Patent ID: 8997960
Filing Date: 2015-04-07
Classification: F16D,Y10T

Abstract:
1. An oil passage structure for a hydraulic clutch for an engine, the hydraulic clutch being mounted on a rotational shaft having an axis parallel to a crankshaft and rotatably supported in a crankcase, the oil passage structure comprising: a plurality of oil passages defined in the rotational shaft and extending axially thereof, the oil passages configured to supply oil to a hydraulic clutch; and a plurality of supply oil passages configured to guide oil from an oil supply source, the supply oil passages being defined in a case cover configured to cover the hydraulic clutch and coupled to the crankcase, the supply oil passages being connected individually to the oil passages in the rotational shaft, wherein a cavity having a closed end wall facing an end of the rotational shaft and receiving the end of the rotational shaft therein is defined in an inner surface of the case cover such that the supply oil passages are open at inner circumferential surfaces of said cavity, wherein at least one radial joint hole is defined in an end portion of said rotational shaft and extends radially of said rotational shaft, the radial joint hole having an inner end connected to one of the oil passages in the rotational shaft, wherein said radial joint hole is connected to a corresponding one of the supply oil passages in said cavity, and wherein the oil passage structure further comprises a cylindrical tubular member entirely interposed between and connected to an outer circumferential surface of the end portion of said rotational shaft and an inner circumferential surface of said cavity.