Abstract: A supercharger (26) has first (28) and second (29) meshed lobed rotors, each having associated therewith a timing gear (62), the timing gears being meshed to prevent contact of the meshed lobes of the rotors (28,29). Input torque to the supercharger (blower) is by an input shaft (54), with torque being transmitted to the timing gear through a torsion damping mechanism. In accordance with the invention, the damping mechanism comprises the timing gear and an input hub (70) defining cylindrical outer (86) and inner (88) surfaces, with a torsion spring (76) disposed radially therebetween. The spring defines a normal inside diameter (90) which is spaced apart from the outer surface (86) by an amount corresponding to a predetermined positive travel limit. For a different engine application, the mechanism may be adapted by merely providing a different diameter for the outer surface (86), thus changing the travel limit.

Abstract: A center differential (17) including a clutch pack (33), a cam ramp actuator (31) for moving the friction discs (65,67) toward an engaged position, and a viscous coupling (29) which will have a “slip speed” representative of the speed difference between the front (11) and rear (23) wheels. There is a one-way clutch (57) disposed between the output (49) of the viscous coupling (29) and the first ramp plate (51) to transmit positive torque when the vehicle is in a forward gear, but negative torque is not transmitted, for example, during braking. An override mechanism (55) is provided, including a plurality of spring biased pins (107), such that, below a predetermined speed of rotation, positive torque can also be transmitted when the vehicle is in reverse gear. The pins (107) are associated with flyweight members (97) so that, above the predetermined speed, the pins are disengaged, and positive torque can be transmitted only in forward gear.

Abstract: An exhaust gas recirculation (EGR) assembly (23) for an internal combustion engine, including an EGR valve (54) having a valve stem (55) reciprocating within a housing (61), between open (FIG. 3) and closed positions. Preferably, the EGR assembly is mounted on the exhaust manifold (15), and the EGR valve can communicate exhaust gas back to the intake manifold (13) in a known manner. The EGR assembly includes an electric motor (41), and a gear train (65) to move the EGR valve (54) in response to changes in an electrical input signal. A plurality of power electronic components (97) are disposed within a controls housing (91), which defines a slot (99) in face-to-face relation to a cooling chamber (81) defined by the housing (61) surrounding the valve stem (55).

Abstract: A method of shifting a transmission having both a hydrostatic portion, including a variable pump (15), and a hydraulic motor (29), and a mechanical transmission (33) portion, including a shift cylinder (37). The method includes relieving the output torque of the motor (29), shifting the mechanical transmission to neutral, and controlling the. displacement of the pump (15) to synchronize motor output speed with the required input speed to the desired gear ratio of the mechanical transmission (33). Then fluid flow to the shift cylinder (37) occurs to shift to the desired gear ratio. The shifting method includes a series of steps in which the feasibility of the prospective shift is determined, and only when the prospective shift can be completed, without detriment to the operation of the vehicle, will the shift be completed. As a result, the shifting between low gear and high gear can occur without bringing the vehicle to a stop each time.

Abstract: A valve deactivator assembly (47) especially for use with a push rod (23) type of valve gear train, the deactivator assembly (47) preferably comprising a roller follower, engaging the engine cam (19). The deactivator includes an outer body (53), driven by the cam (19), and an inner body (61) which transmits cyclical motion to the push rod (23), when the body members are latched (FIG. 2). The inner body member (61) defines a latch chamber (93), oriented radially, and aligned therewith is a circular opening (97) defined by the outer body member (53). A compression spring (107) biases a latch member (99) toward the latched condition (FIG. 2). An end surface (111) of the latch member (99) is in communication with an engine oil passage (P), and a relatively higher pressure in the passage biases the latch member (99) toward an unlatched condition (FIG. 3), in opposition to the compression spring (107).

Abstract: A hydraulic unit of the type including a cylinder block (19) rotatably disposed adjacent a valve plate (51;61) having inlet ports 41a, 41b, and 41c, and further having outlet ports 43a, 43b, and 43c. Disposed between the individual inlet and outlet ports are web portions, having nominal cross-sections and flow restrictions. In one embodiment (FIG. 3), there is a modified web portion (55) toward the trailing end of the outlet port, and in the other embodiment (FIG. 7), there is a modified web portion (65) toward the leading end of the outlet port. In either case, the web portion has its cross-section or flow restriction modified to move the resultant force on the swashplate (33) in a direction tending to reduce the moments on the swashplate, and therefore, reduce the operator effort required to move or maintain the control lever.

Abstract: A hydraulic lash adjuster (1) having a plunger assembly (3) including an upper plunger (4) and a lower plunger (5), the plungers being disposed within a body (2) defining a bore (2b,7), and in conventional leakdown plungers, cooperating with the bore to define a nominal diametral clearance. In accordance with one aspect of the invention, the plungers and the bore are provided with a reduced diametral clearance, substantially less than the nominal clearance, thus substantially improving the consistency of leakdown times. In accordance with another aspect of the invention, the upper plunger element (4) includes a center land (25) which defines a fluid passage (33), such as by having a flat (31) ground into the land, to insure the proper amount of lubrication fluid flowing out of the ball plunger (20).

Abstract: A cartridge valve assembly (19) including a sleeve valve (49) fixed within a valve housing (17), and a spool valve (47) moveable both axially and rotatably within the sleeve valve. Rotation of an input (35,39) causes rotation of a cam member (43) and the spool valve, and the engagement of the cam member (43) with a cam surface (57) results in axial movement of the spool valve within the sleeve valve. The spool and sleeve valves define a neutral axial and rotational position (FIG. 5), and rotation from neutral in a first direction (FIG. 6) communicates fluid from an inlet port (21) to a first actuator port (25), and rotation from neutral in a second direction (FIG. 7) communicates fluid from the inlet port to a second actuator port (27). In either case, the axial movement of the spool valve (47), relative to the sleeve valve (49) is the same. The spool valve defines a load holding land (97) which, in the neutral position (FIG.

Abstract: A differential device (11) of the type including a clutch pack (23), engaged by a ball ramp actuator (21), which is initiated by a viscous coupling (19;101). The output of the device (11) is an output shaft (13) which is hollow and extends through the entire axial extent of the device. The viscous coupling (19;101) includes, in the embodiment of FIG. 1, an annular input coupling member (25) and an annular output coupling member (27), within the input member, to define therebetween a cylindrical viscous shear chamber (29). The output coupling member (27) at least partially surrounds the first ramp plate (41) of the ball ramp actuator (21), and is in driving engagement therewith, for improved packaging.

Abstract: A hydraulic tappet (5) comprises an inverted cup-shaped element with an upper disk (51), welded to a cylindrical body (52) of the tappet which is internally provided with a flange (54), forming a tubular guide sleeve (55) for the axial movement of an internal assembly comprising a movable reservoir portion (57) for low-pressure oil. The tappet has interposed, between an internal surface (51s) of said upper disk (51) of said tappet (5) and a rim (57) of the reservoir portion, an elastic device (A), comprised of two elements (10,20), in order to achieve a rapid recovery of lift loss of said tappet (5) so as to improve the contact between the cam (2) of the cam shaft (1) and the disk (51) of the tappet (5). One result is to eliminate undesirable, early opening of the poppet valve (4) whenever the fuel injector cam (6) deflects under load.

Abstract: A vehicle propel system, including a hydrostatic transmission having wheel motors (37L,37R) and a variable displacement pump (39), variable in response to a pump displacement command signal (51). The system involves determining (67) anticipated motor flow, and generating a signal (69) corresponding thereto. A pressure command signal (77) corresponds to the desired pump pressure. Actual motor flow is sensed (75), and a processor (49) calculates pump flow and compares it to actual motor flow (75) to determine system leakage (107). The processor then modifies the anticipated motor flow signal (69) to compensate for system leakage (107), and generates the appropriate pump displacement command signal (51). The use of feed-forward terms, such as anticipated motor flow (69), pump speed and commanded pressure times leakage gain to calculate desired pump displacement allow a lesser gain to be used for the feedback term (measured pump pressure 59), thereby reducing "wheel hop".

Abstract: A variable displacement hydrostatic pump (11) having its displacement varied by a controller (17) in response to movement of a manual control lever (95) from a neutral position (FIG. 1). The vehicle has at least one other device (125,127) which provides an electrical output signal (133) indicating when operation of the pump (11) is "acceptable", in terms of either vehicle performance or operator safety. Associated with the control lever (95) is an input shaft (103) defining at least one stop surface (121,123). A solenoid assembly (109) has a moveable plunger (111), disposed adjacent the stop surfaces, and moveable between a retracted position (FIG. 4a) and an extended position (FIGS. 2 and 4), engaging one of the stop surfaces, when the output signal (133) indicates that operation of the pump is not acceptable.

Abstract: An integral brake assembly for a gerotor motor of the type including valving (41) disposed forwardly of the gerotor gear set (15). Orbital and rotational movement of the gerotor star member (31) is transmitted to an output shaft (43) by a main drive shaft (51), which includes a rearwardly extending brake portion (107). The motor includes an endcap assembly (21) defining a brake chamber (73) into which the brake portion (107) extends. A cylindrical brake member (91) is disposed in the brake chamber (73), and includes a circular surface (109) for frictional engagement with a lock piston (75). The brake member (91) also includes a forward generally annular surface (115) for frictional engagement with either the gerotor gear set (15) or an adjacent wear plate (89). The invention at least reduces the need for expensive friction discs in order to achieve a desired level of brake torque, and also utilizes inherent friction in various brake parts for some of the required brake torque.

Abstract: A rotary fluid pressure device (11) comprising a gerotor motor of the type including a spool valve member (51) cooperating with a housing (13) to define a nominal valve overlap (X). The motor has a drive shaft (53) for transmitting the rotational movement of a gerotor star (27) to the spool valve member (51) and output shaft (49), such that, under high torque loads, the drive shaft (53) is subjected to drive twist, which would normally effect valve timing. In accordance with the invention, the spool valve member (51) and the housing are provided with a valve overlap (Y) which is substantially greater than the nominal overlap (X). The star (27) defines, on its profile (85), first (87) and second (89) recesses which permit communication between the minimum (30) and maximum (32) volume transition chambers and the respective expanding (29) and contracting (31) volume chambers (FIG. 8).

Abstract: A hydraulic unit including a housing (10,11,13) within which is disposed a rotating cylinder barrel (25) driven by an input shaft (21). The housing means includes an end cap (13) disposed adjacent the end (45) of the cylinder barrel, with a valve plate (39) being disposed intermediate the of the barrel and an interior surface (65) of the end cap (13). The end cap defines a kidney port (59), a high pressure port (63), and a passage (61) interconnecting the kidney port and the high pressure port. In a configuration of the end cap which makes the pump compact, high pressure in the passage can cause deformation of a portion (69) of the end cap. To accommodate such deformation, the valve plate (39) is provided with a relieved area (71) disposed immediately adjacent the deformation portion (69).

Abstract: An exhaust gas recirculation system (11) for an internal combustion engine, including a valve (25) having a closed position (FIG. 2) blocking flow of exhaust gas, the valve being biased by gas pressure in the exhaust gas passage (E) toward a closed position (FIG. 2). The system includes an electric motor (51) having an input gear (55) and a gear train (57,59) driving a sector gear (73). A linkage member (93) has its ends (91,95) connected to the sector gear (73) and the valve stem (29), respectively. The sector gear and the linkage member are configured such that, as the valve begins to open against exhaust gas pressure, the movement of the valve stem is a relatively higher force, and at a relatively lower speed. As the valve moves toward a fully open position (FIG. 7), the movement of the valve stem is at a relatively lower force, but at a relatively higher speed.

Abstract: A center differential device (17) for use in a four wheel drive system, the device including a viscous coupling (29), a ball ramp actuator (31), and a clutch pack (33). Under normal driving conditions, most of the torque is transmitted to the front drive wheels (11), and the device (17) rotates as a unit. If the front wheels (11) begin to slip, the input shaft (15) and input coupling member (35) rotate faster than the output coupling member (43), thus transmitting torque to the output coupling member (43). This torque is transmitted to the first ramp plate (51) of the ball ramp actuator (31), displacing the actuator from its neutral position (FIG. 3), such that the second ramp plate (52) begins to load the clutch pack (33) and transmit torque from the housing (25) to the output shaft (19), and from there to the rear drive wheels (23).

Abstract: A two-speed gerotor motor of the type having a stationary valve member (19) defining a plurality of stationary valve passages, each including an upstream passage portion for commutating fluid communication with a moveable valve member (43), and a downstream passage portion in continuous fluid communication with a volume chamber (33) of the gerotor gear set. In some of the stationary valve passages (113), the upstream (115) and downstream (117) passage portions are blocked from direct fluid communication. A control valve spool (89) has a first position (FIG. 8) permitting unrestricted fluid communication between the upstream and downstream passage portions, for normal low-speed operation. The control valve spool has a second position (FIG.

Abstract: A valve deactivator assembly (13) for an internal combustion engine, the assembly including a drive rocker arm (39) receiving cyclical motion from an engine push rod (23), and a driven rocker arm (41) which engages the engine poppet valve (29). The rocker arms are biased by a lost motion spring (49) to a position in which the rocker arms align to define a latching chamber (63), having a moveable latch member (65) disposed therein and biased by a spring (67) toward a latched position (FIG. 1). An electromagnetic actuator assembly (81) is disposed adjacent the rocker arms (39,41) and in response to an input signal (88), exerts a force on an actuation shaft (93) and an actuation beam (97) to move the latch member (65) toward its unlatched position (FIG. 3). The invention provides an effective, compact valve deactivator which can change quickly between the latched and unlatched conditions.

Abstract: A gerotor motor of the type having an end cap (13), and a stationary valve plate (15) disposed adjacent a rearward surface of the gerotor gear set (17). Adjacent a forward surface of the gerotor star (27) is a balancing plate assembly (19) including a radially outer balance plate (73) and a radially inner balance plate (75), the balance plates defining inner (77) and outer (79) profiles, respectively, which are closely spaced apart and are radially inward from the gerotor volume chambers (29) to provide sufficient sealing land. The inner balance plate (75) is biased toward the star end surface (81) by a Belleville washer (87). The end surface (81) of the gerotor star (27) defines individual star tooth surfaces (97), each of which includes a radial fluid passage (99) receiving system pressure, and a fluid passage (101) oriented generally perpendicular to the radial passage, and having a decreasing flow volume in a direction away from the radial passage (99).