Abstract: A pressure control valve unit includes a valve housing formed with a valve bore. The valve housing is also formed with an inlet port, a drain port and a control port. A valve spool is disposed in the valve bore for selectively establishing fluid communication between the control port and the inlet port, and between the control port and the drain port. The drain port is connected to a first drain path which selectively establishes and blocks fluid communication between the drain port and a working fluid source and to a second drain path which normally connect the drain port to the working fluid source. A flow restricting orifice is provided in the second drain path for constantly permitting limited flow rate of the working fluid from the drain port and the working fluid source. The flow restricting orifice generates damping force for damping surge pressure.

Abstract: A rotary actuator comprises a housing made of a synthetic resin. A rotor carrying a plurality of permanent magnet of alternate polarity with respect to the adjacent magnet, and stator having a plurality of electromagnet which is selectively energized, are aligned in axial alignment to each other. Magnetic conductor plates are provided in alignment with the rotor and the stator. The magnetic conductor plates are supported on the inner periphery of the resin housing in opposition to the rotor and the stator for forming part of a magnetic circuit.

Abstract: A trochoid type gear pump features an outer rotor formed with internal teeth and an inner rotor formed with external teeth which can be receivable in the external ones. The profiles of one or both of the internal and external teeth are rendered asymmetric and arranged to engage only in the region of an intake opening formed in the casing in which the two rotors are housed.

Abstract: A piston head block is provided with smaller exernal diameter at the portion where a cut-out for receiving a lubricant injection nozzle that remaining portion. With the smaller diameter, a clearance or gap is formed between the internal surface of an engine cylinder and the external surface of the smaller diameter portion. Therefore, during piston stroke, the smaller diameter portion, in which the lubricant injection nozzle receptacle cut-out is formed, becomes free from the transverse stress.

Abstract: A seal structure comprises a combination of a dynamic seal assembly which is active while a rotary body is rotating and a static seal assembly which is active while the rotary body is not rotating. The dynamic seal assembly includes a seal member mode of low friction material. On the other hand, the static seal assembly has an elastically deformable seal member. A rotary receptacle bore has two different diameter sections. The dynamic seal assembly is designed and sized to be installed in a smaller diameter section of the bore and the static seal assembly is designed and sized to be installed in a larger diameter section. The seal structure is assembled by inserting the dynamic seal between the smaller diameter bore section via the larger diameter section. Subsequently, the static seal is inserted into the larger diameter section.

Abstract: A signal processing system employs a triangular signal generator for generating an alternating polarity triangular signal having a positive and negative peak level which is variable depending upon the pulse period of a rectangular pulse signal. A direct current voltage signal is generated to have a voltage level proportional to the amplitude of the triangular signal.

Abstract: A vane-type rotary compressor employs a cam ring made of an aluminium type metal which is different from the metal to form a rotor and rotor vanes and has a linear expansion coefficient selected to be greater than that of the metal of the rotor and vanes so as to compensate temperature difference therebetween.

Abstract: A vane-type rotary compressor is provided with front and rear side plates for closing both axial ends of a cam ring, are provided boss sections for receiving bearing for rotatably supporting rotor shaft, and a flange sections radially extending from the associated boss sections. The boss section and the flange section are made of different material and formed into integral form by insert casting. Namely, the boss section is made of a material having a linear expansion coefficient substantially equal to the linear expansion coefficient of a bearing. Furthermore, the boss section is formed with one or more radially extending projections.

Abstract: A piston structure includes protection of the peripheral edge portion of a lubricant injection nozzle receptacle cut-out. The piston structure employs mechanisms for reinforcing the peripheral edge portion of the cut-out to an extent that can avoid concentration of the stress and thus can avoid the formation of cracks.

Abstract: In a variable-delivery vane-type rotary compressor, a rotational displacement of an adjust member relative to a front member fixedly closing a front end of a cam ring varies a compression starting point of a rotary vane in a working chamber formed in the cam ring. The rotational displacement of the adjust member is controlled by an adjust member actuating unit in response to a pilot pressure applied to the adjust member actuating unit from a pilot pressure applying unit. The pilot pressure applying unit includes a first passage communicating the adjust member actuating unit with a valve unit, a second passage communicating an induction chamber with the valve unit, and a third passage communicating a discharge chamber with the valve unit.

Abstract: A fan drive clutch is provided which includes a fluid coupling for coupling a drive shaft and a clutch housing on which a fan for blowing air to a radiator is disposed. This clutch has a pump plate for defining a fluid reservoir chamber and a working chamber. The pump plate includes a valve opening through which working fluid passes from the reservoir chamber into the working chamber. The fan drive clutch further includes a valve arm which has a valve plate for opening and closing the valve opening. The valve arm includes an elastically transformable section at a connecting portion between it and the valve plate. This section is operable to absorb movement of the valve arm which may be caused due to a clearance between the shaft for supporting the valve arm and the bearing hole for rotatably supporting the shaft.

Abstract: An intake- and/or exhaust-valve timing control system for internal combustion engines in which a ring gear mechanism is provided between a timing pulley and a cam shaft for adjusting the phase angle between the pulley and the cam shaft. A drive mechanism is also provided for driving the ring gear mechanism depending upon the operating state of the engine. The drive mechanism includes a hydraulic circuit having oil supply and exhaust passages, a flow control valve having a spool valve for controlling the amount of working fluid flowing through the hydraulic circuit, a controller for monitoring the operating state of the engine, and an electromagnetic actuator having a plunger rod for actuating the flow control valve in response to the control signal from the controller. The flow control valve and the actuator are integrally mounted in the cylinder head. Therefore, relative friction between the facing ends of the spool valve and the plunger rod is avoided.

Abstract: A structure of an electromagnetic valve for opening and closing a passage of a fluid flow which is applicable to a air suspension system of a vehicle. The electromagnetic valve includes a plunger linked with an armature, a first valve attached to the plunger for defining a first chamber and a second chamber in a body of the electromagnetic valve, together with a valve seating member installed within the body, a second valve attached to the plunger for opening and closing the fluid flow passage opened to the first chamber, and a spring for biasing the plunger in an open direction of the first valve and second valve, a second fluid flow passage being opened to the first chamber for introducing the fluid from the first fluid flow passage, a fluid pressure in the fluid passage being introduced to the second chamber via another passage, and an effective pressure applied area of the first valve (A2) being substantially equal to that (A1) of the second valve.

Abstract: A plunger pump including a plurality of plunger chambers, each slidably accommodating a plunger associated with a rotatable cam shaft having an eccentric cam for pressurizing fluid within said plunger chamber, comprises an essentially cylindrical casing with the plunger chamber and a partition wall dividing an internal space defined within the casing into a low-pressure chamber communicaitng through a fluid passage formed in type plunger with the plunger chamber and a high-pressure for receiving the pressurized fluid from the plunger chamber. The casing and the partition wall are integrally formed. The casing has a circular opening through which the shaft is inserted into the low-pressure chamber and another circular opening which is sealingly closed by a lid having high-rigidity. The casing also has an inlet port through which fluid is introduced into the low-pressure chamber and an outlet port through which the pressurized fluid is discharged from the high-pressure chamber.

Abstract: An automotive suspension system employs a pressure sensor means designed for monitoring fluid pressure in a fluid chamber of shock absorber to be compressed during piston bounding stroke. Variable suspension characteristics to vary suspension mode between HARD mode and SOFT mode so that suspension mode is normally set in SOFT mode and switched into HARD mode when variation rate of the output of the sensor means becomes greater than a predetermined rate and when the output of the sensor means represents a pressure higher than a predetermined level in the piston bounding stroke.

Abstract: A sealing plug has a stem portion inserted into an inlet of the compressor and contacted with a valve body of a check valve for forcing the check valve from closed position to maintain the check valve at open position. The sealing plug is also provided with a seal body for establishing a fluid tight seal at the sealing position. The seal body can be shifted from the sealing position to gas discharge position with maintaining the stem portion contacting the valve body of the check valve to keep the latter open. At the gas discharge position, the sealing plug permits the pressurized gas in the compressor to be discharged for lowering the internal gas pressure.

Abstract: A lock-up torque converter for automatic transmissions which transmits the torque of an internal combustion engine from the engine crankshaft to the transmission input shaft is disclosed. The torque converter includes a converter cover, a turbine hub receiving the input shaft to provide a driving connection, a clutch piston slidably mounted on the turbine hub, and a turbine runner having the outer shell drivingly connected to the hub. The torque converter comprises a first torsional damper operably connected between the clutch piston and the turbine hub to provide a driving connection only when the clutch piston engages the converter cover, and a second torsional damper operably connected between the crankshaft and the converter cover to provide a driving connection during operation of the engine. During operation of the lock-up mechanism, the two dampers cooperatively operate in series with each other to provide an optimum damping effect.

Abstract: A shock absorber is provided a piston stroke dependent variable shock absorbing characteristics by means of a first and second flow restriction valves associated with a piston. The first and second flow restriction valves are arranged in a fluid path for communicating first and second working chambers defined within a shock absorber cylindrical housing in series. The first flow restriction valve is associated with an orifice forming a part of the fluid path and has variable flow restriction rate in response to a pressure difference between the first and second chambers greater. The second flow restriction means is disposed in tandem fashion with the first flow restriction valve for providing a predetermined constant flow restriction rate in response to the pressure difference smaller than a predetermined criterion and providing a variable flow restriction as a function of the piston stroke speed in response to the pressure difference greater than the predetermined criterion.

Abstract: A power-assist device for an automotive steering system employs spool valves with different external diameters to control the fluid pressure in smaller and larger area chambers of a pressure control valve which controls pressure in an unbalanced cylinder device. The different size of spool valves are disposed within different sizes of bores formed through a housing of the pressure control valve for defining wider fluid path area for introducing larger amount of working fluid into the smaller area chamber in comparison with that for the larger area chamber and narrower fluid path for draining the working fluid in the smaller area chamber for lower drainage rate in comparison with that for the larger area chamber.

Abstract: A friction clutch for a transmission is provided. The clutch includes release levers disposed between a release bearing and a diaphragm spring. The diaphragm spring provides pressure to a pressure plate which is required to hold a clutch disc against a flywheel. The outer end of each release lever is pivotably supported by a clutch cover and the inner end thereof engages with the release bearing. The pulling of the release bearing in the axial direction away from the flywheel causes the release lever to swing about the supported position thereof against the pressure exerted by the diaphragm spring, thereby causing the clutch to be released, or disengaged. The release lever is comprised of a lever body and a movable lever for engaging the release bearing. The insertion of the release bearing into the clutch allows secure engagement between it and the release lever. The release bearing is therefore removed from the clutch easily.