Uninterruptible oil supply system

• US 6,463,819 B1
• Filed: 10/24/2000
• Issued: 10/15/2002
• Est. Priority Date: 10/24/2000
• Status: Expired due to Term

• Current Assignee: Pratt & Whitney Canada Corporation (Rtx Corporation)
• Original Assignee: Pratt & Whitney Canada Corporation (Rtx Corporation)
• Inventors: Rago, Giusseppe
• Primary Examiner(s): Bucci, David A.
• Assistant Examiner(s): Stefanon, Justin
• Application Number:
  US09/694,266
• Time in Patent Office: 721 Days
• Field of Search: 184/6.23, 184/6.2, 184/55.1, 184/57, 137/112, 137/115.26
• US Class Current: 184/6.2
• CPC Class Codes: B64D 37/22 facilitating emptying in any position of tank
• CPC Class Codes: F01D 25/20 using lubrication pumps
• CPC Class Codes: F01M 11/067 inverted, e.g. for inverted flight
• CPC Class Codes: F16N 17/00 Lubrication of machines or apparatus working under extreme conditions additives to lubricating oil or lubricating grease C10M
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft
• CPC Class Codes: Y10T 137/2567 Alternate or successive inflows
• CPC Class Codes: Y10T 137/2642 Sensor rigid with valve

Abstract

An oil supply system supplies oil under pressure to a bearing or journal enclosure during normal positive gravity conditions as well as negative gravity and zero gravity conditions. A closed oil storage tank containing a volume of oil below a gas filled headspace with primary drain in a bottom portion normally supplies a pressure pump which passes a pressure control valve before entering an inlet of the enclosure. In negative gravity or zero gravity conditions oil is absent from the tank bottom and the primary pressure pump is starved of oil. The invention solves this problem with an auxiliary tank outlet disposed above the bottom drain (at the top and/or sides of the tank) and the oil-air separator separates the air before pumping the oil under pressure to the bearing or journal enclosure past a directional switch. The directional control switch (1) connects the switch oil inlet to the switch oil return outlet and oil tank when oil pressure delivered by the pressure pump exceeds a predetermined minimum threshold pressure; and (2) connects the switch inlet to the oil supply outlet and enclosure when oil pressure delivered by the pressure pump is less than the threshold pressure.

Claims

1. An oil supply system for supplying oil under pressure to an enclosure, the system comprising:

a closed oil storage tank containing a volume of oil below a gas filled headspace, the tank having a primary drain in a bottom portion;

a pressure pump having;

a pump inlet communicating with the tank drain; and

a pump outlet;

an oil-air separator with;

an inlet communicating with an enclosure outlet;

an air outlet venting separated air; and

an oil outlet;

an auxiliary tank outlet disposed above the drain;

the oil-air separator having an auxiliary inlet communicating with the auxiliary tank outlet; and

a unitary valve and directional switch having;

a primary oil inlet communicating with the pressure pump outlet;

a gas pressure inlet communicating with gas within the enclosure;

an auxiliary oil inlet in communication with the oil outlet of the separator;

an oil return outlet in communication with an oil tank return inlet; and

an oil supply outlet in communication with the enclosure, the unitary valve and directional switch;

connecting the switch auxiliary oil inlet to the switch oil return outlet when oil pressure, relative to gas pressure in the enclosure, delivered by the pressure pump exceeds a predetermined minimum threshold pressure differential; and

connecting the switch auxiliary oil inlet to the oil supply outlet when oil pressure, relative to gas pressure in the enclosure, delivered by the pressure pump is less than the threshold pressure differential.

2. An oil supply system according to claim 1 wherein the auxiliary tank outlet has a location selected from the group consisting of:

a top portion of the tank;

a central portion of the tank;

a rear side portion of the tank;

a lateral side portion of the tank; and

a front side portion of the tank.

3. An oil supply system according to claim 1 wherein said unitary valve and directional switch comprises:

a unitary housing having a movable plug with a first end defining a primary oil pressure chamber, an opposing second end defining a control gas pressure chamber, and lateral surface co-acting with an interior of the housing to contain pressurised oil and control gas in said chambers;

the primary oil pressure chamber communicating with the primary oil inlet that communicates with the pressure pump outlet and with the oil supply outlet communicating with the enclosure inlet;

the plug being biased to a closed position wherein oil passage between the primary oil inlet and oil supply outlet is impeded when the difference between oil pressure within the primary oil pressure chamber and gas pressure in the control gas pressure chamber is less than said predetermined minimum threshold pressure differential, and moved to an open position when the difference between oil pressure within the primary oil pressure chamber and gas pressure in the control gas pressure chamber exceeds said predetermined minimum threshold pressure differential; and

the plug including a switch passage in said lateral surface, the switch passage communicating between the switch auxiliary oil inlet and the oil return outlet when the plug is in the open position, and communicating between the switch auxiliary oil inlet and the oil supply outlet when the plug is in the closed position.

4. An oil supply system according to claim 3 wherein the lateral surface of said plug impedes oil flow to the oil return outlet when in the closed position.

5. An oil supply system according to claim 1 wherein the the unitary valve and directional switch connects the primary oil inlet to the switch oil return outlet when oil pressure, relative to gas pressure in the enclosure, delivered by the pressure pump exceeds a predetermined maximum operating pressure differential.

6. An oil supply system according to claim 5 wherein the unitary directional switch includes a plug travel limit stop.

7. An oil supply system according to claim 1 wherein the oil pressure pump and the oil-air separator are driven by a common shaft.