Electric power steering assembly

A steering assembly for turning steerable wheels of a vehicle in response to rotation of a vehicle steering wheel, said steering assembly comprising:

• a housing;
• a member which is movable axially within said housing to effect turning movement of the steerable wheels, said member having an externally threaded screw portion;
• a ball nut disposed in said housing, said ball nut extending around said screw portion of said member and having an internal thread;
• a plurality of balls disposed between said internal thread on said ball nut and said externally threaded screw portion of said member for transmitting force between said ball nut and said screw portion to cause axial movement of said member;
• an electric motor for providing a drive force to move said member in response to rotation of the steering wheel, said electric motor including a rotatable output shaft which is rotatable about a motor axis which extends transverse to said member;
• gearing for transmitting the drive force of said electric motor to said ball nut, said gearing providing a first gear reduction between said output shaft of said electric motor and said ball nut;
• said gearing comprising first and second gears, said first gear being fixed for rotation with said ball nut about a first axis, said second gear being fixed for rotation with said output shaft of said electric motor about said motor axis;
• said first and second gears being contained within said housing, said electric motor being adjustably mounted to said housing;
• and
• adjusting means for adjusting backlash between said first and second gears, said adjusting means including eccentric surface means for shifting said motor axis of said electric motor and said second gear relative to said first gear.

A steering assembly for turning steerable wheels of a vehicle in response to rotation of a vehicle steering wheel, said steering assembly comprising:

• a housing;
• a member which is movable axially within said housing to effect turning movement of the steerable wheels, said member having an externally threaded screw portion;
• a ball nut disposed in said housing and extending around said screw portion of said member, said ball nut having an outer surface and an internal surface which is threaded,
• said ball nut including a first gear fixed to said outer surface for causing rotation of said ball nut about a first axis;
• a plurality of balls disposed between said threaded internal surface of said ball nut and said externally threaded screw portion of said member for transmitting force between said ball nut and said screw portion to cause axial movement of said member;
• an electric motor for providing a drive force to move said member in response to rotation of the steering wheel, said electric motor including a rotatable output shaft which is rotatable about a motor axis which extends traverse to said member;
• a second gear meshed with said first gear for transmitting the drive force of said electric motor to said first gear on said ball nut, said second gear being fixed for rotation with said output shaft about said motor axis, said first and second gears providing a first gear reduction between said electric motor and said ball nut;
• said first and second gears being contained within said housing, said electric motor being adjustably mounted to said housing;
• and
• adjusting means for adjusting backlash between said first and second gears, said adjusting means including eccentric surface means for shifting said motor axis of said electric motor and said second gear relative to said first gear.

A steering assembly for turning steerable wheels of a vehicle in response to rotation of a vehicle steering wheel, said steering assembly comprising:

• a housing;
• a member which is movable axially within said housing to effect turning movement of the steerable wheels, said member having an externally threaded screw portion;
• a ball nut disposed in said housing and extending around said screw portion of said member, said ball nut having an outer surface and an internal surface which is threaded,
• said ball nut including a first bevel gear fixed to said outer surface for causing rotation of said ball nut about a first axis;
• a plurality of balls disposed between said threaded internal surface of said ball nut and said externally threaded screw portion of said member for transmitting force between said ball nut and said screw portion to cause axial movement of said member;
• an electric motor for providing a drive force to move said member in response to rotation of the steering wheel, said electric motor including a rotatable output shaft which is rotatable about a motor axis which extends traverse to said member and which intersects said first axis;
• and
• a second bevel gear meshed with said first bevel gear for transmitting the drive force of said electric motor to said first bevel gear on said ball nut, said second bevel gear being fixed for rotation with said output shaft about said motor axis, said second bevel gear rotating about said motor axis which extends transverse to said first axis about which said first bevel gear rotates, said first and second bevel gears providing a first gear reduction between said electric motor and said ball nut.