Abstract: A stop valve for a gas tank is provided which achieves favorable sealing performance by inhibiting rotation of a sealing member attached to a valve element. A passage is formed inside a valve body, and a valve seat is provided in the passage. The valve element which is engaged and disengaged from the valve seat is slidably inserted to a sliding hole bored in the valve body. The annular sealing member is arranged in sliding contact with the outer peripheral surface of the valve element and the inner peripheral surface of the sliding hole. A screw hole connecting to the sliding hole and coaxial thereto is provided in the valve body. A rotating operation member having a male screw is rotatably screwed into the screw hole from the outside of the valve body. One end of the rotating operation member is made to abut the valve body.

Abstract: A high pressure valve for hydrogen gas includes a valve seat and a valve member, which is movable to selectively open and close the valve seat. One of the valve member and the valve seat is formed of austenitic stainless steel, and the other one of the valve member and the valve seat is formed of flexible synthetic resin or soft metal.

Abstract: Disclosed is a cylindrical grinding machine of the type that a workpiece support device composed of a work head and a foot stock is mounted on a forward upper portion of a bed while a wheel head unit composed of a slide base and a wheel head is mounted on a rear upper portion of the bed. A coolant collecting vent which takes a rectangular shape as viewed from above vertically extends in the bed and opens to the upper surface of the bed to cover an area that extends from under the workpiece on the workpiece support device to under the forward portion of the wheel head unit. A horizontal vent is provided in the bed to open to the rear surface of the bed and to communicate with the collecting vent. A coolant supply device is inserted at a part thereof into the horizontal vent from the rear surface of the bed to extend an inlet opening into the collecting vent.

Abstract: A hydraulic bearing that supports a rotating shaft comprises a bearing metal. On a surface of the bearing metal, a hydrostatic pocket and a land portion are formed. The land portion is defined by the hydrostatic pocket and generates hydrodynamic pressure in response to a rotation of the rotating shaft. The hydraulic bearing further comprises a pressure fluid supplying source and an oil-supplying hole. The oil-supplying hole is opened in the hydrostatic pocket and provides pressure fluid from the pressure fluid supplying source to the hydrostatic pocket. On the land portion, a drain hole that drains the fluid is formed. On the way of a drain passage, a check valve is disposed. Since the drain hole does not separate the land portion, deterioration of bearing rigidity is restrained. Further, since the fluid is drained through the drain hole, thermal expansion of the bearing metal due to heat generation of the fluid is restrained.

Abstract: A hydraulic bearing device that supports a rotating shaft comprises a bearing metal. On a surface of the bearing metal, a hydrostatic pocket and a land portion are formed. The land portion is defined by the hydrostatic pocket and generates hydrodynamic pressure. The hydraulic bearing device further comprises a pressure fluid supplying source and an oil-supplying hole. The oil-supplying hole is opened in the hydrostatic pocket and provides pressure fluid from the pressure fluid supplying source to the hydrostatic pocket. On the land portion, a drain hole that drains the fluid is formed. Since the fluid is drained through the drain hole, thermal expansion of the bearing metal due to heat generation of the fluid is restrained. Moreover, since the drain hole does not separate the land portion, deterioration of bearing rigidity is restrained.

Abstract: A hydraulic bearing device that supports a rotating shaft comprises a bearing metal. On a surface of the bearing metal, a hydrostatic pocket and a land portion are formed. The land portion is defined by the hydrostatic pocket and generates hydrodynamic pressure. The hydraulic bearing device further comprises a pressure fluid supplying source and an oil-supplying hole. The oil-supplying hole is opened in the hydrostatic pocket and provides pressure fluid from the pressure fluid supplying source to the hydrostatic pocket. On the land portion, a drain hole that drains the fluid is formed. Since the fluid is drained through the drain hole, thermal expansion of the bearing metal due to heat generation of the fluid is restrained. Moreover, since the drain hole does not separate the land portion, deterioration of bearing rigidity is restrained.

Abstract: A wheel-head feed mechanism for a grinder comprising a base and a wheel head which is guided by a linear guide section provided on the base and rotatably supports a grinding wheel via a wheel spindle driven by a motor. The wheel-head feed mechanism includes feed screw mechanism composed of a screw shaft and a nut unit engaged with the screw shaft, the feed screw mechanism advancing and retracting the wheel head with respect to a workpiece, and servomotor for rotating one of the screw shaft and the nut unit. The screw shaft is offset from the linear guide section toward the wheel spindle. The nut unit includes a radial hydrostatic bearing section for supporting the root of a male thread of the screw shaft in the radial direction of the screw shaft by hydrostatic pressure, as well as a thrust hydrostatic bearing section for supporting the flanks of the male thread of the screw shaft in the axial direction of the screw shaft by hydrostatic pressure.

Abstract: A machining spindle apparatus has a hydrostatic bearing for machine tools. The machining spindle apparatus includes a built-in motor built into the middle of a housing, as well as front and rear hydrostatic bearings respectively mounted on the front side and the rear side of the housing. A machining spindle is driven by the built-in motor and rotatably supported by the front and rear hydrostatic bearings. The front hydrostatic bearing comprises a radial bearing pocket and a thrust bearing pocket. In addition, a pair of pneumatic seals lie over the radial and thrust bearing pockets. The rear hydrostatic bearing includes a radial bearing pocket and a constant-pressurized oil chamber. The constant-pressurized oil chamber operates as a piston cylinder. Accordingly, a predetermined pressure acts forward, i.e. opposite the thrust bearing pocket of the front hydrostatic bearing. And another pair of pneumatic seals lies over both of the radial bearing pocket and the constant-pressurized oil chamber.

Abstract: A feed screw mechanism includes a nut having a female thread, and a feed screw shaft having a male thread screw-engaged with the female thread. A thrust pocket is formed along a flank of the female thread of the nut, and pressurized fluid is supplied thereto. A plurality of separated radial pockets are formed on the crest surface of the female thread of the nut, and pressurized fluid is supplied thereto. The thrust pocket is a continuous spiral groove formed along the flank of the female thread of the nut. This structure provides sufficient rigidity in both the radial and thrust directions while reducing the size of the feed screw mechanism.