Abstract: An example hydraulic system includes a hydraulic actuator; a pump driven by an electric motor and having an inlet port and an outlet port; a boost flow line configured to provide boost fluid flow or receive excess fluid flow; a reservoir fluid line fluidly coupled to a reservoir; and a valve assembly configured to operate in a plurality of states to allow the pump to operate in a closed-circuit configuration in which fluid discharged from the hydraulic actuator is provided to the inlet port of the pump or an open-circuit configuration in which fluid discharged from the hydraulic actuator is provided to the reservoir.

Abstract: An example hydraulic system includes a hydraulic cylinder actuator comprising a cylinder and a piston, wherein the piston comprises a piston head and a rod extending from the piston head, wherein the piston head divides an internal space of the cylinder into a first chamber and a second chamber, and wherein the hydraulic cylinder actuator is unbalanced; a first pump driven by a first electric motor to provide fluid flow to the first chamber or the second chamber of the hydraulic cylinder actuator to drive the piston; a boost flow line; a hydraulic motor actuator; and a second pump driven by a second electric motor, wherein the second pump is fluidly coupled to the boost flow line to provide boost fluid flow to the hydraulic cylinder actuator.

Abstract: An example hydraulic system includes a hydraulic actuator; a pump driven by an electric motor and having an inlet port and an outlet port; a boost flow line configured to provide boost fluid flow or receive excess fluid flow; a reservoir fluid line fluidly coupled to a reservoir; and a valve assembly configured to operate in a plurality of states to allow the pump to operate in a closed-circuit configuration in which fluid discharged from the hydraulic actuator is provided to the inlet port of the pump or an open-circuit configuration in which fluid discharged from the hydraulic actuator is provided to the reservoir.

Abstract: An example hydraulic system includes a hydraulic cylinder actuator comprising a cylinder and a piston, wherein the piston comprises a piston head and a rod extending from the piston head, wherein the piston head divides an internal space of the cylinder into a first chamber and a second chamber, and wherein the hydraulic cylinder actuator is unbalanced; a first pump driven by a first electric motor to provide fluid flow to the first chamber or the second chamber of the hydraulic cylinder actuator to drive the piston; a boost flow line; a hydraulic motor actuator; and a second pump driven by a second electric motor, wherein the second pump is fluidly coupled to the boost flow line to provide boost fluid flow to the hydraulic cylinder actuator.

Abstract: A hydraulic system for recovering potential energy of a load implement of a mobile construction vehicle. The hydraulic system includes first and second actuators and control valving. The first and second actuators are configured to be coupled to the load implement for controlling raising and lowering of the load element. The control valving is operable between a first position at which, during a lowering of the load implement, the control valving directs hydraulic fluid from one of the first and second actuators to an accumulator to charge the accumulator, and a second position at which the control valving directs hydraulic fluid from the accumulator to one or more of the first and second actuators to power the one or more of the first and second actuators to raise the load element.

Abstract: A hydraulic system for recovering potential energy of a load implement of a mobile construction vehicle. The hydraulic system includes first and second actuators and control valving. The first and second actuators are configured to be coupled to the load implement for controlling raising and lowering of the load element. The control valving is operable between a first position at which, during a lowering of the load implement, the control valving directs hydraulic fluid from one of the first and second actuators to an accumulator to charge the accumulator, and a second position at which the control valving directs hydraulic fluid from the accumulator to one or more of the first and second actuators to power the one or more of the first and second actuators to raise the load element.

Abstract: A hydraulic system for recovering potential energy of a load implement of a mobile construction vehicle. The hydraulic system includes first and second actuators and control valving. The first and second actuators are configured to be coupled to the load implement for controlling raising and lowering of the load element. The control valving is operable between a first position at which, during a lowering of the load implement, the control valving directs hydraulic fluid from one of the first and second actuators to an accumulator to charge the accumulator, and a second position at which the control valving directs hydraulic fluid from the accumulator to one or more of the first and second actuators to power the one or more of the first and second actuators to raise the load element.

Abstract: A hydraulic system for recovering potential energy of a load implement of a mobile construction vehicle. The hydraulic system includes first and second actuators and control valving. The first and second actuators are configured to be coupled to the load implement for controlling raising and lowering of the load element. The control valving is operable between a first position at which, during a lowering of the load implement, the control valving directs hydraulic fluid from one of the first and second actuators to an accumulator to charge the accumulator, and a second position at which the control valving directs hydraulic fluid from the accumulator to one or more of the first and second actuators to power the one or more of the first and second actuators to raise the load element.

Abstract: A hydraulic system for recovering potential energy of a load implement of a mobile construction vehicle. The hydraulic system includes first and second actuators and control valving. The first and second actuators are configured to be coupled to the load implement for controlling raising and lowering of the load element. The control valving is operable between a first position at which, during a lowering of the load implement, the control valving directs hydraulic fluid from one of the first and second actuators to an accumulator to charge the accumulator, and a second position at which the control valving directs hydraulic fluid from the accumulator to one or more of the first and second actuators to power the one or more of the first and second actuators to raise the load element.

Abstract: A hydraulic system for recovering potential energy of a load implement of a mobile construction vehicle. The hydraulic system includes first and second actuators and control valving. The first and second actuators are configured to be coupled to the load implement for controlling raising and lowering of the load element. The control valving is operable between a first position at which, during a lowering of the load implement, the control valving directs hydraulic fluid from one of the first and second actuators to an accumulator to charge the accumulator, and a second position at which the control valving directs hydraulic fluid from the accumulator to one or more of the first and second actuators to power the one or more of the first and second actuators to raise the load element.

Abstract: A hydraulic system for recovering potential energy of a load implement of a mobile construction vehicle. The hydraulic system includes first and second actuators and control valving. The first and second actuators are configured to be coupled to the load implement for controlling raising and lowering of the load element. The control valving is operable between a first position at which, during a lowering of the load implement, the control valving directs hydraulic fluid from one of the first and second actuators to an accumulator to charge the accumulator, and a second position at which the control valving directs hydraulic fluid from the accumulator to one or more of the first and second actuators to power the one or more of the first and second actuators to raise the load element.

Abstract: A control system for a working machine that includes a power consumer (14) includes a prime mover (12), an energy storage unit (24) for storing energy, an auxiliary power unit (20) for generating power or consuming power, the auxiliary power unit (20) having a first connection (20a) coupled to the prime mover (12) and a second connection couplable to the energy storage unit (24). A controller (18) operatively coupled to the prime mover (12) and operatively couplable to the power consumer (14) is configured to estimate a required power of the power consumer (14), and to command the prime mover (14) to operate at an optimal operating point that produces the estimated required power.

Abstract: A hydraulic system for recovering potential energy of a load implement of a mobile construction vehicle. The hydraulic system includes first and second actuators and control valving. The first and second actuators are configured to be coupled to the load implement for controlling raising and lowering of the load element. The control valving is operable between a first position at which, during a lowering of the load implement, the control valving directs hydraulic fluid from one of the first and second actuators to an accumulator to charge the accumulator, and a second position at which the control valving directs hydraulic fluid from the accumulator to one or more of the first and second actuators to power the one or more of the first and second actuators to raise the load element.

Abstract: A control system for a working machine that includes a power consumer (14) includes a prime mover (12), an energy storage unit (24) for storing energy, an auxiliary power unit (20) for generating power or consuming power, the auxiliary power unit (20) having a first connection (20a) coupled to the prime mover (12) and a second connection couplable to the energy storage unit (24). A controller (18) operatively coupled to the prime mover (12) and operatively couplable to the power consumer (14) is configured to estimate a required power of the power consumer (14), and to command the prime mover (14) to operate at an optimal operating point that produces the estimated required power.

Abstract: A hydraulic hybrid vehicle 10 includes a powersplit transmission 11, a prime mover 13, a primary hydraulic pump motor unit 42, a secondary pump motor unit 43, a high pressure hydraulic accumulator 46, a planetary gear set 71, and drive wheels 15. Under certain conditions when vehicle 10 is operated at relatively higher cruising speeds, the secondary unit 43 may be hydraulically disabled by valve 55 and/or mechanically disabled by clutch 101 and/or connected to the drive wheels 15 through high gear ratio connection 101a, 101b, 79a. Also under these conditions, primary unit 42 may be oscillated or repeatedly cycled through a power additive mode in which primary unit 42 rotates in one direction to charge accumulator 46 and a power regeneration mode in which primary unit 42 rotates in the opposite direction and receives hydraulic fluid from accumulator 46.

Abstract: A compressor is provided suitable for compressing natural gas from a pressure associated with a residential gas supply to a pressure suitable for an automotive gas tank. The compressor utilizes a par of pneumatic cylinders driven by a hydraulic cylinder to compress the gas in a multi-stage process. Various embodiments are provided with respect to the gas compressor portion and the drive portion. A pressure boost system is also provided which utilizes an internal control valve and internal orifice through the piston of one of the pneumatic cylinders.

Abstract: A power split transmission includes a rotatable input shaft, a rotatable output shaft, and a planetary gear assembly connected between the input shaft and the output shaft. The transmission also includes a first hydraulic unit operable as a pump or a motor, the first hydraulic unit being coupled to the output shaft via the planetary gear assembly; a second hydraulic unit operable as a pump or a motor, the second hydraulic unit being coupled to the output shaft independently of the planetary gear assembly; and a braking mechanism coupled to the input shaft that is selectively engageable to retard rotation of the input shaft in at least one direction. The braking mechanism enables the power split transmission to use both the first hydraulic unit and the second hydraulic unit to provide enhanced torque at the output shaft without damaging a prime mover coupled to the input shaft.

Abstract: A powersplit transmission having a compact configuration that readily can be incorporated in a vehicle, particularly within the vehicle frame, includes (a) a mechanical transmission having a rotatable input shaft, a rotatable output shaft, and multiple gears for mechanically transmitting power between the input shaft and the output shaft; and (b) a hydraulic transmission containing a fluid for transmitting power between the input shaft and the output shaft. The mechanical transmission has a housing from which the input shaft and the output shaft extend. The hydraulic transmission includes first and second hydraulic units, each of which can function as a pump or a motor. The first hydraulic unit is coupled to the mechanical transmission system and the second hydraulic unit is coupled to the output shaft. The first and second hydraulic units are offset to the same side of the input shaft and the output shaft.

Abstract: A power split transmission includes a rotatable input shaft, a rotatable output shaft, and a planetary gear assembly connected between the input shaft and the output shaft. The transmission also includes a first hydraulic unit operable as a pump or a motor, the first hydraulic unit being coupled to the output shaft via the planetary gear assembly; a second hydraulic unit operable as a pump or a motor, the second hydraulic unit being coupled to the output shaft independently of the planetary gear assembly; and a braking mechanism coupled to the input shaft that is selectively engageable to retard rotation of the input shaft in at least one direction. The braking mechanism enables the power split transmission to use both the first hydraulic unit and the second hydraulic unit to provide enhanced torque at the output shaft without damaging a prime mover coupled to the input shaft.

Abstract: A powersplit transmission having a compact configuration that readily can be incorporated in a vehicle, particularly within the vehicle frame, includes (a) a mechanical transmission having a rotatable input shaft, a rotatable output shaft, and multiple gears for mechanically transmitting power between the input shaft and the output shaft; and (b) a hydraulic transmission containing a fluid for transmitting power between the input shaft and the output shaft. The mechanical transmission has a housing from which the input shaft and the output shaft extend. The hydraulic transmission includes first and second hydraulic units, each of which can function as a pump or a motor. The first hydraulic unit is coupled to the mechanical transmission system and the second hydraulic unit is coupled to the output shaft. The first and second hydraulic units are offset to the same side of the input shaft and the output shaft.