Variable displacement vane pump with variable target regulator

• US 6,790,013 B2
• Filed: 07/10/2002
• Issued: 09/14/2004
• Est. Priority Date: 12/12/2000
• Status: Expired due to Fees

• Current Assignee: SLW Automotive, Inc.
• Original Assignee: BorgWarner Incorporated
• Inventors: Hunter, Douglas G., Niemiec, Albin J.
• Primary Examiner(s): Yu, Justine R.
• Assistant Examiner(s): Sayoc, Emmanuel
• Application Number:
  US10/192,578
• Publication Number:
  US 20030031567A1
• Time in Patent Office: 797 Days
• Field of Search: 417/220, 417/221, 417/216, 417/205, 417/212, 417/213, 417/202, 417/203, 184/6.16, 418/30
• US Class Current: 417/220
• CPC Class Codes: F01C 21/0836 comprising guiding means, e.g. cams, rollers
• CPC Class Codes: F01C 21/0863 the fluid being the working fluid
• CPC Class Codes: F04C 14/226 by pivoting the cam around an eccentric axis
• CPC Class Codes: F04C 14/26 using bypass channels

Abstract

A variable displacement vane-type fluid pump is provided which permits improved regulation of the pump discharge such that the pump can meet the various requirements of lubrication for internal combustion engines at all speeds with minimized use of power. Of course, the vane pump may also be utilized in a wide range of power transmission and other fluid distribution applications. The vane pump of the invention may also use both hydrostatic and mechanical actuators to control the position of its containment ring or eccentric ring and hence, regulate the output of the pump. According to yet another aspect of the present invention, to prevent inlet flow restriction or cavitation, a valve may be provided to permit some of the pump outlet or discharge flow to bleed into the pump inlet to provide needed velocity energy to the fluid flow into the pump inlet. A system for lubrication of an engine using a fixed displacement pump for providing an engine speed input for controlling a second main variable displacement type oil pump and maintaining a target oil pressure in the oil pressure circuit.

Claims

1. A lubricant pumping system for providing lubrication of an apparatus having a variable speed rotating shaft and an oil pressure circuit comprising:

a first pump having a variable displacement capability which is variably adjustable in response to a control input; and

a second fixed displacement pump operably connected to said variable speed rotating shaft, an output said second pump providing an actuation signal proportional to the speed of said variable speed rotating shaft, for varying the displacement of said first pump in response to the speed of said variable speed rotating shaft;

wherein a portion of the output of said second pump is operable to be directed to an intake of said first pump for supercharging an input flow;

wherein a portion of an output of said second pump is operable to be directed to a discharge of said first pump;

wherein a portion of said output of said second pump is operable to be directed to an oil sump.

2. The lubricant pumping system of claim 1 wherein said first pump and said second pump are both powered by said variable speed rotating shaft.

3. The lubricant pumping system of claim 1 wherein said first pump is a variable displacement vane pump with an eccentric ring for varying the displacement thereof in response to said control input.

4. The lubricant pumping system of claim 3 wherein said output of said second pump has a calibrated flow resistance for providing a calibrated pressure signal indicative of the pump drive speed as said control input.

5. The lubricant pumping system of claim 4 wherein a control piston is positioned in a bore, said control piston being located on a first side by a pressure from said control input and on a second side by a grounded spring, the position in said bore acting as a reference for a regulation system to provide a predetermined regulation target pressure in said oil pressure circuit.

6. The lubricant pumping system of claim 5 wherein a multifunctional valve provides for varying the displacement of said first pump by directing pressurized fluid to an on-stroke or de-stroke side of said first pump in response to said control piston acting on said valve in a first direction, and a pressure input from said oil pressure circuit acting on said valve in a second direction.

7. The lubricant pumping system of claim 6 wherein said multifunctional valve is a spool type valve having a biasing spring connected between said control piston and said spool valve, said control piston compressing said biasing spring and biasing said spool valve for providing a target position in response to a control input from said second pump, said spool valve having passages for directing a control flow of fluid to said first pump, a control pressure from said oil pressure circuit acting on said spool valve against said biasing spring for seeking said predetermined target pressure.

8. The lubricant pumping system of claim 7 wherein said first pump includes an actuatable eccentric ring for varying the displacement of said first pump, wherein the control flow of fluid acts directly on said eccentric ring for moving said eccentric ring in either an on-stroke or de-stroke control path depending on the target set by the position of said control piston and said biasing spring.

9. The lubricant pumping system of claim 7 wherein a pair of hydraulic pistons actuate said eccentric ring and wherein said multifunctional valve provides input through said pistons to move said eccentric ring for increasing or decreasing the displacement thereof in response to changing target inputs from said second pump and said oil circuit pressure moving said multi-functional valve for seeking the target set by said second pump.

10. The lubricant pumping system of claim 8 wherein said eccentric ring is biased toward movement toward maximum displacement by a spring which is overcome by actuation flow from said multi-functional valve for controlling displacement of said first pump.

11. The lubricant pumping system of claim 5 wherein a pre-load spring is provided for pre-biasing said control piston to provide a higher targeting pressure during initial engine start-up.

12. The lubricant pumping system of claim 5 further comprising a biasing spring connected to said control piston and being compressed against a control actuator, the position of said control piston creating a position reference for creating a target to which the displacement of said first pump is regulated.

13. The lubricant pump system of claim 12 wherein said control actuator is a control piston contacting said eccentric ring and a control pressure from said oil pressure circuit acts against said control piston from an opposite side of said eccentric ring.

14. The lubricant pumping system of claim 7 wherein said control flow to said control actuator is from a discharge line of said first pump.

15. The lubricant pumping system of claim 14 wherein a pressure regulating valve regulates the pressure of said discharge line used for control of said control actuator.

16. A lubricant pumping system for providing lubrication of an apparatus having a variable speed rotating shaft and an oil pressure circuit comprising:

a first pump having a variable displacement capability which is variably adjustable in response to a control input; and

a second fixed displacement pump operably connected to said variable speed rotating shaft, an output of said second pump providing an actuation signal characteristic of a speed of said variable speed rotating shaft for varying the displacement of said first pump in response to the speed of said variable speed rotating shaft;

wherein said first pump is a variable displacement vane pump with an eccentric ring for varying the displacement thereof in response to said control input;

wherein said output of said second pump has a calibrated fixed flow orifice for providing a calibrated pressure signal proportional to the second pump drive speed as said control input.

17. The lubricant pumping system of claim 16 wherein said first pump and said second pump are powered by the same rotating shaft.

18. The lubricant pumping system of claim 16 wherein a control piston is positioned in a bore, said control piston being located on a first side by a pressure from the said control input and on a second side by a grounded spring, the position in the bore acting as a reference for the regulation system to provide a predetermined regulation target pressure in the oil pressure circuit.

19. The lubricant pumping system of claim 18 wherein a multifunctional valve provides for varying the displacement of the second pump by directing pressurized fluid to an on-stroke or de-stroke side of the first pump in response to said control piston acting on said valve in a first direction, and a pressure input from the engine oil circuit acting on said valve in a second direction.

20. The lubricant pumping system of claim 19 wherein the multifunctional valve is a spool type valve having a biasing spring connected between said control piston and said spool valve, said control piston compressing the spring and biasing the spool valve for providing a target position in response to a control input from the second pump, said spool valve having passages for directing a control flow of fluid to the variable displacement pump, a control pressure from an engine oil pressure circuit acting on said spool valve against said biasing spring for seeking a predetermined target pressure.

21. The lubricant pumping system of claim 20 wherein said first pump is a variable displacement vane pump which includes an actuatable eccentric ring for varying the displacement of said first pump, wherein the control flow of fluid acts directly on said eccentric ring for moving said eccentric ring in either an on-stroke or de-stroke control path depending on the target set by the position of said control piston and said biasing spring.

22. The lubricant pumping system of claim 20 wherein a pair of hydraulic pistons actuate the ring and wherein said multifunctional valve provides input through the pistons to move the eccentric ring for increasing or decreasing the displacement thereof in response to changing target inputs from said fixed displacement pump and said oil circuit pressure moving the multi-functional valve for seeking the target set by said fixed displacement pump.

23. The lubricant pumping system of claim 21 wherein the eccentric ring is biased toward movement toward maximum displacement by a spring which is overcome by actuation flow from said multi-functional valve for controlling displacement of said first pump.

24. The lubricant pumping system of claim 18 wherein a pre-load spring is provided for pre-biasing the control piston to provide a higher targeting pressure during initial engine start-up.

25. The lubricant pumping system of claim 18 further comprising a biasing spring connected to said control piston and being compressed against a control actuator, the position of said piston creating a position reference for creating a target to which the displacement of said second pump is regulated.

26. The lubricant pump system of claim 25 wherein said control actuator is a control piston contacting said eccentric ring and a control pressure from the engine oil circuit acts against said control piston from an opposite side of said eccentric ring.

27. The lubricant pumping system of claim 20 wherein said control flow to said control actuator is from a discharge line of said first pump.

28. The lubricant pumping system of claim 21 wherein a pressure regulating valve regulates the pressure of said discharge line used for control of said control actuator.

29. The lubricant pumping system of claim 16 wherein a portion of the output of said second pump is directed to an intake of the first pump for supercharging the input flow.

30. The lubricant pumping system of claim 16 wherein a portion of the output of said second pump is directed to the discharge of said first pump.

31. The lubricant pumping system of claim 16 wherein a portion of the output of said second pump is directed to an oil sump.