Abstract: A valve apparatus has a flow control valve having a supply passage communicating with a hydraulic fluid supply source, a load passage communicating with an actuator, and a first meter-in variable restrictor disposed between the supply passage and the load passage and opened dependent on an operation amount there; a first signal passage located downstream of the first variable restrictor and having a passage section for detecting load pressure of the actuator; a tank passage communicating with a reservoir tank; a discharge passage for communicating the first signal passage with the tank passage; and a second variable restrictor provided in the discharge passage and having its opening variable dependent on the operation amount of the flow control valve to produce in the first signal passage a control pressure different from the load pressure, the control pressure in the first signal passage being led to the hydraulic fluid supply source though a second signal passage.

Abstract: A variable displacement hydraulic piston pump and servo displacement control which combines a rotary vane type actuator and a port plate to obtain both servo and actuation functions for a hydraulic piston pump. The control includes a construction which provides feel to the operator for how much work is being performed. The control also incorporates a failsafe mechanism so that the control is capable of transmitting torque to manually stroke the pump if charge pressure is lost.

Abstract: A compressing mechanism includes a slidable section which is constructed by combining a first slidable member made of a cast iron having a Vickers hardness within the range of 200 to 300 with a second slidable member made of a carbon steel having a Vickers hardness within the range of 200 to 300 and an average number of crystalline grains per 1 mm.sup.2 within the range of 2000 to 3200. The slidable section is composed of a shaft and a bearing. Additionally, the slidable section includes a cylinder, a rotor and a piston. Each crystalline grain in the carbon steel constituting the second slidable member has a substantially isotropic shape and a size of the crystalline grain is suitably enlarged to exhibit a coarse structure. As a result, elasticity of the grain structure of the carbon steel is increased and a very small number of crystalline grains are peeled off from the surface of the substrate.

Abstract: A variable capacity compressor comprises a control element for determining the timing of start of compression of refrigerant gas. Control pressure which acts on the control element to displace same between the minimum capacity position and the maximum capacity position is created in a high-pressure chamber by introducing discharge pressure thereinto. An electromagnetic valve opens and closes a passageway which commincates between the high-pressure chamber and a suction chamber by a pulse signal supplied from an ECU to control an amount of refrigerant gas leaking from the former into the latter to thereby control the level of the control pressure. The ECU makes the width of at least a first pulse or at least a first pulse base of the pulse signal wider than that of the following pulses or pulse bases, when the control element should start to be displaced between the minimum capacity position and the maximum capacity position.

Abstract: A rotary piston internal combustion engine of trochoidal type of construction with a piston slidably journalled and controlled via a synchronous transmission gear drive unit. An eccentric bearing of the piston is sealed-off on both sides of the remaining machine chambers or spaces with sealing rings located around the eccentric shaft. Circulation of the lubricating oil and cooling oil that is under pressure being delimited as to this bearing and the cooling hollow chambers of the piston with such lubricating oil and cooling oil being kept away from the working chambers and also eliminating any oil inner seals otherwise required therewith.

Abstract: An oil injection type screw compressor which includes an oil tank for separating lubricating oil from gas discharged from a compressor body and collecting the thus separated lubricating oil is constituted such that the oil tank has a substantially L-shaped vertical section composed of a base portion and a column portion provided uprightly on the base portion such that a spacing in the base portion located above an oil storage portion at a lower location in the base portion is formed such that it extends from an upper portion in the base portion to the inside of the column portion, and an oil separating element is provided on the inner side of an exit of gas at an upper portion of the column portion while the compressor body is disposed on the base portion.

Abstract: A thermal control variable speed DC brushless fan, especially a DC brushless fan which may change speed in accordance with the temperature sensed, includes a fan speed control circuit and a DC brushless fan. The fan speed control circuit is composed of drive ICs, operation amplifiers, transistors, diodes, capacitors resistors, and a thermal sensor. Under normal conditions, the change in the fan's rotation speed relation to the temperature is almost linear, but when the thermal sensor is open or shorted the speed control circuit of the fan causes the fan to operate at full speed to maintain a cooling effect.

Abstract: High pressure cutoff controls are useful for variable displacement hydraulic pumps for reducing power losses at high pressure levels. Some operators, however, believe that they get more work from pumps not having the high pressure cutoff control. The subject on-off high pressure cutoff control includes an on-off valve disposed in a pilot passage connected to an output port of a pump and to an end of a high pressure cutoff valve. The on-off valve is selectively movable between a first position at which pressurized fluid passes through the pilot passage to the end of the high pressure cutoff valve to prevent it from functioning as a high pressure cutoff valve. Thus, an operator has the option of operating the hydraulic pump with or without the high pressure cutoff control.

Abstract: A reciprocating piston hermetic compressor including a two piece suction valve used for fluid control. The reexpansion volume between the valve leaf and valve spacer is reduced to a minimum. The valve leaf is located within the compressor and valve spacer by an attachment means such as locating pins.

Abstract: A fluid pump with rotary impeller is disclosed which comprises an electromagnetically-driven, bearing-free, seal-free rotary impeller levitated by localized opposed, repulsive, permanent magnetic forces and by fluid forces, or by localized opposed repulsive magnetic forces only. Levitation by localized opposed magnetic or magnetic and fluid forces of an impeller driven by electromagnetic forces eliminates the need for bearings and seals in the driving mechanism. This avoids the heat build-up and leakage associated with other pumping mechanisms, which can be of importance in pumping of physiological fluids such as blood. The levitating forces of the present invention are applied repulsively both axially and radially with respect to the impeller and are auto-adjusting, such that any attempted displacement of the impeller will automatically incur a corrective change in levitating forces.

Abstract: The invention consists of a liquid end for a plunger pump, having vertical inlet and outlet, with the suction and discharge valves readily accessible for maintenance without disturbig the suction and discharge piping. The liquid end also includes a relief valve which is accessible without disturbing suction or discharge piping. The passages to and from the relief valve are internal to the housing. Inserts are provided in the valves to eliminate dead space and to facilitate the removal of any trapped air which might adversely affect the performance of the pump.

Abstract: A multistage compressor includes a lower pressure side compression part, a higher pressure side compression part, an intermediate conduit placing the lower and higher side compression parts in communication, and a cooler disposed midway of the intermediate conduit for allowing gas to flow from the lower pressure side compression part to the higher pressure side compression part and for cooling the flowing gas. The cooler includes a drain outlet port. The compressor further includes an electromagnetic valve disposed at the drain outlet port and a controller for controlling the valve. The valve is opened when the compressor is started or re-started after a pause, is kept open during a predetermined period of time, and is then closed.

Abstract: This invention relates to a variable capacity pump controller for an industrial vehicle such as a shovel loader using a static hydraulic driving system. In a hydraulically driven vehicle equipped with a variable capacity hydraulic pump (P), the controller of the invention includes variable throttle devices (11, 13) (21, 24), (31, 35), (41, 46) which are disposed in pilot hydraulic circuits (10, 12), (20, 22), (30, 32), (40, 42) of a pump capacity control cylinder (C) for controlling the capacity hydraulic pump (P) and operate in such a manner as to change the operation speed of the pump capacity control cylinder (C) in accordance with the oil pressure of a main hydraulic circuit (S). According to this construction, the variable throttle device operates in such a manner as to open a check valve or a throttle valve in the pilot circuit of the pump capacity control cylinder when the hydraulic driving main circuit is at a high pressure.

Abstract: A reciprocating actuator is axially connected to drive a reciprocating pump. An exhaust tube, open to the outside, passes through a piston of the reciprocating actuator and into an inner hole axially disposed in a working rod that connects an actuator piston of the reciprocating actuator to the reciprocating pump. A valve mechanism communicates a chamber above the actuator piston with the inner hole during upward motion of the piston, whereby actuator fluid above the piston is exhausted to the outside through the exhaust tube. The resulting axial exhausting of the actuating fluid permits inserting a large portion of the device into a drum for pumping of liquid. The invention permits use of a two-stage rod system, which is capable of obtaining high pumping pressure. The inner hole is communicated with a space whose volume changes when the working rod makes a vertical movement.

Abstract: In the present fluid system, a variable pressure inlet system is provided and operational to control the operating pressure level of a charge pump in response to various operating parameters of the fluid system. The charge pump provides pressurized fluid to an inlet of a hydraulic pump to insure filling of the pumping chambers therein. By having the operating pressure level of a variable pressure relief valve that is connected to the charge pump controlled between a minimum pressure level and a maximum pressure level responsive to various operating perimeters of the system, the degree of horsepower needed to drive the charge pump is controlled.

Abstract: This invention relates to a fluid mechanism with two cylinder capacities, comprising a distributor valve defining first and second enclosures containing supply and exhaust fluids comprising two groups of distribution conduits, and a device for selecting the cylinder capacity, constituted by a bore and a slide element for selection. According to the invention, a first and a second connection conduit connect the first and second enclosures to the bore and open out between transverse planes; distribution conduits open out in the bore between these planes; and the slide element comprises a groove contained between said planes and establishing communication between the distribution conduits and the connection conduit. One application of the invention is the production of a compact motor.

Abstract: A power limiter control for a variable displacement axial piston pump monitors systems flow and automatically adjusts pump displacement proportionally as the pressure of working fluid changes to maintain a substantially constant power output as the working fluid output reaches a set maximum power.

Abstract: A swash plate type compressor which includes a pair of cylinder blocks. The cylinder blocks contains a crank case and a plurality of cylinders leading to a suction port. A pair of housing sections cover the cylinder blocks, and contain a suction chamber leading to each about the center of the cylinders, and a discharge chamber which is fluidly connected to the cylinders. The cylinder blocks rotatably support a drive shaft. The suction chamber contains a shaft sealing device in order to seal a forward section of the drive shaft. A refrigerant fluid within the crank case is sucked into the cylinders via the suction chamber. A refrigerant passage is provided along the central axis of the drive shaft. A plurality of inlet and outlet ports are connected to the refrigerant passage and to the crank case and suction chamber. The refrigerant passage, the outlet ports and the inlet ports form a refrigerant suction passage.

Abstract: A swash plate type compressor is provided with a front and rear cylinder blocks having a crank case connected to a suction port. The cylinder blocks include a plurality of cylinders, and are connected to a front and rear housing sections for covering the cylinders. Each housing section contains a discharge chamber. A drive shaft is rotatabley supported by the cylinder blocks. A swash plate is mounted on the drive shaft and is rotatably disposed within the crank case. Two-head pistons move within their respective cylinders in cooperation with the swash plate. The refrigerant is drawn into, and compressed in each cylinder. Thereafter, it is discharged into the external refrigerating circuit through the front and rear discharge chambers, and a final discharge port. A discharge passage includes a hollow primary passage which is provided within the drive shaft. The primary passage communicates with the front and rear discharge chambers. A groove is provided on an inner wall of the primary passage.

Abstract: A variable capacity wobble plate compressor including a cylinder block, the cylinder block having a plurality of cylinders formed therein and a bearing-receiving hole formed therethrough, bearings received within the bearing-receiving hole, a discharging space defined on one side of the cylinder block, a crankcase defined on the other side of the cylinder block, a wobble plate accommodated within the crankcase and mounted on a drive shaft, a plurality of outlet ports communicating between respective ones of the cylinders and the discharging space, discharge valve means having a plurality of valve elements for closing and opening respective ones of the outlet ports, and a fixing member securing the discharge valve means to the cylinder block at the one side thereof, wherein the fixing member has a high pressure-introducing passage formed therethrough for introducing high-pressure refrigerant gas within the discharging space to the bearing-receiving hole, and then into the crankcase.