A power transmission shaft has a shaft member having, on an outer peripheral surface thereof, a male spline; a cylindrical member having, on an inner peripheral surface thereof, a female spline; and a seal member provided in a pressed state between an outer peripheral seal surface formed on the outer peripheral surface of the shaft member and an inner peripheral seal surface formed on the inner peripheral surface of the cylindrical member. The cylindrical member is spline-engaged with the shaft member by one end side of the shaft member being inserted into the cylindrical member from an other end side of the cylindrical member. Axial direction shock is absorbed by sliding of the splines. The outer peripheral seal surface is positioned at the other end side with respect to the male spline, and the inner peripheral seal surface is positioned at the other side with respect to the female spline.

A power transmission shaft has a shaft member having, on an outer peripheral surface thereof, a male spline; a cylindrical member having, on an inner peripheral surface thereof, a female spline; and a seal member provided in a pressed state between an outer peripheral seal surface formed on the outer peripheral surface of the shaft member and an inner peripheral seal surface formed on the inner peripheral surface of the cylindrical member. The cylindrical member is spline-engaged with the shaft member by one end side of the shaft member being inserted into the cylindrical member from an other end side of the cylindrical member. Axial direction shock is absorbed by sliding of the splines. The outer peripheral seal surface is positioned at the other end side with respect to the male spline, and the inner peripheral seal surface is positioned at the other side with respect to the female spline.

A power transmission shaft has a shaft member having, on an outer peripheral surface thereof, a male spline; a cylindrical member having, on an inner peripheral surface thereof, a female spline; and a seal member provided in a pressed state between an outer peripheral seal surface formed on the outer peripheral surface of the shaft member and an inner peripheral seal surface formed on the inner peripheral surface of the cylindrical member. The cylindrical member is spline-engaged with the shaft member by one end side of the shaft member being inserted into the cylindrical member from an other end side of the cylindrical member. Axial direction shock is absorbed by sliding of the splines. The outer peripheral seal surface is positioned at the other end side with respect to the male spline, and the inner peripheral seal surface is positioned at the other side with respect to the female spline.

A friction damper includes a cylindrical core member and a cylindrical elastic body. The core member is disposed between an outer circumferential surface of an inner shaft and an inner circumferential surface of an outer shaft, and is fixed to one of the inner and outer shafts. The elastic body is in compressive contact with the other of the inner and outer shafts, and has an axial length larger than that of the core member. The elastic body includes a portion extending in an axial direction away from the core member and has a thick-walled section which extends in a radial direction away from the core member. The thick-walled section has a larger wall thickness than a section of the elastic body which overlaps the core member in an axial direction of the core member, and is held in pressing contact with the other of the inner and outer shafts.

A device for transmitting a torque between an internal combustion engine and a generator has a motor-side shaft, a generator-side shaft, a separate transmission element for transmitting the torque between the two shafts, and a seal device. The motor-side shaft and the generator-side shaft are situated in each case substantially coaxially with respect to one another and are in each case connected by way of a shaft-hub connection to the transmission element, wherein a lubricant chamber which is situated radially outside the transmission element and between the motor-side shaft and the generator-side shaft and which couples the two shaft-hub connections with regard to a flow of lubricant is sealed off with respect to the outside by the seal device.

A power transmission shaft has a shaft member having, on an outer peripheral surface thereof, a male spline; a cylindrical member having, on an inner peripheral surface thereof, a female spline; and a seal member provided in a pressed state between an outer peripheral seal surface formed on the outer peripheral surface of the shaft member and an inner peripheral seal surface formed on the inner peripheral surface of the cylindrical member. The cylindrical member is spline-engaged with the shaft member by one end side of the shaft member being inserted into the cylindrical member from an other end side of the cylindrical member. Axial direction shock is absorbed by sliding of the splines. The outer peripheral seal surface is positioned at the other end side with respect to the male spline, and the inner peripheral seal surface is positioned at the other side with respect to the female spline.

A power transmission shaft has a shaft member having, on an outer peripheral surface thereof, a male spline; a cylindrical member having, on an inner peripheral surface thereof, a female spline; and a seal member provided in a pressed state between an outer peripheral seal surface formed on the outer peripheral surface of the shaft member and an inner peripheral seal surface formed on the inner peripheral surface of the cylindrical member. The cylindrical member is spline-engaged with the shaft member by one end side of the shaft member being inserted into the cylindrical member from an other end side of the cylindrical member. Axial direction shock is absorbed by sliding of the splines. The outer peripheral seal surface is positioned at the other end side with respect to the male spline, and the inner peripheral seal surface is positioned at the other side with respect to the female spline.

A friction damper comprising a cylindrical core member and a cylindrical elastic body bonded to an inner or outer circumferential surface of the core member, the core member being disposed within an annular space between an outer circumferential surface of an inner shaft and an inner circumferential surface of an outer shaft, which outer and inner circumferential surfaces are held in spline-fitting with each other, the core member being fixed to one of the inner and outer shafts, while the elastic body being disposed in pressing contact with the other of the inner and outer shafts, with compressive deformation of the elastic body, wherein the elastic body has an axial length larger than that of the core member, and includes an extending portion extending in its axial direction away from the core member, and wherein the extending portion of the elastic body has a thick-walled section which extends in a radial direction of the elastic body away from the core member and has a larger wall thickness than a section of the elastic body which overlaps the core member in an axial direction of the core member, the thick-walled section being held in pressing contact with the above-indicated other of the inner and outer shafts.

A drive axle assembly includes a wheel bearing mounted to an axle housing, a shaft assembly including a first shaft on an inboard side thereof to which a driving force of a power train is transmitted, and a second shaft on an outboard side thereof which is shaft-connected to the inside of the axle housing by a constant-velocity joint and is separably assembled to the first shaft, and a boot assembly including a first end portion fixed to an external ring of the wheel bearing and a second end portion assembled to the shaft assembly to be rotatable relative to the shaft assembly, and configured to restrict rotation of the boot and prevent foreign substances from being introduced therein.