Hydraulic energy storage systems
AssigneeShep Limited
InventorsHugh Ivo Frazer, William Raymond Evans, Peter Russell Martin
Life of this patent
Estimating the term…
Abstract
A hydraulic energy storage system for vehicles to provide higher efficiency, smaller package size, lower weight, unitary construction, durability and enhanced reliability while maintaining the capability to efficiently store and restore energy at high power levels.
Claims25
A hydraulic energy storage system for use in a vehicle comprising a high pressure accumulator, a first low pressure accumulator and a second low pressure accumulator in parallel, a pump/motor in fluid communication with the high pressure accumulator and with the fist and second low pressure accumulators for pumping a fluid from the first and second low pressure accumulators to the high pressure accumulator when the pump/motor is driven in a pump mode and for returning fluid to the first and second low pressure accumulators when the pump/motor is in a motor mode, said pump/motor having a case for circulating fluid therethrough, a first check valve in series between the pump/motor and the second low pressure accumulator when the pump/motor is in the motor mode for unidirectional flow of a portion of fluid from the pump/motor to the second low pressure accumulator, a cooler in fluid communication in series between the case of the pump/motor, the second low pressure accumulator, and the pump/motor, and a second check valve in series between the second low pressure accumulator and the pump/motor case for unidirectional flow of fluid from the second low pressure accumulator through pump/motor case and the cooler to the pump/motor for cooling of said portion of the fluid when the pump/motor is in the pump mode.
A hydraulic energy storage system for use in a vehicle comprising a high pressure accumulator, a first low pressure accumulator and a second low pressure accumulator in parallel, a pump/motor in fluid communication with the high pressure accumulator and with the first and second low pressure accumulators for pumping a fluid from the first and second low pressure accumulators to the high pressure accumulator when the pump/motor is driven in a pump mode and for returning fluid to the first and second low pressure accumulators when the pump/motor is in a motor mode, said pump/motor having a case for circulating fluid therethrough, a first check valve in series between the pump/motor, the pump case and a cooler for unidirectional flow of a portion of fluid from the pump/motor through the pump case and the cooler and a second check valve in series with the cooler and the second low pressure accumulator for unidirectional flow of said portion of fluid from the cooler to the second low pressure accumulator for cooling said portion of fluid when the pump/motor is in the motor mode, a third check valve in series with the second low pressure accumulator and the pump/motor and a fourth check valve in series with the cooler and the first check valve for unidirectional flow of a portion of fluid from the second low pressure accumulator to the pump/motor case and through the cooler to the pump/motor for cooling said portion of the fluid when the pump/motor is in the pump mode.
A compensated accumulator for use in a hydraulic energy storage system for use in a vehicle comprising a cylindrical housing having a longitudinal axis and having a high pressure chamber and a low pressure chamber concentric with the longitudinal axis, a high pressure piston mounted transversely in the high pressure chamber for reciprocal axial travel in the high pressure chamber and a low pressure piston mounted transversely in the low pressure chamber for reciprocal axial travel in the low pressure chamber, and at least three equispaced rods connecting the high pressure piston to the low pressure piston for maintaining the pistons perpendicular to the longitudinal axis of the cylindrical housing during reciprocal travel.
A compensated accumulator for use in a hydraulic energy storage system for use in a vehicle comprising a cylindrical housing having a longitudinal axis with a high pressure chamber and a low pressure chamber concentric with the longitudinal axis, said low pressure chamber having a gas end remote from the high pressure chamber and a fluid end adjacent the high pressure chamber, a high pressure piston slidably mounted for reciprocal axial travel in the high pressure chamber and a low pressure piston mounted for reciprocal axial travel in the low pressure chamber, at least one connecting rod for connecting the high pressure piston and the low pressure piston together, a first position sensor mounted in the low pressure chamber adjacent the low pressure end and a second position sensor mounted in the low pressure chamber adjacent the high pressure end, whereby the first and second position sensors control reciprocal travel of the low pressure piston in the low pressure chamber.
A compensated accumulator for use in a hydraulic energy storage system for use in a vehicle comprising a cylindrical housing having a longitudinal axis and having a high pressure chamber and low pressure chamber concentric with said longitudinal axis, each said high pressure chamber and said low pressure chamber having a gas end remote from each other and a fluid end adjacent each other, a high pressure piston slidably mounted for reciprocal axial travel in the high pressure chamber and a low pressure piston slidably mounted for reciprocal axial travel in the low pressure chamber, at least one connecting rod for connecting the high pressure and low pressure pistons together in axial alignment, a valve block at one end of the cylindrical housing, and a high pressure conduit communicating the high pressure fluid end to the valve block and a low pressure conduit communicating the low pressure fluid end to the valve block.
A compensated accumulator for use in hydraulic energy storage system for use in a vehicle comprising a cylindrical housing having a longitudinal axis and having a high pressure chamber and a low pressure chamber concentric with the longitudinal axis, one of said high pressure chamber and said low pressure chamber having a larger diameter than the other, a high pressure piston slidably mounted for reciprocal travel in the high pressure chamber and a low pressure piston slidably mounted for reciprocal travel in the low pressure cylinder, one of said high pressure piston and low pressure piston having a larger diameter than the other for creating a flow imbalance between the high pressure cylinder and the low pressure cylinder, a pump/motor in fluid communication with the high pressure chamber and with the low pressure chamber for pumping a fluid from the low pressure chamber to the high pressure chamber when the pump/motor is driven in a pump mode and for returning fluid to the low pressure chamber when the pump/motor is in a motor mode, said pump/motor having a case for circulating fluid therethrough, a low pressure accumulator in parallel with the low pressure chamber for receiving and discharging a portion of fluid from the high pressure or low pressure chambers due to the flow imbalance between the high pressure cylinder and the low pressure cylinder, during the pump mode or the motor mode, a cooler in fluid communication with the pump/motor casing, a first check valve in series between the pump/motor, the pump case and the cooler for unidirectional flow of a portion of fluid from the pump/motor through the pump case and the cooler and a second check valve in series with the cooler and the low pressure accumulator for unidirectional flow of said portion of fluid from the cooler to the low pressure accumulator for cooling said portion of fluid when the pump/motor is in the motor mode, a third check valve in series with the low pressure accumulator and the pump/motor and a fourth check valve in series with the cooler and the first check valve for unidirectional flow of a portion of fluid from the low pressure accumulator to the pump/motor case and through the cooler to the pump/motor for cooling a portion of the fluid when the pump/motor is in the pump mode.
A compensated accumulator for use in a hydraulic energy storage system for use in a vehicle comprising a cylindrical housing having a longitudinal axis and having a high pressure chamber and a low pressure chamber concentric with the longitudinal axis, a high pressure piston mounted transversely in the high pressure chamber for reciprocal axial travel in the high pressure chamber and a low pressure annular piston mounted transversely in the low pressure chamber for reciprocal travel in the low pressure chamber, at least three equispaced rods connecting the high pressure piston to the low pressure piston for maintaining the pistons perpendicular to the longitudinal axis of the cylindrical housing during reciprocal travel, a low pressure accumulator cylinder formed centrally in the low pressure chamber concentric with and within the low pressure annular piston, sealing means formed between the low pressure accumulator cylinder and the annular piston whereby the annular piston is in sliding engagement with the low pressure accumulator piston, a pump/motor in fluid communication with the high pressure chamber and with the low pressure chamber and the low pressure accumulator for pumping a fluid from the low pressure chamber and from the low pressure accumulator to the high pressure chamber when the pump/motor is in a pump mode and for returning fluid to the low pressure chamber and to the low pressure accumulator from the high pressure chamber when the pump/motor is in a motor mode, said pump/motor having a case for circulating fluid therethrough, a cooler in fluid communication with the pump/motor casing and the low pressure accumulator whereby the fluid flowing to and from the low pressure accumulator flows through the cooler when the pump/motor is in the pump and motor modes.
A unitized accumulator system comprising the compensated accumulator as claimed in the foregoing claims in which the cylindrical housing is incorporated with a valve block and with an overcentre-type pump/motor or non-overcentre-type pump/motor for a unitary structure for direct mounting to a vehicle final drive.
Dependencies are inferred from the claim text.