US2504747A - Compressor shaft assembly - Google Patents

Description

April 18, 1950 c. sTEENsTRuP COMPRESSOR SHAFT ASSEMBLY l l I Original Filed June 20, 1944 I'f/l/l//l/l//l/V/f ...Eil

Inventor- CI'n-istian Steensbrup His Atto-VI e5.

Patented Apr. 18, 1950 COMPRESSOR SHAFT ASSEMBLY Christian Steenstrup, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Original application June 20, 1944, Serial No. 541,145. Divided and this application May 29, 1945, Serial No. 596,497

4 Claims. 1

My invention relates to compressors for re- 'frigerating machines and the like and particularly to shaft assemblies for reciprocating compressors. This application is a division of application Serial No. 541,145, filed June 20, 1944, now Patent No. 2,394,409 of February 5, 1946, and assigned to the same assignee as the present application. g

In the manufacture of compressors on large scale production it is desirable to eliminate as far as possible the rejection of parts due to even very slight inaccuracies in alignment. It is desirable that relatively7 Wide tolerances be permissible for the interftting moving parts of the compressor. For example, when a reciprocating compressor is driven by a crank it is difcult to machine accurately large numbers of parts so that they are interchangeable and still make possible the exact alignment of the crank with respect to the cylinder. Inaccuracies in alignment of the crank and cylinder will result in binding and eventuallyin loose fits due to wear and will cause noise to be produced during the operation of the compressor. In the assembly of a reciprocating compressor, such as employed in refrigeratng machines, it is necessary to provide proper alignment of the crank shaft and cylinder and also to provide proper spacing and clearances for the crank shaft itself. Accordingly it is an object of my invention to provide a compressor for refrigeratingf machines and the like including an improved arrangement for aligning and adjusting the crank shaft thereof.

Further objects and advantages of my invention will become apparent as the following descripton proceeds and the features of novelty which characterize my invention will be pointed out with partcularity in the claims annexed to and forming part of this specification.

For a better understanding of my invention, reference may be had to the accompanying drawing in which Fig.v 1 is a longitudinal side elevation, partly in section, of a hermetcally sealed refrigerant compressor embodying my invention; Fig. 2 is an end view of the compressor shown 'in Fig. 1 with the casing cut away and with portions of the compressor shown in section; and Fig. 3 is an enlarged view of the shaft alignment device shown in Fig. 1.

Referring now to Figs. 1 and 2, I have provided a hermetically sealed motor-driven refrigerant compressor unit I including a cylindrical shell 2 having end plates 3 and 4 welded or otherwise suitably bonded thereto to form an enclosing casing. The shell 2 is constructed preferably of steel and constitutes the frame in which is supported a laminated core structure 5 of an alternating current driving motor 6. 'I'he laminations 5 are held in place between annular rings 'I and 8 which are welded or otherwise suitably secured to the shell 2. The motor is provided with stator windings 9 which are energized I through leads I0 passing through sealed fittings II to the exterior of the casing. A compressor I2 is arranged within the casing I and comprises a cylinder block I3 which is rigidly secured to the ring 8 by suitable bolts or screws I4. The cylinder block I3 is provided with a cylinder I5 in which is located a piston I6. The piston is driven by a crank shaft I'I mounted in a bearing I 8in the block I3, the motor 6 being provided with a squirrel cage rotor I9 mounted on the shaft I1. The shaft II is provided with annular shoulders 20 and 2| on either side of the crank and the end of the vshaft remote from the motor I9 is mounted in a bearing block 22 which is slidably arranged in a circular opening 23 in the cylinder block I3. The shoulders 20 and 2I are mounted in running engagement with annular thrust bearings 24 and 25, respectively, and are retained in position by a dished bridging member or disk 26 in cooperation with a movable camming member or adjusting plate 21. The compressor is provided with intake and exhaust valves (not shown) which are located within a cylinder head 28. Refrigerant gas which is admitted to the compressor through a pair of intakes 29 ows through an intake muilier 30 and thence into the compressor head through a conduit 3l. The gas compressed within the cylinder I5 by operation of the piston I6 is discharged through a connection 32 into an exhaust muliler 33 and flows from the exhaust muilier and out of the casing through a conduit 34 to the circuit of the refrigerating system (not shown). Vaporized refrigerant returning from the refrigerating system is admitted to the casing through a suction line or return conduit 35. A body of oil or other lubricating fluid is maintained in the casing I to a level indicated at 36, the bottom of the casing forming a lubricant sump. Lubricant is withdrawn from the sump through an intake baffle 3l by operation of a rotary oil pump 38 which circulates the oil to the moving parts of the compressor. This intake baille construction is the invention of Carl H. Steenstrup and is described and claimed in application Serial No. 541,143, led June 20, 1944, now Patent No. 2,394,- 409 of February 5,1946, and assigned to the same assignee as the present invention.

The motor compressor unit may be supported in any suitable manner on the structure with which it is to be employed and has been illustrated as resiliently suspended on springs 39 and 4I).

During the assembly of the motor compressor unit, the shaft I1 is rst inserted in the bearing I8, the opening 23 in the block I3 providing room for the passage of the shoulders 20 and 2| longitudinally into position. The block 22 is then placed over the right-hand end of the shaft I1 and is moved into engagement with the thrust .bearing 25, it being noted that the end of the shaft projects slightly beyond the end of the block 22. The dished disk 26 is then placed in position bridging the end of the shaft I1 and engaging the block 22. 'I'he block and disk are made approximately of the same diameter as the opening 23 so that they have a sliding fit in the opening and are guided by the walls of the opening in their axial movement, and the block pref.

erably is keyed or otherwise held against rotation in the opening. The camming plate 21 is then adjusted to press the bearing block 22 axially against the shoulder 2l' and also to press the shoulder 20 against the thrust bearing 24. The camming plate 21 is constructed so that the correct clearances between the thrust bearings and the shoulders 20 and 2| may be adjusted quickly and plate 21 may then be locked in place to maintain the adjustment.

The details of construction of the camming device 21 and the associated parts will be apparent from the drawing'. The plate is secured to the block I3 by suitable cap screws 4I and 42, the plate being arranged to pivot on the screw 4I and being provided with a slot 43 aording lateral adjustment of the plate with respect to the shaft I1. As clearly shown in Fig. 3, the plate 21 is provided with a sloping camming surface 44 which engages the outermost portion or apex of the disk 26. By loosening the screws 4| and 42 and pivoting the plate in a clockwise direction about the screw 4I, the camming surface 44 may be made to force the disk 26 toward the left thereby to press the block 22 into engagement with the shaft shoulder 2|. After the shaft is in position, the piston I6, together with aconnecting rod 45 and wrist pin 46, is inserted in the cylinder so that the top half of the crank bearing formed in the connecting rod engages the crank indicated at 41. The lower half of the connecting rod bearing indicated at 48 is then secured in place by suitable screws 49. The compressor block is then placed in a suitable fixture vand the crank I3 turned until the piston I6 is in its outermost position so that the crank is on dead center. The camming plate 21 is then turned in a counterclockwise direction to force the block 22 against the shoulder 2I and the screws 4I and 42 are tightened in a position such that the shaft is locked against rotation, the

4 of the thrust bearings and shoulders, is within the required tolerances. The plate 21 is then locked in place by tightening of the screws 4I and 42 to maintain the required running engagement of the thrust bearings 24 and 25 with the shoulders 20 and 2l.

It is readily apparent that the arrangement just described for adjusting the shaft to its required position provides a simple and effective way for adjusting large numbers of parts in production. Further alignment of the connecting rod and piston is accomplished by employing the self-aligning wrist pin illustrated and which is described and claimed in the aforesaid parent application.

While I have described my invention in connection with a particular type ofv refrigerant compressor, other applications will readily be apparent to those skilled in the art. Ido not, therefore, desire my invention to be limited to the particular construction described and illustrated and I intend by the appended claims to cover all modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a compressor or the like, a support having a shaft bearing therein, a shaft journaled in said bearing, an annular thrust bearing on said support about Vsaid shaft` bearing, an annular shoulder on said shaft arranged to engage said thrust bearing, said support having an opening therein through which said shaft may be withdrawn by longitudinal movement, a second annular shoulder on said shaft facing toward said 2. In a compressor or the like, a support hav-V ing a shaft bearing therein, a shaft journaled in camming plate forcing the shoulders and thrust other fixture provided with means for guaging thelongitudinal movement of the shaft I1. The plate 21 is then adjusted until the movement of the shaft, which is a measure of the clearances said bearing, an annular thrust bearing onsaid support about said shaft bearing, an annular shoulder on said shaft arranged to engage said thrust bearing, said support having an opening therein through which said shaft may be withdrawn by longitudinal movement, a second vannular shoulder on said shaft facing 'toward Isaid opening, a bearing block slidably fitted in said 'opening and having a journal bearing engaging said shaft and a thrust bearing adapted to engage said second shoulder, the end of said shaft extending beyond said bearing block, a bridging member arranged within said opening in engagement with said bearing block and out of engagement with the end of said shaft, camming means for pressing said bridging member against said bearing block for adjusting the clearances between said thrust bearings and said shoulders, and a lock for said camming-meansA for retaining said bearing block in position to maintain said shoulders in running engagement with said thrust bearings. y

3. Ina compressor or the like, a supportl havy ing a shaft bearing therein, a shaft journaled in said bearing, an annular thrust bearing on said support about said shaft bearing, an annular shoulder on said shaft arranged to engage said thrust bearing, said support having an opening therein through which said shaft may be withdrawn by longitudinal movement, a second annular shoulder on said shaft facing toward said opening, a bearing-block slidably fitted in said opening and having a journal bearing engaging said shaft and a thrust bearing adapted to engage said second shoulder, the end of said shaft extending beyond said bearing block, a dished disk arrange within said opening in engagement with said bearing block and extending across the end ofsaid shaft out of engagement therewith, a cam' -pivotally mounted on said support and movable with respect to said shaft and arranged to engage said disk and press said disk against said bearing block for adjustingr the clearances between said thrust bearings and said shoulders, and means for locking said cam in position on said support to maintain said shoulders in running engagement with said thrustbearings.

4. In a compressor or the like, a cylinder block having a main shaft bearing therein, an enlarged opening in axial alignment with said bearing, a shaft journaled in said bearing and movable longitudinally out of said bearing through said opening, a. crank on said shaft within said opening and annular shoulders on said shaft adjacent both ends of said crank, a thrust bearing on said block about said main bearing and arranged to engage the adjacent one of said shoulders, a bearing block slidably fitted in said opening and having a journal bearing engaging said shaft and a thrust bearing arranged to engage the other of said shoulders, the end of said shaft extending beyond said bearing block, a dished disk arranged in engagement with said bearing block and out of engagement with the end of said shaft, a plate -pivoted on said cylinder block and having a sloping cam surface engaging said disk, said plate being movable with respect to said shaft for adjusting the clearances between said thrust bearings and said shoulders, and a lock for retaining said plate in position on said cylinder block.

CHRISTIAN STEENSTRUP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,185,192 Gillespie May 30, 1916 2,113,691 Heller Apr. 12. 1938

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