US2868443A - Refrigerating apparatus - Google Patents

Description

Filed June 24. 1954 INVENTOR. John Do/za His Aflorney United States Patent REFRIGERATING APPARATUS John Dolza, Davisburg, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delta ware.

Application June 24, 1954, Serial No. 438,986 1 Claim. (Cl. 230-186) This invention relates to refrigerating apparatus and more particularly to an improved type of refrigerant compressor.

It is an object of this invention to provide an improved low cost bearing arrangement for an axial compressor. More particularly it is an object of this invention to provide an improved type of low cost end thrust bearing for the wobble plate element of an axial compressor.

Still another object of this invention is to provide an improved oil handling arrangement for an axial type multiple cylinder compressor.

A further object of this invention is to provide an improved compressor housing which may be manufactured at a low cost and which facilitates aligning the various bearing surfaces.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Figure l is a vertical sectional view of a compressor embodying the invention; and,

Figure 2 is a sectional view taken substantially on line 22 of Figure 1.

Referring now to the drawings wherein a preferred embodiment of the invention has been shown, reference numeral designates the main casing which is made of sheet metal so as to reduce both the cost and weight of the compressor. A main shaft 12 is provided as shown and is supported for rotation within the casing 10 with one end of the shaft projecting through the casing so as to receive a drive pulley (not shown) for use in driving the compressor. The shaft12 has its one end journalled in a cylinder block 14 and has its other end journalled in a bearing block 16. The bearing block 16 has a press fit within the reduced or neck portion 18 of the sheet metal casing 10. A bearing element 20 is provided as shown which has a press fit on the drive shaft 12. The cylinder block 14 is provided with a beveled surface 22 which fits up against a complementary beveled surface 24 provided on the casing 10. The beveled surface 24 is made concentric, to the inner surface of the neck portion 18 so as to facilitate accurate alignment between the front and rear bearing surfaces for the drive shaft 12. i

It will be noted that the drive shaft has been made straight and that a cast bearing element 26 has been pressed onto the midportion of the shaft so as to rotate with the shaft and form a support for the wobble plate 39. A plurality of connecting rods 32 drivingly connect the wobble plate with a plurality of pistons 34 which operate within bores 36 provided in the cylinder block 14. For purposes of illustration, a five-cylinder compressor has been shown whereas the number of cylinders may be varied without departing from the spirit of the invention.

r 2,868,443 Patented Jan. 13, 1959 The end thrust on the wobble plate as: a result of the operation of the compressor is taken up by a stamped sheet metal end thrust bearing 40 which is attached to the bearing block 16. The end thrust bearing 40 is cup-shaped with the rim of the cup beveled as at 42 to engage the spherical bearingsurface44 on the wobble plate 30L The refrigerant to be compressed enters the housing 10 through the suction line 60 which communicates with a central suction chamber 62 at the head end of the cylinder block 14. A vent passage 64 has been provided as shown for equalizing the pressure within the main crankcase 63 and the chamber 62 with the result that the crankcase of the compressor which serves as an oil sump is maintained at a pressure corresponding substantially to the low side pressure of the refrigerant system. A valve plate 66 has been provided as shown and includes the usual inlet and outlet ports 65 and 67 respectively communicating with the ends of the compression chambers. The compressed refrigerant discharges through the usual outlet ports 67 into an outlet chamber 68 provided in surrounding relationship to the suction chamber 62. The chambers 62 and 68 are separated from one another by the insert element 69 which is held in place by the end wall 71 of the main casing 10. As shown in Figure l, the element 69 abuts against the valve plate 66 which in turn abuts against the cylinder block 14 so as to hold the bevelled surfaces 22 and 24 in firm contact with one another. The end wall 71 is brazed to the casing 10 at 73 along its outer periphery. The compressed refrigerant leaves the chamber 68 through the usual high side line 70 which would lead to the condenser (not shown) of a refrigerating system.

A conventional shaft seal generally designated by the reference numeral 72 has been provided for preventing the escape of lubricant and/or refrigerant at the point which the shaft projects through the end of the housing 10. A conventional oil pump 74 is provided as shown and serves to withdraw oil from the bottom of oil sump through the inlet tube 75 and to discharge the oil directly into the shaft seal cavity 76 from whence a portion of the oil fiows under pressure through oil passages 77 and 79 into the space 78 provided between the spherical portion of the wobble plate 30 and the end thrust bearing 40 so as to force lubricant to How outwardly between the rim of the end thrust bearing 40 and the wobble plate. By virtue of this construction, the wobble plate in effect floats on a film of oil with the result that the friction losses are maintained at a minimum. A portion of the oil enters a passage 80 in the shaft through a radial passage 81 and then flows through a radially extending passage 82 to the rear shaft bearing 84. Some of the excess oil leaving the rear bearing 84 feeds back into the suction chamber 62 where it is picked up by the refrigerant entering the suction ports of the various compression chambers so as to lubricate the pistons of the compressor. Much of the oil handled by the pump 74 will of course be returned to the crankcase as it escapes from the various bearing surfaces for the shaft 10 and the wobble plate assembly.

In acordance with the provisions of rule 78a, reference is made to the following prior filed applications: Serial No. 347,556, filed April 8, 1953, and Serial No. 398,319, filed December 15, 1953, now Patent No. 2, 798,663.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claim which follows.

What is claimed is as follows:

In an axial type of compressor, a stamped sheet metal housing having a circular portion provided with an in ice 3 ternal beveled surface adjacent its one end and and having a reduced cylindrical neck portion adjacent its opposite end, a bearing insert having a press fit within said neck portion, a cylinder block having a beveled surface complementary to said first named beveled surface, said cylinder block being shiftable sideways relative to the axis of said circular portion in response to engagement of said complementary beveled surface, a bearing aperture in said block concentric to said beveled surface, a compressor shaft having its one end journalled in said bearing aperture and having its other end journalled in said bearing insert, and means for holding said beveled surfaces in firm contact with one another, a wobble plate mechanism operated by said shaft, and an end thrust bearing for said wobble plate mechanism carried by said bearing insert.

References Cited in the file of this patent UNITED STATES PATENTS 1,418,951 Martin June 6, 1922 2,062,035 McCormack Nov. 24, 1936 2,106,236 Burke Jan. 25, 1938 2,329,912 Kent Sept. 21, 1943 2,365,309 Talbot Dec. 19, 1944 2,405,938 Beck Aug. 20, 1946 2,433,222 Huber Dec. 23, 1947 2,492,688 Dall Dec. 27, 1949 2,570,698 1951 Manseau Oct. 9,

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