Abstract: A turning system for use in a track-laying vehicle comprising: a power source; a steering motor driven by the rotation of the power source, for driving crawler belts provided at both sides of the vehicle such that a relative travel difference is caused between the crawler belts, thereby turning the vehicle rightwards or leftwards; a power source revolution speed detector for detecting the actual revolution speed of tile power source; and a steering motor control unit for performing a control such that, a target revolution speed set for the steering motor is decreased when the actual revolution speed of the power source detected by the power source revolution speed detector decreases below a target revolution speed set for the power source by a specified revolution speed or more.

Abstract: A steering control system for use in a track-laying vehicle comprising: a power source; a steering motor driven by the rotation of the power source, for driving crawler belts provided at both sides of the vehicle such that a relative travel difference is caused between the crawler belts, thereby turning the vehicle rightwards or leftwards; a steering instructing device which can be displaced from a neutral position by operation and which instructs, according to the direction and distance of its displacement, a turning direction and a turning radius for the vehicle, the turning radius decreasing as the displacement distance increases; a displacement detector for detecting the displacement of the steering instructing device; and a steering motor revolution speed control unit for obtaining a target steering motor revolution speed which is made proportional to the revolution speed of the power source based on the displacement of the steering instructing device detected by the displacement detector and controlling

Abstract: A mechanical - hydraulic transmission for a crawler-type vehicle is provided having a reduced dimension in a widthwise direction perpendicular to input/output shafts and capable of ready installation on an existent crawler steering device. The transmission is arranged such that a power input shaft (1), directly connected to a prime mover, an intermediate shaft (9) and an output shaft (19), are concentrically related and arranged in a longitudinal column. Normal- and reverse-rotation planetary gear devices (5, 6), having respective clutches (7, 8) thereof, are mounted on a periphery of the power input shaft (1), and the power input shaft (1) is connected to a variable displacement hydraulic pump (2).

Abstract: A vuilleumier heat pump device comprises: a hot-side heat pump (2) in which a hot side displacer (22) is housed in a hot side cylinder (21); and a cold-side heat pump (3) in which a cold side displacer (32) is housed in a cold side cylinder (31). Rods (23, 33) respectively connected to the displacers (22, 32) are connected to each other through a connection mechanism (4). In the vuilleumier heat pump device, a volume of the cold side rod (33) in a middle-temperature space (35) is adjusted. In this case, a rotation speed of a crank shaft (42) of the connection mechanism (4) is detected, a volume of the rod in a middle-temperature space (35) according to the rotation speed is calculated, and then the volume of the cold side rod (33) in a middle-temperature space (35) is adjusted so as to reach the calculated volume of the rod.

Abstract: Coefficient of performance (COP.sub.L), (COP.sub.H) is lowered when cooling capability or heating capability (Qk) is increased by increasing a revolution speed (N) because an working gas temperature (Tc) of a cold space (9L) drops and an working gas temperature (Tm) of a middle-temperature spaces (10H), (10L) rises. In order to avoid the lowering thereof, a vuilleumier heat pump device is provided with sensors (26), (29) for respectively detecting the respective working gas temperatures (Tc), (Tm), adjusting means (27), (30) for increasing or decreasing heat input of an endothermic heat exchanger (23) of a heat input circuit (22) and heat output of a radiation heat exchanger (25) of a radiation circuit (24) respectively, and control means (28), (31) for controlling the respective adjusting means (27), (30) so as to increase the heat input and the heat output in accordance with rise or drop of the gas temperature (Tc), (Tm).

Abstract: A transmission and control mechanism for a hydrostatic-mechanical power transmission system, provided with a mechanical transmission driven through an input shaft connected to a engine, a hydrostatic transmission connected to the input shaft, and a differential unit for connecting an output shaft to the mechanical and hydrostatic transmissions. The hydrostatic transmission includes a swashplate type pump and motor, with at least one of the swashplates being variable in angle. There is an engine revolution speed sensor, a target motor speed ratio setting device for setting a target motor speed ratio based on whether the engine speed is above, below or within a predetermined speed range, and a swashplate angle controller for controlling the swashplates according to the target motor speed ratio.

Abstract: Disclosed is a clutch changeover circuit suitably used for a multi-stage stationary non-stage transmission. Valve bodies of pressure regulating valves (211, 221, 231, 241) are respectively provided with throttle passages (311, 321, 331, 341) communicating therewith in such a manner that hydraulic oil flows to the clutch sides when they are closed, since the sliding of the clutches or damage thereto can occur if pressure regulating valves having good override characteristics are used. Accordingly, at the time of changing over the clutch, since hydraulic oil flows at least by a portion corresponding to the rate of flow of leaking oil, it is possible to prevent the clutches from sliding or becoming damaged while using regulating valves having good override characteristics.

Abstract: Disclosed is a clutch changeover circuit suitably used for a multi-stage stationary non-stage transmission. Valve bodies of pressure regulating valve (211, 221, 231, 241) are respectively provided with throttle passages (311, 321, 311, 341) communicating therewith in such a manner that hydraulic oil flows to the clutch sides when they are closed, since the sliding of the clutches or damage thereto can occur if pressure regulating valves having good override characteristics are used. Accordingly, at the time of changing over the clutch, since hydraulic oil flows at least by a portion corresponding to the rate of flow of leaking oil, it is possible to prevent the clutches from sliding or becoming damaged while using regulating valves having good override characteristics.

Abstract: A driving control device in a crawler type tractor comprises a lever capable of being operated in the forward or reverse (backward) direction and capable of being operated in the right or left direction when the lever is operated so as to move to the end of the forward or reverse direction, and a speed-stage command device capable of generating and transmitting commands for speed stages for the forward and the reverse directions. When a first sensor detects the lever operation in the forward or reverse direction; the transmission speed stages can be selected in accordance with the first sensor output and the output of the speedstage command device, and the operation amount of the lever in the right or left direction is detected by a second sensor so that steering clutches of the tractor can be controlled in accordance with the output of the second sensor.