Trw Limited

Trw Automotive U.S. LLC

Zf Active Safety and Electronics US LLC

Mark J Bugosh

Brian A Urbach

John F Santori

John Walter Spetz

Michael J Boyer

Richard R Fraley, Jr

William Albert Konior

Colleen Kalczynski

Changming Wu

Andrew Dixon

Paul Webber

A vehicle steering assembly comprises a steering member with a rack portion having rack teeth, a pinion gear having pinion teeth configured to be engaged with the rack teeth, a yoke support assembly supporting the steering member in a housing, and a ball nut operatively connected to the steering member. The pinion gear divides the steering member into a first side having the yoke support assembly outboard of an area of engagement of the rack and pinion teeth and a second side having the ball nut. The yoke support assembly includes complementary convex and concave bearing surfaces configured to provide relative rotation between the convex and concave bearing surfaces. The yoke assembly also includes a spring member configured to produce a variable rate spring force to maintain an engagement between the rack and pinion teeth.

Yoke support assembly for a rack and a pinion gear of a steering assembly for a vehicle

A rack drive assembly adapted for use in a vehicle electric power steering assembly includes a bearing assembly disposed in a rack housing and carried by a ball nut assembly for rotatably supporting the ball nut assembly relative to a steering member; and a spanner nut carried by the rack housing for securing the bearing assembly in the rack housing. A first isolator, a second isolator and a first shim are provided wherein the first isolator is disposed between an inner surface of the housing and a first surface of an outer race of the bearing, the second isolator is disposed between an opposite second surface of the outer race of said bearing and the first shim, the first shim is disposed between the second isolator and the spanner nut. The first shim is provided with a member configured to be coupled to the housing to allow for axial movement but prevent rotational motion of the shim during installation of the spanner nut.

Electric power steering assembly

An improved structure for a rack drive assembly adapted for use in a vehicle electric power steering assembly includes a ball nut assembly operatively connected to a screw portion of a rack portion of a steering member of the power steering assembly for effecting axial movement of the steering member upon rotation of a vehicle steering wheel. According to one embodiment, the ball nut assembly includes a ball nut having an outer surface; a bearing assembly fixedly disposed in the rack housing and carried by the ball nut for rotatably supporting the ball nut assembly relative to the steering member; and a damper disposed on an outer race of the bearing assembly. The damper includes a pair of dampers disposed on the outer race of the bearing assembly, each of the dampers including at least a first member formed from a first rigid material and a second member formed from a second damping material.

This invention relates to an improved structure for a rack drive assembly adapted for use in a vehicle electric power steering assembly. The electric power steering assembly includes a steering member (), a ball nut assembly (), a bearing assembly () and an electric motor (). The steering member () is disposed in a rack housing () and includes a rack portion () operatively connected to a vehicle steering wheel () and a screw portion () having an external thread convolution (). The ball nut assembly () is operatively connected to the screw portion () of the rack portion () of the steering member () for effecting axial movement of the steering member () upon rotation of the vehicle steering wheel (). The ball nut assembly () includes a rotor shaft () and a ball nut () fixed to the shaft () for rotation therewith. The ball nut () includes an outer surface () and the rotor shaft () includes an inner surface (). The bearing assembly () is carried by the rotor shaft () for rotatably supporting the ball nut assembly () relative to the steering member (). The electric motor () is operatively coupled to the rotor shaft () via a pulley assembly (). The power steering assembly further includes an insulator () disposed between at least a portion of the outer surface () of the ball nut () and the inner surface () of the rotor shaft (). The insulator () isolates the ball nut () from at least one of the pulley assembly () and the bearing assembly () to thereby reduce the noise in the ball nut assembly ().

The invention relates to a tensioning device for use in vehicle power steering assembly, in particular, having a drive unit for rotating an input pulley rotatably connected to an output pulley via a flexible belt. The tensioning device includes a housing and an arm movably attached relative to the housing. A contact device is mounted on the arm and is adapted to be engaged with a portion of the belt between the input and output pulleys. The arm is movable relative to the belt to position the contact device against the belt to provide tension on the belt.

Belt tensioner for electric power steering unit

A rack and pinion steering gear ( ) comprises a housing ( ). A yoke assembly ( ) is in the housing ( ) for at least partially supporting and guiding movement of a rack bar ( ) relative to a pinion gear ( ). The yoke assembly ( ) comprises a yoke ( ) and a plurality of rotatable members. The yoke ( ) has a first end surface ( ) and an axis (A) that extends transverse to the direction of movement of the rack bar ( ). Each of the plurality of rotatable members is supported by the yoke ( ). A portion of each rotatable member projects outward of the first end surface ( ) of the yoke ( ) for contacting the rack bar ( ). Each rotatable member is rotatable about its axis and is fixed against movement along the yoke axis (A) relative to the yoke ( ).

Rack and pinion steering gear with low friction yoke assembly

The present invention is directed to a power assisted steering system ( ). The power assisted steering system ( ) comprises a rotatable member ( ) capable of rotating about an axis. The system further comprises a ballnut ( ) that is coaxial with the rotatable member ( ). The ballnut ( ) has a threaded cylindrical inner surface ( ) and a plurality of drive balls ( ). The system ( ) further comprises a steering member ( ). The steering member ( ) is coaxial with the rotatable member ( ) and the ballnut ( ). The steering member ( ) has a threaded portion ( ). The steering member ( ) extends through the inner surface ( ) of the ballnut ( ) such that the drive balls ( ) of the ballnut ( ) engage the threaded portion ( ) of the steering member ( ). The ballnut ( ) is rotatably driven by the rotatable member ( ) about the axis and is pivotal relative to the rotatable member ( ) in a direction transverse to the axis.

Pivotal ballnut connection for a power assisted steering system

A tool (,) for installing a radially compressible bushing (,) into a housing (,) of a rack and pinion steering system (,). The housing has an end portion (,) that includes a ring-shaped bushing chamber (,) and a circular opening (,) into the bushing chamber. The opening (,) has a first diameter, and the bushing chamber (,) has a second diameter greater than the first diameter of the circular opening. The tool (,) comprises a plunger (,) having a first portion (,) with an outer diameter that is less than the first diameter of the opening (,) in the housing (,). The first portion (,) of the plunger (,) has a circumferential groove (,) defined by a pair of annular end surfaces (,) and a cylindrical base surface (,). The groove (,) receives the bushing (,) during installation of the bushing in the housing (,). The annular end surfaces (,) of the groove (,) block axial movement of the bushing (,) along the plunger (,) while the bushing is on the plunger. The tool (,) also includes a sleeve (,) slidable along the first portion (,) of the plunger (,) to radially compress the bushing (,) and hold the bushing in the groove (,) during installation of the bushing in the housing (,).

Bushing installation tool

A winding tool (10) is used for connecting pairs of motor stator winding leads (91b-98b, 91c-98 c) and cutting of the connected pairs of leads to a predetermined length. The winding tool (10) includes a first part (100) received in the rotor space (88) in the motor stator (12) and a second part (102) projecting from a first end portion (72) of the motor stator. The first part (100) of the winding tool (10) has a cylindrical outer surface (116) engageable in an interference fit with a cylindrical inner surface (86) of the motor stator core (80) to resist radial and axial movement of the winding tool relative to the motor stator (12). The winding tool (10) has a plurality of slots (131-138) spaced circumferentially about an axis (30) and extending along an outer surface (126) of the second part (102) of the winding tool (10). The number of slots (131-138) is equal to the number of magnetic poles of the motor stator (12). The slots (131-138) have an axial length approximately equal to the predetermined length of the connected pairs of leads (91b-98b, 91c-98c).

Motor stator winding tool

A method of manufacturing a rack and pinion steering gear (10) comprises the steps of: providing a housing (12) with first and second chambers (36 and 42) and threads (44) which partially define the second chamber (42); positioning a rack (14) in the first chamber (36); positioning a yoke (70) in the second chamber (42); screwing threads (94) of a plug (90) into the threads (44) which at least partially define the second chamber (42) to cause the plug to press the yoke (70) into engagement with the rack (14) by rotating the plug about an axis (38) relative to the housing (12) in a first direction (A); and simultaneously deforming the threads (44) which at least partially define the second chamber (42) at a plurality of locations spaced about the axis (38) to limit the amount of rotation of the plug (90) in a second direction (B) about the axis opposite the first direction (A).

Method of manufacturing a rack and pinion steering gear

A steering assembly (10) for turning steerable wheels of a vehicle in response to rotation of a steering wheel (12) includes a pinion (30). A steering member (14) is movable axially to effect turning movement of the steerable wheels of the vehicle. The steering member (14) has a rack portion (34) for engagement with the pinion (30) and an externally threaded screw portion (38). A ball nut (140) extends around the screw portion (38) of the steering member (14) and has an internal thread (144). A plurality of balls (200) are disposed between the internal thread (144) on the ball nut (140) and an external thread (40) on the steering member (14) for transmitting force between the ball nut and the screw portion (38) of the steering member. An electric motor (50) includes a rotor (132) drivingly connected to the ball nut (140) and a stator (70). The stator (70) when energized effects rotation of the rotor (132) and, thereby, rotation of the ball nut (140). The steering assembly includes a one-piece molded plastic member (60) having a first axial portion (62) disposed adjacent to the pinion (30), a second axial portion (66) encapsulating and supporting the stator core (72) and the stator windings (82), and a third axial portion (110) supporting the ball nut (140) for rotation with the rotor (132).

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Sterling Heights, MI, United States of America

Mark J Bugosh