Abstract: A variable capacity pump and two variable capacity motors are connected in a closed circuit. First to fourth drive gears are fitted to motor shafts of the variable capacity motors via clutches. A first driven gear, which meshes with the first and third drive gears, and a second driven gear which meshes with the second and fourth drive gears are fitted to an output shaft. Equivalent capacities of the variable capacity motors are made different. Control is exerted such that the capacities are decreased to zero in order of equivalent capacities. To decrease the capacity of each variable capacity motor, the gear change ratio of the variable capacity motor the capacity of which has decreased to zero is changed to decrease the equivalent capacity and, at the same time, the capacity is increased to maximum. This increases the gear change ratio for the continuously variable transmission and controls acceleration.

Abstract: A fan drive system for driving an engine cooling fan mounted in a working machine is described. The fan drive system includes a variable displacement pump that supplies oil to an actuator and is also used as a hydraulic pump for the hydraulic motor that drives the cooling fan. A pump displacement of a variable displacement pump can be controlled in accordance with the load of the working machine, and when a load is not generated in the working machine, the pump displacement of the variable displacement pump can be controlled in accordance with a load pressure of a hydraulic motor which drives a cooling fan. Examples of such working machines include a forklift, a skid steer loader (SSL) and a crawler dump.

Abstract: The present invention relates to an improvement of an bent axis type variable displacement pump/motor in which a piston moves reciprocatingly inside a cylinder and a state in which three parties of a cylinder block, a valve plate member, and a case are always in close contact with each other is secured by configuring the valve plate member with a plurality of valve plate parts comprising a first valve plate part and a second valve plate part and placing the valve plate member between a block side sliding surface of a cylinder block and a concave guide surface of the case while the plurality of valve plate parts are slidably brought into close contact with each other via sliding contact surfaces.

Abstract: A variable capacity pump and two variable capacity motors are connected in a closed circuit. First to fourth drive gears are fitted to motor shafts of the variable capacity motors via clutches. A first driven gear, which meshes with the first and third drive gears, and a second driven gear which meshes with the second and fourth drive gears are fitted to an output shaft. Equivalent capacities of the variable capacity motors are made different. Control is exerted such that the capacities are decreased to zero in order of equivalent capacities. To decrease the capacity of each variable capacity motor, the gear change ratio of the variable capacity motor the capacity of which has decreased to zero is changed to decrease the equivalent capacity and, at the same time, the capacity is increased to maximum. This increases the gear change ratio for the continuously variable transmission and controls acceleration.

Abstract: A transmission is provided which has a very compact system configuration and is capable of exerting high energy efficiency over all speed regions from a low speed region to a high speed region, while providing improved operability free from a torque shortage. To this end, the transmission has an input shaft, an intermediate output shaft, a planetary gear mechanism, a first pump-motor, and a second pump-motor connected to the first pump-motor, the input shaft being coupled to a first element of the planetary gear mechanism, the second pump-motor being coupled to a second element of the planetary gear mechanism, the intermediate output shaft being coupled to a third element of the planetary gear mechanism, and the transmission further comprising a switching mechanism for selectively coupling the first pump-motor to either the input shaft or the intermediate output shaft.

Abstract: A transmission is provided which has a very compact system configuration and is capable of exerting high energy efficiency over all speed regions from a low speed region to a high speed region, while providing improved operability free from a torque shortage. To this end, the transmission has an input shaft 3, an intermediate output shaft 8, a planetary gear mechanism 9, a first pump-motor 7, and a second pump-motor 15 connected to the first pump-motor 7, the input shaft 3 being coupled to a first element (planetary carrier 12) of the planetary gear mechanism 9, the second pump-motor 15 being coupled to a second element (sun gear 19) of the planetary gear mechanism 9, the intermediate output shaft 8 being coupled to a third element (ring gear 16) of the planetary gear mechanism 9, and the transmission further comprising a switching mechanism (synchromesh mechanism 6) for selectively coupling the first pump-motor 7 to either the input shaft 3 or the intermediate output shaft 8.

Abstract: A transmission is provided which has a very compact system configuration and is capable of exerting high energy efficiency over all speed regions from a low speed region to a high speed region, while providing improved operability free from a torque shortage. To this end, the transmission has an input shaft, an intermediate output shaft, a planetary gear mechanism, a first pump-motor, and a second pump-motor connected to the first pump-motor, the input shaft being coupled to a first element of the planetary gear mechanism, the second pump-motor being coupled to a second element of the planetary gear mechanism, the intermediate output shaft being coupled to a third element of the planetary gear mechanism, and the transmission further comprising a switching mechanism for selectively coupling the first pump-motor to either the input shaft or the intermediate output shaft.

Abstract: The present invention lowers energy loss while at the same time enhancing the responsiveness of a steering control system. When a steering controller is operated rapidly, the aperture area of a steering flow control valve 4 rapidly increases, and the differential pressure (Pp?-PL) across the steering flow control valve 4 rapidly decreases. When the differential pressure (Pp?-PL) across the steering flow control valve 4 rapidly decreases, a flow control valve 6 is biased by the spring force of a spring 6f and quickly moves to the side of a valve position 6b to increase the differential pressure (Pp?-PL) and make it correspond to a set pressure. Thus, the pressure oil of a surplus flow ?, which up to this point has been flowing to a discharge oil line 7, is quickly supplied from the flow control valve 6 to a steering hydraulic cylinder 5 via the steering flow control valve 4. Thus, an output Q? starts quickly relative to an input St.

Abstract: A hydromechanical transmission having a continuously variable transmission function and occupying a small area for installation is provided. For this purpose, the transmission includes a driving source (3), a planetary gear speed reducer (5) connected to the driving source, a variable displacement hydraulic pump (11), which is connected to the planetary gear speed reducer, and to which one part of an output force of the driving source is outputted, an output shaft (717), which is connected to the planetary gear speed reducer, and to which the other part of the output force of the driving source is outputted, a first and a second variable displacement hydraulic motors (31, 37) receiving pressure oil from the hydraulic pump and outputting a driving force to the output shaft, and a clutch (45) placed between the second hydraulic motor (37) and the output shaft.

Abstract: An aerogenerator is provided wherein a fluid-driven transmission and a gear-driven transmission are arranged between a propeller and a generator. The fluid-driven transmission has a variable hydraulic pump and a variable hydraulic motor. The fluid-driven transmission varies a change gear ratio by varying the displacements of the pump and motor. The gear-driven transmission varies a speed increasing ratio between a rotating speed of the propeller and a rotating speed of the generator in synchronization with the gear change ratio of the fluid-driven transmission. A wind velocity of the propeller is detected by an anemometer. And the rotation speed of the propeller is controlled.

Abstract: The present invention intends to provide a hydraulic signal output device having a smaller installation space, and thereby enabling to make an installation space of hydraulic machines in an operation room smaller and that of other than the hydraulic machines larger. In addition to this, the present invention intends to allow externally restricting an operation in the operation room. In order to attain the intentions, in a hydraulic signal output device of the present invention, a PPC valve, an EPC valve and a shuttle valve are integrally formed. In one invention, in addition to the above, a pressure oil output port in a pressure-reducing valve in the PPC valve is communicated with a pressure oil input port of a switching valve in an electromagnetic valve, and a pressure oil output port of the switching valve in the electromagnetic valve is communicated with a pilot pipe line.

Abstract: The present invention lowers energy loss while at the same time enhancing the responsiveness of a steering control system. When a steering controller is operated rapidly, the aperture area of a steering flow control valve 4 rapidly increases, and the differential pressure (Pp?-PL) across the steering flow control valve 4 rapidly decreases. When the differential pressure (Pp?-PL) across the steering flow control valve 4 rapidly decreases, a flow control valve 6 is biased by the spring force of a spring 6f and quickly moves to the side of a valve position 6b to increase the differential pressure (Pp?-PL) and make it correspond to a set pressure. Thus, the pressure oil of a surplus flow ?, which up to this point has been flowing to a discharge oil line 7, is quickly supplied from the flow control valve 6 to a steering hydraulic cylinder 5 via the steering flow control valve 4. Thus, an output Q? starts quickly relative to an input St.

Abstract: A hydromechanical transmission having a continuously variable transmission function and occupying a small area for installation is provided. For this purpose, the transmission includes a driving source (3), a planetary gear speed reducer (5) connected to the driving source, a variable displacement hydraulic pump (11), which is connected to the planetary gear speed reducer, and to which one part of an output force of the driving source is outputted, an output shaft (717), which is connected to the planetary gear speed reducer, and to which the other part of the output force of the driving source is outputted, a first and a second variable displacement hydraulic motors (31, 37) receiving pressure oil from the hydraulic pump and outputting a driving force to the output shaft, and a clutch (45) placed between the second hydraulic motor (37) and the output shaft.

Abstract: The invention provides a volume control apparatus of a radial pump or motor which downsizes a hydraulic pump or motor, reduces a weight thereof and improves a freedom in arrangement, and a positioning apparatus. Accordingly, a servo piston (8) is operated following to a control valve (9), presses a cam ring (2) so as to position the cam ring at a position in correspondence to a volume control pressure, and regulates a volume.

Abstract: It is designed that an oil pressure signal can be output by operating an operation lever in a twisting direction; a structure can be made simple and its assembly and adjustment are easy; an operation force can be reduced; and a layout is not restricted. It is also designed that when the operation lever is left free after it is twisted, it returns smoothly to the original neutral position. When the operation lever is twisted about the lever axis, the shaft supported by bearings is twisted. The twist of the shaft is converted into the movement in a direction to move the pistons by first and second levers, and the pistons are moved. When the pistons are moved, the oil pressure signal is output from the discharge ports. A disk plate is separated into a first disk plate to which the root of the operation lever is attached and a second disk plate which is tiltably supported by a tilting fulcrum.

Abstract: An aerogenerator is provided wherein a fluid-driven transmission and a gear-driven transmission are arranged between a propeller and a generator. The fluid-driven transmission has a variable hydraulic pump and a variable hydraulic motor. The fluid-driven transmission varies a change gear ratio by varying the displacements of the pump and motor. The gear-driven transmission varies a speed increasing ratio between a rotating speed of the propeller and a rotating speed of the generator in synchronization with the gear change ratio of the fluid-driven transmission. A wind velocity of the propeller is detected by an anemometer. And the rotation speed of the propeller is controlled.

Abstract: A high versatility can be obtained, the pipe laying can be configured easily and, by virtue of the fact that a pilot pressured oil is managed, a hydraulic apparatus can be compacted. A differential pressure &Dgr;P between a pressure of the pressured oil on an upstream side and a pressure of the pressured oil on a downward side of operation valves is set to a certain value by a front-to-rear differential pressure stabilizer. As a result, flow rates Q1, Q2 of the operation valves are determined univocally in accordance with opening surface areas (opening amounts) A1, A2 of the operation valves, irrespective of load fluctuations, that is to say, a fluctuation of &Dgr;P. When one of operation members are operated, the opening amount A2 of the other operation valve correspondent with the other operation member is changed in accordance with an operation amount S1 of that operation member, and the other hydraulic actuator correspondent with the other operation valve is driven.

Abstract: The present invention intends to provide a hydraulic signal output device having a smaller installation space, and thereby enabling to make an installation space of hydraulic machines in an operation room smaller and that of other than the hydraulic machines larger. In addition to this, the present invention intends to allow externally restricting an operation in the operation room. In order to attain the intentions, in a hydraulic signal output device of the present invention, a PPC valve, an EPC valve and a shuttle valve are integrally formed. In one invention, in addition to the above, a pressure oil output port in a pressure-reducing valve in the PPC valve is communicated with a pressure oil input port of a switching valve in an electromagnetic valve, and a pressure oil output port of the switching valve in the electromagnetic valve is communicated with a pilot pipe line.

Abstract: The aim is to improve operability in vehicles such as skid steer loaders and to reduce the burden on the operator. It is made easy to switch between a first operation pattern wherewith only one operation apparatus of two operation apparatuses is used in driving two actuators, and a second operation pattern wherewith the two actuators are driven using both of the two operation apparatuses. It is made possible to hold operation positions, and to release held positions, whether with an operation lever apparatus that is capable of operation in only one directional component or with an operation lever apparatus that is capable of operation in two directional components in the forward and backward direction and in the left and right direction. When a change to a first combination is designated by a pattern switching lever, the first combination (first operation pattern) is switched to by switching means.

Abstract: It is designed that an oil pressure signal can be output by operating an operation lever in a twisting direction; a structure can be made simple and its assembly and adjustment are easy; an operation force can be reduced; and a layout is not restricted. It is also designed that when the operation lever is left free after it is twisted, it returns smoothly to the original neutral position. When the operation lever is twisted about the lever axis, the shaft supported by bearings is twisted. The twist of the shaft is converted into the movement in a direction to move the pistons by first and second levers, and the pistons are moved. When the pistons are moved, the oil pressure signal is output from the discharge ports. A disk plate is separated into a first disk plate to which the root of the operation lever is attached and a second disk plate which is tiltably supported by a tilting fulcrum.