Power transmission device and constant velocity universal joint therefor
AssigneeNtn Corporation
InventorsMasazumi Kobayashi, Takeshi Kohara, Haruo Nagatani, Yoshikazu Fukumura
Life of this patent
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Abstract
A double offset type constant velocity universal joint for use in a power transmission system of an automobile comprises an inner member, an outer member, and a plurality of balls for transmitting torque between the Inner and outer members, the balls being retained by means of a cage also interposed between the inner and outer members, the cage being so designed as to allow the inner and outer members to move axially relatively to each other by an effective amount to absorb not only slight vibrations of an engine but also a greater movement of the engine caused by starting acceleration of the automobile.
Claims31
A constant velocity universal joint for coupling together two rotary axes in a drive system for an automobile, comprising:
- an outer member adapted to connect with one of the rotary axes, said outer member having a cylindrical hole with a plurality of axially extending guide grooves formed in a cylindrical inner surface thereof,
- an inner member adapted to connect with the other of the rotary axes, said inner member having an outer surface which is at least partly spherical, with the same number of axially extending guide grooves as the guide grooves of said outer member formed in the outer surface,
- a plurality of balls for transmission of torque, each of said balls being received in a ball track defined by a pair of opposing guide grooves of said outer and inner members, and
- a cage having ball pockets for receiving the respective balls, said cage having partial spherical inner and outer surfaces of which centers of curvature are offset axially of the joint by the same distance on the opposite sides of the ball center line and the partial spherical surfaces of the cage are respectively guided by contact with the partial spherical outer surface of said inner member and the cylindrical hole of said outer member, a pocket clearance is axially defined between said ball and the ball pocket of said cage allowing for smooth rolling of said ball, and the inner surface of said cage is comprised of a cylindrical surface portion, the inner partial spherical surfaces being connected to opposite sides of said cylindrical surface portion, said cylindrical surface portion has a sufficient length measured axially of a central portion of the cage to allow for relative movement of the inner member with respect to the cage thereby bringing a portion of the outer surface of the inner member into engagement with one of the partial spherical surfaces of the cage, to absorb an amount of movement of an engine produced during starting acceleration of the automobile.
A power transmission device for an automobile including a drive shaft connected at one end thereof directly to the engine through a slide type constant velocity universal joint and at the other end thereof to the wheels through a fixed type constant velocity universal joint, said slide type constant velocity universal joint comprising:
- outer member adapted to connect with one of the rotary axes, said outer member having a cylindrical hole with a plurality of axially extending guide grooves formed in a cylindrical inner surface thereof,
- an inner member adapted to connect with the other of the rotary axes, said inner member having an outer surface which is at least partly spherical, with the same number of axially extending guide grooves as the guide grooves of said outer member formed in the outer surface,
- a plurality of balls for transmission of torque, each of said balls being received in a ball track defined by a pair of opposing guide grooves of said outer and inner members, and
- a cage having ball pockets for receiving the respective balls, said cage having partial spherical inner and outer surfaces of which centers of curvature are offset axially of the joint by the same distance on the opposite sides of the ball center line and the partial spherical surfaces are respectively guided by contact with the partial spherical outer surface of said inner member and the cylindrical hole of said outer member,
- a pocket clearance is axially defined between said ball and the ball pocket of said cage allowing for smooth rolling of the ball, and the inner surface of said cage is comprised of a cylindrical surface portion, the inner partial spherical surfaces being connected to opposite sides of said cylindrical surface portion, said cylindrical surface portion has a sufficient length measured axially of a central portion of the cage to allow for relative movement of the inner member with respect to the cage thereby bringing a portion of the outer surface of the inner member into engagement with one of the partial spherical surfaces of the cage, to absorb an amount of movement of an engine produced during starting acceleration of the automobile.
Dependencies are inferred from the claim text.