Patent GB-607084-A (GB)
Title: Improvements in combined dynamometers and eddy current slip couplings
IPC: H02K49/04
Filed: 1946-01-25
Abstract: 607,084. Dynamometers. WINTHER, M. P. Jan. 25, 1946, No. 2502. Convention date, Aug. 11, 1943. [Class 106 (ii)] A combined dynamometer and eddy current slip coupling comprises field and inductor members mounted one on the driving shaft and one on the driven shaft, a clutch adapted to connect the field member and a casing, which surrounds the field member, and measuring means associated with the casing for determining the resultant moment acting on the casing. The casing 5 (Fig. 1) swings on bearings 7, the outer races of which may be periodically rotated, in supports 1, 3 and carries bearings 25 for the driving shaft 9 connected to the engine under test. The shaft 9 is coupled to the inductor drum 15 which carries bearings 19, 23 for the driven shaft 21 also supported by bearings 27 in the casing 5. The shaft 21 carries the field spider 29 which carries coils 31 suitably energized from an outside source for cooperation with the inductor drum 15. To cool the inductor drum, water is fed through a pipe 39 and passes through spray openings 41. The water flows to a sump 33 from which it may be removed by suitable means, seals being provided to prevent water from entering any of the bearings. The driven shaft 21 is connected to the rotor 43 of a synchronous generator G, Fig. 2, the field member of which is carried in a swinging housing 47. The swinging housings 5, 47 of the slip coupling and generator respectively have projecting arms 59, 55 which cooperate with force-measuring means 61, 57 to enable the torque on the housings to be measured. A clutch C enables the driven shaft 21 to be coupled to the casing 5 of the slip coupling. If the output of the engine E connected to the driving shaft 9 is within the power-absorption capacity of the slip coupling, the clutch C is closed, thus rendering the generator ineffective and the torque is measured by means of the arm 59 and its associated forcemeasuring means 61. If the speed of the shaft 9 is known, the power may then be calculated. If the output of the engine E is greater and its speed is greater than the synchronous speed of the generator G, the clutch C is opened and the generator is operated at its synchronous speed, a slip occurring between the members of the slip coupling. The generator thus supplies current and the torque exerted on its field member may be measured by means of the arm 55 and its associated force-measuring means 57. The torque on the casing 5 of the slip coupling is similarly measured and the speeds of the shafts 9 and 21 being known, the total power output of the engine E may be calculated. The generator may be operated as a motor to drive an engine E through the slip coupling for making friction, lubrication or like tests. Moreover, when running-in on engine E, the latter may drive the generator G as a means of power recovery. In these cases, the housing 47 of the generator may be foot-mounted. In an alternative arrangement, the clutch is replaced by an arm carried by the shaft 21 which is associated with force-measuring means, the torque on the casing 5 being allowed for by means of an arm, secured thereto and engaging the torque-measuring arm. Power recovery is obtained, when running-in the engine E, by means of a generator G as described.