US3577891A

US3577891A - Swash plate compressor

Info

Publication number: US3577891A
Application number: US851687A
Authority: US
Inventors: Mamoru Nemoto; Seijiro Tani
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 1968-08-21
Filing date: 1969-08-20
Publication date: 1971-05-11
Anticipated expiration: 1988-05-11

Abstract

Two cylinder blocks of a swash plate compressor are so shaped as to form a chamber between the cylinder block assembly, a shell and a head cover of the compressor near the junction of said two cylinder blocks. The chamber thus formed is communicated with the discharge ends of respective cylinder bores through high pressure passageways having a cross-sectional area smaller than that of said chamber. A pipe having a large number of apertures perforated through the wall thereof is disposed at that end of the high pressure passageway which is open in said chamber.

Description

Umted States Patent 1 1 3,577,891

[72] Inventors Mamoru Nemoto Refereflm Cited Katsuta-shi; UNITED STATES PATENTS 1 Tamfllmhl'sh'ilapan 3,212,483 10/1965 B31261 92/70x I 1 PP 851,687 3,360,193 12/1967 l-larrisetal. 417/312 1 FM Aug-2011969 3,389,853 6/1968 Dirk 417/312 [451 patemed P 1!,1971 3,411,705 11/1968 Grover.... 417/312 [731 Asslgnee 3,462,075 8/1969 Dirk et al 417/312 kYMaPan 3,462,949 8/1969 Anderson et a1 417/312x [32] Pnority Aug. 21, 1968 33 Japan Primary Examiner-Martin P. Schwadron [31] 43.59171 and 43.71435 Assistant Examiner-Leslie J. Payne Attorney-Craig, Antonelli, Stewart & Hill ABSTRACT: Two cylinder blocks of a swash plate compressor are so shaped as to fonn a chamber between the cylinder blockassembly, a shell and a head cover of the compressor [54] H 533 polgPREssok near the junction of said two cylinder blocks. The chamber aims awmg thus formed is communicated with the discharge ends of [52] US. Cl 92/72, respective cylinder bores through high pressure passageways 417/312 having a cross-sectional area smaller than that of said [51] lnt.Cl Folb 1/00 chamber. A pipe having a large number of apertures per- [50] Field of Search 92/69, 70, forated through the wall thereof is disposed at that end of the high pressure passageway which is open in said chamber.

Patented. May 11, 1971 3,577,891

4 Sheets-Sheet l Patented "May I I, I971 4 Sheets-Sheet 2 Patented May 11, 1971 3,577, 91

4 Sheets-Sheet 4 INVENTOR5 MAMoRu NEMOT'O and SEIJ'Z'RO v-nur ATTORNEYS BACKGROUND OF THE INVENTION Swash plate compressor is adapted for use in an air conditioning system for an automotive vehicle byreason of the advantages that a variation in torque is small because the number of cylinder bores per shaft can'be increased, that the noise is small and that the compressorcan be formed in an elongate cylindrical shape so as to facilitate to mount the same within an engine room of the vehicle. Particularly, a rotary swash plate compressor actually used for air conditioning system in an automotive vehicle or the like comprises about six pistons mounted on a single shaft, so that the pressure pulsation is suppressed to some extent by the mutual action of these pistons. However, with such construction alone it is impossible to completely absorb the pressure pulsation of the compressor and the compressor still generates a pulsating sound providing a cause of noise. When the compressor is used in an air conditioning system, the noise from the compressor is smaller than that from the engine and is negligible where the engine is in high speed operation ,but theformer becomes larger than the latter where the engine is in low speed operation during idling of the vehicle or during low speed running of the vehicle under a light load condition. It is obviously desirable to reduce such noise to minimum. As a method of eliminating the noise, it has been practiced to provide silencing means downstream of the outlet at the high pressure side of the compressor. In this method, however, the position of mounting the silencing means in the engine room and the size of the silencing means are subjected to a limitation and it has been impossible to incorporate silencing means in a small size automotive vehicle in particular, which has a sufficient silencing effect.

. SUMMARY OF THE INVENTION An object of the present invention is to provide a swash plate compressor having silencing means incorporated therein integrally therewith.

Another object of the invention is to provide a compressor in which silencing means is incorporated integrally therewith, without particularly making the compressor large in size and complicate in construction.

Still another object of the invention is to provide a compressor at a low cost which is small in size and high in operation efficiency.

The objects of the present invention set forth above can be attained by forming a recessed portion near the junction of two cylinder blocks of the compressor so as to form a chamber defined by the cylinder block assembly, a shell and a head cover of the compressor when the cylinder block assembly is fitted in the shell and covered by the head cover, communicating said chamber with the discharge ends of respective cylinder bores through high pressure passageways and providing a large number of apertures at that end of said high pressure passageway which is open in said chamber.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional view of a swash plate compressor embodying the present invention;

FIG.- 2 is a sectional view taken on the line "-11 of FIG. I;

FIG. 3 is a sectional view taken on the line III-III of FIG. 1;

FIG. 4 is a sectional view taken on the line lV-IV of FIG. 2 to better show the state of a passageway for coolant on the low pressure side; and

FIG. 5 is a sectional view taken on the line V-V' of FIG. 2 to better show the state of a passageway for coolant on the high pressure side.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the drawings, cylinder blocks 1, 2 are clamped between

cylinder heads

5, 6 with valve plates 3, 4 intervening therebetween which valve plates are in contact with the outer 'faces' of said cylinder blocks 1, 2 respectively, and the resultant assembly is mounted in a cylindrical shell 7 and a head cover 36 which is fastened to the shell 7 by means of bolts 37. The cylinder blocks 1, 2 are formed therein with three

cylinder bores

8, 8, 9, 9 and l0, 10' respectively and a piston 11 is slidably disposed in each of said cylinder bores.

On the other hand, a drive shaft 12 extends through the centers of the cylinder blocks 1, 2 and is supported by bearings l3, 14. The drive shaft 12 has a swash plate 15 fixedly mounted thereon and the peripheral edge portion of said swash plate extends into a cavity formed in the central portion of each piston 11 and engaged by said piston through balls 16, 16.

The

cylinder heads

5, 6 respectively have low pressure chamber '17, 18 and high pressure chamber 19, 20 formed therein which are respectively communicated with each other through a low pressure passageway 21 and a high pressure passageway 22 formed between the cylindrical shell 7 and the cylinder blocks], 2. The low pressure chamber 17 formed in the cylinder head 5 is connected with a refrigerant intake pipe 23 and communicated with the

cylinder bores

8, 8, 9, 9' and l0, 10 through the valve portions of the valve plates 3, 4. As shown in FIG. 4,

projections

24 and 25 are formed on the shell 7 and the cylinder block 1 or 2 respectively, which extend into I the low pressure passageway 21 so as to change the direction and the cross-sectional area of said passageway. The high pressure passageway 22 is communicated with the

cylinder bores

8, 8, 9, 9' and l0, 10 through holes formed in the valve plates 3, 4 and a silencing chamber 26 is formed intermediate of said high pressure passageway. The silencing chamber 26 is formed by mounting the cylinder blocks in such a manner as to form an air space 27 defined by said cylinder blocks 1, 2, the cylindrical shell 7 and the head cover 36 and fitting a partition plate 28 to the cylinder blocks for sealing. Two pipes 29 having a large number of apertures 30 perforated through the wall thereof pass through the partition plate 28 near the either end thereof respectively and are fixed to the latter with a shoulder 29' formed on the outer surface of pipe. The lower portion of each pipe 29 is press fitted into the respective cylinder block 1 or 2 and thus constitutes a part of the high pressure passageway 22. The silencing chamber 26 is in communication with a discharge port 31 formed in the cylindrical shell 7. The lower end of the low pressure passageway 21 is communicated with an air space 32, formed in the cylinder blocks, through an oil return passageway 33. Reference numeral 34 designates an oil reservoir and 35 designates an oil supply pipe.

The swash plate compressor of the invention constructed as described above operates in the following manner: Namely, when the drive shaft 12 is driven by making use of the driving force of an associated engine, the swash plate is rotated causing a reciprocatory movement of the pistons 11 in the

respective Cylinder bores

8, 8, 9, 9' and 10, 10'. Incident to the reciprocatory movement of the pistons, a refrigerant gas is suckedfrom the low pressure chambers 17, 18. After having been compressed, the refrigerant gas is discharged from the discharge port 31 through the high pressure chambers 19, 20 and the high pressure passageway 22. The refrigerant entering the low pressure chamber 17 is partially sucked into the

cylinder bores

8, 9 and 10 directly through the valve portions of the valve plate 3 and partially flows into the other low pressure chamber 17 through the low pressure passageway 21 and sucked into the cylinder bores 8', 9 and 10' through the valve portions of the valve plate 4. During passage of the refrigerant through the low pressure passageway 21, a lubricant oil entrained in the refrigerant is separated therefrom by the effects of velocity change and directional change of the flow of refrigerant, and returned to the oil reservoir 34 through the oil return passageway 33 and the air space 32 in the cylinder blocks.

On the other hand, the refrigerant discharged from the respective cylinders enters the high pressure chambers 19, 20,

thence enters the silencing chamber 26 through the pipe 29 and further flows into the discharge port 31. In this case, the refrigerant is subjected to an abrupt volumetric change and thus the noise generated incident to the pulsation of the compressor is absorbed. lt is also to be noted that since the silencing chamber is equidistant from the left and right high pressure chambers, the pressure pulsation is smoothed excellently and the operation efficiency of the compressor is enhanced accordingly.

The silencing chamber must have a certain volume for producing a desired silencing effect. According to the present invention, the cylinder blocks are concaved on the outer periphery thereof between two cylinder bores 8, so as to form the silencing chamber 26 defined by the concaved portion of the cylinder blocks, the shell 7 and the head cover 36 near the junction of the cylinder blocks. Owing to such arrangement, it is possible to provide the silencing chamber without substantially increasing the size of the compressor as a whole. The experiment conducted by the present inventors has revealed that the noise generated by a compressor which is not provided therein with silencing means was 70 phons at the rpm. of 1,000, whereas the noise generated by the present compressor having the same capacity and the same outer dimensions was as low as about 62 phons at the same r.p.m. Another advantage of the present invention is that since the silencing chamber is formed by making use of the component parts of the compressor, the compressor according to the invention can be produced at a lower cost than that which is provided with silencing means separately therefrom.

Furthermore, the silencing means according to the present invention can be easily assembled in such a manner that the preformed pipes 29 are jointed to the preformed partition plate 28, the lower portion of each pipe 29 is pushed into the high pressure passageway 22 fonned in the cylinder block 1 or 2 settled in the shell 7 and then the partition plate 28 is firmly fastened between the shell 7 and the head cover 36.

We claim:

1. In a swash plate compressor of the type wherein a swash plate is fixedly mounted on a drive shaft and a plurality of pistons in engagement with said swash plate are slidably received in respective cylinder bores fonned in a cylinder block in concentrical relation to the axis thereof whereby said pistons are caused to make a reciprocatory movement in the respective cylinder bores incident to rotation of the drive shaft, said cylinder block being fitted in a shell and a head cover, a silencing chamber being formed between said shell and head cover, said silencing chamber being communicated with the discharge ends of the respective cylinder bores through high pressure passageways and also with a discharge port of the compressor, and said high pressure passageway being communicated with said silencing chamber through a plurality of apertures.

2. In a swash plate compressor of the type wherein a swash plate is fixedly mounted on a drive shaft and a plurality of pistons in engagement with said swash plate are slidably received in respective cylinder bores fonned in a cylinder block in concentrical relation to the axis thereof whereby said pistons are caused to make a reciprocatory movement in the respective cylinder bores incident to rotation of the drive shaft, said cylinder block consisting of two sections defining a recessed portion near the junction thereof and fitted in a shell and a head cover so as to form a silencing chamber between it and said shell and head cover, said silencing chamber being communicated with the discharge ends of the respective cylinder bores through high pressure passageways formed in the cylinder blocks and also with a discharge port of the compressor, and said high pressure passageway being communicated with said silencing chamber through a pipe fixed to each section of the cylinder block and having a large number of apertures formed therein.

Claims

1. In a swash plate compressor of the type wherein a swash plate is fixedly mounted on a drive shaft and a plurality of pistons in engagement with said swash plate are slidably received in respective cylinder bores formed in a cylinder block in concentrical relation to the axis thereof whereby said pistons are caused to make a reciprocatory movement in the respective cylinder bores incident to rotation of the drive shaft, said cylinder block being fitted in a shell and a head cover, a silencing chamber being formed between said shell and head cover, said silencing chamber being communicaTed with the discharge ends of the respective cylinder bores through high pressure passageways and also with a discharge port of the compressor, and said high pressure passageway being communicated with said silencing chamber through a plurality of apertures.

2. In a swash plate compressor of the type wherein a swash plate is fixedly mounted on a drive shaft and a plurality of pistons in engagement with said swash plate are slidably received in respective cylinder bores formed in a cylinder block in concentrical relation to the axis thereof whereby said pistons are caused to make a reciprocatory movement in the respective cylinder bores incident to rotation of the drive shaft, said cylinder block consisting of two sections defining a recessed portion near the junction thereof and fitted in a shell and a head cover so as to form a silencing chamber between it and said shell and head cover, said silencing chamber being communicated with the discharge ends of the respective cylinder bores through high pressure passageways formed in the cylinder blocks and also with a discharge port of the compressor, and said high pressure passageway being communicated with said silencing chamber through a pipe fixed to each section of the cylinder block and having a large number of apertures formed therein.