Abstract: A lead screw apparatus includes a screw shaft having a spiral channel on an outer circumferential surface thereof, a plurality of rollers rotatable with contact with the spiral channel, and a cage rotatably supporting the rollers for conversion between relative rotation and linear motions between the screw shaft and the cage bi-directionally. The lead screw apparatus further includes a bearing and a holder 6 supported by the case for supporting the bearing. An inner ring of the bearing and the roller are integrally formed. An outer ring of the bearing has a protrusion on an outer circumferential surface thereof on a side closer to the screw shaft. Rollers of the bearing having a circular truncated cone shape are disposed in the bearing in a circumferential direction with substantially no gap. The outer ring has a thread part to shift the bearing and the roller.

Abstract: Upon assembly of a mechanism for converting rotary motion into linear motion, since a plurality of rollers are different from one another in the tilt direction with respect to a holder, a difficulty occurs in fixing one end sides thereof to the holder and thereafter making fixation for the other end sides.

Abstract: The invention provides an electro-mechanical brake system which can keep a stop state even if a malfunction is generated in a parking brake, and an electro-mechanical brake apparatus used for the electro-mechanical brake system. An electro-mechanical brake actuator presses a brake pad to a disc rotor so as to independently brake a braking force of each of wheels. A parking brake is constituted by a pawl portion attached to a motor of a motor driving the electro-mechanical actuator and a latch. A main controller detects a failure of the parking brake on the basis of a motor displacement at a time of reducing a motor current, and increases the pressing force in the remaining normal parking brake in the case that the parking brake failure in one wheel or more is detected.

Abstract: In a gear pump equipped with a pump assembly formed from a driving gear supported by a driving shaft, a driven gear supported by a driven shaft, a pair of side plates disposed at both sides in an axial direction of driving and driven shafts, and a seal block that seals tips of the gears and forms a first fluid chamber by installation onto the side plates, and a casing that houses the pump assembly and forms a second fluid chamber therein, ribs are provided for at least one member of the side plates or the seal block, and fluid tightness between the first and second fluid chambers is secured by exerting pressure between the side plates and seal block and additionally plastically deforming the ribs. By this, it is possible to provide the gear pump which is capable of achieving improvement of the seal integrity while reducing the parts count.

Abstract: Provided is a liquid chromatograph pump system which sucks eluent from an eluent reserving container, and which feeds pressurized high pressure eluent into a column, wherein a plunger reciprocating in a cylinder is formed on its outer peripheral surface with a stepped part along the sliding direction of the plunger in the cylinder so as to define a working chamber between the stepper part and the inner wall surface of the cylinder, the flow rate of the liquid chromatograph pump being determined by the volume of the working chamber and the traveling speed of the plunger, thereby it is possible to stably feed a liquid at an extremely low flow rate, and to satisfactorily expel air bubbles upon a start of the liquid chromatograph pump system.

Abstract: In a gear pump equipped with a pump assembly formed from a driving gear supported by a driving shaft, a driven gear supported by a driven shaft, a pair of side plates disposed at both sides in an axial direction of driving and driven shafts, and a seal block that seals tips of the gears and forms a first fluid chamber by installation onto the side plates, and a casing that houses the pump assembly and forms a second fluid chamber therein, ribs are provided for at least one member of the side plates or the seal block, and fluid tightness between the first and second fluid chambers is secured by exerting pressure between the side plates and seal block and additionally plastically deforming the ribs. By this, it is possible to provide the gear pump which is capable of achieving improvement of the seal integrity while reducing the parts count.

Abstract: The invention provides an electro-mechanical brake system which can keep a stop state even if a malfunction is generated in a parking brake, and an electro-mechanical brake apparatus used for the electro-mechanical brake system. An electro-mechanical brake actuator presses a brake pad to a disc rotor so as to independently brake a braking force of each of wheels. A parking brake is constituted by a pawl portion attached to a motor of a motor driving the electro-mechanical actuator and a latch. A main controller detects a failure of the parking brake on the basis of a motor displacement at a time of reducing a motor current, and increases the pressing force in the remaining normal parking brake in the case that the parking brake failure in one wheel or more is detected.

Abstract: In a pump for feeding a liquid for chromatography, first and second plungers form first and second volumes respectively together with first and second chambers, the first plunger is prevented from changing the first volume sufficiently for feeding the liquid between the first and second volumes when the second plunger decreases the second volume to discharge the fluid from the second volume to an outlet path of the pump for the chromatography.

Abstract: The invention provides a pump for liquid chromatography excellent in feeding liquid stably at an extremely low flow rate with high accuracy and in discharging bubbles at startup. At startup, a first plunger feeds solvent at a large flow rate to discharge bubbles in a pump and to fill the solvent into the pump in a short time and in a normal operation, the first plunger is stopped and the second plunger is pushed into a second pressure chamber at a low speed to feed the solvent at a low flow rate. When the second plunger reaches full stroke, the second plunger is pulled back at a high speed and at the same time the first plunger is pushed into a first pressure chamber in synchronization with the pullback of the second plunger to control the flow rate passing a discharge passage to a constant value at all times by a controller.

Abstract: In a pump for feeding a liquid for chromatography, first and second plungers form first and second volumes respectively together with first and second chambers, the first plunger is prevented from changing the first volume sufficiently for feeding the liquid between the first and second volumes when the second plunger decreases the second volume to discharge the fluid from the second volume to an outlet path of the pump for the chromatography.

Abstract: In a pump for feeding a liquid for chromatography, first and second plungers form first and second volumes respectively together with first and second chambers, the first plunger is prevented from changing the first volume sufficiently for feeding the liquid between the first and second volumes when the second plunger decreases the second volume to discharge the fluid from the second volume to an outlet path of the pump for the chromatography.

Abstract: The invention provides a pump for liquid chromatography excellent in feeding liquid stably at an extremely low flow rate with high accuracy and in discharging bubbles at startup. At startup, a first plunger feeds solvent at a large flow rate to discharge bubbles in a pump and to fill the solvent into the pump in a short time and in a normal operation, the first plunger is stopped and the second plunger is pushed into a second pressure chamber at a low speed to feed the solvent at a low flow rate. When the second plunger reaches full stroke, the second plunger is pulled back at a high speed and at the same time the first plunger is pushed into a first pressure chamber in synchronization with the pullback of the second plunger to control the flow rate passing a discharge passage to a constant value at all times by a controller.

Abstract: Provided is a liquid chromatograph pump system which sucks eluent from an eluent reserving container, and which feeds pressurized high pressure eluent into a column, wherein a plunger reciprocating in a cylinder is formed on its outer peripheral surface with a stepped part along the sliding diretion of the plunger in the cylinder so as to define a working chamber between the stepper part and the inner wall surface of the cylinder, the flow rate of the liquid chromatograph pump being determined by the volume of the working chamber and the traveling speed of the plunger, thereby it is possible to stably feed a liquid at an extremely low flow rate, and to satisfactorily expel air bubbles upon a start of the liquid chromatograph pump system.

Abstract: The unevenness of injection rates of cylinders is reduced in a fuel supply system of a direct injection engine which uses a variable-displacement single plunger pump. The unevenness of injection rates of cylinders can be reduced by effecting a control such that the cam 100, which drives the high-pressure fuel pump 101, makes one reciprocation, while the engine makes explosions in two cylinders, and by causing the controller 55 to extend the injection time width of one of two injectors 54 which inject during one discharge of the high-pressure fuel pump and to shorten the injection time width of the other injector.

Abstract: In a fuel supply apparatus disclosed, a variable displacement mechanism is driven once every two or more reciprocating motions of the plunger of a high-pressure fuel pump to control the delivery flow rate, so that the delivery flow rate control can be performed without having to raise the responsiveness of the variable displacement mechanism even when the reciprocating cycle of the plunger is short.

Abstract: In order to provide a method for high volume and high pressure operation of a variable delivery type single cylinder plunger pump, the displacement of the piezoelectric element 20 is magnified by a hydraulic displacement magnifying mechanism comprising a large-diameter bellows 204, a small diameter bellows 202 and working fluid 208, and an engaging member 201 is displaced to control the time interval of opening and closing the intake valve 5. The large-diameter bellows 204 is used at all times in the state compressed in the direction of displacement transfer, thereby ensuring that the pressure of the working fluid 208 is maintained at a positive value to prevent vapor from being generated.

Abstract: In order to provide a method for high volume and high pressure operation of a variable delivery type single cylinder plunger pump, the displacement of the piezoelectric element 20 is magnified by a hydraulic displacement magnifying mechanism comprising a large-diameter bellows 204, a small diameter bellows 202 and working fluid 208, and an engaging member 201 is displaced to control the time interval of opening and closing the intake valve 5. The large-diameter bellows 204 is used at all times in the state compressed in the direction of displacement transfer, thereby ensuring that the pressure of the working fluid 208 is maintained at a positive value to prevent vapor from being generated.

Abstract: A fuel supply system for a direct injection engine which has a variable capacity single cylinder plunger pump and two fuel rails. Offices are disposed at the upstream side inlets of both fuel rails, respectively. At the opposite sides to the inlet sides, the fuel rails are interconnected with each other by a connecting pipe. Using this fuel supply system, it is possible to increase a characterisitic frquency of the fuel columns, and to stabilize, suppress, and smooth out pressure pulsation in the fuel rails, thereby reducing uneven fuel injections into the cylinders. The system may have a cam which drives a plunger of a high pressure fuel pump to reciprocate once for every two combustions in two engine cylinders.

Abstract: The present invention reduces the unevenness of injection rates of cylinders in a fuel supply system of a direct injection engine which uses a variable-displacement single plunger pump. The unevenness of injection rates of cylinders can be reduced by constructing so that the cam 100 which drives the high-pressure fuel pump 101 may make one reciprocation while the engine makes explosions by two cylinders and causing the controller 55 to extend the injection time width of one of two injectors 54 which inject while one discharge of the high-pressure fuel pump and to shorten the injection time width of the other injector.

Abstract: In a fuel supply apparatus disclosed, a variable displacement mechanism is driven once every two or more reciprocating motions of the plunger of a high-pressure fuel pump to control the delivery flow rate, so that the delivery flow rate control can be performed without having to raise the responsiveness of the variable displacement mechanism even when the reciprocating cycle of the plunger is short.