Abstract: A heater includes a substrate, a first heating element and a second heating element disposed on a first surface of the substrate, a temperature detection element, and a conductor. The temperature detection element is disposed on a second surface of the substrate opposite the first surface of the substrate. The conductor is disposed on the second surface and connected to the temperature detection element. The first heating element has a first distance from the temperature detection element in a lateral direction of the substrate orthogonal to a longitudinal direction of the substrate, and the second heating element has a second distance that is greater than the first distance from the temperature detection element in the lateral direction. As viewed in a thickness direction of the substrate orthogonal to the lateral direction and the longitudinal direction of the substrate, the conductor overlaps the first heating element and the second heating element.

Abstract: A planetary gear device as a central differential is provided. The planetary gear device has a first sun gear connected to an output shaft of a transmission, a carrier, first and second planetary pinions rotatably supported on the carrier through a shaft, and a second sun gear. The first planetary pinion is engaged with the first sun gear, and the second planetary pinion is engaged with the second sun gear. Each of the sun gears and the planetary pinions is arranged such that resultant force produced by a separative load and a tangential load at a contact point of the pinion and the sun gear is exerted on a bearing on the shaft, so that friction at the bearing produces a differential operation restricting torque.