Abstract: An apparatus for use with a centrifugal clutch having a drum with a threaded opening. The apparatus includes an output hub having first and second ends, where the first end has threads for engaging the threaded opening of the drum. The hub has a longitudinal axis. The apparatus also includes a sprocket associated with the second end of the hub where the sprocket has a sprocket plane generally perpendicular to the longitudinal axis of the hub. The apparatus includes a ball bearing assembly disposed in an interior surface of the hub where the ball bearing has a bearing plane substantially aligned with the sprocket plane. The apparatus also includes at least one retaining member disposed on one side of the ball bearing assembly to secure the ball bearing assembly along the interior surface of the hub.

Abstract: A magnetic coupling assembly has a supporting base, a first disk, a second disk and two piezoelectric actuators. The piezoelectric actuators are mounted between the supporting base and the first disk to drive the first disk to move along an axial direction of the supporting base and to adjust the air gap between the first and second disks. Each piezoelectric actuator has a housing, a pushing arm and at least one piezoelectric block. The pushing arm is mounted slidably in and extends out of the housing along a longitudinal direction parallel with the axial direction of the supporting base and has an end securely connected with the first disk. The at least one piezoelectric block is mounted in the housing and is attached to the pushing arm to push the pushing arm to move along the longitudinal direction.

Abstract: A clutch for selective transmission of torque and power, utilizing pairs of coded arrays of permanent magnets affixed respectively to the driving member and the driven member. A shape memory alloy actuator brings to driving member and the driven member into proximity to engage the clutch via a higher-order mutual magnetic correspondence between the coded magnetic regions of the permanent magnet arrays. Also provided is a clutch having a magnetorheological fluid between the driving member and the driven member, to increase the torque and power transfer through the fluid when its viscosity is increased by the magnetic field of the arrays in proximity. Sets of corresponding teeth on the driving member and driven member mesh when the rotation of the members is synchronized, providing positive direct drive to prolong the service life of the fluid.

Abstract: A rotational coupling device for use as a clutch, a brake, or a combination clutch and brake is provided having structure to compensate for wear on braking surfaces. The device includes an armature coupled to an output member and movable between positions of engagement with a rotor and a brake plate. The brake plate is coupled to a stationary field shell that houses a conductor on one side of the rotor opposite the armature and brake plate. The brake plate is axially spaced from the field shell and a removable shim or adjustable spacer is disposed between the brake plate and the field shell. Removal of the shim or adjustment of the spacer permit movement of the brake plate towards the field shell to compensate for wear in any of the clutch or brake engagement surfaces of the device.

Abstract: A rotational coupling device for use as a clutch, a brake, or a combination clutch and brake is provided having structure to compensate for wear on braking surfaces. The device includes an armature coupled to an output member and movable between positions of engagement with a rotor and a brake plate. The brake plate is coupled to a stationary field shell that houses a conductor on one side of the rotor opposite the armature and brake plate. The brake plate is axially spaced from the field shell and a removable shim or adjustable spacer is disposed between the brake plate and the field shell. Removal of the shim or adjustment of the spacer permit movement of the brake plate towards the field shell to compensate for wear in any of the clutch or brake engagement surfaces of the device.

Abstract: A tuning method for the exciting current-transmission torque characteristic of a power transmission apparatus is provided. A yoke (36), which supports an electromagnet (33), is accommodated in a groove (53) and is apart from the groove by a first distance (L2) and a second distance (L4). The exciting current-transmission torque characteristic is tuned by varying the first distance while keeping the second distance fixed. When the first distance is varied, the variation of the magnetoresistance of a magnetic path is relatively small. Therefore, the exciting current-transmission torque characteristic is more accurately tuned.

Abstract: The continuously variable electromagnetic transmission comprises a commutator-less, axial flux dynamoelectric machine (3) provided with an input shaft (2) and an output shaft (4), and means (20) for controlling and supplying electric power at a variable frequency to said machine. The dynamoelectric machine comprises a stator (16), a first rotor (12) which is connected to the input shaft, and a second rotor (15) which is connected to the output shaft and arranged in such a way that it can interact with the first rotor and the stator, whereby the two rotors and the stator are formed by discoid elements. The transmission comprises means for axially displacing at least one of the discoid elements in order to modify the width of the axial air gap between said element and an adjacent discoid element, whereby the magnetic field can be regulated by variations in said gap and the two rotors can be mechanically coupled to each other.

Abstract: An adjustable coupler has a group of magnet rotors with permanent magnets separated by air gaps from non-ferrous conductor rotors presented by a group of conductor rotors. One of the rotors is mounted to its shaft via a slidable hub. The hub and the rotor attached thereto rotate with the shaft, but are movable lengthwise along the shaft. The air gaps are adjusted by axial movement of the hub and one of the groups relative to the other to vary the slip of the coupler and control the load speed under varying load conditions.

Abstract: A safety clutch for an electric hand-held tool and including a rotor (8), an anchor disc (9) frictionally engageable with the rotor (8) for transmitting a torque there-between, a stationary axial stop (13) for limiting the air gap (s) between the rotor and the anchor disc and engageable by the anchor disc under an axial reserved pre-stress applied to the anchor disc (g); and a stationary electromagnetic coil (11) provided on a side of the rotor (8) remote from the anchor disc (9) and coaxial with the rotor (8) for generating a rotationally symmetrical magnetic flux (&phgr;) for attracting of the anchor disc (g) to magnetic poles (12a, 12b) associated with the rotor (8).

Abstract: A permanent magnet coupler has a conductor rotor assembly mounted on one shaft and a magnet rotor assembly mounted on a coaxial shaft. The magnet rotor assembly provides two magnet rotors spaced by the adjustable air gaps from two conductor elements provided by the conductor rotor assembly. The air gap adjustment includes adjustable stops, such, for example, as swing arms having an adjustable effective length. These stops operate in conjunction with swing arms causing the magnet rotors to move axially in unison in opposite directions. The air gaps are set so that the coupler will automatically release when subjected to an overloaded condition.