# US 2012/0073403 A1 · Variable Lubricant Level in a Differential Sump

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- Number: US 2012/0073403 A1
- Document ID: US20120073403A1
- Status: Published application
- Kind: A1
- Application number: 12/888,451
- Filed: 2010-09-23
- Published: 2012-03-29
- Earliest claimed: 2010-09-23
- Assignees: Ford Global Technologies, LLC
- Inventors: Andreas E. Perakes; Jason C. Marcath; Shaun G. Knowles
- Web page: https://patentgrep.com/patent/US20120073403A1

## CPC

- F16H 57/0457: {Splash lubrication}
- F16H 57/0409: {characterised by increasing efficiency, e.g. by reducing splash losses}
- F16H 57/0447: {Control of lubricant levels, e.g. lubricant level control dependent on temperature}
- F16H 57/045: {Lubricant storage reservoirs, e.g. reservoirs in addition to a gear sump for collecting lubricant in the upper part of a gear case}
- F16H 57/0471: {Bearing}
- F16H 57/0483: {Axle or inter-axle differentials}
- Y10T 74/2188: Axle and torque tubes
- F16H: GEARING
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A system for lubricating a differential mechanism includes a housing containing a ring gear, a pinion meshing with the ring gear, a sump containing fluid, and a reservoir that receives fluid flung from the ring gear as the ring gear rotates through the sump fluid, and an orifice restricting the flow rate of fluid from the reservoir.

## Claims

### Claim 1

A system for lubricating a differential, comprising:
a housing containing a ring gear;
a pinion meshing with the ring gear;
a fluid sump;
a reservoir that receives fluid flung from the ring gear as the ring gear rotates through the sump fluid; and
an orifice restricting the flow rate of fluid from the reservoir.

### Claim 2 (depends on 1)

The system of claim 1 further comprising:
a bearing fitting in the housing, supporting the pinion for rotation, the bearing located to receive at least a portion of the fluid exiting the orifice before the exiting fluid returns to the sump.

### Claim 3 (depends on 1)

The system of claim 1 further comprising:
first and second mutually spaced bearings, each bearing fitted in the housing, supporting the pinion for rotation, and located to receive at least a portion of the fluid exiting the orifice before the exiting fluid returns to the sump.

### Claim 4 (depends on 1)

The system of claim 1 wherein:
the sump has a volumetric capacity sufficient to retain fluid whose upper surface is at an elevation that is higher than an elevation of a mesh between the ring gear and pinion.

### Claim 5 (depends on 4)

The system of claim 4 wherein:
the sump retains a second volume of fluid while the ring gear is rotating, the upper surface of the second volume being lower than the upper surface of the first volume.

### Claim 6 (depends on 1)

The system of claim 1 wherein:
a mesh between the ring gear and pinion is located at an elevation that is lower than an upper surface of a volume of fluid in the sump while the reservoir is drained of fluid and the ring gear is not rotating.

### Claim 7

A system for lubricating a differential, comprising:
a housing containing a ring gear;
a pinion meshing with the ring gear;
a fluid sump;
a reservoir at a higher elevation that the sump, partially separated from the ring gear by a wall;
an orifice restricting the flow rate of fluid from the reservoir.

### Claim 8 (depends on 7)

The system of claim 7 wherein an inner surface of the housing and the wall directing into the reservoir fluid flung from the ring gear as the ring gear rotates through the fluid in the sump.

### Claim 9 (depends on 7)

The system of claim 7 further comprising:
a bearing supporting the pinion for rotation, the bearing located to receive at least a portion of the fluid exiting the orifice before the exiting fluid returns to the sump.

### Claim 10 (depends on 7)

The system of claim 7 further comprising:
first and second mutually spaced bearing, each bearing fitted in the housing, supporting the pinion for rotation, and located to receive at least a portion of the fluid exiting the orifice before the exiting fluid returns to the sump.

### Claim 11 (depends on 7)

The system of claim 7 wherein:
the sump has a volumetric capacity sufficient to retain fluid whose upper surface is at an elevation that is higher than an elevation of a mesh between the ring gear and pinion.

### Claim 12 (depends on 11)

The system of claim 11 wherein:
the sump retains a second volume of fluid while the ring gear is rotating, the upper surface of the second volume being lower than the upper surface of the first volume.

### Claim 13 (depends on 7)

The system of claim 7 wherein:
a mesh between the ring gear and pinion is located at an elevation that is lower than an upper surface of a volume of fluid in the sump while the reservoir is drained of fluid and the ring gear is not rotating.

### Claim 14

A system for lubricating a differential, comprising:
a housing containing a ring gear;
a pinion meshing with the ring gear;
a fluid sump;
a reservoir at a higher elevation that the sump, partially separated from the ring gear by a wall;
an orifice restricting the flow rate of fluid from the reservoir. a bearing supporting the pinion and located to receive fluid exiting the orifice.

### Claim 15 (depends on 14)

The system of claim 14 wherein an inner surface of the housing and the wall directing into the reservoir fluid flung from the ring gear as the ring gear rotates through the fluid in the sump.

### Claim 16 (depends on 14)

The system of claim 14 further comprising:
a second bearings supporting the pinion and located to receive at least a portion of the fluid exiting the orifice before the exiting fluid returns to the sump.

### Claim 17 (depends on 14)

The system of claim 14 wherein:
the sump has a volumetric capacity sufficient to retain fluid whose upper surface is at an elevation that is higher than an elevation of a mesh between the ring gear and pinion.

### Claim 18 (depends on 17)

The system of claim 17 wherein:
the sump retains a second volume of fluid while the ring gear is rotating, the upper surface of the second volume being lower than the upper surface of the first volume.

### Claim 19 (depends on 14)

The system of claim 14 wherein:
a mesh between the ring gear and pinion is located at an elevation that is lower than an upper surface of a volume of fluid in the sump while the reservoir is drained of fluid and the ring gear is not rotating.