Abstract: A linear actuator includes a screw shaft rotatably supported within a housing with play in motion in the axial direction of the screw shaft, and a cushioning stopper disposed between the housing and the screw shaft and elastically deformable to absorb a force acting from the screw shaft to the housing when the screw shaft is forced to move relative to the housing in the axial direction within the range of the play at an abutment of a rod with an obstacle or stopper. When the rod is stopped moving, the motor current increases with the degree of elastic deformation of the cushioning stopper. An overload sensor cuts off the supply of power to an electric motor when excessive current in the motor is detected.

Abstract: A linear actuator includes a screw shaft rotatably supported within a housing with play in motion in the axial direction of the screw shaft, and a cushioning stopper disposed between the housing and the screw shaft and elastically deformable to absorb a force acting from the screw shaft to the housing when the screw shaft is forced to move relative to the housing in the axial direction within the range of the play at an abutment of a rod with an obstacle or stopper. When the rod is stopped moving, the motor current increases with the degree of elastic deformation of the cushioning stopper. An overload sensor cuts off the supply of power to an electric motor when excessive current in the motor is detected.

Abstract: A linear actuator includes two axially opposed bearings with built-in one-way clutch assembled in a housing member with respective outer races secured to the housing member such that respective directions in which inner races of the bearings are locked against rotation are opposed to each other, a ball bearing shaft relatively and rotatably supported on the inner races of the bearings with bearing bushings disposed between the ball screw shaft and the respective bearings, and two load transmitting collars fixed on the ball screw shaft. When the ball screw shaft is subjected to a thrust load applied from a ball nut in a direction to retract the ball screw shaft, one of the inner race is locked against rotation to thereby exert a braking torque to the corresponding load transmitting collar via an associated friction collar.

Abstract: A reformer assembly includes fuel introduction plates, combustion chamber plates and reforming chamber plates. The fuel introduction plate includes a first plate member and a first masking frame on the periphery of the first plate member. The combustion chamber plate includes a second plate member and a second masking frame on the periphery of the second plate member, and combustion catalyst is placed in the combustion chamber plate. The reforming chamber plate includes a third plate member and a third masking frame on the periphery of the third plate member, and reforming catalyst is placed in the reforming chamber plate. The first masking frame has a fuel feeding port. The second plate member has a number of dispersion holes and the second masking frame has air feeding and exhaust gas discharging ports. The third masking frame has raw material gas feeding and reformed gas discharging ports. These plates are stacked to define a multi-layer unit.

Abstract: A power generation system uses fuel cells stacked via separators. Cooling plates are provided in the fuel cell stack. Passages are formed in each cooling plate for allowing raw-material-gas-for-reformation (which also serves as stack-cooling-gas) to flow therethrough and the passages are filled with reforming catalyst. An external reformer which includes a combustion section and a reforming section is provided outside of the fuel cell stack. A stack-cooling-gas-line is connected to the passages of the cooling plates for introducing the raw-material-gas-for-the-reformation (the stack-cooling-gas) into the passages. A line for gas-for-processing is connected to the reforming section of the external reformer for feeding raw-material-gas-for-processing to the reforming section. An anode gas feed line is provided for feeding to the anode the reformed gas which has been reformed through the passages of the cooling plates and the reformed gas which has been reformed by the reforming section of the external reformer.