Rotary hydraulic machine and controls

• US 20070028608A1
• Filed: 08/10/2006
• Published: 02/08/2007
• Est. Priority Date: 02/11/2004
• Status: Active Grant

• Current Assignee: Concentric Rockford Inc. (Concentric AB)
• Original Assignee: Concentric Rockford Inc. (Concentric AB)
• Inventors: Kadlicko, George
• Granted Patent: US 7,992,484 B2
• Time in Patent Office: Days
• US Class Current: 60/443
• CPC Class Codes: F04B 1/324 by changing the inclination of the swash plate
• CPC Class Codes: F04B 2201/0805 Rotational speed of a rotating cylinder block
• CPC Class Codes: F04B 2201/1201 Rotational speed of the axis
• CPC Class Codes: F04B 2201/12051 Angular position
• CPC Class Codes: F04B 49/002 Hydraulic systems to change the pump delivery
• CPC Class Codes: F04B 49/08 Regulating by delivery pressure
• CPC Class Codes: F16D 31/02 using pumps with pistons or plungers working in cylinders
• CPC Class Codes: Y10S 92/02 Fluid bearing

Abstract

A variable capacity hydraulic machine has a rotating group located within a casing and a control housing secured to the casing to extend across and seal an opening in the casing. The control housing accommodates a control circuit and a pair of sensors to sense change in parameters associated with the rotating group. One of the sensors is positioned adjacent the barrel on the rotating group to sense rotational speed and the other senses displacement of the swashplate. The control housing accommodates a control valve and accumulator to supply fluid to the control valve.

Claims

1. A rotary hydraulic machine comprising a housing, a rotating group within said housing including a barrel and a plurality of pistons slideable within cylinders formed in said barrel, a swashplate operable upon said pistons to induce reciprocation thereof in respective ones of said cylinders to transfer fluid between an inlet port and an outlet port as said barrel rotates about its axis of rotation, and an actuator operable upon said swashplate to adjust the disposition thereof relative to said housing and thereby vary the stroke of said pistons in said cylinders, said swashplate having a bearing surface engagable with a complementary surface on said housing and a fluid bearing interposed between said surfaces, said fluid bearing including a pair of recesses formed between said surfaces and each extending in a direction to bridge said ports and a fluid supply to provide fluid to said recesses.

2. A rotary hydraulic machine according to claim 1 wherein said fluid bearing is supplied with fluid from one of said ports.

3. A rotary hydraulic machine according to claim 2 wherein said fluid is supplied through a pressure compensating flow control valve to maintain a predetermined flow of fluid as pressure at said port varies.

4. A rotary hydraulic machine according to claim 3 wherein said recesses are configured to provide a bearing area to balance forces imposed on said swashplate by connection of said pistons to respective ones of said ports.

5. A rotary hydraulic machine according to claim 4 wherein said recesses vary in width along their length.

6. A rotary hydraulic machine according to claim 5 wherein each recess has an enlarged head and an elongated tail.

7. A rotary hydraulic machine according to claim 6 wherein said enlarged head is aligned with said actuator to oppose forces imposed thereby.

8. A rotary hydraulic machine according to claim 7 wherein said elongate tail has a varying width with a greater width aligned with said outlet ports.

9. A rotary hydraulic machine according to claim 7 wherein a land is provided in said enlarged head.

10. A rotary hydraulic machine according to claim 6 wherein said recesses are spaced apart on opposite sides of said axis of rotation with said elongate tails extending parallel to one another.

11. A rotary hydraulic machine having a rotating group including a plurality of variable capacity chambers defined by pistons sliding within respective cylinders, said pistons being displaceable relative to said cylinders upon rotation of said group to vary the volume of said chambers and thereby induce a flow of fluid through said chambers from an inlet port to an outlet port, an adjustment assembly including an actuator operable upon said rotating group to adjust the stroke of said pistons and thereby vary the capacity of said machine, a fluid supply for said actuator and a control valve interposed between said fluid supply and said actuator to control flow to said actuator, said valve having a first position in which flow through said valve is inhibited and being movable from said first position to vary the capacity of said machine, said valve being controlled by a controller having an output to adjust said valve and receiving input signals from at least one transducer, said one transducer sending a signal representative of pressure delivered at said outlet port and said controller operating upon said actuator to maintain pressure at said outlet at a predetermined valve.

12. A rotary hydraulic machine according to claim 11 wherein a plurality of transducers provide respective inputs to said controller.

13. A rotary hydraulic machine according to claim 12 where said inputs include indications of a condition of said machine.

14. A rotary hydraulic machine according to claim 13 wherein said indications of condition of a machine include speed of rotation and capacity of said machine.

15. A rotary hydraulic machine according to claim 11 wherein supply of fluid to said control valve is provided by an accumulator interposed between said outlet port and said control valve.

16. A rotary hydraulic machine according to claim 15 wherein a check valve is provided between said outlet port and said accumulator to inhibit flow of fluid from said accumulator to said outlet port.

17. A rotary hydraulic machine according to claim 11 wherein said controller receives inputs indicative of a manual control, pressure of fluid and flow rate of fluid and implements a control algorithm using at least one of said inputs.

18. A rotary hydraulic machine according to claim 17 wherein said controller receives inputs indicative of capacity of said capacity and rotational speed of said machine.