Patent GB-737187-A (GB)
Title: Improvements in or relating to hydro-kinetic power absorption or power transmission devices
IPC: G01L3/20
Filed: 1952-09-11
Abstract: 737,187. Rotary-absorbtion dynamometers. CLAYTON MANUFACTURING CO. Sept. 11, 1952 [Oct. 12, 1951], No. 22843/52. Class 106(2). [Also in Groups XXIX and XXXIV] In a hydraulic dynamometer the rotor shaft serves both as a driving connection to the rotor and as a cantilever support for the stator. Figs. 1 and 3 show views illustrating a hydraulic brake or powerabsorption unit in the form of a chassis dynamometer. The vehicle is moved up the ramp 7, 8 and the driving wheels are placed between the rollers 4 and 5, for test purposes, of which the latter roller forms the drive roller. Both rollers are dynamically balanced and all vibration is reduced to a minimum by the use of rubber mountings, and the whole unit is supported by frame assemblies 2 and 3; both rollers being carried in their respective bearing housings, 40 and 41 for roller 4 and 30 and 33 for roller 5. Supported on a shaft 23, which is carried by one end of the drive roller 5, is a small hydraulic brake unit 6 which is shown in detail in Fig. 5. This unit comprises a rotor hub 66 secured to the shaft 23 and the rotor hub carries a rotor shell 76 which is provided with a series of twenty-one stainless steel vanes. Adjacent the rotor shell 76 lies a stationary stator unit which comprises a stator shell 97 provided with a series of eighteen stainless steel vanes, four of which are hollow, one for admitting the brake liquid and the others act as air-bleed vanes. As the hydraulic brake unit 6 absorbs the power developed by the drive roller 5, the brake liquid becomes heated and it is necessary to provide a heat exchanger unit 180 for the purposes of cooling of the brake liquid and its subsequent re-entry into the working space of the hydraulic brake unit. The brake liquid passes over the heat exchanger unit 180 via the arcuate discharge opening 143, is cooled and re-enters the working space of the unit via ports 210, 211, 212. Details of the various constructions and corresponding performance of different shapes of the rotor and stator vanes and chambers are given in the Specification but are not claimed independently and a modified form of hydraulic brake unit is also illustrated. The load-adsorption capacity of the brake unit 6 can be varied at will by manipulation of the loading valve 140 and the unloading valve 148. Secured to the outer casing of the brake unit 6 is a torque arm 242 which is connected to a rod 244 of a torque bridge device 245 adapted for use with indicating means (not shown) for visually indicating the power being developed by the engine of the vehicle undergoing test. To enable the vehicle to be driven off the rollers when the test has been completed, rotation of the roller 5 is prevented in one direction by means of a pawl 36 adapted to engage a ratchet 35 formed at one end of the roller. A similar pawl 45 is adapted to engage a ratchet 44 formed at one end of the idle roller 4 to prevent rotation at such times as the ramps 7 and 8 are disposed adjacent the roller 4. Specification 711,539 is referred to.