# US 4,400,142 A · Motor-compressor unit

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- Number: US 4,400,142 A
- Document ID: US4400142A
- Status: Granted
- Kind: A
- Application number: 06/260,498
- Filed: 1981-05-04
- Granted: 1983-08-23
- Earliest claimed: 1981-05-04
- Assignees: Carrier Corporation
- Inventors: Harry E. Ohlson, Jr.
- Web page: https://patentgrep.com/patent/US4400142A

## CPC

- F04B 39/0246: {in the rotating shaft}
- F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F)

## Abstract

A motor-compressor unit comprising a compressor including a rotatable crankshaft, a motor, a shell enclosing the compressor and the motor, a supply of lubricant, and a lubrication system for circulating lubricant through the compressor. The lubrication system includes a first stage axial passage, a second stage axial passage extending upward from an upper portion of the first stage axial passage, a first stage radial passage extending outward from the first stage axial passage, and a second stage radial passage extending outward from the second stage axial passage. The lubrication system further comprises an interstage collection chamber for receiving lubricant directed through the first stage radial passage, and an interstage conduit for conducting lubricant from the interstage collection chamber into the second stage axial passage.

## Claims

### Claim 1

A motor-compressor unit comprising:
a compressor including a rotatable crankshaft;
a motor connected to the compressor crankshaft to rotate the crankshaft;
a shell enclosing the compressor and the motor;
a supply of lubricant located in the bottom of the shell; and
a lubrication system for circulating lubricant through the compressor and including
a first stage axial passage defined by and coaxial with the crankshaft, extending upward from a bottom thereof, in communication with the lubricant supply, and wherein surfaces of the crankshaft which define the first stage axial passage project around a first portion of the rotational axis of the crankshaft,
a second stage axial passage defined by and coaxial with the crankshaft, extending upward from an upper portion of the first stage axial passage, and wherein surfaces of the crankshaft which define the second stage axial passage project around a second portion of the rotational axis of the crankshaft,
a first stage radial passage defined by the crankshaft and extending radially outward from the first stage axial passage,
a second stage radial passage defined by the crankshaft and extending radially outward from the second stage axial opening,
means defining an interstage collection chamber for receiving lubricant directed outward through the first stage radial passage, and
an interstage conduit having a first end in communication with the interstage collection chamber, and extending downward therefrom and then upward through the first stage axial passage and into the second stage axial passage;
wherein rotation of the crankshaft draws lubricant from the lubricant supply, through the first stage axial passage, and into the first stage radial passage; forcibly directs the lubricant therethrough to increase the pressure of the lubricant and to direct the lubricant through the interstage collection chamber, the interstage conduit, the second stage axial passage, and into the second stage radial passage; and forcibly directs the lubricant therethrough to further increase the pressure of the lubricant.

### Claim 2 (depends on 1)

The motor-compressor unit as defined by claim 1 further including
a lubricant pick-up tube having a first end located within the first stage axial passage, connected to the crankshaft for rotation therewith, and axially extending downward from the first stage axial passage into the lubricant supply, and having a second end defining a tube inlet, and
wherein the interstage conduit axially extends through the lubricant pick-up tube and the tube inlet.

### Claim 3 (depends on 2)

The motor-compressor unit as defined by claim 2 wherein:
the lubricant pick-up tube projects above the first stage radial passage; and
sides of the lubricant pick-up tube define an opening to allow lubricant to flow from the interior of the lubricant pick-up tube into the first stage radial passage.

### Claim 4 (depends on 1, 2)

The motor-compressor unit as defined by claim 1 or 2 wherein the crankshaft defines a downwardly and inwardly inclined surface generally facing the first stage radial passage to facilitate centrifuging lubricant therethrough.

### Claim 5 (depends on 4)

The motor-compressor unit as defined by claim 4 wherein:
the crankshaft defines a beveled edge surrounding a lower end of the second stage axial passage to facilitate inserting the interstage conduit thereinto; and
a second end of the interstage conduit is in a close fitting engagement with the surfaces of the crankshaft defining the second stage axial passage, and the interstage conduit extends thereinto a major portion of the axial distance between the lower end of the second stage axial passage and the second stage radial passage to inhibit lubricant leakage from the second stage axial passage to the first stage axial passage.

### Claim 6 (depends on 5)

The motor-compressor unit as defined by claim 5 wherein:
the compressor further includes a compressor block;
the crankshaft is supported for rotation within the compressor block;
the interstage collection chamber is defined by the compressor block, radially outside and adjacent to the crankshaft; and
the interstage collection chamber annularly extends around the crankshaft.