US2060752A - Lubricating system - Google Patents

Description

NOV. 10, 1936. A, c b ET AL 2,060,752

LUBRICAT ING SYSTEM Filed'Jan. 2, 1955 2 Sheets-Sheet 1 JNVENTOR. PHIL /P 19. (4 mwE/a men/UR 01/010472 BY 0 Y ATTORNEY. v

N 10, 1936. P. A. CELANDER mp 2.060.752

LUBRICATING SYSTEM- 2 Sheets-Sheet 2 Filed Jan. 2, 1935 ATTORNEY.

Patented Nov. 10, 1936 UNITED STATES PATENT OFFICE LUBRICATING SYSTEM poration of Illinois Application January 2, 1935,. Serial No. 14

Claims.

This invention relates to improvements in lubricating systems and more particularly to a system for automatically lubricating the pistons of a compressor.

5 It has been found that in the compressors employed in the compression type of refrigerating apparatus, which employ a splash system of lubrication, insuflicient lubrication is provided for the pistons of the compressor, and it is an object of this invention to provide a means actuated by the operation of the compressor to automatically lubricate the pistons of the compressor.

While the embodiment of this invention is illustrated and described in connection with a compressor employed in a closed system compression type of refrigerating apparatus, yet it may be applied as well to any type of compressor in which there is a differential in pressure between the high and low sides.

With these and other objects in view, reference is made to the accompanying sheets of drawings which illustrate preferred embodiments of this invention with the understanding that minor changes may be made without departing from the scope thereof.

In the drawings:

Figure 1 is a view in transverse central vertical section taken through a compressor employed in a closed system compression type refrigerating machine, with parts shown in elevation, illustrating a preferred form of this invention.

Figure 2 is a fragmentary enlarged detail view of the preferred form of automatic compression cylinder lubricating means, shown in Figure 1.

Figure 3 is a View in section taken on the line 33, Figure 2, looking in the direction of the arrows but omitting the showing of the cap means.

Figure 4 is a View in section taken on the line 4-4, Figure 1, looking in the direction of the 40 arrows.

Figure 5 is a fragmentary view in section taken at right angles to Figure 1, illustrating a modified form of this invention.

Figure 6 is a view similar to Figure 5, illustrating the third form of this invention.

Figure 7 is a fragmentary sectional view taken on the line 44, Figure 1, illustrating an additional means for lubricating the wrist pin bearings of the connecting rods, with parts in elevation.

Figure 8 is a view in central vertical section through a piston showing said additional means for lubricating the wrist pin bearings.

In the form of this invention illustrated in Figure 1, the crank shaft l is mounted in suitable bearings, not shown, in the crank case 2 with one end extending therethrough and provided with a pulley wheel 3 to be driven by a belt from an electric motor, or other means, not shown. A compression cylinder head 4 is preferably formed integral with the crank case upon the upper side thereof and the bottom of the crank case is shown provided with a removable cap 5. The eccentrics or cranks 6 of the shaft I mount the usual connecting rods 1 of the pistons 8. The shaft bearings and the bearings of the connecting rods 1 upon the wrist pins are lubricated upon the rotation of the shaft by a bath of lubricant contained in the bottom of the crank case, as indicated upon the drawings.

In this embodiment, the gaseous refrigerant is compressed by the operation of the pistons and is expelled under compression through the top 9 of the cylinder head to be delivered through a pipe II] to the high side of an evaporator or cooling unit, not shown. The low side of the evaporator or cooling unit is connected by a pipe II to the port I2 opening into the crank case 2 considerably above the level of the lubricant, all of which is usual construction.

In order to provide sufiicient lubrication to the pistons reciprocating within the compressor 4, a pump cylinder is mounted upon the bottom of the cap 5, preferably centrally located thereon, to extend upward between the eccentrics or cranks 6 of the shaft I. As shown in Figures 1 and 2, the pump cylinder comprises a cylindrical casing I3 receiving within its lower end a plug I4 preferably threaded through an aperture provided therefor in the center of the cap 5. The portion of the plug I4 entering the interior of the cap 5 is provided with a transverse port I5 communicating with an axial port l6 which passes upward through the body of the plug. The upper side of the plug within the cylinder casing I3 is recessed and mounts a valve plate I! adapted to reciprocate between the bottom of the recess and an abutment I8, preferably formed of a split ring engaged in a circumferential groove in the side walls of the recess. In one position the valve plate I! is adapted to seat over the axial port I6. It is preferable to provide the periphery of the valve plate II with a plurality of circumferential cutaway portions I9, as shown in Figure 3, to allow passage of fluid thereabout when the plate I! is unseated. The upper end of the casing I3 is provided with a closure 20 which axially mounts a tube 2I depending therefrom and terminated a short distance above the recessed end of the plug I4. The pipe 2| communicates with an axial 55 recess 22 in the closure 20 which mounts a ball check valve 23. The axial recess 22 is provided with a closure 24 which axially mounts a pipe 25 communicating with the recess 22. The pipe 25 is extended through the crank case, preferably through a connection 26 provided at one side of the cap 5, which in turn is connected by the pipe 21 to a similar connection 28 threaded into the side of the cylinder head 4 intermediate the respective cylinders thereof to communicate with ports 29 extending through the walls thereof which in turn open into the interior of the cylinders below the piston rings of the pistons 8 in their lowermost position, and preferably arranged to be aligned with circumferential grooves 29 upon the pistons when the pistons are at the end of their downward stroke.

When the compressor is first installed, the crank case is filled with lubricant to the proper level. The lubricant will enter through the ports l5 and 16 to unseat the valve plate I! and enter within the casing I3 of the cylindrical pump cylinder until the pressure of the air entrapped therein above the level of the lubricant is equal to the pressure of the lubricant in the crank case above the level of the lubricant within said casing. Upon the initiation of operation of the compressor, the pressure Within the crank case 2 is reduced and as the ports 29 are alternately uncovered by the pistons, the expansion of the air within the casing l3 of the cylindrical pumping member will cause the valve plate I! to seat upon the axial port l6 and force the lubricant therein through the pipes 21, 25, and 21 to the ports 29 to deliver the lubricant to the grooves 29 of the cylinders 8. In compressors employed for the purpose described, their operation is intermittent, and upon the cessation of operation the pressure within the crank case 2 will increase and thereby force the lubricant within the crank case 2 to enter the casing [3 of the lubricant pump to again compress the air therein, so that as soon as the exterior pressure is reduced, lubricant will again be fed to the cylinders.

Figure 5 illustrates a modified form of this device in which a metal disc 30 is mounted between the crank casing 2 and cap 5. The disc 36 is provided with a central opening 3| communicating with a chamber 32 provided upon the upper side thereof mounting a ball check 33 and communicating with the pipe 34 extending upwardly and about the eccentrics of the shaft l to enter into the web 35 between the cylinders in the cylinder head 4 to communicate with the transverse port 36 opening into the respective cylinders. The bottom of the cap 5 may be provided with a small central opening 31 which communicates with the interior of a metallic bellows 38 mounted upon the interior of the cap 5 concentric with the opening 31. The bellows 38 is closed at its upper end and is normally maintained in extended position by a spring 39 mounted upon the interior thereof. The metal disc 36 is provided with a port 40 and a flap valve 4| upon the under side thereof.

When the interior pressure of the crank case 2 increases, it will force lubricant through port 48 and past the valve 4| to compress the bellows 3B, exhausting the air therein through the opening 31, so that as the pressure within the crank case 2 decreases, the flap valve will be closed and the lubricant entrapped by the valve below the disc 30 will be forced by the expansion of the springpressed bellows 38 through the chamber 32 and pipe 34 to lubricate the pistons, as hereinbefore described.

Figure 6 illustrates another form of thisinvention which includes the mounting of a metallic bellows 42 upon a cylindrical base 43 formed upon the interior of the cap 5. The bellows is closed at its upper end and is normally maintained in extended position by a spring 44. The cap 5 is provided with a port 45 leading from the interior at one side of the bellows 42 and then extended upward to communicate with the interior of the bellows 42. This port is provided upon the interior of the cylindrical base within the bellows with a flap valve 46. The cap 5 is provided with another port 41 passing through the cylindrical base and leading from the interior of the bellows to a chamber 48, which chamber is provided with a flapper valve 49 adapted to close said port 41. The chamber 48 communicates with a pipe 49 passing through the lower end of the cap which is connected to the cylinder head 4 of the compressor in the manner shown in Figure 1.

Upon an increase in pressure within the crank case 2 the lubricant will be passed through the port 45 to the interior of the bellows 42 and compress the air entrapped therein until the pressures within and without the bellows are equal so that as the pressure within the crank case 2 decreases, the pressure of the air within the bellows will force the lubricant through the port 41, chamber 48, and pipe 49 to lubricate the cylinders, as hereinbefore described, as the pressure within the crank case decreases.

If desired, the wrist pins 50 of the pistons 8 may be provided with an axial bore 5| adapted to open into the circumferential groove 29 upon the piston 8. The bore 50 is provided with a central port 52 leading at right angles therefrom to the connecting rod bearing 53 about the wrist pins 58. By this means, each time the groove 29 registers with the port 29 during operation of the pistons, then a part of the lubricant delivered from the crank case through the port 29 will enter the wrist pin bore 5| and be delivered through the port 52 to the connecting rod bearing 53.

From the above description, it is readily seen that by the provision of the lubricant pump within the crank case that during operation of the compressor, a simple and effective automatic lubricating means for the pistons and piston wrist pin bearings is actuated by the differential in the pressure upon the lubricant resulting from the operation of the compressor.

What we claim is:

l. A compressor for a closed system compression type refrigeration apparatus having a crank case containing a bath of lubricant, a lubricant pump for automatically lubricating the compressor pistons actuated by the decrease in pressure within the crank case resulting from the operation of the pistons, including a chamber closed at one end and a valved port at the other provided with a valve permitting lubricant to enter the chamber until the pressure of the air entrapped therein equals the pressure within the crank case when the compressor is idle, and means for delivering lubricant from the chamber to the piston cylinders upon a reduction of crank case pressure upon initiation of operation.

2. The structure of claim 1 wherein the said delivery means includes a pipe leading from the lubricant contained within the pump chamber provided with a check valve preventing the return of lubricant therefrom to the pump chamber.

3. The structure of claim 1 wherein the lubricant pump chamber includes a vertical cylindrical casing supported upon the bottom of the crank case having said valved port adjacent the bottom thereof and wherein the said delivery means includes a pipe entering the casing and extending adjacent the bottom above the said valved port.

4. The structure of claim 1 wherein the said pump chamber includes a compressible metallic bellows mounted upon a base formed upon the crank case provided with a valved port leading from the interior of the bellows to the interior of the crank case and with an additional port leading from the interior of the bellows to the said delivery means.

5. The structure of claim 1 wherein each piston is provided with a circumferential groove below the piston rings arranged to receive the lubricant delivered to the cylinder and wherein each wrist pin of each piston terminates within the circumference of the piston forming circumferential pockets traversing each circumferential piston groove and wherein each wrist pin is provided with a lubricating duct leading from said circumferential pockets to the bearing of the connecting rod upon the wrist pin.

PHILIP A. CELANDER. ARTHUR C. HOLLATZ.

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