Abstract: In a wobble removal shaft coupling device including a wobble removal gear having an internal gear with a first central axial line and an external gear meshing with the wobble removal gear and having a second central axial line. The first and second central axial lines are in parallel with and offset from each other, and the external gear teeth are identical in number to the internal gear teeth of the wobble removal gear. At least one of the two sets of the gear teeth are resiliently deformable in a circumferential and/or radial direction so as to allow the two gears to be meshing with each other while permitting an eccentric wobbling movement of the external gear relative to the internal gear without requiring a play or a sliding engagement. The wobble removal shaft coupling device can be incorporated in a hypocycloid reduction gear device.

Abstract: In a wobble removal shaft coupling device including a wobble removal gear having an internal gear with a first central axial line and an external gear meshing with the wobble removal gear and having a second central axial line. The first and second central axial lines are in parallel with and offset from each other, and the external gear teeth are identical in number to the internal gear teeth of the wobble removal gear. At least one of the two sets of the gear teeth are resiliently deformable in a circumferential and/or radial direction so as to allow the two gears to be meshing with each other while permitting an eccentric wobbling movement of the external gear relative to the internal gear without requiring a play or a sliding engagement. The wobble removal shaft coupling device can be incorporated in a hypocycloid reduction gear device.

Abstract: In a power conversion device including: a converter which steps up or down a voltage of a direct current power supply; and an inverter which converts the direct current voltage obtained by the converter into an alternating voltage to drive an electric motor, a plurality of magnetic parts are arranged above a switching element assembly unit with a water-cooled type second heat sink interposed between the switching element assembly unit and the plurality of magnetic parts, the switching element assembly unit configured by mounting all the switching element modules on upper and lower surfaces of a water-cooled type first heat sink. Accordingly, it is possible to provide a power conversion device capable of housing many switching element modules in a compact space and cooling them effectively, while preventing the influence of a noise due to the magnetic parts from acting on the switching element modules as much as possible.

Abstract: A cooling device for a semiconductor element module and a magnetic part, includes: a water-cooled type heat sink having a cooling water passage; a semiconductor element module including a plurality of chips arranged side by side in a circulation direction in the cooling water passage, the semiconductor element module being mounted on the heat sink; and a magnetic part including a core and a winding portion mounted on the core, the magnetic part being mounted on the heat sink or another heat sink. In the cooling device, a plurality of cooling fins is disposed to extend along the circulation direction in the cooling water passage in a manner that the plurality of cooling fins are separated into groups for the respective chips arranged side by side in the circulation direction, and that the groups of the cooling fins are offset from each other in a direction perpendicular to the circulation direction. Accordingly, it is possible to have improved cooling efficiency of a heat sink with cooling fins.

Abstract: A cooling device for a semiconductor element module and a magnetic part, includes: a water-cooled type heat sink having a cooling water passage; a semiconductor element module including a plurality of chips arranged side by side in a circulation direction in the cooling water passage, the semiconductor element module being mounted on the heat sink; and a magnetic part including a core and a winding portion mounted on the core, the magnetic part being mounted on the heat sink or another heat sink. In the cooling device, a plurality of cooling fins is disposed to extend along the circulation direction in the cooling water passage in a manner that the plurality of cooling fins are separated into groups for the respective chips arranged side by side in the circulation direction, and that the groups of the cooling fins are offset from each other in a direction perpendicular to the circulation direction. Accordingly, it is possible to have improved cooling efficiency of a heat sink with cooling fins.

Abstract: In a power conversion device including: a converter which steps up or down a voltage of a direct current power supply; and an inverter which converts the direct current voltage obtained by the converter into an alternating voltage to drive an electric motor, a plurality of magnetic parts are arranged above a switching element assembly unit with a water-cooled type second heat sink interposed between the switching element assembly unit and the plurality of magnetic parts, the switching element assembly unit configured by mounting all the switching element modules on upper and lower surfaces of a water-cooled type first heat sink. Accordingly, it is possible to provide a power conversion device capable of housing many switching element modules in a compact space and cooling them effectively, while preventing the influence of a noise due to the magnetic parts from acting on the switching element modules as much as possible.

Abstract: A power semiconductor module having an integral circuit board with a metal substrate electrode, an insulation substrate and a heat sink joined is disclosed. A SiC semiconductor power device is joined to a top of the metal substrate electrode of the circuit board. A difference in average coefficients of thermal expansion between constituent materials of the circuit board in a temperature range from room to joining time temperatures is 2.0 ppm/° C. or less, and a difference in expansion, produced by a difference between a lowest operating temperature and a joining temperature, of the circuit-board constituent materials is 2,000 ppm or less.

Abstract: A power semiconductor module having an integral circuit board with a metal substrate electrode, an insulation substrate and a heat sink joined is disclosed. A SiC semiconductor power device is joined to a top of the metal substrate electrode of the circuit board. A difference in average coefficients of thermal expansion between constituent materials of the circuit board in a temperature range from room to joining time temperatures is 2.0 ppm/° C. or less, and a difference in expansion, produced by a difference between a lowest operating temperature and a joining temperature, of the circuit-board constituent materials is 2,000 ppm or less.