In-wheel motor
An in-wheel motor with improved driving force has a simplified cooling structure for the motor and a braking device. The in-wheel motor has a motor that transmits motive power to a wheel, at least a portion of the motor being disposed inside the wheel; a first cooling part and a second cooling part that cool a stator of the motor; and a braking device that applies braking to the wheel. The braking device 25 is formed from a brake disc that rotates with the wheel and a brake caliper that induces braking by imparting friction to the brake disc. The brake caliper operates in the axial direction of the motor to induce braking in the brake disc. A portion of an axial-direction end of the brake caliper is in contact with the stator. The first cooling part and the second cooling part cool the braking device through the stator.
1 . An in-wheel motor, comprising:
a motor at least a part of which is disposed inside a wheel and which transmits power to the wheel;
a cooling device that cools a stator of the motor; and
a brake device that applies a brake to the wheel,
wherein the brake device includes a brake disc that rotates together with the wheel, and a brake caliper that applies friction to the brake disc for braking,
wherein the brake caliper operates in an axial direction of the motor to apply a brake to the brake disc,
wherein a part of an axial end portion of the brake caliper is in contact with the stator,
wherein the cooling device cools the brake device via the stator,
wherein the cooling device includes a liquid refrigerant,
wherein the cooling device includes a first cooling portion through which the liquid refrigerant circulates and a second cooling portion through which the liquid refrigerant does not circulate, and
wherein the brake caliper is in contact with the first cooling portion via the second cooling portion.
2 . The in-wheel motor according to claim 1 , wherein
the stator includes a stator housing that is open on one side in an axial direction and includes a rotor inside, and a stator housing cover that closes an open side of the stator housing,
the stator housing includes a housing annular portion having a cylindrical shape and extending in the axial direction, and a housing flat plate portion extending in a radial direction orthogonal to the axial direction, and
in the brake caliper, an axial end surface of the brake caliper is in contact with the housing flat plate portion.
3 . The in-wheel motor according to claim 1 , wherein the brake caliper is in contact with the stator via an elastic body having a Young's modulus smaller than Young's moduli of the brake caliper and the stator.
4 . The in-wheel motor according to claim 1 , wherein a part of the brake caliper is disposed at a position overlapping the stator in a radial direction.
5 . The in-wheel motor according to claim 4 , wherein
the stator includes a stator core to which a stator coil is attached, and
the brake caliper is disposed on an inner diameter side of the stator core.
6 . The in-wheel motor according to claim 1 , wherein the first cooling portion and
the second cooling portion are formed by partitioning an internal space of the stator with a rotor.
7 . The in-wheel motor according to claim 1 , wherein
the brake caliper is disposed such that a longitudinal direction of the brake caliper is an up-down direction, and
both end portions of the brake caliper in the up-down direction are fixed to the stator by fixing bolts.
8 . The in-wheel motor according to claim 1 , wherein the brake caliper is fixed to the stator from the wheel.