Abstract: A pump-motor unit (35) including a swashplate (95) having a neutral position (FIG. 3) and first and second displaced positions and comprising first (87) and second (89) pressure actuators associated with the swashplate. Displacement of the swashplate is proportional to substantially only the difference in fluid pressure between a high pressure source (41) and a low pressure source (39). The first pressure actuator includes a first control piston (121) having a first effective area (A1), and the second pressure actuator includes a second control piston (127) having a second effective area (A2), the second effective area being at least somewhat greater than the first effective area. If the high and low pressure sources are at substantially the same pressure, the pressure acting on both of the first and second effective areas will displace the swashplate from neutral toward the second displaced position.

Abstract: A coupling device (11) of the type including a clutch assembly (29) actuation of which is responsive to fluid pressure in a clutch piston apply chamber (43), and a series of fluid passages (53,55,57,59) communicating the chamber to a control valve assembly (69). A housing (15) defines a hub portion (61) surrounded by a plenum member (17) carrying two high pressure seals (63;163). The housing is formed such that the outer surface (60) of the hub portion is free of graphite porosity, to improve the life of the seals. Preferably, each of the seals (63;163) has a height/width ratio selected to provide the desired radially inward sealing force, but wherein the seals are still able to be assembled within the respective seal cavities (73,75;173,175).

Abstract: A method of controlling a pressure control valve assembly (69) to control a control pressure (43,71) in a system (11) including a source (47,49) of pressurized fluid. The control valve assembly is operable to vary the control pressure in response to variations in an electrical input signal (87) to an electromagnetic coil (81). The control valve assembly defines an inlet (77) in communication with the control pressure, an outlet (93) in communication with the low pressure, and a valve seat (89) disposed intermediate the inlet (77) and the outlet (93). A poppet valve member (91) is biased toward the valve seat by a biasing means including an armature (95), the biasing force being generally proportional to the input signal to the coil. The method comprises the steps of selecting a predetermined, minimum pressure for the control pressure corresponding to a minimum condition of the system.

Abstract: A dual shaft gerotor motor (11) of the type comprising a gerotor gear set (13) including an internally-toothed ring member (15) and an externally-toothed star member (17). The motor (11) includes substantially identical first (25) and second (27) motor housing assemblies attached to first (21) and second (22) axially opposite ends of the gerotor gear set (13), and defining first (47) and second (45) fluid ports, respectively. Each of the motor housing assemblies defines a plurality N of fluid passages (65), each of which is in fluid communication with one of said fluid volume chambers (19) defined by the gerotor gear set (13). The first fluid port (47) comprises an inlet port and the first motor housing assembly (25) and the first valve means (37) cooperate to provide first commutating fluid communication from said inlet port (47) to said expanding fluid volume chambers (19).

Abstract: An integrated valve system (51) for use with a variable displacement hydrostatic pump (11), including a relief and check valve assembly (75) and a pressure override (POR) section, operable to communicate pressure above a predetermined POR setting from the high pressure side (15) of the HST closed loop to a stroking cylinder (29) to destroke the pump (11). A high pressure relief spring (83) determines the relief setting, and a POR compression spring (109) determines the POR setting, the relief spring and the POR spring being seated independently of each other, such that the POR setting may be adjusted without effecting the operation of the relief and check valve assembly (75).

Abstract: A hydraulic accumulator of the liquid-gas type, comprising a housing (11) defining a chamber (11C), a gas port (30) and a liquid port (19). A gas charging valve (31) is disposed in the gas port (30) to control admission of high pressure gas. A semi-permeable separator (35) is disposed within the housing (11) to separate the internal chamber (11C) into a gas chamber (33) in communication with the gas port (30), and a liquid chamber (21) in communication with the liquid port. A means (41) is within the liquid chamber for collecting gas which passes from the gas chamber (33), through the semi-permeable separator, and into the liquid chamber. Included is a conduit (45) having one end (45a) in communication with the gas collecting means (41), and another end (45b) operably associated with the housing (11,27) to communicate gas from the collecting means (41) out of the liquid chamber.

Abstract: A control valve assembly (43) for use in a system in which a pump-motor unit (35) can either receive drive torque from a drive-line (17) or transmit torque thereto. The system includes a high pressure accumulator (41) and the control valve assembly is disposed between the pump-motor unit and the accumulator, and includes a mode valve (45) normally biased closed by pressure in a control cavity (89), the fluid pressure in which is controlled by a pilot valve assembly (49) in response to an electrical signal (133). A step-orifice valve (47) associated with the mode valve poppet member (79) provides a relatively larger orifice (115) into the control cavity (89) when pressure therein is high, and a relatively smaller orifice (119) into the control cavity when pressure therein is low, i.e., when the pilot valve assembly (49) is open.

Abstract: A hydraulic lash adjuster (11) for an internal combustion engine, and an improved method of assembly of such a lash adjuster. The lash adjuster (11) is of the type having a body (13), a plunger (15), and a check valve assembly (17). In accordance with one aspect of the invention, the check valve assembly comprises a cartridge (17A;17B) comprising a member (27;41) separate from the plunger (15) and defining a valve seat (27S;41S). The check valve cartridge is capable of being assembled and tested for compliance with a predetermined relationship of flow versus pressure differential, prior to assembly into the plunger (15). In accordance with the improved method of assembly, a plurality of different bodies (13A;13B) and plungers (15A;15B;15C;15D) is provided, as well as a plurality of different, interchangeable check valve cartridges (17A;17B), and the assembly operator selects a body, a plunger, and a cartridge to provide an assembled lash adjuster having the predetermined, desired operating parameters.

Abstract: A rocker arm assembly (55) for a valve control system in an internal combustion engine including a cylinder head (11), and a poppet valve (15). The valve control system comprises an HLA (41) having a ball plunger portion (39). The assembly (55) comprises a rocker arm (57) including axially spaced apart side walls (59,61) and a portion (63) for engagement with the ball plunger (39). The rocker arm assembly (55) further comprises a cam follower (29) disposed about a mounting shaft (31) extending into shaft openings (65) defined by the side walls (59,61), and a pin member (67) defining a valve pad for engagement with a stem tip portion (17), the pin member extending into pin openings (71) defined by the side walls. The assembly (55) includes a clip member (75) including spaced apart clip side walls (77,79) disposed on the outside of the side walls of the rocker arm (57). A connection portion (81) interconnects the clip side walls to restrain axial movement of the mounting shaft (31) and of the pin member (67).

Abstract: A rotary blower (26) includes a torsion damping mechanism for transmitting torque from an input drive (48) to a first timing gear (62), the mechanism including an input hub (52), an output hub (64), and a torsion spring (70) having an input end (72) and an output end (74). The housing (42) defines a chamber (44) containing fluid rotation of the timing gears resulting in an air-oil mist. The input hub and output hub define an axial gap (82) intermediate the input and output ends of the torsion spring. The output hub (64) defines an angled passage (86) having a radially outer end (84) in communication with the axial gap (82), and a radially inner end, whereby rotation generates a flow of the air-oil mist through the angled passage (86) and between the outer cylindrical surface of the hubs and the inside surface (76) of the torsion spring (70).

Abstract: A valve control system (13) for an internal combustion engine including a cylinder head (11), and a poppet valve (15). A camshaft (21) has a first cam profile (25) and a second cam profile (27), and a rocker arm assembly (29) includes a first cam follower (49) and a second cam follower (61) engageable with the second cam profile (27). The poppet valve (15) is disposed toward a first axial end of said rocker arm assembly (29), and there is a first fulcrum surface (39) toward a second axial end of the rocker arm assembly. The first and second axial ends of the rocker arm assembly are oppositely disposed about the first (49) and second (61) cam followers, and a first lash compensation device (83) is operably associated with the cylinder head and includes a first plunger (97) in engagement with the first fulcrum surface (39).

Abstract: A swashplate centering and holddown mechanism (55) for an axial piston unit (11) comprising a cylinder barrel (29) disposed for rotation about an axis of rotation (A). A cam member (39) is tiltable about a transverse axis and has a swashplate (37). The swashplate (37) is perpendicular to the axis of rotation (A), in a neutral position, and has a displaced position (FIG. 4). The swashplate centering and holddown mechanism biases the cam member (39) axially toward a cradle surface (41) and pivotably toward the neutral position (FIG. 3). The mechanism (55) comprises a pair of arms (67,69), each of which defines a pivot location (71,73), at one axial end thereof, fixed relative to a pump housing (19) on one side of the axis of rotation (A), and a swashplate-engaging portion (95,97), at the opposite axial end thereof, engaging the swashplate, on the other side of said axis of rotation (A), when said swashplate is in neutral.

Abstract: A method of controlling shifting of a multiple ratio fluid motor (10) between first and second speed ratios. The motor includes a shift valve (61) operable to achieve the second speed ratio by interconnecting recirculating volume chambers (33R). The method includes providing a pressure control valve (75) in communication with a source (73) of pressure fluid, the valve (75) being operable to communicate a pilot pressure to the shift valve in response to changes in a command signal between a first signal (113B) and a second signal (113C). When a shift to the second condition is commanded, the method changes the command signal (113) from the first to the second over a first time (T1). For a shift back to the first condition (FIG. 3), the method changes the electrical command signal (113) from the second to the first over a second time (T2), wherein T2 is greater than T1.

Abstract: A fluid controller (21) of the static load signal type which includes controller valving (25), a fluid inlet port (27), a control fluid port (33), a fluid return port (37), and a load signal port (39). The controller includes valving (25) which defines a neutral position (N) and an operating position (R), and further defines a variable load sense drain orifice, having a maximum flow area when the valving is in the neutral position and a decreasing flow area as the valving is displaced toward the operating position. The valving defines a variable load sense boost orifice (91) communicating from the inlet port (27) to the load signal port (39), the boost orifice having a maximum flow area when the valving is in neutral, and a decreasing flow area as the valving is displaced toward the operating position.

Abstract: In a control unit for use with a power steering apparatus, there are provided and integrated into a single body, a main operating fluid feed device for supplying the hydraulic cylinder with an amount of oil corresponding to the amount of rotation of the steering wheel H, an auxiliary operating fluid feed device for supplying a correcting oil for adjusting drive of said hydraulic cylinder according to control signal, and a steering wheel angle sensor disposed around the rotating shaft of the steering wheel connected to said main operating fluid feed device, to detect steering wheel angle corresponding to the rotating position of said steering wheel.

Abstract: An open center fluid controller (15) controls the flow from a pump (11) to a steering cylinder (17) and to a downstream auxiliary device (99) requiring a predetermined minimum flow availability. The open center fluid controller (15) includes controller valving (19) having a neutral position (N) a normal operating position (R) and a maximum displacement position (R-M). The controller defines an auxiliary fluid path providing communication between an inlet port (31) and an auxiliary or power beyond port (87), which is in communication with the auxiliary device (99). The auxiliary fluid path includes a neutral variable orifice (AN) having a decreasing flow area as the valving (19) is displaced toward the maximum displacement position (R-M). The valving defines an auxiliary flow control orifice (AA) providing communication from the inlet port to the auxiliary port (87) when the valving approaches the maximum displacement position.

Abstract: A fluid controller (27) for use with a fluid pressure operated device (45) having an inlet (47) and an outlet (49) and defining a fluid leakage path therebetween. The controller (27) includes valving (61) defining a main fluid path and further defines a fluid bleed passage including a variable bleed orifice (AB), having a substantially zero flow area when the controller valving (61) is in its neutral position (N) and in the normal operating position (R), but beginning to open as the valving approaches its maximum displacement position (R-M).

Abstract: A rotary blower (26) of the Roots type, used as an engine supercharger, comprising a housing (50,52) including a forward wall portion (52F) defining an inlet port (30) disposed toward the upper portion of the housing. Typically, the housing defines an outlet port (34) on the underside (54) of the blower. Disposed within the housing is a pair of meshed, lobed rotors (28,29), with one of the rotors being driven by an input shaft (62). The blower includes a pair of timing gears (58,60) disposed adjacent the rearward end (52R) of the housing. The housing includes an inlet duct (32) disposed above the input shaft (62) and extending forwardly and transversely (FIG. 2) from the housing, and having a duct opening (70) in open communication with the inlet port (30). The arrangement of the invention provides substantially improved air flow efficiency through the blower, which corresponds to improved horsepower output of the engine on which the rotary blower is being used.

Abstract: A gerotor motor including a brake package, and a method for setting the load holding torque of the brake package. The endcap assembly (21) defines a set of internal threads (85) disposed adjacent a brake package piston member (75). An enclosure member (87) defines a spring seat (115) for a set of Belleville washers (105), and defines a set of external threads (88) engaging the internal threads (85). Upon assembly of the motor and brake package, a resistance load is applied to a motor output shaft (43) corresponding to a desired load holding torque. The motor is pressurized sufficiently to rotate the output shaft in opposition to the resistance load. The enclosure member (87) is rotated so that it moves axially in a direction to increase the bias preload on the Belleville washers (105) until the output shaft (43) no longer rotates.

Abstract: A method of operating a control system to move an EGR valve (24) toward its seat (32), in which the control system includes an actuator (16) operable in response to an electrical position command signal (84, 86). The method comprises the steps of determining (102) if the valve is being commanded toward a closed position, and determining (106) if the valve is still at least a predetermined distance (X) from a Stage 1 Position. If both answers are affirmative, the valve is commanded toward the Stage 1 Position, then the logic determines when the valve is within a predetermined tolerance (T) of the Stage 1 Position, and when it is, the logic provides a position command signal corresponding to an unchanging position of the valve for a predetermined period of time (Y), while any overshoot of the valve position settles out, and the valve position stabilizes before the logic proceeds with the rest of the closing operations.