Abstract: A clutch includes a clutch assembly having radially spaced input and output members, torque transmission members therebetween, and a cage retaining the torque transmission members. Rotation of the input member relative to the output member in a first direction engages the clutch assembly while rotation of the output member relative to the input member in the first direction disengages the clutch assembly. The clutch further includes a drag assembly including a rotatable member coupled to the cage of the clutch assembly and a fixed member. The rotatable member rotates in the first direction relative to the fixed member, but rotation of the rotatable member in a second direction relative to the fixed member is limited thereby limiting rotation of the input member of the clutch assembly in the second direction.

Abstract: A power take-off includes bell housing disposed about an axis and configured for coupling to a housing of an engine or other driving device at a first axial end and to a housing of a driven device at a second axial end. The bell housing defines an air inlet port and an air outlet port between the first and second axial ends. A clutch is disposed within the bell housing and configured to transfer torque from an input member coupled to the engine to an output member coupled to the driven device. A fan is configured for rotation with the input member to draw air into the bell housing through the air inlet port, move air through the bell housing from the air inlet port to the air outlet port in a substantially radial direction across the clutch and exhaust air from the bell housing through the air outlet port.

Abstract: A brake and method of assembly are provided. The brake includes a friction plate configured for coupling to a rotatable body for rotation with the rotatable body about an axis of rotation, a pressure plate disposed about the axis on a first side of the friction plate and fixed against rotation, and an armature plate disposed about the axis on a second side of the friction plate. An electromagnet is disposed about the axis on an opposite side of the armature plate relative to the friction plate. A spring biases the armature plate in a first axial direction towards the friction plate and away from the electromagnet to engage the brake. A fastener couples the pressure plate to the electromagnet. The fastener conforms to a space between opposed surfaces of the pressure plate and the electromagnet and, upon hardening, bonds the pressure plate to the electromagnet.

Abstract: A brake and method of assembly are provided. The brake includes a friction plate configured for coupling to a rotatable body for rotation with the rotatable body about an axis of rotation, a pressure plate disposed about the axis on a first side of the friction plate and fixed against rotation, and an armature plate disposed about the axis on a second side of the friction plate. An electromagnet is disposed about the axis on an opposite side of the armature plate relative to the friction plate. A spring biases the armature plate in a first axial direction towards the friction plate and away from the electromagnet to engage the brake. A fastener couples the pressure plate to the electromagnet. The fastener conforms to a space between opposed surfaces of the pressure plate and the electromagnet and, upon hardening, bonds the pressure plate to the electromagnet.

Abstract: A rotational coupling includes a rotor configured for rotation about a rotational axis. The rotor includes a hub disposed about the axis and configured to receive a shaft and a disc extending radially outwardly from the hub. An armature and electromagnet are disposed on opposite axial sides of the disc. The electromagnet is fixed against rotation. A bearing is disposed between the hub and the electromagnet. The hub and electromagnet engage the inner and outer races, respectively of the bearing on opposite axial sides of the bearing. A spacer is disposed radially inwardly of the electromagnet and engages the inner race of the bearing on the same axial side of the bearing as the electromagnet. An air gap separates the spacer from the electromagnet. A shield is supported by the spacer and extends radially outwardly therefrom such that a portion of the shield is axially aligned with the air gap.

Abstract: A rotational coupling device includes an armature configured for coupling to a shaft for rotation with the shaft about an axis, but axially movable relative to the shaft. An electromagnet assembly is disposed on one side of the armature and fixed against rotation. A collar is disposed on the opposite side of the armature. The collar is configured for rotation with the shaft, but fixed against axial movement relative to the shaft and includes a permanent magnet. When a current having a first polarity is provided to the electromagnet assembly, the armature moves in one axial direction into engagement with a member of the coupling device to transmit a torque between the member and the armature. The permanent magnet urges the armature in the opposite axial direction to disengage the armature from the member when the current is not provided to the electromagnet assembly.

Abstract: A fluid pump for a linear actuator causes a rod in the actuator to extend or retract by controlling fluid flow to and from portions of a fluid chamber on either side of a piston disposed within the fluid chamber and supporting the rod. The pump includes check valves that control fluid flow between a driven pump element and each portion of the fluid chamber and a shuttle movable in response to fluid pressure along a shuttle axis extending through the valves. At least one valve includes a valve member movable between a closed position and an open position defining a fluid flow path between the driven pump element and fluid chamber and means for limiting movement of the shuttle towards the valve such that the shuttle may, depending on the position of the limiting means, move the valve member to an intermediate position between the closed and open positions.

Abstract: An electromagnetic brake is provided in which short duration current pulses move the brake between engaged and disengaged states. A first current pulse having a first polarity is delivered to a conductor within a field shell when the brake is engaged and establishes an electromagnetic circuit including the field shell and an armature plate that urges the armature plate away from a rotating friction plate and towards the field shell to disengage the brake. A magnetic circuit is maintained after termination of the first current pulse due to a remanence in at least one of the armature plate and the field shell. A second current pulse having a second polarity opposite the first polarity delivered to the conductor when the brake is disengaged weakens the magnetic circuit thereby allowing a spring to move the armature plate away from the field shell and towards the friction plate to engage the brake.

Abstract: A clutch includes inner and outer races, each with pluralities of teeth. A pawl is supported on the inner race and a shift ring disposed outward of the pawl defines pawl engagement surfaces on an inner perimeter. Pins engage cam surfaces formed in the ring and outer race. When the inner race rotates faster than the outer race, the pawl engages the ring causing relative movement between the ring and outer race that moves the pins radially inward along the cam surfaces to locate the pins between corresponding teeth on the races and rotatably couple the races. When the outer race rotates faster than the inner race, the ring moves relative to the outer race and the pins move radially outward along the cam surfaces away from the corresponding teeth to uncouple the races, disengage the ring from the pawl and allow the outer race to overrun the inner race.

Abstract: A rotational coupling device includes a rotor configured for rotation about a rotational axis, a brake plate disposed on a first axial side of the rotor, an armature disposed on a second axial side of the rotor opposite the brake plate, and an electromagnet disposed on one axial side of the armature opposite the rotor and the brake plate. A spacer is disposed axially between the brake plate and the electromagnet and radially outwardly of the rotor and the armature. A seal is supported on a radially inner surface of the spacer radially outward of the armature and seals the interface between armature and electromagnet.

Abstract: A fluid pump for a linear actuator is provided. The pump causes a rod in the actuator to extend or retract by controlling the flow of fluid to and from portions of a fluid chamber on either side of a piston disposed within the fluid chamber and supporting the rod. The pump includes a valve structure that enables the pump to redistribute fluid obtained from one portion of the fluid chamber on one side of the piston to the other portion of the fluid chamber on the other side of the piston without first returning the fluid to a fluid reservoir thereby increasing the efficiency of the pump.

Abstract: A brake is provided that employs an electromagnetic or magnetic circuit to disengage the brake and in which a reed switch is used to indicate an operating condition of the brake. The reed switch is positioned across an air gap between two members of the electromagnetic or magnetic circuit. The reed switch is oriented such that a longitudinal axis of the reed switch extends in a direction other than parallel to one or both of (i) the axis of rotation for rotating components of the brake and (ii) a direction of a magnetic force at a point in the air gap where the magnetic force is greatest.

Abstract: An electromagnetic brake includes a hub disposed about a shaft and configured for rotation with the shaft about a rotational axis. An electromagnet assembly is fixed against rotation about the axis and includes a housing defining axially extending, radially spaced inner and outer poles and a brake plate extending radially therebetween. A conductor is disposed between the poles on one side of the brake plate. An armature is disposed on the other side of the brake plate and coupled to a body driven by the shaft. The electromagnet assembly, armature and hub form an electromagnetic circuit when the conductor is energized urging the armature towards the brake plate. A portion of the magnetic flux in the circuit travels radially inwardly across a first radial air gap from the inner pole to the hub and then radially outwardly across a second radial air gap from the hub to the brake plate.

Abstract: A rotational coupling device drives an output synchronous with either of two inputs. The device includes a hub disposed about an axis and an output member supported on the hub for rotation about the axis. First and second input members disposed about the hub are configured to rotate in first and second rotational directions and at first and second speeds, respectively, with at least one of the directions and speeds differing. A clutch member is disposed axially between the input members and coupled to the output member. An electromagnet is on an opposite side of the second input member relative to the clutch member. When the electromagnet is deenergized, the clutch member engages the first input member and the output member rotates with the first input member. When the electromagnet is energized, the clutch member engages the second input member and the output member rotates with the second input member.

Abstract: A rotational coupling includes a coupling disc configured to be disposed about a shaft having a rotational axis. An electromagnet assembly on one side of the coupling disc includes a housing and a conductor within the housing. An armature is disposed on an opposite side of the coupling disc opposite the conductor and the coupling disc, electromagnet assembly and armature form an electromagnetic circuit when current is supplied to the conductor to urge the armature towards engagement with the coupling disc. An anti-rotation mechanism for the electromagnet assembly includes one or more coupling permanent magnets and one or more fixed permanent magnets configured to be mounted to an outer surface of the housing of the electromagnet assembly and a fixed support structure, respectively. The coupling and fixed permanent magnets are arranged to inhibit movement of the coupling permanent magnets and electromagnet assembly in either rotational direction about the rotational axis.

Abstract: A fluid pump for a linear actuator is provided. The pump causes a rod in the actuator to extend or retract by controlling the flow of fluid to and from portions of a fluid chamber on either side of a piston disposed within the fluid chamber and supporting the rod. The pump includes a valve structure that enables the pump to redistribute fluid obtained from one portion of the fluid chamber on one side of the piston to the other portion of the fluid chamber on the other side of the piston without first returning the fluid to a fluid reservoir thereby increasing the efficiency of the pump.

Abstract: An overrunning clutch is provided having inner and outer members disposed about a rotational axis with the outer member radially outward of the inner member. The clutch further includes a plurality of pins projecting from one of a radially inner surface of the outer member and a radially outer surface of the inner member. The clutch further includes one or more pawls coupled to one of the inner and outer members. Each of the pawls is movable between an engagement position wherein the pawl is engaged with one of the pins to transmit torque between the inner and outer members and a disengagement position wherein the pawl is disengaged from the pin to permit relative rotation of the inner and outer members. In one embodiment, different pawls assume their respective engagement position depending on the rotational direction of the one member.

Abstract: A liquid cooled brake is provided having an improved housing that provides strong yet lightweight structural support. The brake includes end plates disposed about a driven shaft and axially spaced from one another. A plurality of axially extending pins connect the end plates. A friction plate is coupled to the driven shaft for rotation therewith and is axially movable relative to the driven shaft. Another friction plate defines a fluid jacket and is coupled to the pins. The friction plate is fixed against rotation, but axially movable, relative to the pins. A pressure plate is configured for selective movement towards the friction plates. Support columns are disposed radially outwardly of each pin and fixed to the end plates The support columns prevent undue strain on the pins. Ventilated guards may also be located between each pair of columns to limit access to internal working components of the brake.

Abstract: A bi-directional clutch is provided having inner and outer members disposed about a rotational axis. One or more pawls are coupled to one of the members and configured for rotation about separate rotational axes. One end of each pawl moves between first and second engagement positions with corresponding engagement surfaces formed in the other member and a position of disengagement with the other member permitting relative rotation of the inner and outer members. A pair of magnets are disposed at the opposite end of each pawl with each magnet in the pair defining a pole adjacent the end of the pawl and the poles having opposite polarity. An electromagnetic actuator selectively generates electromagnetic fields of different polarities to urge the pawls away from the position of disengagement to one of the engagement positions to cause rotation of the other member in either rotational direction.

Abstract: A rotational coupling device is provided with an integrated rotor and brake disc to simplify design of the device and remove liquids from the device when used in a wet environment. The rotor is configured for rotation about a rotating hub and includes a first member defining one pole of the rotor and a second member defining a second pole of the rotor and a braking surface. The second member is coupled to the first member, but axially movable relative to the first member. During clutch engagement, an electromagnetic circuit used to engage the clutch urges the second member into engagement with the first member for rotation. When the clutch is disengaged, the second member disengages from the first member to create a fluid flow path between the members and engages a brake plate to halt rotation of the rotor.