Lubrication arrangement

• US 20090020365A1
• Filed: 09/17/2008
• Published: 01/22/2009
• Est. Priority Date: 06/25/2004
• Status: Active Grant

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: Swainson, Richard J.
• Granted Patent: US 7,971,507 B2
• Time in Patent Office: Days
• US Class Current: 184/6.120
• CPC Class Codes: F16H 1/14 comprising conical gears only
• CPC Class Codes: F16H 57/0409 characterised by the problem to increase efficiency, e.g. by reducing splash losses
• CPC Class Codes: F16H 57/0421 on or within the casing, e.g. shields or baffles for collecting lubricant, tubes, pipes, grooves, channels or the like
• CPC Class Codes: F16H 57/0434 relating to lubrication supply, e.g. pumps arrangement of pumps F16H57/0441; Pressure control grooves with pumping effect for supplying lubricant F16H57/0428; generation and variation of line pressure for transmission control F16H61/0021
• CPC Class Codes: F16H 57/0493 Gearings with spur or bevel gears differentials with spur or bevel gears F16H57/0483
• CPC Class Codes: Y10T 74/2186 Gear casings

Abstract

A lubrication arrangement for interlocking gears 2, 3 is configured by a housing 1 which incorporates sections 1a, 1b of a snail cross-section. Thus, rotating gears 2, 3 are positioned to generate a centrifugal pumping effect between those gears 2, 3 and the housing sections 1a, 1b which drives scavenged oil flow into a volute 11 formed by the opposing surface of the housing 1a, 1b. The scavenged oil is driven in the direction 13 towards an off-take 12 configured such that there is a minimum available cross-sectional area 14 between the housing at the intermeshing of the gears 2, 3 at an interlocking location 4. In such circumstances the scavenged oil is driven at relatively high speed through the off-take 12. Such relatively high speed scavenged oil 15 can be used for displacement scavenging in other parts of an engine or machine where problems exist with oil residence.

Claims

1. A lubrication arrangement for a gear combination, the arrangement comprising a housing for positioning about inter-locking gears, the housing including a scavenge off-take position substantially where the inter-locking gears come together at a mesh location and substantially tangential to the outer diameter of those inter-locking gears for scavenging oil at that mesh position.

2. An arrangement as claimed in claim 1 wherein an oil injector is positioned immediately after the mesh location.

3. An arrangement as claimed in claim 1 wherein the scavenge off-take has a maximised chordal cross-sectional area towards the centre of the interlocking gears to improve oil scavenging effect.

4. An arrangement as claimed in claim 2 wherein the oil injector is perpendicular to and directed towards the centre of the inter-locking gears.

5. An arrangement as claimed in claim 2 wherein the oil injector is positioned at a location for minimised cross-sectional area between the housing and the oil injector.

6. An arrangement as claimed in claim 1 arranged such that in use rotation of the inter-locking gears creates an oil pressure directing scavenged oil flow towards the off-take.

7. An arrangement as claimed in claim 1 wherein the inter-locking gears are bevel gears.

8. An arrangement as claimed in claim 7 wherein the bevel gears are arranged perpendicular to each other.

9. A housing for a gear combination, the housing including a scavenge off-take positioned in use relative to inter-locking gears where those inter-locking gears come together at a mesh position and substantially tangential to the outer diameter of those inter-locking gears for scavenging oil at that mesh location.

10. A housing as claimed in claim 9 wherein the housing has a spiral cross-section whereby in use variation in the available cross-sectional area between the inter-locking gears and the housing creates an effective centrifugal pump facilitating oil scavenging in use towards the scavenge off-take.