Abstract: A brushless electrical machine has at least one phase winding which produces torque to drive a load. The control system for the machine is able to vary the flux and current supplied to a phase so as to vary the torque output as a function of the rotor position. The energization is reduced at particular angles to produce a dip in the torque profile, thus ensuring that, if the drive stalls, it does so at a predetermined position, for example where the losses in the drive are minimized.

Abstract: A system for cooling an electrical machine is disclosed. The electrical machine includes a rotor, a stator, and at least one cooling pathway extending through the stator. During operation of the electrical machine, fluid flows through the pathway and carries away heat generated by the electrical machine.

Abstract: A brushless electrical machine has at least one phase winding which produces torque to drive a load. The control system for the machine is able to vary the flux and current supplied to a phase so as to vary the torque output as a function of the rotor position. The energisation is reduced at particular angles to produce a dip in the torque profile, thus ensuring that, if the drive stalls, it does so at a predetermined position, for example where the losses in the drive are minimised.

Abstract: A system for cooling an electrical machine is disclosed. The electrical machine includes a rotor, a stator, and at least one cooling pathway extending through the stator. During operation of the electrical machine, fluid flows through the pathway and carries away heat generated by the electrical machine.

Abstract: A method and system for controlling a vehicle comprises a torque detector for detecting a first torque level and a second torque level applied to at least one wheel of the vehicle. The first torque level is associated with a lower boom position of a boom. An accelerometer detects an acceleration level of the boom during or after raising of the boom. A first hydraulic cylinder is capable of raising a boom from the lower boom position to raise an available torque from the first torque level. A second hydraulic cylinder is adapted to upwardly rotate or curl a bucket associated with the vehicle if the detected acceleration level of the boom is less than a minimum level during an attempt to raise the boom.

Abstract: A method and system for controlling a vehicle comprises a torque detector for detecting a first torque level and a second torque level applied to at least one wheel of the vehicle. The first torque level is associated with a lower boom position of a boom and a second torque level is associated with an elevated boom position higher than the lower boom position. A first hydraulic cylinder is capable of raising a boom from the lower boom position to raise an available torque from the first torque level. A second hydraulic cylinder is adapted to upwardly rotate or curl a bucket associated with the vehicle when the detected second torque level meets or exceeds a second torque threshold, for example.

Abstract: A system for cooling an electrical machine is disclosed. The electrical machine includes a rotor, a stator, and at least one cooling tube extending through the stator. During operation of the electrical machine, fluid flows through the tube and carries away heat generated by the electrical machine.

Abstract: A method and system for controlling a vehicle comprises a torque detector for detecting a first torque level and a second torque level applied to at least one wheel of the vehicle. The first torque level is associated with a lower boom position of a boom. An accelerometer detects an acceleration level of the boom during or after raising of the boom. A first hydraulic cylinder is capable of raising a boom from the lower boom position to raise an available torque from the first torque level. A second hydraulic cylinder is adapted to upwardly rotate or curl a bucket associated with the vehicle if the detected acceleration level of the boom is less than a minimum level during an attempt to raise the boom.

Abstract: A method and system for controlling a vehicle comprises a torque detector for detecting a first torque level and a second torque level applied to at least one wheel of the vehicle. The first torque level is associated with a lower boom position of a boom and a second torque level is associated with an elevated boom position higher than the lower boom position. A first hydraulic cylinder is capable of raising a boom from the lower boom position to raise an available torque from the first torque level. A second hydraulic cylinder is adapted to upwardly rotate or curl a bucket associated with the vehicle when the detected second torque level meets or exceeds a second torque threshold, for example.

Abstract: This invention concerns a bulldozer blade having a blade tilt function effected by independently functioning lift cylinders thereby eliminating separate tilt hardware and controls.

Abstract: A vehicle is disclosed having a hydraulic system. The hydraulic system includes a steering input and a feedback to the steering input. In another aspect of the disclosure, an adjustable gain is provided between steering inputs to the system and the steering output from the system.

Abstract: A closed circuit hydraulic system includes a fluid reservoir, a hydraulic cylinder having a cylinder rod, a bidirectional variable displacement hydraulic pump that pumps fluid to either extend or retract the cylinder rod on demand, a flow control valve for relieving pressure between the variable displacement hydraulic pump and the cylinder, and a low pressure check valve between the variable displacement hydraulic pump and the fluid reservoir. Also included is a charge pump for charging the variable displacement hydraulic pump and an accumulator for saving extra energy and fluid from the hydraulic cylinder during the retraction of an extended cylinder rod and using that fluid and energy during the extension of the hydraulic cylinder to reduce a load on the charge pump. The flow control valve opens on demand to allow floating. The low pressure check valve opens when pressure at an inlet of the variable displacement hydraulic pump is low to provide additional fluid and pressure so as to avoid cavitation.

Abstract: Hydraulic circuits used to manipulate tools in, for example construction equipment, uses less power for a retraction of a hydraulic cylinder than for an extension of that cylinder. Provided is a hydraulic circuit that uses the stored energy from the low energy phase to lower the energy load on the hydraulic pump during the high energy phase. Energy from the hydraulic pump is increased during the low energy phase to increase the amount of stored hydraulic energy. The increased amount of stored energy is then used to intensify or add to the energy generated by the hydraulic pump for the high energy phase.

Abstract: A spool-type hydraulic directional control valve having improvements to reduce cavitation when the spool is in the float position. The flow area of a first passageway on the valve spool is appropriately sized to reduce the flow hydraulic fluid flow from the head end of the hydraulic cylinder to the hydraulic fluid reservoir, such that a sufficient proportion of that hydraulic fluid instead flows internally through control valve and back to the rod end of the hydraulic cylinder to reduce cavitation when the valve spool is in the “float” position. Additionally, a second passageway on the valve spool may be blocked-off, eliminating the hydraulic fluid flow path from the hydraulic fluid reservoir to the rod end of the hydraulic cylinder when the valve spool is in the “float” position.

Abstract: A magnetorheological fluid brake utilizing a positive displacement fluid pump adapted to pump a magnetorheological fluid through a viscosity regulator. The viscosity regulator is adapted to controllably vary the viscosity of the magnetorheological fluid, altering the pumping restriction against the fluid pump, resulting in variable resistance to pump shaft rotation relative to the pump housing. An electronic steering system for a work vehicle utilizing the illustrated magnetorheological brake as a resistance device to provide tactile feedback as a function of steering shaft rotational position.

Abstract: A magnetorheological fluid brake utilizing a positive displacement fluid pump adapted to pump a magnetorheological fluid through a viscosity regulator. The viscosity regulator is adapted to controllably vary the viscosity of the magnetorheological fluid, altering the pumping restriction against the fluid pump, resulting in variable resistance to pump shaft rotation relative to the pump housing. An electronic steering system for a work vehicle utilizing the illustrated magnetorheological brake as a resistance device to provide tactile feedback as a function of steering shaft rotational position.