Patent GB-1131220-A (GB)
Title: Improvements in or relating to hydraulic oscillatory actuators
IPC: F15B15/26
Filed: 1966-05-19
Abstract: 1,131,220. Rotary hydraulic motors. HOUDAILLE INDUSTRIES. Inc. May 19, 1966 [July 7, 1965], No.22386/66. Heading F1F. [Also in Division F2] A hydraulic oscillatory-actuator includes a brake to prevent angular displacement of a shaft 22 and/or a housing 17 relative to each other whenever the actuator is rendered inoperative, which brake comprises a member 30 engaging with a splined portion 29 of said shaft and having an outwardly-tapering tubular portion 33 that is held in firm contact with a similarly shaped surface 35 on the housing by a plurality of adjusting screws 38 situated in a flanged ring 37, the latter being in abutment with a ring 40 adjacent a shoulder 41 on the housing. The ring 37 is retained by a ring 43, and sealing rings 40a, 42, 48 are provided so that when pressurized hydraulic-fluid enters an annular channel 47 within the member 30 through passages 44, 45 in the housing the member in question expands radially and permits the angular displacement aforesaid, lubrication of the surface 35 being effected by a proportion of said fluid wetting this surface. The hydraulic fluid may be furnished by a source of such fluid for actuating a radial vane 23, which is lodged in a chamber 19 containing a fixed abutment 24 and is integral with the shaft 22. In a modification, Fig. 3 (not shown), the brake includes a member (30') comprising a tapered tubular-portion (33') having its greatest diameter at its end adjacent the splined portion (29') of the shaft, the outer surface (35') being of matching profile. The portion (35') is pressed against the surface (35') by screws (38') lodged in a flanged plate (31') abutting a shoulder (41') on the housing adjacent the beforementioned end, a boss (32') on said plate being in engagement with the splined portion (29'). The brake is released by hydraulic fluid in a channel (47') within the portion (33') effecting expansion of the latter. In a further modication, Fig. 4 (not shown), the brake includes a member (30") having two separate and oppositely tapered portions (33", 51) that are clamped together by screws (38") so as to press them against tapering surfaces (35", 54) on the housing, the brake being released by hydraulic fluid in a manner similar to that indicated above. In another modification, Fig. 5 (not shown), the brake includes a pair of discs (70) mounted on the splined portion of the shaft and having oppositely tapering flanges (72) with friction linings (74) on their radially outermost surfaces, which linings are engaged by tapering surfaces (75) on a sleeve (67) coupled by splines (68) to an end wall (61) of the housing. The discs are clamped together by screws (71), which permit adjustment of the axial spacing of these discs. A second embodiment, Fig. 6 (not shown), differs from the first one as modified according to Fig. 5 chiefly in that the sleeve aforesaid is attached to a clamping ring (88), which is engaged by bolts (87) for fixing end walls of the housing to a peripheral wall (82) thereof. The brake according to Fig. 5 may be modified, Fig. 7 (not shown), in that the sleeve is attached to the housing by screws (119) and pins (120) and in that it is protected by a housing (134). Alternatively, the sleeve is fixed to the housing by radial pins (149), Fig. 8 (not shown), and a sealing ring (160) is lodged between the flanged discs. The discs (70) may be replaced by a single flanged disc (178), Fig. 9 (not shown), having a profile that tapers in one direction only, the associated sleeve being of similar shape. In place of the flanged discs in the modification according to Fig. 5, a disc (193), Fig. 10 (not shown), may be provided, which disc has a friction lining (195) on one side thereof that is engaged by a flat annular-plate (197) that is clamped against said lining and attached to the housing by screws or bolts (198), the latter being stretched to release the brake by hydraulic fluid in an annular chamber (205) defined by rings (199, 200) between the plate (197) and the housing. The rings (199, 200) are axially movable relative to each other, one ring abutting the housing and the other ring abutting the plate (197). Alternatively, the brake includes a disc (214), Fig. 11 (not shown), which is somewhat similar to the disc (193) and is clamped between a pair of annualr discs (213) by bolts or screws (215), the latter being stretched to release the brake by hydraulic fluid entering an annular chamber (224) between the discs (213). As a further alternative, the brake may include a disc (242), Fig. 12 (not shown), which is similar to the disc (214) and has a friction lining (244) on either side thereof, this disc being clamped between an end wall (230) of the housing and an axially-movable tubular body or plunger (240) by a ring (237) fixed to an immovable tubular body (234) by a resilient ring (238). The body (234) surrounds the disc (214) and plunger (240) and is fixed to the housing by radial pins or dowels (235). To release the brake, hydraulic fluid enters an annular chamber (250) between the body (234) and the ring (237) and effects deflection of the latter away from the plunger (240).