A Prony brake used as a rotational load absorption unit, or dynamometer, to measure power output of a prime mover includes a cylindrical tube disposed within a sealed tank containing coolant water. Disposed within the cylindrical tube is a fixed stator shaft, which is attached to the center of a stator plate having its outer periphery disposed in closely spaced relation to the tube's inner surface, with the stator shaft further coupled to a hydraulic control system. Disposed within the stator plate's outer periphery are plural radially spaced pistons for applying a radially outward friction braking force to the inner surface of the rotating cylindrical tube. The stator shaft is provided with first and second ports and passageways for respectively transporting hydraulic control fluid and lubrication fluid. Also included is a supplemental cooling water supply wherein cooling water is circulated with the Prony brake by the rotating cylindrical tube.

A tailstock assembly includes a housing, a torque cell supported on the housing and configured to measure loads in a first load range, and a load cell supported on the housing and configured to measure loads in a second load range that is different from the first load range. The tailstock assembly is configured so that the torque cell can be selectively mechanically isolated from the housing. In particular, the torque cell and the load cell are supported on the housing through a low friction bearing, and the tailstock assembly can be selectively switched between a first measurement mode in which the torque cell is fixed to the housing, and a second measurement mode in which the torque cell is mechanically isolated from housing via the bearing. The tailstock assembly may be used as part of a brake dynamometer for accurately measuring both active braking torques and residual drag torques.

A tailstock assembly includes a housing, a torque cell supported on the housing and configured to measure loads in a first load range, and a load cell supported on the housing and configured to measure loads in a second load range that is different from the first load range. The tailstock assembly is configured so that the torque cell can be selectively mechanically isolated from the housing. In particular, the torque cell and the load cell are supported on the housing through a low friction bearing, and the tailstock assembly can be selectively switched between a first measurement mode in which the torque cell is fixed to the housing, and a second measurement mode in which the torque cell is mechanically isolated from housing via the bearing. The tailstock assembly may be used as part of a brake dynamometer for accurately measuring both active braking torques and residual drag torques.

A Prony brake used as a rotational load absorption unit, or dynamometer, to measure power output of a prime mover includes a cylindrical tube, or drum, disposed within a sealed tank containing coolant water. Disposed within the cylindrical tube in a sealed manner is a fixed stator shaft. The stator shaft is attached to the center of a generally circular, planar stator plate having its outer periphery disposed in closely spaced relation to the tube's inner surface, with the stator shaft further coupled to a hydraulic control system. Disposed within the stator plate's outer periphery are plural radially spaced pistons responsive to the hydraulic control system for applying a radially outward friction braking force to the inner surface of the rotating cylindrical tube. The stator shaft is provided with first and second ports and passageways for respectively transporting hydraulic control fluid and lubrication fluid. Also included is a supplemental cooling water supply wherein cooling water is circulated with the Prony brake by the rotating cylindrical tube.

A Prony brake used as a rotational load absorption unit, or dynamometer, to measure power output of a prime mover includes a cylindrical tube, or drum, disposed within a sealed tank containing coolant water. Disposed within the cylindrical tube in a sealed manner is a fixed stator shaft. The stator shaft is attached to the center of a generally circular, planar stator plate having its outer periphery disposed in closely spaced relation to the tube's inner surface, with the stator shaft further coupled to a hydraulic control system. Disposed within the stator plate's outer periphery are plural radially spaced pistons responsive to the hydraulic control system for applying a radially outward friction braking force to the inner surface of the rotating cylindrical tube. The stator shaft is provided with first and second ports and passageways for respectively transporting hydraulic control fluid and lubrication fluid. Also included is a supplemental cooling water supply wherein cooling water is circulated with the Prony brake by the rotating cylindrical tube.

To reduce a length in an axial direction of a driving mechanism including a rotation motor, a reduction gear, and a torque sensor to downsize the driving mechanism. A force receiver (32) fixed between a motor case (16) and a reduction gear case (22) is disposed outside the reduction gear case (22) so as to surround the reduction gear case (22). A frame (36) fixed to an attachment part (26) is disposed outside the reduction gear case (22) so as to surround the reduction gear case (22). A plurality of beams (40) are disposed around the reduction gear case (22) so as to be spaced from each other. A strain measurement part (42) is provided to at least one of the beams (40).

To reduce a length in an axial direction of a driving mechanism including a rotation motor, a reduction gear, and a torque sensor to downsize the driving mechanism. A force receiver (32) fixed between a motor case (16) and a reduction gear case (22) is disposed outside the reduction gear case (22) so as to surround the reduction gear case (22). A frame (36) fixed to an attachment part (26) is disposed outside the reduction gear case (22) so as to surround the reduction gear case (22). A plurality of beams (40) are disposed around the reduction gear case (22) so as to be spaced from each other. A strain measurement part (42) is provided to at least one of the beams (40).

Methods and apparatus to simulate torque are disclosed. A disclosed example apparatus to characterize a tool includes a tool interface to be couplable to the tool, a brake to apply a rotational resistance to the tool interface, and a transducer to measure an output torque of the tool for characterization of the tool with respect to the rotational resistance.

Methods and apparatus to simulate torque are disclosed. A disclosed example apparatus to characterize a tool includes a tool interface to be couplable to the tool, a brake to apply a rotational resistance to the tool interface, and a transducer to measure an output torque of the tool for characterization of the tool with respect to the rotational resistance.