Patent ID: 8021260

Claim:
A transmitting torque limiting apparatus for a vehicle, constructing a part of a power transmitting apparatus disposed in a power transmitting path extending from a power source to driving wheels, for limiting inputting of an excessive torque into the power transmitting apparatus, comprising: a first rotary member rotated about an axis by the power source; a second rotary member disposed adjacent to the first rotary member on the power transmitting path to be rotated about the axis; first engaging teeth and second engaging teeth respectively provided on the first rotary member and the second rotary member to be meshed with each other; and a biasing mechanism for biasing one of the first rotary member and the second rotary member which is shiftable toward other of the first rotary member and the second rotary member so that the first engaging teeth and the second engaging teeth are meshed with each other, the biasing mechanism being disposed coaxially with the second rotary member and one end of the biasing member being abutted to the shiftable rotary member to bias the shiftable rotary member toward the non-shiftable rotary member; wherein each of the first engaging teeth and each of the second engaging teeth are provided with a pressure angle of predetermined value which function to shift the shiftable rotary member against biasing force by the biasing mechanism to thereby disengage engagement between the first engaging teeth and the second engaging teeth, when an excessive torque larger than a predetermined value is inputted to the first rotary member or the second rotary member, wherein the transmitting torque limiting apparatus is a differential gear unit including a pair of side gears, a pair of side gear pieces, and a pair of side gear shafts, and wherein the side gears constructing the first rotary member are rotatably fitted on an outer peripheral surface of the side gear shafts, the side gear pieces constructing the second rotary member are spline-fitted on an outer peripheral surface of the side gear shafts to be rotated integral therewith and axially shiftable relative thereto, and to be adjacent to the side gears, and the first engaging teeth and the second engaging teeth are respectively provided on an abutment surface of the side gears and an abutment surface of the side gear pieces adjacent thereto.