US3080106A - Hermetic compressors having horizontal crankshafts - Google Patents

Description

R. W. AYLING March '5, 1963 HERMETIC COMPRESSORS HAVING HORIZONTAL CRANKSHAFTS Filed May 22, 1962 United rates i atent 3,030,166 HERMETIC COMPRESSORS HAVING HQRIZQNTAL CRANKSHAFTS Robert W. Ayling, Staunton, Va., assignor to Westinghouse Electric Qorporation, East Pittsburgh, Pin, a

corporation of Pennsylvania Filed May 22, 1962, Ser. No. 6,819 7 Claims. (Cl. lid-4.06)

This invention relates to refrigerant compressors, and relates more particularly to hermetic compressors having horizontal crankshafts connected to electric driving motors.

In refrigerant compressors having horizontal crankshafts, it is desirable to maintain the crankcase oil charge while maintaining the motor compartment essentially dry. This assures an adequate supply of oil for the lubricating pump located in the crankcase, and prevents oil from building up in the motor compartment to the level of the motor rotor and causing increased power requirements and excessive oil circulation. During normal operation, blowby past the piston rings of the compressor tends to pressurize the crankcase and inhibit oil return, resulting in high oil circulation and decreased heat transfer in the refrigeration system in which the compressor is connected. During a flooded start, the churning of the oil-refrigerant mixture promotes oil loss in the system at the time lubricant is most needed.

An object of this invention is to maintain a high oil level in the crankcase of a hermetic, motor driven compressor, and to maintain the motor compartment of the compressor essentially dry.

Another object of this invention is to reduce the loss of oil to a refrigeration system in which a refrigerrant compressor is connected, during flooded starts of the com-.

pressor. 1

This invention will now be described with reference to the annexed drawings, of which:

FIG. 1 is a fragmentary cross section of a hermetic compressor embodying this invention, and

FIG. 2 is an enlarged fragmentary view of the outer end of the motor rotor of FIG. 1.

Referring now to the drawings, a refrigerant compressor has a horizontal crankshaft having an inner portion 10 with a throw 11 for a connecting rod of a piston which is not shown, in a crankcase compartment 12. The crank shaft portion extends through spaced-apart bearings 13 in a bearing housing 14 into motor compartment 15. The housing 14 is supported by partition 16 from casing 17 of the compressor, and with the partition 16 separates the crankcase compartment 12 from the motor compartment 15. The outer ends of the crankshaft portion 10, the outer bearing 13 and the housing 14 extend almost to the center of quill 18 of electric motor rotor 19. The crankshaft has an outer portion 20 of reduced diameter, the outer end of which extends almost to the outer end of the quill 18, and has a shoulder 21 where its inner portion 10 and outer portion 20 join.

The inner surface of the outer portion of the quill 18 contacts the outer portion 20 of the crankshaft and is attached thereto for rotation therewith. The bearing housing 14 has a cylindrical portion 22 which extends within the quill 18 almost to the outer crankshaft portion 20, the inner portion of the quill having a very small clearance passage 23 around the inner portion of the hous ing portion 22, forming an elfective seal. A seal ring could be used in which case the passage 23 could be larger. The housing portion 22 has an outer end portion 24 with a reduced diameter. A passage 25 larger than the seal passage 23 is formed between the housing portion 24 and the adjacent quill surface. The quill 18 has a vertically extending shoulder 27 spaced outwardly from the outer end of the housing portion 24 and forming therewith a vertically extending passage 30 which connects at its periphery with the passage 25. The housing 14 has a horizontally extending, upper hole 32 therein, the inner end of which connects through an opening 3?: in the housing 14 with the crankcase compartment 12, and the outer end of which connects with the passage 39. The housing 14 has a lower, horizontally extending, circular hole 34 therein, the inner end of which connects through an opening 35 in the housing 14 with the crankcase compartment 12, and the outer end of which contains a plug 36. The bottom of the passage 25 connects through a hole 37 in the housing portion 24 with the hole 34.

A circular rotor retaining plate 43 is attached to the rotor quill 18 by machine screws 49. A smaller, rectangular rotor lock plate at is in contact with the central portion of the outer surface of the plate 43. A bolt 4 extends through the plates 40 and i3 and is threaded into the outer end of the shaft portion 20.

The outer end of the crankshaft portion 2t} terminates slightly short of the outer end of the quill l8, and the central portion of the outer end of the quill is recessed, the recess so formed and the space between the outer end of the crankshaft portion 26 and the inner surface of the plate 43 forming a vertically extending passage 42. The outer portion of the quill 18 around the crankshaft por tion 2% has a pair of diametrically opposite holes 33 and 39 therein, the inner ends of which open into the passage Eli, and the outer ends of which open into the passage 42. The holes 38 and 39 converge towards their outer ends. The plate 4-3 has extending therethrough a pair of diametrically opposite, inwardly slanted holes 45 and 46, the inner ends of which open into the passage 42. The holes 45 and 46 contain the inner ends of gas pumping tubes 47 and 48 respectively, the outer portionsof which extend radially, and the outer ends of which open into the motor compartment 15. The inner ends of the holes 45 and 46 are nearer the axis of the crankshaft than are the outer ends of the holes 38 and 39 so that centrifugal force can prevent oil in the holes 38 and 39 from entering the holes 45 and 46.

There is a conventional stator 52 with a coil 53 around the rotor 19. The outer end of the casing 17 has a cap 55 with a suction gas connection 56. The upper portion of the casing 17 has near the inner end of the motor compartment a passage 58 for connecting the motor compartment with the suction sides of the compressor cylinders which are not shown. The lower portion of the partition 16 has check valve 60 therein for permitting oil flow from the motor compartment into the crankcase compart ment, and for preventing flow in the reverse direction.

Operation in operation, rotation of the gas pumping tubes 47 and 48 by the rotor 19, through well known centrifugal fan action, reduces pressure within the crankcase compartment 12 by applying suction through the holes 45 and 46, the passage 42, the holes 3% and 39, the passage 30, the holes 32 and 34 and the openings 33, 35 and 37 so that the pressure within the crankcase compartment 12 is lower than it is in the motor compartment 15. The mixed gas and oil from the crankcase compartment 12 passes through the upper hole 32 into the passage 30 Where initial oil separation takes place as a result of centrifugal force. Oil pressure builds up in the passage 25 and causes the separated oil to fiow from the bottom of the passage 25 through the opening 37 into the hole 34 and through the opening 35 back into the crankcase compartment. Further separation of any oil which passes into the holes 38 and 39 in the rotor quill 18 takes place in these holes. Due to the rotation of the quill, any oil in the holes 38 and 39 is thrown by centrifugal force from passing into the holes :5 and 4d.

against the surfaces of the quill around the holes and flows through the holes back into the passage 39, this flow being aided by the slope of the holes towards the passage 30 when the holes are in their lowermost positions. This .Oil flows from the passage 30 back into the crankcase compartment along with the oil separated in the initial separation. v

The holes 38 and 39 preferably are displaced circumferentially from the holes 45 and 46 respectively, as shown at 38A and 39A on FIG. 2, for providing increased centrifugal separation.

When the compressor is shut down, oil that has accumulated in the annular passage 25 drains through the opening 37, hole 34 and opening 35 into the crankcase compartment.

The refrigerant gas from which all oil is separated passes out the tubes d7 and 4%; into the motor compartment 215, this flow being from the outer ends of the tubes 38 and 39 into the passage 42 and from the latter through the holes 45 and as into the tubes 4?? and 4s respectively. Since the outer ends of the holes 38 and 39' are spaced further from the axis of the crankshaft than are the inner ends of the holes 45 and i6, centrifugal force prevents any oil It should be apparent that the centrifugal forces acting on the oil that is separated from the gas are greater than theforce resulting from the pressure difference between the crankcase and motor compartments.

V The flow through the holes 32 and 34 in the bearing housing 14 elfectively cools the bearings 13. Since such holes are not in the crankshaft, the latter is not weakened.

The machine screws 49 not only serve to attach the plate 43 to the rotor quill 13 but they, the plate 43 and the bolt 41 provide a convenient means for jacking the rotor off the crankshaft, eliminating the necessity for the previously used wheel puller. By removing the screws 49, the bolt 41 and the plate 43, reinserting the bolt 41 in the crankshaft, placing the plate 43 against the outer end of the bolt 41, reinserting the screws 49' through the plate 43 into the quill l8, and tightening the screws 49, the rotor can he pulled off the crankshaft.

What is claimed, is:

1. In a hermetic compressor-motor unit having a crankcase compartment, a motor compartment horizontally aligned wtih said compartment, means including a bearing housing forming a partition between said compartments, said housing having an outer cylindrical portion extending into said motor compartment, said unit having a crankshaft bearing in said housing, having a check valve in said partition, and having a motor in said motor compartment,

- the combination of a horizontal crankshaft having an inner portionwithin said bearing and extending into said compartments and having an outer portion within said motor compartment, said housing having upper and lower holes therein above and below respectively, said inner crankshaft portion and connecting at their inner ends with said crankcase compartment, said motor having a rotor quill having an outer portion around and attached to said outer crankshaft portion and having an inner portion around and spaced from said outer housing portion, the outer end portion of said housing having a reduced diameter and forming with said inner quill portion an annular passage around the outer ends of said holes, said quill having an intermediate portion with a vertically extending surface spaced from and forming with the outer end of said housing a passage connecting with said annular passage and said upper hole and connecting through said annular passage with said lower hole, and gas pumping means connected to said quill for rotation with said quill, said pumping means having a gas inlet connected to said passage connecting with said annular passage and having a gas outlet in said motor compartment.

2. In a hermetic compressor-motor unit having a crankcase compartment, a motor compartment horizontally aligned with said compartment, means including a bearing housing forming a partition between said compartments, said housing having an outer cylindrical portion extending into said motor compartment, said unit having a crankshaft bearing in said housing, having a check valve in said partition, and having a motor in said motor compartment, the combination of a horizontal crankshaft having an inner portion within said bearing and extending into said compartments and having an outer portion within said motor compartment, said housing having upper and lower holes therein above and below respectively, said inner crankshaft portion and connecting at their inner ends with said crankcase compartment, said motor having a rotor quill havingan outer portion around and attached to said outer crankshaft portion and having an inner portion around and spaced from said outer housing portion, the outer end portion of said housing having a reduced diameter and forming with said inner quill portion an annular passage around the outer ends or" said holes, said quill having an intermediate portion with a vertically extending surface spaced from and forming with the outer end of said housing a vertically extending passage connecting with said annular passage and the outer end of said upper hole and connecting through said annular passage with said lower hole, said outer portion of said quill having diametrically opposite holes therein connecting at their inner ends with said vertically extending passage, the outer end of said quill having alrecess with which the outer ends of said last mentioned holes connect, a rotor locking plate extending across said outer end of said quill and said recess, and gas pumping means attached to said plate and having a gas inlet connecting with said recess and spaced closer to the axis of said crankshaft than said last mentioned hole ends and having a gas outlet discharging into said motor compartment, said gas outlet being spaced further from said axis than said gas inlet.

3. in a hermetic compressor-motor unit having a crankcase compartment, a motor compartment horizontally aligned with said compartment, means including a hearing housing forming a partition between said compartments, said housing having an outer cylindrical portioncxtending into said motor compartment, said unit having a crankshaft bearing in said housing, having a check valve in said partition, and having a motor in said motor compartment, the combination of a honizontal crankshaft having an inner portion within said bearing and extending into said compartments and having an outer portion within said motor compartment, saidihousing having therein upper and lower holes above and below respectively, said inner crankshaft portion and connecting at their inner ends with said crankcase compartment, said motor having a rotor quill having an outer portion around and attached to said outer crankshaft portion and having an inner portion around and spacedfrom said outer housing portion, the outer end portion of said housing having a reduced diameter and forming with said inner quill portion an annular passage around the outer ends of said holes, said quill having an intermediate portion with a vertically extending surface spaced from and forming with the outer end of said housing a vertically extending passage connecting with said annular passage and the outer end of said upper hole and connecting through said annular passage with the outer end of said lower hole, said outer portion of said quill having diametrically opposite holes therein connecting at their inner ends with said vertically extending passage, means forming a passage at the outer end of said quill connecting with the outer ends of said last mentioned holes, and gas pumping means connected to said quill for rotation therewith, said pumping means having an inlet connecting with said last mentioned passage closer to the axis of said crankshaft than said last mentioned hole ends, and having an outlet further from said'axis than said inlet.

4. In a hermetic compressor-motor unit having a crankcase compartment, a motor compartment horizontally aligned with said compartment, means including a bearing housing forming a partition between said compartments,

said housing having an outer cylindrical portion extending into said motor compartment, said unit having a crankshaft bearing in said housing, having a check valve in said partition, and having a motor in said motor compartment, the combination of a horizontal crankshaft having an inner portion within said bearing and extending into said compartments and having an outer portion within said motor compartment, said housing having therein upper and lower holes above and below respectively, said inner crankshaft portion and having inner ends connecting with said crankcase compartment, said motor having a rotor quill having an outer portion around and attached to said outer crankshaft portion and having an inner portion around and spaced from said outer housing portion, the outer end portion of said housing having a reduced diameter and forming with said inner quill portion an annular passage around the outer ends of said holes, said quill having an intermediate portion with a vertically extending surface spaced from and forming with the outer end of said housing a vertically extending passage connecting with said annular passage and the outer end of said upper hole and connecting through said annular passage with the outer end of said lower hole, said outer portion of said quill having diametrically opposite holes therein connecting at their inner ends with said vertically extending passage and converging towards the outer end of said quill, means forming a passage at said outer end of said quill connecting with the outer ends of said last mentioned holes, and gas pumping means connected to said quill for rotation therewith, said pumping means having an inlet connecting with said last mentioned passage closer to the axis of said crankshaft than said last mentioned hole ends, and having an outlet further from said axis than said inlet.

5. In a hermetic compressonmotor unit having a crankcase compartment, a motor compartment horizontally aligned with said compartment, means including a bearing housing forming a partition between said compartments, said housing having an outer cylindrical portion extending into said motor compartment, said unit having a crankshaft bearing in said housing, having a check valve in said partition, and having a motor in said motor compartment, the combination of a horizontal crankshaft having an inner portion Within said bearing and extending into said compartments and having an outer portion in said motor compartment, said housing having therein upper and lower holes above and below respectively, said inner crankshaft portion and having inner ends connecting with said crankcase compartment, said motor having a rotor quill having an outer portion around and attached to said outer crankshaft portion and having an inner portion around and spaced from said outer housing portion, the outer end portion of said housing having a reduced diameter and forming with said inner quill portion an annular passage around the outer ends of said holes, said quill having an intermediate portion with a vertically extending surface spaced from and forming with the outer end of said housing a vertically extending passage connecting with said annular passage and the outer end of said upper hole, said housing having an opening connecting the bottom of said annular passage with the outer end of said lower hole, and gas pumping means connected to said quill for rotation therewith and having a gas inlet connected to said vertically extending passage and having a gas outlet discharging into said motor compartment.

6. In a hermetic compressor-motor unit having a crankcase compartment, a motor compartment horizontally aligned with said compartment, means including a hearing housing forming a partition between said compartments, said housing having an outer cylindrical portion extending into said motor compartment, said unit having a crankshaft bearing in said housing, having a check valve in said partition, and having a motor in said motor compartment, the combination of a horizontal crankshaft having an inner portion within said bearing and extending into said compartments and having an outer portion Within said motor compartment, said housing having therein upper and lower holes above and below respectively, said inner crankshaft portion and connecting at their inner ends with said crankcase compartment, said motor having a rotor quill having an outer portion around and attached to said outer crankshaft portion and having an inner portion around and spaced from said outer housing portion, the outer end of said housing having a reduced diameter and forming with said inner quill portion an annular passage around the outer ends of said holes, said quill having an intermediate portion with a vertically extending surface spaced from and forming with the outer end of said housing a vertically extending passage connecting with said annular passage and the outer end of said upper hole, said housing having an opening connecting the bottom of said annular passage with the outer end of said lower hole, said outer quill portion having diametrically opposite holes therein connecting at their inner ends with said vertically extending passage, means forming a passage at the outer end of said quill connecting with the outer ends of said last mentioned holes, and gas pumping means connected to said quill for rotation therewith, said pumping means having an inlet connecting with said last mentioned passage closer to the axis of said crankshaft than said last mentioned hole ends, and having an outlet further from said axis than said inlet.

7. In a hermetic compressor-motor unit having a crankcase compartment, a motor compartment horizontally aligned with said compartment, means including a bearing housing forming a partition between said compartments, said housing having an outer cylindrical portion extending into said motor compartment, said unit having a crankshaft hearing in said housing, having a check valve in said partition, and having a motor in said motor compartment, the combination of a horizontal crankshaft having an inner portion Within said bearing and extending into said compartments and having an outer portion within said motor compartment, said housing having therein upper and lower holes above and below respectively, said inner crankshaft portion and connecting at their inner ends with said crankcase compartment, said motor having a rotor with a rotor quill having an outer portion around and attached to said outer crankshaft portion and having an inner portion around and spaced from said outer housing portion, the outer end of said housing having a reduced diameter and forming with said inner quill portion an annular passage around the outer ends of said holes, said quill having an intermediate portion with a vertically extending surface spaced from and forming with the outer end of said housing a vertically extending passage connecting with said annular passage and with the outer end of said upper hole, said housing having an opening connecting the bottom of said annular passage with the outer end of said lower hole, said outer quill portion having diametrically opposite holes therein connecting at their inner ends with said vertically extending passage and converging towards the outer end of said quill, means forming a passage at said outer end of said quill connecting with the outer ends of said last mentioned holes, and gas pumping means connected to said quill for rotation therewith, said pumping means having an inlet connecting with said last mentioned passage closer to the axis of said crankshaft than said last mentioned hole ends, and having an outlet further from said axis than said inlet.

No references cited.

Claims (1)

1. 4. IN A HERMETIC COMPRESSOR-MOTOR UNIT HAVING A CRANKCASE COMPARTMENT, A MOTOR COMPARTMENT HORIZONTALLY ALIGNED WITH SAID COMPARTMENT, MEANS INCLUDING A BEARING HOUSING FORMING A PARTITION BETWEEN SAID COMPARTMENTS, SAID HOUSING HAVING AN OUTER CYLINDRICAL PORTION EXTENDING INTO SAID MOTOR COMPARTMENT, SAID UNIT HAVING A CRANKSHAFT BEARING IN SAID HOUSING, HAVING A CHECK VALVE IN SAID PARTITION, AND HAVING A MOTOR IN SAID MOTOR COMPARTMENT, THE COMBINATION OF A HORIZONTAL CRANKSHAFT HAVING AN INNER PORTION WITHIN SAID BEARING AND EXTENDING INTO SAID COMPARTMENTS AND HAVING AN OUTER PORTION WITHIN SAID MOTOR COMPARTMENT, SAID HOUSING HAVING THEREIN UPPER AND LOWER HOLES ABOVE AND BELOW RESPECTIVELY, SAID INNER CRANKSHAFT PORTION AND HAVING INNER ENDS CONNECTING WITH SAID CRANKCASE COMPARTMENT, SAID MOTOR HAVING A ROTOR QUILL HAVING AN OUTER PORTION AROUND AND ATTACHED TO SAID OUTER CRANKSHAFT PORTION AND HAVING AN INNER PORTION AROUND AND SPACED FROM SAID OUTER HOUSING PORTION, THE OUTER END PORTION OF SAID HOUSING HAVING A REDUCED DIAMETER AND FORMING WITH SAID INNER QUILL PORTION AN ANNULAR PASSAGE AROUND THE OUTER ENDS OF SAID HOLES, SAID QUILL HAVING AN INTERMEDIATE PORTION WITH A VERTICALLY EXTENDING SURFACE SPACED FROM AND FORMING WITH THE OUTER END OF SAID HOUSING A VERTICALLY EXTENDING PASSAGE CONNECTING WITH SAID ANNULAR PASSAGE AND THE OUTER END OF SAID UPPER HOLE AND CONNECTING THROUGH SAID ANNULAR PASSAGE WITH THE OUTER END OF SAID LOWER HOLE, SAID OUTER PORTION OF SAID QUILL HAVING DIAMETRICALLY OPPOSITE HOLES THEREIN CONNECTING AT THEIR INNER ENDS WITH SAID VERTICALLY EXTENDING PASSAGE AND CONVERGING TOWARDS THE OUTER END OF SAID QUILL, MEANS FORMING A PASSAGE AT SAID OUTER END OF SAID QUILL CONNECTING WITH THE OUTER ENDS OF SAID LAST MENTIONED HOLES, AND GAS PUMPING MEANS CONNECTED TO SAID QUILL FOR ROTATION THEREWITH, SAID PUMPING MEANS HAVING AN INLET CONNECTING WITH SAID LAST MENTIONED PASSAGE CLOSER TO THE AXIS OF SAID CRANKSHAFT THAN SAID LAST MENTIONED HOLE ENDS, AND HAVING AN OUTLET FURTHER FROM SAID AXIS THAN SAID INLET.

Images