Motor-equipped gear box mounting structure
View Patent ↗A motor-equipped gear box mounting structure includes a motor-equipped gear box. This motor-equipped gear box includes a motor and a gear box. The gear box has a main body portion that is fixed to the frame member and within which is housed a reduction gear group that transmits driving force from the motor to an output shaft, and a motor mounting portion that mounts the motor to the main body portion. The gear box also has a weak portion between the main body portion and the motor mounting portion. A rotating shaft of the motor is coaxially and detachably connected to a rotating shaft of a worm gear that is one gear in the reduction gear group.
1. A motor-equipped gear box mounting structure that is configured to be attached to a frame member that extends in a front-rear direction of a vehicle power seat and to vertically adjust a seating surface of the vehicle power seat, the motor-equipped gear box mounting structure comprising:
a motor-equipped gear box that includes a motor and a gear box, wherein
the gear box comprises:
a main body portion that is configured to be fixed to the frame member and within which is housed a reduction gear group that transmits a driving force from the motor to an output shaft, the main body portion including a motor-side bearing holding portion that holds a motor-side rotary bearing;
a motor mounting portion that mounts the motor to the main body portion;
a weak portion defining a plane and disposed between the main body portion and the motor mounting portion such that the weak portion is provided on a motor-side of the motor-side bearing holding portion,
the weak portion being configured to break such that the motor and the motor mounting portion detach from the main body portion as a result of a pressing force being applied to the motor-equipped gear box due to deformation of the frame member when the motor-equipped gear box mounting structure is attached to the frame member, and
a rotating shaft of the motor is coaxially and detachably coupled to a rotating shaft of a worm gear by a connection, wherein the worm gear is one gear in the reduction gear group,
wherein at least a portion of the connection is disposed in the plane defined by the weak portion.
2. The motor-equipped gear box mounting structure according to claim 1 , wherein
the main body portion, the motor mounting portion, and the weak portion are an integrated resin part, and
the weak portion is narrower than the main body portion and the motor mounting portion.
3. The motor-equipped gear box mounting structure according to claim 1 , wherein
the rotating shaft of the motor is connected to the rotating shaft of the worm gear by a rubber shaft coupling that detachably connects the rotating shaft of the motor to the rotating shaft of the worm gear via a rubber spacer.
4. The motor-equipped gear box mounting structure according to claim 1 , wherein
a reinforcing plate is attached to a surface of the main body portion that is on a side where the main body portion is configured to attach to the frame member, the reinforcing plate reinforces the main body portion and supports a rotating shaft of an other gear in the reduction gear group that transmits driving force from the worm gear to the output shaft, and
at least one fixing position, where the reinforcing plate is fixed to the main body portion, is provided adjacent to the weak portion.
5. The motor-equipped gear box mounting structure according to claim 1 , wherein
the worm gear comprises a torsion angle direction configured such that an axial thrust force applied to the rotating shaft of the worm gear acts in a direction away from the motor when a rotational force applied to the output shaft is transmitted to the worm gear when a vehicle collision occurs.
6. The motor-equipped gear box mounting structure according to claim 1 , wherein
the main body portion and the motor mounting portion taper to the weak portion.
7. The motor-equipped gear box mounting structure according to claim 1 , wherein
the main body portion, the motor mounting portion, and the weak portion define a unitary portion of the gear box.
8. The motor-equipped gear box mounting structure according to claim 1 , wherein
the weak portion is thinner in cross section than both the main body potion and the motor mounting portion.
9. The motor-equipped gear box mounting structure according to claim 1 , wherein
a perimeter of an outer portion of the weak portion is less than both a perimeter of an outer portion of the main body portion and a perimeter of an outer portion of the motor mounting portion.
10. The motor-equipped gear box mounting structure according to claim 1 , wherein:
the rotating shaft of the motor has a terminal end having a plurality of columnar bodies, and
the connection comprises:
a connecting member fixed to the rotating shaft of the worm gear having a plurality of connecting member columnar bodies; and
a spacer arranged between the rotating shaft of the motor and the connecting member, the spacer having a plurality of notches that accommodate the columnar bodies and the connecting member columnar bodies.