Radial hydraulic motor for a hydraulic hybrid vehicle
OwnerCharles L. Gray, JR.inventor
Life of this patent
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Abstract
A radial hydraulic pump/motor for use in place of a mechanical transmission for a hydraulic hybrid vehicle is described. Means for disengaging and reengaging individual working pistons are provided, allowing partial or zero effective displacement. Methods for using the radial pump/motor to supplement power from other pump/motors for the vehicle are also described.
Claims20
A hydraulic machine, comprising:
- a housing;
- a power shaft, including an eccentric cam, configured to rotate about a common longitudinal axis;
- a plurality of working pistons positioned in respective cylinders, wherein the cylinders are oriented in a radial arrangement each being substantially perpendicular to the axis, and wherein each piston has a connecting rod and wherein each connecting rod has a bearing surface for slidably bearing upon a bearing surface of the eccentric cam;
- a high-speed control valve for each cylinder, configured to switchably connect the respective cylinder with a high pressure fluid source and a low pressure fluid source;
- a high pressure fluid line connecting each high-speed control valve with the high pressure fluid source;
- a low pressure fluid line connecting each high-speed control valve with the low pressure fluid source;
- a shut off valve for isolating the high pressure fluid line from the high pressure fluid source;
- and
- a pressure relieving valve on the high pressure fluid line for depressurizing fluid in the high pressure fluid line to facilitate disengagement of the connecting rod from the bearing surface.
A method for deactivating and reactivating a radial hydraulic pump/motor having a plurality of working pistons positioned in respective cylinders, each piston having a connecting rod, each connecting rod having a bearing surface for slidably bearing upon an eccentric cam, the cam being connected to and rotating with a mechanical power shaft, comprising:
- deactivating a piston by causing the respective bearing surface of the respective connecting rod to move to a position at or beyond the maximum radius of the eccentric cam;
- and
- reactivating a piston by causing the respective bearing surface of the respective connecting rod to be in contact with the cam.
A method for providing torque to a drivetrain, comprising:
- providing a first variable displacement pump/motor having a range of allowable displacements;
- providing a second pump/motor having a substantially fixed displacement larger than the maximum displacement of the first pump/motor and having a power shaft connected to the output shaft of the first pump/motor;
- determining a torque demand of the drivetrain;
- and
- apportioning the torque demand between the first pump/motor and the second pump/motor by selecting a displacement and/or state of utilization of each, wherein the first pump/motor, if utilized, is utilized at a displacement within its range of allowable displacements, and wherein the second pump/motor, if utilized, is utilized at its substantially fixed displacement.
Dependencies are inferred from the claim text.