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AXLE, FIXED DYNAMIC

AXLE, FIXED - A shaft which is fixed in the end truck and about which the wheel revolves.

AXLE, ROTATING - A shaft which is fixed in the wheel and which rotates on bearings fixed in the end truck.

BEARING LIFE - the B-10 life of an anti-friction bearing is the minimum expected life in hours of 90% of a group of bearings which are operating at a given speed and loading.

BEARING, LIFETIME LUBRICATED - An anti-friction bearing which is provided with seals and a high-stability oxidation-resistant grease to permit operation of the bearing without re-lubrication for not less than the specified B-10 life.

BLOCK, LOAD - The assembly of hook, swivel, bearings, sheaves, pins and frame suspended from the hoisting ropes. In a "short type" block, the hook and the sheaves are mounted on the same member, called the swivel. In a "long type" block, the hook and the sheaves are mounted on separate members. (The supporting member for the sheaves is called the sheave pin and the supporting member for the hook is called the trunnion.)

BLOCK, UPPER - A fixed assembly of sheaves, bearings, pins and frame, located on the trolley cross members, and which supports the load block and its load by means of the ropes.

BOGIE - A short end truck attached to the end of one girder (or to a connecting member if more than one bogie is used per girder). This type of end truck is used when more than four wheels are required on a crane due to the design of the runway.

BOGIE, EQUALIZING - A short end truck which is flexibly connected to one girder (or connecting member) by means of a pin upon which the truck can oscillate to equalize the loading on the two truck wheels. This construction uses a very rigid end tie between the girders.

BOGIE, FIXED - A short end truck which is rigidly connected to one girder. A flexible end tie is used between the girders to permit equalization of the wheel loads by torsional deflection of the girders and flexing of the end tie.

BRAKE, EDDY CURRENT - A device for controlling load speed in the hoisting or lowering direction by placing a supplementary load on the motor. This load results from the interaction of magnetic fields produced by an adjustable direct current in the stator coils and induced currents in the rotor.

BRAKE, PARKING - A friction brake for bridge or trolley, automatically applied when power to the crane is interrupted.
CAMBER- The slight, upward, vertical curve given to girders to partially compensate for deflection due to rated load and weight of the crane parts.

CLEARANCE - The minimum distance from any part of the crane to the point of nearest obstruction.

CONTROL BRAKING MEANS - A method of controlling lowering speed of the load by removing energy from the moving load or by imparting energy in the opposite direction.

COUNTERTORQUE - A method of control by which the power to the motor is reversed to develop torque in the opposite direction to the rotation of the motor.

DYNAMIC - A method of controlling speed by using the motor as a generator, with the energy being dissipated in resistors.