, and the sealing performance will deteriorate. There are limits to miniaturization.

Furthermore, the dimensional tolerances of the cylinder block 1 and the three-dimensional cam 6,
Alternatively, it is necessary to prepare a plurality of thrust bearings 32 of different sizes during the assembly process due to the assembly tolerance between the rotating shaft 2 and the three-dimensional cam 6, and also to absorb deformation of the cylinder block 1 and the like. In addition, after assembly, the thrust bearing 32 must be bent to some extent during use, and as a result of an unreasonable external force acting on the thrust bearing 32, not only is there a problem with its durability, but the assembly process is troublesome and compression The problem was that it was not possible to reduce the cost of the machine.

Structure of the Invention (Means for Solving the Problems) In order to solve the above problems, the present invention forms a cam chamber at the joint of a pair of cylinder blocks, and a suction chamber and a discharge chamber are formed on the outer end surfaces of both cylinder blocks. The front and rear housings forming the cylinder block are fixed together through a valve plate, and a rotating shaft is supported via a radial bearing in the shaft hole penetrated through both cylinder blocks, and the rotating shaft is located in the cam chamber with respect to the rotating shaft. A three-dimensional cam is fitted and fixed in such a manner that a double-headed piston is slidably reciprocally accommodated in a cylinder bore formed in the cylinder block parallel to the rotation axis, and the piston is connected to the three-dimensional cam through a shoe. moored to
In a three-dimensional cam type reciprocating compressor in which a piston is reciprocated by rotation of the three-dimensional cam to compress refrigerant gas, the rear end of the rotating shaft extends into the rear housing, and the rear end of the rotating shaft extends into the rear housing. A flange portion is provided on the rotating shaft located at the rear housing, and a thrust bearing is interposed between the flange portion and the inner wall of the rear housing.

(Function) Since the present invention does not require thrust bearings to be interposed between the front and rear side surfaces of the three-dimensional cam and the front and rear side wall surfaces of the cam chamber, the cylinder bore can be brought closer to the rotating shaft and the compressor can be downsized in the radial direction. In addition, the sliding distance in the thrust direction between the inner circumferential surface of the cylinder bore and the outer circumferential surface of the piston is shortened (without
The side wall surface of the cam chamber is moved closer to the three-dimensional cam, the width of the cam chamber in the thrust direction is reduced, and the compressor is downsized.

Furthermore, since the thrust bearing can be placed with plenty of room within the rear housing, no excessive external force is applied to the bearing, improving the durability of the thrust bearing.

(Example) Hereinafter, an example embodying the present invention will be described based on FIGS. 1 to 3.

As shown in FIG. 1, a shaft hole 1a penetrating through the center of a pair of cylinder blocks 1.1 facing each other has a rotation ItlI+
2 is rotatably supported by a radial needle bearing 3.4 (hereinafter simply referred to as a radial bearing). A three-dimensional cam 6 is fitted and fixed to the rotating shaft 2 so as to be positioned within a cam chamber 5 formed at the joint of the cylinder block 1.1. A plurality of cylinder bores 7 are formed in the cylinder block 1 at equal intervals, and a double-headed piston 8 is fitted into each cylinder bore 7 so as to be able to reciprocate.

A fitting recess 8a through which the three-dimensional cam 6 passes is formed in the center of each piston 8, and a shoe engaging recess 8b formed in the vertical wall of the fitting recess 8a and the cam of the three-dimensional cam 6. Surface 6a
A shoe 9° IO is interposed between the two. When the three-dimensional cam 6 is rotated within the cam chamber 5, each piston 8 is reciprocated in the front-rear direction.

A front housing I2 is joined to the front end surface of the cylinder block 1 via a front valve plate 11, and a rear housing 14 is joined to the rear end surface of the cylinder block 1 via a valve plate 13. The front and rear housings 12 and 14 are formed with a suction chamber 15 in the center and an annular discharge chamber 16 on the outside. The front and rear valve plates 11.13 are provided with a suction valve mechanism 18 which communicates the suction chamber 15 with the compression chamber 17 in the cylinder bore 7 and is equipped with a suction valve plate 18A.
A discharge valve mechanism 19 is provided which communicates between the discharge chamber 16 and the discharge chamber 16 and includes a discharge valve plate 19A and a retainer plate 19B.

Further, the suction chamber 15 is connected to the cylinder block 1. The cam chamber 5 is communicated with the cam chamber 5 through a plurality of suction passages 20 formed in the cam chamber 5 .

Furthermore, the joint part of the cylinder block 1.1 has an inlet (not shown) for introducing refrigerant gas from an external refrigerant circuit into the cam chamber 5, and a discharge chamber 16 for discharging compressed refrigerant gas to the external circuit. A discharge port (not shown) is opened for this purpose.

The cam chamber 5 and the suction chamber 15 are connected to the shaft hole 1a of the cylinder block 1.1, the slit of the radial bearing 3.4,
Shaft holes 2 formed in the valve plates 11 and 13, the suction valve plate 18A, the discharge valve plate 19A, and the retainer plate 19B.
It is communicated by a throttle passage 26 consisting of 5 and 5.

As shown in FIG. 2, the rear end of the rotating shaft 2 is connected to the shaft hole 2.
A support member 21 extends into the suction chamber 15 of the rear housing 14 by penetrating through the support member 5 and has a flange portion 21a integrally formed at the rear end portion of the support member 21, which is fixed by a bolt 22. Thrust needle bearings 23 and 24 (hereinafter simply referred to as thrust bearings) are provided between the flange portion 21a and the retainer plate 19B and between the flange portion 21a and the inner wall surface 14a of the rear housing 14 facing the suction chamber 15, respectively. The three-dimensional cam 6 is interposed so as to receive the thrust in the thrust direction due to the rotational movement of the three-dimensional cam 6.

The retainer ring 23A that holds the needle 23B of the thrust bearing 23 is connected to the retainer plate 19B.
It is held immovably in the radial direction by a plurality of locking protrusions 19c (see FIG. 3) cut and raised in the radial direction.

Further, the retainer ring 24A that holds the needle 24B of the thrust bearing 24 is held immovably in the radial direction by an annular protrusion 14b integrally formed on the inner wall surface 14a of the rear housing 14.

Next, the operation of the three-dimensional cam type reciprocating compressor configured as described above will be explained.

Now, when the three-dimensional cam 6 is rotated by the rotary shaft 2, the piston 8 is reciprocated, and suction and compression operations are performed. Refrigerant gas in the cam chamber 5 is guided to the suction chamber 15 through the suction passage 2o, introduced into the compression chamber 17 via the suction valve mechanism 18, compressed, and sent from the discharge valve mechanism 19 to the discharge chamber 16.

Since the cam chamber 5 and the suction chamber 15 are communicated through the throttle passage 26, the radial bearing 3.4 and the thrust bearing 23.24 are lubricated by oil contained in the refrigerant gas passing through the road 26. Further, the thrust bearings 23 and 24 are lubricated by the refrigerant gas in the suction chamber 15.

Now, in the embodiment of the present invention, the thrust bearings 23 and 24 are disposed at the rear end of the rotating shaft 2, that is, inside the rear housing 14, so the thrust bearings are interposed between the three-dimensional cam 6 and the front and rear both wall surfaces of the cam chamber 5. There are no dimensional restrictions in the case where the cylinder bore 7 is moved closer to the rotating shaft 2 side, and the radial length of the cylinder block l can be shortened. Wall surface 5
By bringing the cam chambers 5 closer to each other, the width of the cam chamber 5 can be reduced, and the length of the cylinder block 1 in the thrust direction can also be shortened. As a result, the compressor can be made smaller.

Further, since the thrust bearings 23, 24 are arranged with a margin between the inner wall surface 14a of the rear housing 14 and the retainer plate 19B, which are not subject to dimensional restrictions, they do not bend due to thrust, and therefore, Improves durability. Also, unlike the cylinder block 1, the rear housing 14 is bent to some extent during assembly, so there is no need to prepare thrust bearings with different dimensions to absorb the dimensional tolerances of the rear housing 14, etc., and as a result, the compression The machine is easy to assemble and manufacturing costs can be reduced.

Further, in the embodiment described above, the cam chamber 5 and the suction chamber 15 are communicated with each other through the throttle passage 26, but in this case, the radial bearing 3.4 and the thrust bearing 23.24 are connected without providing a separate communication passage in the cylinder block 1. lubricity can be improved.

Note that in the embodiment described above, the rotating shaft 2 and the support member 21 having the flange portion 21a are separated, but they may be integrated.

Effects of the Invention As detailed above, the present invention allows the compressor to be made smaller, and there is no need to prepare multiple thrust bearings of different sizes during the assembly process, making assembly easier and reducing parts. Management is also simplified and therefore the manufacturing cost of the compressor can be significantly reduced,
Furthermore, in order to absorb dimensional tolerances of the cylinder block and three-dimensional cam and to absorb deformation of the cylinder block, there is no need to bend the thrust bearing, and as a result, the durability of the thrust bearing can be improved.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of the central part of a three-dimensional cam type reciprocating compressor showing an embodiment of the present invention, FIG. 2 is an enlarged vertical cross-sectional view of the main parts, and FIG. AA line sectional view of
4 and 5 are longitudinal sectional views of the vicinity of the three-dimensional cam of a conventional three-dimensional cam type reciprocating compressor, respectively. Cylinder block 11 rotating shaft 2, radial needle bearings 3, 4, cam chamber 5, three-dimensional cam 6, front valve plate 11, rear pulp plate 13, front housing 12, rear housing 14, suction chamber 15, discharge chamber 16, support member 21, flange portion 21a, bolt 22,
Thrust needle bearings 23 and 24, distance R from the central axis O of the rotating shaft 2 to the cylinder bore, and width of the cam chamber 5 in the thrust direction.

Claims (2)

[Claims] 1. The front and rear housings, which form a cam chamber at the joint of a pair of cylinder blocks and a suction chamber and a discharge chamber at the outer end surfaces of both cylinder blocks, are joined and fixed via a valve plate, and are installed through both cylinder blocks. The rotating shaft is supported via a radial bearing in the shaft hole,
A three-dimensional cam is fitted and fixed to the rotational shaft so as to be positioned in the cam chamber, and a double-headed piston is accommodated in a cylinder bore formed in the cylinder block parallel to the rotational shaft so as to be able to reciprocate and slide; In a three-dimensional cam type reciprocating compressor, the piston is moored to the three-dimensional cam via a shoe, and the rotation of the three-dimensional cam reciprocates the piston to compress refrigerant gas. A three-dimensional cam type reciprocating compressor with an end extending into the rear housing, a flange on the rotating shaft located inside the housing, and a thrust bearing interposed between the flange and the inner wall of the rear housing. bearing structure. 2. A rear end portion of the rotating shaft extends into a suction chamber in the rear housing, and a support member integrally formed with a flange portion is fixed to the rear end portion with bolts.
Bearing structure in the three-dimensional cam type reciprocating compressor described in .