Abstract: A hydraulic automatic tensioner for adjusting the tension of a bell includes a first member with a piston formed integrally, a second member combined with the first member and axially movable relative to the first member, a cylinder formed integrally with the second member, together defining a fluid-reservoir chamber for hydraulic fluid, axially slidably receiving the piston, and a spring pushing the members apart. The piston and cylinder form a pressure chamber filled with hydraulic fluid. The second member has a leak passage through which fluid flows from the pressure chamber into the fluid-reservoir chamber. A control valve is placed in the leak passage, inhibiting flow of fluid from the pressure chamber into the fluid-reservoir chamber. A control device moves the control valve to close the leak passage when activated and makes it ineffective when deactivated so that the pressure chamber communicates with the fluid-reservoir chamber via the leak passage.

Abstract: A motor/generator housed in an annular space formed between an engine side wall and a crank pulley fixed to an end of a crank shaft includes a stator supported on the engine side wall and a rotor supported on the inner surface of a peripheral wall of the pulley. Air is introduced into the annular space via an air inlet passage by means of cooling fan blades formed on a side wall of the crank pulley, and coils are cooled by passing the air through air passages formed between adjacent coils. The entrance of an air gap between the stator and the rotor is shielded by means of shields provided on bobbins so as to prevent any foreign matter from entering the air gap.

Abstract: In an engine-starting and stopping system in a vehicle, a crank pulley for driving auxiliary parts by an endless belt is mounted at an end of a crankshaft protruding from a cylinder block of an engine, and a starter motor for cranking the crankshaft is accommodated in an internal space in the crank pulley. The starter motor includes a rotor having a permanent magnet fixed to an inner peripheral surface of a peripheral wall of the crank pulley, and a stator having a coil fixed to an outer surface of a chain cover. Thus, the starter motor for automatically carrying out the restarting of the engine after stopping of the engine can be laid out compactly.

Abstract: A hydraulic automatic tensioner for adjusting the tension of an endless belt in a power transmitting mechanism for transmitting power to engine accessories of an internal combustion engine through the belt comprises: a fixed first member (11), a piston (PS) formed integrally with the first member (11), a movable second member (12) coaxially combined with the first member (11) so as to be axially movable relative to the first member (11), a cylinder (CY) formed integrally with the second member (12), defining a fluid-reservoir chamber (R) for storing a hydraulic fluid together with the first member (11), and provided with a leak passage (20), axially slidably receiving the piston (PS), a spring (S) pushing the first and the second member (11, 12) away from each other. The piston (PS) and the cylinder (CY) form a pressure chamber (P) filled with the hydraulic fluid.

Abstract: An outer rotor type brushless direct current motor has an outer rotor including a plurality of permanent magnets attached along the inner circumference of an annular yoke such that the magnetic poles face the S magnetic poles. Thin sections are formed by chamfering the radially outer periphery of the two end sections in the circumferential direction of each of the permanent magnets. Magnetic flux passage sections of the yoke providing connection between the thin sections of adjacent permanent magnets are expanded radially inwards. In accordance with the above-mentioned arrangement, the cross section of the magnetic path in the magnetic flux passage sections is increased, thereby suppressing the occurrence of magnetic saturation and preventing the maximum torque of the permanent magnets from decreasing while reducing their size. Moreover, because the magnetic flux passage sections of the yoke are expanded radially inwards, the external dimensions of the yoke do not increase.

Abstract: An outer rotor type brushless direct current motor has an outer rotor including a plurality of permanent magnets attached along the inner circumference of an annular yoke such that the magnetic poles face the S magnetic poles. Thin sections are formed by chamfering the radially outer periphery of the two end sections in the circumferential direction of each of the permanent magnets. Magnetic flux passage sections of the yoke providing connection between the thin sections of adjacent permanent magnets are expanded radially inwards. In accordance with the above-mentioned arrangement, the cross section of the magnetic path in the magnetic flux passage sections is increased, thereby suppressing the occurrence of magnetic saturation and preventing the maximum torque of the permanent magnets from decreasing while reducing their size. Moreover, because the magnetic flux passage sections of the yoke are expanded radially inwards, the external dimensions of the yoke do not increase.

Abstract: A fluid coupling is provided between a pump shaft of a water pump and a water pump pulley and includes a liquid chamber formed inside housings and filled with a fluid, and a rotor fixed to the pump shaft and housed in the liquid chamber. When the housings connected to a crank pulley via an endless belt rotate, the rotor is dragged by the viscosity of the fluid and the pump shaft rotates. Since the fluid coupling has the property of decreasing the rate of increase in the output rotational speed of the fluid coupling as the input rotational speed increases, the required rotational speed of the water pump can be guaranteed when the rotational speed of the engine is low, and the water pump can be prevented from rotating excessively when the rotational speed of the engine is high.

Abstract: A motor/generator housed in an annular space formed between an engine side wall and a crank pulley fixed to an end of a crank shaft includes a stator supported on the engine side wall and a rotor supported on the inner surface of a peripheral wall of the pulley. Air is introduced into the annular space via an air inlet passage by means of cooling fan blades formed on a side wall of the crank pulley, and coils are cooled by passing the air through air passages formed between adjacent coils. The entrance of an air gap between the stator and the rotor is shielded by means of shields provided on bobbins so as to prevent any foreign matter from entering the air gap.

Abstract: A fluid coupling is provided between a pump shaft of a water pump and a water pump pulley and includes a liquid chamber formed inside housings and filled with a fluid, and a rotor fixed to the pump shaft and housed in the liquid chamber. When the housings connected to a crank pulley via an endless belt rotate, the rotor is dragged by the viscosity of the fluid and the pump shaft rotates. Since the fluid coupling has the property of decreasing the rate of increase in the output rotational speed of the fluid coupling as the input rotational speed increases, the required rotational speed of the water pump can be guaranteed when the rotational speed of the engine is low, and the water pump can be prevented from rotating excessively when the rotational speed of the engine is high.