A clutch, including: inner and outer races; a wedge plate; an electromagnetic actuator including a coil and an attenuating circuit. The coil is arranged to be energized by a power source to switch the wedge clutch between: a locked mode in which the inner and races are locked in a circumferential direction and a free-wheel mode in which the inner race is rotatable with respect to the outer race in the circumferential direction. The attenuating circuit includes a capacitor parallel with the coil and a switch wired to the capacitor. During the free-wheel mode: the switch is arranged to connect the capacitor to an electrical ground; and the electrical power source is arranged to energize the coil and charge the capacitor with a voltage. Following initiation of the locked mode: the switch isolates the capacitor from the electrical ground; and the capacitor discharges the voltage through the coil.

A pump is provided. The pump includes a fluid inlet section; a fluid outlet section; a stator axially between the fluid inlet section and the fluid outlet section; a rotor axially between the fluid inlet section and the fluid outlet section, the rotor and the stator defining a fluid flow space radially therebetween; a movable inlet guide configured for guiding fluid flow from the fluid inlet section into the fluid flow space; and a movable outlet guide configured for guiding fluid flow from the fluid flow space into the fluid outlet section. The rotor is rotatable inside of the stator by electromagnetic forces urging the rotor towards the stator. Rotation of the rotor inside of the stator and movement of the inlet guide and the outlet guide create a pressure in a first portion of the fluid flow space that forces fluid from the fluid flow space through the fluid outlet section and create a vacuum in a second portion of the fluid flow space that pulls fluid from the fluid inlet section into the fluid flow space. A method of forming a pump is also provided.

A pump includes a fluid inlet section; a fluid outlet section; a stator axially between the fluid inlet section and the fluid outlet section; a rotor axially between the fluid inlet section and the fluid outlet section, the rotor and the stator defining a fluid flow chamber radially therebetween, the rotor being rotatable inside of the stator by electromagnetic forces urging the rotor towards the stator; an inlet control section configured for regulating fluid flow from the fluid inlet section into the fluid flow chamber; and an outlet control section configured for regulating fluid flow from the fluid flow chamber into the fluid outlet section. The rotor, the stator, the inlet control section and the outlet control section are arranged and configured such that rotation of the rotor in the stator generates in the fluid flow chamber a first pressure portion and a second pressure portion that rotate about a center axis of the rotor. The first pressure portion has a lower pressure than the second pressure portion. The inlet control section is configured such that fluid from the fluid inlet section is forced through the inlet control section to the first pressure portion as the first pressure portion rotates about the center axis of the rotor. The outlet control section is configured such that fluid from the fluid flow chamber is forced through the outlet control section from the second pressure portion to the fluid outlet section as the second pressure portion rotates about the center axis of the rotor.

A driving power transmission device includes a fluid pressure type clutch device that transmits driving power between two shaft members, and a pump that supplies a fluid to the clutch device. The pump includes a pump that makes a pressure of sucked fluid high; a first flow passage through which the fluid according to a pressure discharged from the pump is supplied to the clutch device during a driving of the pump; a second flow passage through which the fluid discharged from the pump is held during a stop of the pump and a pressing force is applied to the clutch device by the fluid to be held; and a switching valve that is switchable between a normal mode where a discharge port of the pump communicates with the first flow passage and a locking mode where the discharge port of the pump communicates with the second flow passage.

A disc valve assembly for control of a flow of hydraulic fluid in a hydraulic fluid system may include a disc element comprising an inlet facing side and a second side opposite to the inlet facing side, and flow pathways configured as a plurality of different pressure zones with the flow pathways extending axially along a longitudinal axis of the disc element from at or adjacent to the inlet facing side to the second side. A valve housing houses the disc element and includes porting configured as part of the plurality of different pressure zones respectively in fluid communication with the flow pathways of the disc element. The disc element is configured to rotate to control a flow of hydraulic fluid through the disc valve assembly. The different pressure zones are isolated from each other using a plurality of annular sealing rings located on the inlet facing side of the disc element.

An internal-gear pump has a housing which has a first fluid port and a second fluid port. An inner rotor is mounted in the housing so as to be rotatable about an inner rotor axis and has an external toothing. An outer rotor is rotatable in the housing about an outer rotor axis and has an internal toothing which, to generate a pump action, engages with the external toothing of the inner rotor. The internal-gear pump furthermore has a ring element which is mounted movably in the housing so as to be pivotable between a first position and a second position. At least a third fluid port is formed on the housing. The third fluid port is arranged relative to the ring element such that, in the first position of the ring element, the third fluid port is connected to the second fluid port. In the second position, said third fluid port is separated from the second fluid port.

A transmission actuator for a vehicle includes a housing, a first rocker for engaging a toothed wheel, a second rocker for rotating the first rocker to engage the toothed wheel, an engagement rod for rotating the second rocker, a solenoid arranged to displace the engagement rod, and a solenoid control circuit. The solenoid includes an iron core, a wire coil wrapped around the iron core, and a ferromagnetic plunger. The plunger is arranged to linearly displace in a first direction when a first directional current is applied to the wire coil, and linearly displace in a second direction when a second directional current is applied to the wire coil. The solenoid control circuit is arranged supply the first directional current when energized by a power source, and supply a decaying alternating current that includes the first directional current and the second directional current when the solenoid control circuit is de-energized.

A driving power transmission device includes a fluid pressure type clutch device that transmits driving power between two shaft members, and a pump that supplies a fluid to the clutch device. The pump includes a pump that makes a pressure of sucked fluid high; a first flow passage through which the fluid according to a pressure discharged from the pump is supplied to the clutch device during a driving of the pump; a second flow passage through which the fluid discharged from the pump is held during a stop of the pump and a pressing force is applied to the clutch device by the fluid to be held; and a switching valve that is switchable between a normal mode where a discharge port of the pump communicates with the first flow passage and a locking mode where the discharge port of the pump communicates with the second flow passage.

A pump apparatus with a switching valve includes an actuator that is rotationally driven, a pump, a switching valve and a driving power interrupting device. The pump discharges a fluid sucked by rotational driving of the actuator. The switching valve is changed in phase by the rotational driving of the actuator so as to be switchable among a plurality of destinations of the fluid discharged from a pump chamber of the pump. The driving power interrupting device for a valve is switchable between a state where rotational driving power of the actuator is transmitted to the switching valve and a state where the rotational driving power of the actuator is interrupted.

This invention provides both a pump and a lubrication and cooling system with a pump which includes a pump housing, a rotor, a relief valve and a bypass valve. The relief valve is configured to relieve pump pressure when the pump pressure is indicative of an abnormal restriction of flow. The bypass valve is configured to direct fluid flow from an outlet chamber of the pump to an intake chamber of the pump when pressure in the outlet chamber is at a value associated with a predetermined speed of rotor rotation.