Eaton Corporation

Steven J Zumbusch

Walter K O'Neil

Marvin L Bernstrom

Benjamin Maxfield Hoxie

Maynard W Marts

A method of operating a brake-assist-steering system of a vehicle comprises the steps of receiving a signal from a wheel position detector. A theoretical wheel speed for an inside non-steered wheel is computed. A brake operably associated with the inside non-steered wheel is actuated when an actual wheel speed of the inside non-steered wheel is greater than the theoretical wheel speed of the inside non-steered wheel.

Brake-assist-steering system

A tandem pump assembly of the type including a housing (H), disposed in which is a first pump (), driven by an input shaft (), and a second pump (), also driven by the input shaft (). The assembly is characterized by the tandem pump assembly including pressure override valve means () associated with only the first pump (), and operable, in response to a fluid pressure at a fluid outlet port () in excess of a pressure override setting (), to communicate pressurized fluid to a first fluid pressure responsive means (), in a manner tending to decrease the displacement of the first pump () without effecting the displacement of the second pump (), until said fluid pressure is substantially equal to the pressure override selling (), even if it is necessary for the first pump () to go over-center from its initial displacement.

Pump control override for tandem pumps

A hydraulic unit of the type including a cylinder block (,) rotatably disposed adjacent a valve plate (,) having inlet ports,, and,, and further having outlet ports,, and,. Disposed between the individual inlet and outlet ports are web portions, having nominal cross-sections and flow restrictions. In one embodiment (FIG.,), there is a modified web portion (,) toward the trailing end of the outlet port, and in the other embodiment (FIG.,), there is a modified web portion (,) 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 (,) 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.

Axial piston pump and improved valve plate design therefor

A gerotor pump is disclosed of the fixed-axis type, including an outer rotor (33) and an inner rotor (35). The gerotor is driven by a drive shaft (25) through a driver (51) including a pair of drive members (57), each having a cylindrical drive surface (59). The inner rotor (35) defines a pair of diametrically opposed recesses (61), each including a driven surface (63). With the drive members engaging the driven surfaces, the inner rotor is permitted to deviate from perfect concentricity with the drive shaft to the extent necessary to result in minimum torque input to drive the rotors, without binding occurring between the rotors, as typically occurs if the inner rotor is forced to remain concentric with the drive shaft.

Gerotor pump having an improved drive mechanism

A homoplanar brushless electric gerotor (10) includes a housing assembly (32) defining a substantially closed cavity (52), a fluid inlet port (88). Inner and outer gerotor pump gears (72,74), are eccentrically disposed for relative rotation within the cavity whereupon a working fluid received at the inlet port at a low pressure is discharged from the outlet port at a high pressure. A plurality of alternatingly radially polarized circumferentially aligned permanent magnets (76) are carried by one of the pump gears for rotation therewith. A stator including windings (44) circumferentially distributed and axially spaced from the permanent magnets (76) electromagnetically interact therewith to effect their rotation upon the electrical energization of the windings (44) by a drive circuit (26).

Homoplanar brushless electric gerotor

A closed-loop motor speed control system is disclosed including a gerotor motor (11) having a gerotor gear set (51) operable to transmit rotational torque output by means of a main drive shaft (83) to an output shaft (13) by means of a set of splines (79) formed within a spool member (77). The spool member (77) and the housing section (49) cooperate to define a flow path from a fluid port (27) through the expanding and contracting volume chambers (67) of the gerotor (51), and to the fluid port (29). The motor (11) includes integral flow control capability. Rotation of a control shaft (43) and cam member (101) moves the spool member (77) from a position in which a passage (61) is in open communication with an annular groove (93) (FIG. 3) to a position in which such communication is restricted (FIG. 4).

Hydraulic motor having integral flow control capability

A rotary fluid pressure device is disclosed of the type including housing means defining a fluid inlet (57) and a fluid outlet (61) and including some form of rotary fluid energy-translating displacement mechanism associated with the housing. In one embodiment of the invention, the displacement mechanism comprises a gerotor gear set (17) including a housing member (22), an internally-toothed ring (23), and an externally-toothed star (27). Included is a free-wheeling mechanism (71) having an engagement member (73) and an actuation means (81) operable to move the engagement member between first and second positions. In a first position, the engagement member (73) prevents rotational movement of the ring (23) and the star (27) has its normal and orbital rotational movement to define expanding (28) and contracting (29) fluid volume chambers. In a second position, the engagement member (73) permits the ring (23) to rotate freely and the star (27) and ring (23) rotate together such that the fluid volume chambers neither expand nor contract and no fluid is displaced from the displacement mechanism.

Rotary fluid pressure device having free-wheeling capability

A rotary fluid pressure device is provided of the type in which a valve spool (47) is axially movable within a spool bore (35). In the normal operating position of the valve spool (47), torque output is transmitted from the gerotor gear set (17) by means of a main drive shaft 53 through one spline connection (51, 49) then through a second spline connection (49, 75) to the output device. The valve spool (47) may be moved axially to a position in which the second spline connection (49, 54) is disengaged, and the device operates in a free-wheel mode. The valve spool (47) may also be moved axially to a position in which a set of teeth (71) on the valve spool engage a set of teeth (69) on the stationary housing, such that the device operates in a locked mode.

Hydraulic motor having free-wheeling and locking modes of operation

A shaft seal assembly (55) for use in a rotary fluid pressure device. The device includes a housing (51) and a rotary shaft (31). The shaft seal assembly (55) includes an elastomeric sealing element (65), an inner support member (67) and an outer support member (69). The sealing element (65) includes a cushion portion (81) disposed radially between the inner and outer support members to cushion radial movement of the inner support member when the shaft moves radially. The sealing element (65) includes a sealing lip (71) defining a pivot point (83) and the inner support member extends rearwardly of the pivot point (83), whereby radial movement of the inner support member results in corresponding radial movement of the sealing lip (71), reducing the loading on the lip.

Shaft seal and means to effect radial movement of sealing lip

A rotary fluid pressure device is disclosed of the type including a gerotor displacement mechanism (17), a rotary valve member (55), and a valve seating mechanism (75). The valve seating mechanism includes a balancing ring member (77) seated in an annular groove (81) defined by the valve housing (21). Leakage fluid from the gerotor displacement mechanism passes from the central case drain region (83) through the bearings (33 and 35) to an annular chamber (87). The leakage fluid is communicated from the annular chamber (87) to whichever of the ports (75 or 61) is connected to the system reservoir, through a series of fluid passages (131, 133, 135, 137, and 139). The fluid passage (139) communicates with the annular groove (81), and the leakage fluid flows past whichever of the balancing ring seals (143 or 145) is subjected to low pressure fluid, the balancing ring seal thus acting as a check valve. The invention eliminates the complicated and expensive prior art check valve assemblies (103, 105).

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Eden Prairie, MN, United States of America

Steven J Zumbusch