Patent GB-420161-A (GB)
Title: Improvements in or relating to hydraulic coupling devices and their use in systems for the transmission of power
IPC: F16D67/00
Filed: 1933-05-25
Abstract: 420,161. Hydro-mechanical variablespeed gearing. SWAN, J. G., 14, Old Square, Lincoln's Inn, London. May 25, 1933, No. 15187. [Class 80 (ii)] [See also Group XXIX] In a hydraulic coupling or gear device for transmitting power of the F÷ttinger or like type, an element of the coupling or gear, enclosed in a rotary casing which serves as or is secured to a power input or a power output member of the device, is rendered operative for the transmission of torque or power by being coupled to rotate as one with the casing by a mechanical clutch. A rotary casing 102 secured to the power shaft 101 is adapted to be connected by a friction clutch 107 with a tubular shaft 111 carrying a primary hydraulic element 103 and a brake drum 110 ; a secondary element 104 drives an output shaft 105 through a free wheel device 112 : direct drive between the shafts 101 105 may be obtained by a positive clutch 118, 119. With the clutch 107 open, the element 103 is affected merely by the viscous drag of the liquid and will rotate without transmitting torque to element 104 which, being similarly affected, will rotate at substantially the same speed if the power output shaft has no load thereon : the speed of rotation of the output shaft can therefore be governed by the speed of the engine, and the speed of rotation of members of a change speed gearing, if such be fitted on the output shaft, be synchronized, before engaging, by such control. Constant mesh epicyclic multispeed gearing may be employed in conjunction with the hydraulic coupling or gear. The brake 110 is used to bring down the speed of rotation of the element 103 after the clutch 107 has been freed when the device is used on a vehicle with a train of change speed gearing and it is desired to engage this train with the vehicle stationary. The free wheel 112 may be omitted or may be of a kind that does not disengage under a relatively small torque. The friction clutch 107 and the positive clutch 118, 119 may be interconnected so that the latter will be disconnected whenever the friction clutch is disengaged. A centrifugally actuated clutch coming into operation at a desired speed may replace the friction clutch 107, such clutch, if desired, having means whereby the driving and driven elements may be freed at will: in another form a clutch as described in Specification 393,296 replaces the clutch 107. Only part of the element 103 may be disengageable from the casing the remainder being constituted by means integral with or secured to the casing. A free wheel device may connect the output shaft 105 directly with the casing 102 to permit the engine to be used as a brake. The shaft 105 may be used as the power input shaft and the shaft 101 as the power output shaft. As shown in Fig. 2 a three section gear train may be combined with the device in such a way that a proportion of the total torque transmitted by the device is transmitted through the medium of the hydraulic elements to one section of the gear train, the other sections being secured respectively to the output and the input shafts. The input shaft 201 carries a flywheel 204, gearcasing member 205 and the hydraulic coupling casing 202 which may be coupled to the driving element 207 by the clutch 214, through a sleeve 206, this sleeve also carrying one member 218 of a one way clutch that prevents the primary element rotating in the reverse direction : the secondary element 208 is connected through a sleeve 209 with a sun wheel 210 meshing with planet wheels 216 of a gear train, other planet wheels 213 meshing with a sun wheel 212 on the output shaft 211. As the bearings of the shaft of the planet wheels are carried by the casing 202 and the flywheel 204 a portion only of the torque, depending on the ratio of the gear train, is transmitted hydraulically. The ratio is arranged so that the torque transmitted from the input to the output shaft is small when the input shaft is rotating slowly and the output shaft is not rotating: the clutch 214, which transmits only about half the torque, can thus be readily freed. The member 219 of the one way clutch 218, 219 may be associated with a brake. A reverse device may be obtained by providing an additional gear train including a third sunwheel between the sunwheels 210, 212 secured to an additional tubular shaft connected with a brake drum beyond the one way clutch 218, 219. In a modification, the carrier of the gear train is secured to the sleeve shaft carrying the element 207 so that freeing the clutch 214 causes torque to be transmitted to the output shaft only by the viscous drag of the liquid in the casing : in this form a second gear train may be provided to give additional torque for starting a load from rest. In a further form of the device as shown in Fig. 5, a third hydraulic element 420 is secured to a tubular shaft 421 connected to one member of a one-way clutch 422, the other member being non-rotary: a second oneway clutch 425 prevents the element 420 from rotating faster than the shaft 405. The tubular shaft 421 may be engaged with the tubular shaft 411 carrying the driving element 403 by a clutch 427. By suitable construction of the vanes of the hydraulic elements or reaction member 420 a high torque may be given to the output shaft. A mechanical reduction gear may be combined with the hydraulic gear. Specifications 310,377, [Class 69 (ii)], 374,547, 393,294, 393,295, 399,155, and 408,510 also are referred to.