Patent GB-762805-A (GB)
Title: Method and apparatus for measuring power losses in tyres, belts or the like
Inventor: POWELL ERNEST FREDERICK
IPC: G01M17/02
Filed: 1954-06-11
Abstract: 762,805. Testing transmission of tyres, belts or the like. DUNLOP RUBBER CO., Ltd. May 27, 1955 [June 11, 1954], No. 17169/54. Class 106 (2). Apparatus for measuring the power loss of a tyre comprises a drum 2a, Fig. 2, a'motor 1 coupled thereto, a supporting member 3a for supporting a tyre 40 in driving contact with an outer peripheral surface of the drum, means for applying a load to the tyre, means for transmitting torque from the tyre back to the motor, means for measuring the torque supplied by the motor and means for measuring the torque transmitted from the tyre back to the motor. Preferably a second drum 2b is coupled to the motor at its end remote from that coupled to the first drum 2a, one drum having a peripheral surface of greater diameter than a peripheral surface of the other drum, a second supporting member 3b for supporting a second tyre 41 in driving contact with the second drum, means for loading the second.tyre, intermediate shafts 5a, 5b and universal joints 58, 59 for coupling the first and second tyres and a torquemeter 6 for measuring the torque transmitted between the tyres. As shown, the drums have stepped peripheral portions 20-22 and 23-25 and each drum is rigidly mounted on a sleeve slidable axially on but drivably keyed to the motor shaft 16a, 16b so that each drum may be traversed relatively to its tyre to bring the tyre into contact with any one of the stepped portions of the drum. Each tyre supporting member 3a, 3b comprises a forked bearing carrying member 42, 43, and a spindle 7a, 7b mounted on a pair of axially spaced apart bearings, one located in each arm of the forked member, each spindle being in two parts each having a half coupling member 44, Fig. 5, one half coupling being detachably attached to the other and the half couplings being drivably attached to a wheel and tyre assembly. One or both of the arms of the forked bearing member is hinged so as to swing on a vertically mounted pin 54 to permit insertion and removal of the tyre assembly to be tested. The tyre supporting members 3a, 3b are mounted on carriages 4a, 4b provided with rollers 38 cooperating with rails 39 to bring the tyres into contact with the drums under the action of an hydraulic piston 56 having one end connected to the member 3a, 3b and slidable in a cylinder 55 secured to the apparatus frame. The load is applied to the tyre by the piston through a load-measuring capsule 57. Each of the bearing assemblies 48 is located in its respective arm of the forked member at 90 degree intervals by means of load capsules 49-52 mounted on rubber pads 53. The capsules 49, 50 are pneumatically operated to pre-load the bearing, the capsule 52 is an hydraulic capsule measuring the tangential force transmitted by the drum to the tyre and the fourth capsule 51 measures the part radial load of the tyre against the drum. The motor frame 11 is capable of limited rotational movement and the torque supplied by the motor may be measured by a load capsule subjected to that movement. The motor shaft torque may be measured by torque meters 15a, 15b situated between the motor and the drums.