Patent GB-1071077-A (GB)
Title: Hydraulic laundry machine transmission
IPC: F15B15/12
Filed: 1964-08-21
Abstract: 1,071,077. Washing machines. THE EMERSON ELECTRIC MFG. CO. Aug. 21, 1964 [Aug. 22, 1963], No. 34391/64. Heading D1A. [Also in Division F1] A washing machine, comprising a basket C and agitator E which may be respectively rotated rapidly and oscillated by hydraulic motors I, J, has an hydraulic pump H driven by an electric motor G and valve means K to direct the flow of fluid from the pump to either of the hydraulic motors, the pump motor and valve means being mounted in a common housing F. Basket C may be perforated or may be a solid overflow basket and is carried on a hollow shaft 10 within which oscillates shaft 11 carrying agitator E. Housing F comprises upper and lower housings 15, 16 whose engaging surfaces have the hydraulic circuit and valving surfaces for valve K formed on them. A cover plate (18) co-operates with housing 15 to form an oil reservoir. Motor J is mounted in a steel sleeve (21) in a cylindrical recess in housing 16. Motor I is mounted in a similar recess in housing 15 whose axis is slightly offset from that of shaft 11 and which has a wall (31). Pump H is mounted in a recess in housing 15, closed by a cap 45 and a ported plate (47), whose axis is slightly offset from shaft 50 of the single speed reversible motor G. Pump H may be a piston pump or a rotating vane pump but is preferably a gear pump comprising an externally toothed gear keyed on shaft 50 and an internally toothed ring (64) having one tooth more and being rotatably supported by the recess surface (43) whose axis is offset from that of gear (62). Passages (66i), (67a), (68g) end in ports (66), (67), (68) in the lower surface (42) of the pump cavity which is engaged by the lower surfaces of gears (62), (64). Ports (75), (76), (77) are provided in a plate (72) engaging the upper surfaces of gears (62), (64) and pivotted by a shaft 83 about an axis offset from the axes of gears (62), (64). A tab (80) on plate (72) which extends into an arcuate recess (81) limits the movement of plate (72) which varies the pump output. At all positions of plate (72), port (75) is in communication with passage (75a) through port (75b) in plate (47), groove (75c) in cap 45 and passage (75d) in the upper housing. In the maximum volume position of plate (72), port (76) communicates through port (76a) in plate (47) and a radial groove (76b) in the lower surface of cap 45 with sump 20. Port (77) connects decreasing volume spaces with increasing volume spaces when plate (72) is adjusted. Spin motor I may be a vane motor but, as described, Fig. 10 (not shown), it comprises an externally toothed gear (100) keyed on shaft 10 by key (101) and an internally toothed ring gear (102) with one tooth more than gear (100) mounted within the recess wall (31). The gears are in sliding contact with the lower surface (30) of the recess which has arcuate inlet and outlet ports (110), (111) connected by passages (110a), (111a) with passages (110b), (111b). Grooves (120), (121) in surface (31) are on the high pressure side of the neutral axis (105) and are connected through grooves (120a), (121a) in surface 30 to supply fluid to the space between gear (102) surface (31). Groove (123) communicates with discharge port (111) which is under suction through groove (123a) in surface (30). Grooves (122), (124) are connected by groove (122a) in the upper surface of port 15 to equalise the pressure gradient between grooves 120, 123 and 121, 123 respectively. The high pressure side of motor I is connected by pressure relief valve (139) with sump 20. Valve (147) maintains a back pressure on passage (111b) when fluid discharge is blocked by the valve K to brake spin motor I and hence stop basket C. Agitator motor J, Fig. 12 (not shown), comprises a piston (152) comprising a hub (153) and vane (154) in whose outer end a steel roller (155) is loosely mounted which engages surface (22). A spring biassed key (158) on hub (153) engages one of three or more key ways (162) in shaft 11. Lugs (163) on key (158) engage grooves (164) in surfaces (23), (26) having cam surfaces which. when shaft 11 is rotated sufficiently in one direction, lugs (163) are disengaged and key (158) is retracted leaving shaft 11 free to rotate. The application of high pressure from pump H to either side of vane (154) is controlled by a pivoted member (165) in sliding contact with surfaces 23, 26, a port (168) being provided in surface (23) connected to the fluid inlet (168a) connecting motor J through pressure relief valve (172) to the sump. As valve member (165) rocks, sealing surfaces (173), (174) alternately engage surface (22). Steel rollers (176), (177) are loosely mounted in grooves (178), (179) in member (165) facing hub (153). A surface (182) of member (165) sides in a recess in the surface of sleeve (21). Discharge ports (183), (184) in surface (23) are connected through housing 16 and passages (183a), (183b) and (184a), (184b) to reservoir 20 back pressure being created by a restricted passage between ports (183), (184) and reservoir 20. In operation, when fluid is supplied through port (168) to one side of member (165), surface (173) is pressed against surface (22) and steel roller (177) against the surface of hub (153) and the side of groove (179). The vane then rotates and fluid is discharged through port (183). As piston (152) rotates, a camming surface (180) on hub (153) engages roller (177) pivoting member (165) so that high pressure builds up behind it causing it to snap back when surface (174) and roller (176) engage surface (22) and hubs (153). The vane (154) is then forced to rotate in the opposite direction. Shaft 10 is journaled in a sleeve (201) and its end surface (202) rests on a washer (203) on a shoulder (204) when the shaft is not rotating. Pressure fluid to motor I passes through the clearance round key (101) and between shaft 10 and sleeve (201) to lift the clothes basket when some of the fluid flows into clearance (134) and back to the sump. In neutral position Fig. 8 (not shown), valve K connects the discharge of pump H to its inlet and blocks the discharge of basket spin motor I. In the agitate position Fig. 9 (not shown) the discharge pump H is connected to the inlet of motor J and blocks the flow of liquid to it from basket spin motor I. In the spin position Fig. 10 (not shown) the discharge of pump H is connected to the sump, motor J's inlet being connected to sump suction. Valve K may be a series of solenoid valves but, as described, consists of a piston (250) with bands (251), (252), (253), (254) separated by valve passages (256), (257), (258). The cylinder has bands (261), (262), (263), (264), (265), (266), (267) separated by valve chambers (75e), (20e), (111e), (110e), (66e), (68e), (67e), (278). In neutral and agitate positions of piston (250) chamber (278) communicates with chamber (67e) through passage (296), chambers (20c) and (68e) communicate with reservoir 20 and chamber (75c) communicates with passage (75d) through a branch passage (75f). Helical springs engage the ends of piston (250) and tend to hold it in neutral position. Operation The clothes and water are placed in tub A and the sump 20 and all passages are filled with hydraulic fluid. Switch 56 is turned to agitate and motor G rotates anticlockwise, Fig. 8 (not shown) with hardly any load. The flow of fluid through the system builds up pressure in chamber (67e) which lifts piston (250) and locks it in agitate position so that motor G does not take any load until it is rotating fairly rapidly. Hydraulic fluid is supplied to agitator motor J which reciprocates, continuing until motor G is de-energized and the pressures drop to zero, piston (250) returning to neutral position. On turning switch 56 to spin position, motor G rotates counterclockwise, Fig. 8 (not shown), suction is created in valve chamber (67e) and piston (250) moves downwards and again motor G is rotating fairly rapidly before it takes a load. Hydraulic fluid is supplied to spin motor I, pressure relief valve (139) preventing pressures from building up while the inertia of the basket is overcome. Motor I, Basket C, agitator E, shaft 11 and vane (153) start to rotate together. Drive is transmitted to agitator E through the clothes until lug (163) engages surface (164) to pull key (158) from keyway (162) so that agitator E continues to rotate freely. Rotation of basket C causes water between it and tub A to rotate and form a cup of water in which the basket rests tending to move upwards, fluid flowing upwardly past surface (202) and back to the sump to limit the speed of rotation of motor I e.g. to 100 r.p.m. until all the water has been removed from the tub e.g. by a centrifugal pump. The weight of the basket then brings it down on to surface (202) and the speed is increased e.g. to 600 to 800 r.p.m. When motor G is de-energized, e.g. at the end of a cycle or on opening the door, piston (250) returns to neutral position and pressure from valve (147) brakes the basket. Motors I and J may be controlled by varying either the speed of the pump or its output per revolution. The latter may be varied by adjusting plate (72) but the effect of this varies according to the direction of rotation of the pump.