GB854006A - Improvements in hydrostatic couplings - Google Patents

Abstract

854,006. Hydraulic couplings. SVENSKA ROTOR MASKINER A.B. Aug. 13, 1958 [Aug. 16, 1957], No. 26004/58. Class 69 (2). An hydraulic coupling comprises a housing 18 which is arranged on one shaft 19 of the coupling and provided with recesses 26 containing pairs of gears 28, 30 serving as gear pumps, one gear of each pair engaging a gear 16 on the second shaft 14 of the coupling, and each gear pump being provided with a pressure chamber 46 arranged radially-outwardly of the pumps so that the hydraulic pressure on each pump wheel is directed principally in a direction opposite to that of the centrifugal force acting on the wheel. The gears 28, 30 are supported on needle rollers 32 between the walls of the housing and one of each pair of the gears is spaced further from the centre of the housing than the other by the depth of the gear teeth. During relative rotation between the shafts, liquid in a central chamber 44 is pumped into the chambers 46 from which the liquid passes through circulation ducts 54 provided with relief valves 56 back to the central chamber. The valves are individually adjustable and may be arranged so that the bodies 58 of the valves are free or spring-urged outwardly, inwardly or parallel to the axis of the coupling to provide, with the centrifugal force acting on the bodies, the coupling with different output characteristics. In another embodiment, the axes of the gears of each pump are at equal radii from the centre of the housing and the radius of one wheel of each pair differs from that of the other by the depth of the gear teeth. Alternate pumps may be arranged to operate upon opposite rotation to permit the coupling to be used for forward and reverse rotation. Leaking past the sides of the gears is prevented by sealing plates 48 which are urged towards the sides of the gears by springs or liquid pressure supplied from the chambers 46. Specification 854,007 is referred to.