Speed regulated oil delivery system

• US 20010036413A1
• Filed: 03/28/2001
• Published: 11/01/2001
• Est. Priority Date: 03/28/2000
• Status: Abandoned Application

• Current Assignee: Hydraulic Controls, Inc.
• Original Assignee: Hydraulic Controls, Inc.
• Inventors: Solomon, Richard K., McFadden, Dan C.
• Application Number:
  US09/819,389
• Publication Number:
  US 20010036413A1
• Time in Patent Office: Days
• US Class Current: 417/286
• CPC Class Codes: E02F 9/2239 using two or more pumps with cross-assistance
• CPC Class Codes: E02F 9/226 Safety arrangements, e.g. hydraulic driven fans, preventing cavitation, leakage, overheating
• CPC Class Codes: E02F 9/2292 Systems with two or more pumps
• CPC Class Codes: F15B 11/0423 by controlling pump output or bypass, other than to maintain constant speed
• CPC Class Codes: F15B 11/17 using two or more pumps
• CPC Class Codes: F15B 2211/20538 constant capacity
• CPC Class Codes: F15B 2211/20584 Combinations of pumps with high and low capacity
• CPC Class Codes: F15B 2211/3051 Cross-check valves
• CPC Class Codes: F15B 2211/30515 Load holding valves
• CPC Class Codes: F15B 2211/30525 Directional control valves, e.g. 4/3-directional control valve
• CPC Class Codes: F15B 2211/3105 Neutral or centre positions
• CPC Class Codes: F15B 2211/3116 the pump port being open in the centre position, e.g. so-called open centre
• CPC Class Codes: F15B 2211/40507 with constant throttles or orifices
• CPC Class Codes: F15B 2211/40515 with variable throttles or orifices
• CPC Class Codes: F15B 2211/40584 the flow control means arranged in parallel with a check valve
• CPC Class Codes: F15B 2211/41509 being connected to a pressure source and a directional control valve
• CPC Class Codes: F15B 2211/426 electrically or electronically
• CPC Class Codes: F15B 2211/45 Control of bleed-off flow, e.g. control of bypass flow to the return line
• CPC Class Codes: F15B 2211/455 Control of flow in the feed line, i.e. meter-in control
• CPC Class Codes: F15B 2211/473 without restriction in the reverse direction
• CPC Class Codes: F15B 2211/50518 : using pressure relief valves
• CPC Class Codes: F15B 2211/50536 : using unloading valves controlling the supply pressure by diverting fluid to the return line
• CPC Class Codes: F15B 2211/50581 : using counterbalance valves
• CPC Class Codes: F15B 2211/5151 : being connected to a pressure source and a directional control valve
• CPC Class Codes: F15B 2211/5153 : being connected to an output member and a directional control valve
• CPC Class Codes: F15B 2211/55 : for limiting a pressure up to a maximum pressure, e.g. by using a pressure relief valve
• CPC Class Codes: F15B 2211/615 : Filtering means
• CPC Class Codes: F15B 2211/6313 : the pressure being a load pressure
• CPC Class Codes: F15B 2211/6355 : having valve means
• CPC Class Codes: F15B 2211/7053 : Double-acting output members
• CPC Class Codes: F15B 2211/7128 : the chambers being connected in parallel

Abstract

An exemplary oil delivery system comprises a dual pump system configured for reducing the buildup of pressure by unloading one or both pumps, thus reducing the buildup of heat within the hydraulic system. The dual pump system is configured for delivering oil in combination to a single hydraulic system or to two completely separate hydraulic systems. In addition, the oil delivery system can also be configured to unload one or both of the pumping sections at a pre-determined speed to again limit the flow to any existing open centered hydraulic system. As a result, the oil delivery system recirculates oil back to the reservoir and/or the inlet to the pump in the absence of a buildup of pressure, and thus an absence in the buildup of heat to conserve energy.

Claims

1. An oil delivery system configured to prevent heat buildup in a hydraulic system, said oil delivery system comprising:

a reservoir tank for the storing of a hydraulic fluid;

a dual pump system comprising a first pumping section and a second pumping section, each of said first pumping section and said second pumping section having an outlet configured for coupling to a control valve of the hydraulic system;

a pair of unloader valves comprising a first valve and a second valve, said first valve being coupled between said outlet of said first pumping section and an inlet to said dual pump system, said second valve being coupled between said outlet of said second pumping section and said reservoir tank; and

wherein said oil delivery system is configured to limit the amount of oil flow to the hydraulic system below a threshold level of oil flow by using speed regulation to determine when to recirculate the hydraulic fluid from at least one of said first pumping section and said second pumping section through at least one of said pair of unloader valves.

2. The oil delivery system of

claim 1

, wherein said oil delivery system is configured to limit the amount of oil flow to the hydraulic system below a threshold level of oil flow by determining the speed of operation for at least one of said first pumping section and said second pumping section, and then recirculating the hydraulic fluid when a threshold level of speed has been obtained by said at least one of said first pumping section and said second pumping section.

3. The oil delivery system of

claim 2

, wherein said oil delivery system is configured to recirculate the hydraulic fluid from at least one of said first pumping section and said second pumping section through at least one of said pair of unloader valves when a control valve of the hydraulic system becomes inoperable.

4. The oil delivery system of

claim 2

, wherein said oil delivery system is configured to recirculate the hydraulic fluid from at least one of said first pumping section and said second pumping section through at least one of said pair of unloader valves when said threshold level of speed is greater than 725 RPM.

5. The oil delivery system of

claim 4

, wherein said oil delivery system is configured to recirculate the hydraulic fluid from at least one of said first pumping section and said second pumping section through at least one of said pair of unloader valves when said threshold level of speed is greater than 1450 RPM.

6. The oil delivery system of

claim 2

, wherein said oil delivery system is configured to recirculate the hydraulic fluid from both said first pumping section and said second pumping section.

7. The oil delivery system of

claim 6

, wherein said oil delivery system is configured to recirculate the hydraulic fluid from said first pumping section at a first threshold level of speed and from said second pumping section at a second threshold level of speed.

8. The oil delivery system of

claim 7

, wherein said oil delivery system is configured to recirculate the hydraulic fluid from said first pumping section at a speed of at least 700 PPM and from said second pumping section at a speed of at least 1400 PPM.

9. The oil delivery system of

claim 2

, wherein said oil delivery system further comprises a control mechanism configured for sensing said speed of operation for at least one of said first pumping section and said second pumping section, and then providing at least one output control signal to said at least one of said pair of unloader valves to facilitate recirculation of the hydraulic fluid when a threshold level of speed has been obtained by said at least one of said first pumping section and said second pumping section.

10. The oil delivery system of

claim 9

, wherein said control mechanism is configured to facilitate recirculation of the hydraulic fluid at different threshold levels of speed for said first pumping section and said second pumping section.

11. The oil delivery system of

claim 9

, wherein said control mechanism comprises an electrically operated, single input, dual adjustable output driver card.

12. The oil delivery system of

claim 9

, wherein said control mechanism is configured such that said threshold level of speed can only be adjusted through software adjustment.

13. The oil delivery system of

claim 2

, wherein said dual pump system comprises a double-vane type pumping configuration.

14. The oil delivery system of

claim 2

, wherein said dual pump system comprises a pair of fixed displacement, unidirectional type pumping configurations.

15. The oil delivery system of

claim 13

, wherein said first pumping section and said second pumping section are configured to operate at different speeds at the same time and to provide oil flow to two separate hydraulic systems.

16. The oil delivery system of

claim 2

, wherein said pair of unloader valves comprise at least one of a solenoid vented relief valve and an electrically proportional relief valve.

17. The oil delivery system of

claim 2

, wherein said pair of unloader valves comprise at least one of a solenoid operated two-way valve and an electrically proportional two-way valve.

32. The oil delivery system of

claim 13

, wherein said first pumping section and said second pumping section are configured to operate at different speeds at the same time.

18. A hydraulic system for providing hydraulic power for operation of mobile equipment, the hydraulic system comprising:

a pair of control valves for providing directional control of oil flow to hydraulic cylinders used in the operation of the mobile equipment;

a reservoir tank for the storing of hydraulic oil;

a filter coupled between said pair of control valves and said reservoir tank, said filter configured for conditioning of the hydraulic oil;

a dual pump system comprising a first pumping section and a second pumping section, each of said first pumping section and said second pumping section having an outlet configured for coupling to at least one of said pair of control valves;

a pair of unloader valves comprising a first valve and a second valve, said first valve being coupled between said outlet of said first pumping section and an inlet to said dual pump system, said second valve being coupled between said outlet of said second pumping section and said reservoir tank; and

a control mechanism for controlling operation of said pair of unloader valves;

wherein said oil delivery system is configured to limit the amount of oil flow to the hydraulic system below a threshold level of oil flow by using speed regulation to determine when to recirculate the hydraulic fluid from at least one of said first pumping section and said second pumping section through at least one of said pair of unloader valves.

19. The oil delivery system of

claim 18

, wherein said oil delivery system is configured to limit the amount of oil flow to the hydraulic system below a threshold level of oil flow by using said control mechanism for determining the speed of operation for at least one of said first pumping section and said second pumping section, and then recirculating the hydraulic fluid when a threshold level of speed has been obtained by said at least one of said first pumping section and said second pumping section.

20. The oil delivery system of

claim 19

, wherein said oil delivery system is configured to recirculate the hydraulic fluid from at least one of said first pumping section and said second pumping section through at least one of said pair of valves when said threshold level of speed is greater than 1450 RPM.

21. The oil delivery system of

claim 20

, wherein said oil delivery system is configured to recirculate the hydraulic fluid from both said first pumping section and said second pumping section.

22. The oil delivery system of

claim 21

, wherein said oil delivery system is configured to recirculate the hydraulic fluid from said first pumping section at a first threshold level of speed and from said second pumping section at a second threshold level of speed.

23. The oil delivery system of

claim 19

, wherein said control mechanism is configured for sensing said speed of operation for at least one of said first pumping section and said second pumping section, and then providing at least one output control signal to said at least one of said pair of unloader valves to facilitate recirculation of the hydraulic fluid when a threshold level of speed has been obtained by said at least one of said first pumping section and said second pumping section.

24. The oil delivery system of

claim 23

, wherein said control mechanism is configured to facilitate recirculation of the hydraulic fluid at different threshold levels of speed for said first pumping section and said second pumping section.

25. The oil delivery system of

claim 19

, wherein said first pumping section and said second pumping section are configured to operate at different speeds at the same time.

26. A oil delivery system configured to minimize the overheating of a hydraulic system, said oil delivery system comprising:

a reservoir tank for the storing of a hydraulic fluid;

a dual pump system comprising a fixed-displacement type pumping configuration including a first pumping section and a second pumping section, each of said first pumping section and said second pumping section having an outlet configured for coupling to a control valve of the hydraulic system;

a pair of unloader valves comprising a first unloader valve and a unloader second valve, said first unloader valve being coupled between said outlet of said first pumping section and an inlet to said dual pump system, said second unloader valve being coupled between said outlet of said second pumping section and said reservoir tank; and

a control mechanism for controlling operation of said pair of unloader valves, said control mechanism being configured for sensing a speed of operation for at least one of said first pumping section and said second pumping section, and then for providing at least one output control signal to said at least one of said pair of unloader valves to facilitate recirculation of the hydraulic fluid when a threshold level of speed has been obtained by said at least one of said first pumping section and said second pumping section such that said oil delivery system is capable of limiting the amount of oil flow to the hydraulic system to minimizing the overheating of the hydraulic system.

27. The oil delivery system of

claim 26

, wherein said oil delivery system is configured to recirculate the hydraulic fluid from at least one of said first pumping section and said second pumping section through at least one of said pair of unloader valves when a control valve of the hydraulic system becomes inoperable.

28. The oil delivery system of

claim 26

, wherein said oil delivery system is configured to recirculate the hydraulic fluid from at least one of said first pumping section and said second pumping section through at least one of said pair of unloader valves when said threshold level of speed is greater than 1450 RPM.

29. The oil delivery system of

claim 26

, wherein said oil delivery system is configured to recirculate the hydraulic fluid from both said first pumping section and said second pumping section, with the hydraulic fluid being recirculated from said first pumping section at a first threshold level of speed and from said second pumping section at a second threshold level of speed.

30. The oil delivery system of

claim 26

, wherein said control mechanism is configured to facilitate recirculation of the hydraulic fluid at different threshold levels of speed for said first pumping section and said second pumping section.

31. The oil delivery system of

claim 30

, wherein said control mechanism is configured such that said threshold level of speed can only be adjusted through software adjustment.