Abstract: Methods and systems for transmission control are provided. In one example, a transmission system operating method includes maintaining a displacement set-point of a variable displacement hydraulic motor in a hydrostatic assembly within a working zone, where at least a portion of a boundary of the working zone is determined based on a torque constraint of the hydrostatic assembly. The transmission system includes the hydrostatic assembly that includes the hydraulic motor that is hydraulically coupled in parallel with a variable displacement hydraulic pump and a gearbox mechanically coupled to the hydrostatic assembly and including one or more clutches.

Abstract: The invention relations to a hydraulic machine of the Dry-Case construction type comprising a hydraulic machine housing for receiving a hydrostatic driving mechanism for conveying hydraulic fluid with a driving shaft operational connected with the driving mechanism. The driving shaft is mounted rotatable about its longitudinal axis in the hydraulic machine housing. Neither the driving mechanism, nor the driving shaft nor its bearings splash or move in a sump of the hydraulic fluid. Lubricant can be pumped to bearings of the driving shaft and to the driving mechanism by a lubrication pump arranged on the driving shaft and being driven by driving shaft. The lubrication pump do not splash in a sump of the hydraulic fluid either and comprise a suction port which leads to a hydraulic fluid reservoir.

Abstract: A method for manufacturing radial pistons for a hydraulic motor by machining cylindrical transverse holes at regular intervals in a bar, and, in order to form two adjacent pistons, cutting up the bar on a transverse cutting-up plane passing through one of said holes so that a first portion of said hole forms a cradle-shaped recess in the base of the first one of the two adjacent pistons and so that another portion of said hole forms a cradle-shaped recess in the top of the second one of the two adjacent pistons.

Abstract: A piston for a hydraulic motor including a body having a guiding and sealing surface, a base, and a top, which top is providing with a cradle-shaped recess. The base is provided with an additional cradle-shaped recess whose concave surface faces in the direction in which the concave surface of the recess in the top faces.

Abstract: A hydraulic system for synchronized movement of multiple cylinders in a horizontal plane includes a bidirectional pump, a shuttle valve cross-connected between pump outlets, flow-control check valves, and control valves which combine to reduce the number of valves in the hydraulic circuit and to reduce total cost of components for the system. The shuttle valve of the hydraulic system provides fluid for resynchronizing extension and retraction of multiple cylinder assemblies without disconnection of lines, provides air removal without disconnection of lines, allows easy addition/refill of hydraulic fluid, and allows excellent control of the extendable cylinder assemblies.

Abstract: A rotary displacement machine with radial pistons, comprising a supporting structure, with a main body and a cover, a centrally mounted distributor, a rotating unit consisting of a rotor provided with a number of radially extending cylindrical chambers, each chamber containing a respective piston mounted for sliding movement in a first direction along a first axis coaxial with the longitudinal centerline of the respective cylindrical chamber; wherein the rotor is mounted by support bearings means in the main body and cover and the distributor is mounted to float within a space defined by the cover and with coaxial relationship in the rotor by bearing means.

Abstract: A rotary displacement machine (10) with radial pistons (19), includes a bearing (29) having a rotating thrust ring (28) and a stationary outer ring (30), with bearing rollers (31) therebetween. The thrust ring (28) includes one engagement device (43, 45) per piston (19), the engagement device (43, 45) allowing movement in a straight line along a second direction defined by a second axis (b) perpendicular to a first longitudinal centerline (a) of the piston (19).

Abstract: A rotary fluid machine is provided that includes a rotor chamber (14), a rotor (41), vanes (48) guided by vane channels formed in the rotor (41), and pistons (47) slidably fitted in cylinders (44) provided in the rotor (41). Rollers (71) provided on support shafts (48d) of the vane (48) are rollably engaged with annular channels (74) of a casing (11) so as to interconvert reciprocation of the pistons (47) and rotational movement of the rotor (41). By capturing water of a hydrostatic bearing, which supports the vane (48) in the vane channel in a floating state, by a U-shaped lubricating water guide channel (43g) formed on the end face of a rotor segment (43) and discharging it into the annular channels (74), the water is prevented from flowing into the rotor chamber (14) and decreasing the temperature of steam, thereby preventing the output of the rotary fluid machine from being degraded.

Abstract: An outer periphery of an output shaft integral with a rotor of an expander of a vane-type operated by a high-pressure vapor is supported at its opposite ends by a static-pressure bearing mounted at one end thereof in a floated state provided by a liquid film of a pressurized liquid-phase fluid supplied from a pressurized liquid-phase fluid feed bore through a pressurized liquid-phase fluid passage, and by a static-pressure bearing mounted at the other end thereof in a floated state provided by a liquid film of a pressurized liquid-phase fluid supplied from a pressurized liquid-phase fluid feed bore through pressurized liquid-phase fluid passages. Vanes supported radially in the rotor for reciprocal movement are supported in floated states by a liquid film of a pressurized liquid-phase fluid supplied through pressurized liquid-phase fluid passages extending radially outwards within the rotor.

Abstract: In a rotary fluid machine for converting the reciprocal movement of pistons and the rotational movement of a rotor from one into another by the engagement of rollers and annular grooves with each other, a value in a positive peak region of a pressure load of pistons received by the rollers engaged in the annular grooves and a value of a positive peak region of a centrifugal force load received by the rollers are set, so that they are substantially equal to each other, and phases of the two peak regions are deviated from each other. In addition, the phase negative peak region of a vane pushing-down load received by the rollers and the phase of the positive peak region of the pressure load of the pistons received by the rollers are established, so that they are overlapped at least partially on each other.

Abstract: In a rotary fluid machine including pistons (37) reciprocally received in cylinders (33) provided in a rotor (27), and vanes (44) fitted in vane grooves provided in the rotor (27) for reciprocal movement, the rotor (27) includes a rotor core (31) which is supported on a rotary shaft (21) and in which the cylinders (33) are accommodated, and twelve rotor segments (32) separated in a circumferential direction and fixed to surround an outer peripheral surface of the rotor core (31); and each of the vane grooves (43) is defined between the adjacent rotor segments (32). Thus, the dimensional accuracy of the vane grooves (43) can be enhanced without need for a special accurate working or processing.

Abstract: A rotary cylinder apparatus which prevents a fluid from leaking from a contact portion of a piston and a cylinder member and consequently enables efficient rotation. The rotary cylinder apparatus comprises: a rotary cylinder member 2 which has cylinder chambers 22 and 23 formed thereto so as to pass through a rotary shaft center O and rotates around the rotary shaft center O; pistons 3 and 4 demonstrating reciprocating linear motion in the cylinder chambers 22 and 23; a piston holding member 5 which holds the pistons 3 and 4 and rotates around a rotation center X eccentric from the rotary shaft center O of the rotary cylinder member 2; and a casing 6 which rotatably supports the rotary cylinder member 2 and has at least one inlet 61 and at least one outlet 62, wherein the pistons 3 and 4 are rotatably supported at a position away from the rotation center X of the piston holding member 5 by a fixed distance and with that position at the center thereof.

Abstract: A radial piston pump has a support ring disposed on an eccentric longitudinal section of a pump shaft for rotation relative to the pump shaft. The support ring has at least three mutually offset flat support faces uniformly distributed about the circumference and adapted to contact piston shoes connected with pistons that extend radially from the pump shaft. The piston shoes engage from behind with radial flanges support rails disposed on the support ring. Spring-supported pressure rings prevent the piston shoes from rotating relative to the support ring. The pistons extend through guide bushing with an outside diameter that is greater than the diameter of the radial flanges and also greater than the outside diameter of the pressure rings.

Abstract: An apparatus for hydraulically operating a rear cover, covering top or the like (1) on a vehicle, with at least one double-acting hydraulic working cylinder (3), which, on the one hand, is connected to the vehicle and, on the other hand, to the covering top, includes working chambers (8, 9) in connection with each one side of a switched pressure source (12) via one check valve (10, 11) each, wherein both of the check valves have an mutually releasing device and each of the working chambers parallel with respect to the check valves is kept via a pre-stress valve (15, 16), which steers into the tank, at a specified pressure level. To realize, in a simple and safe way, a passive wedging protection, in at least one connection line (4, 5) to the working cylinder (3), a line (22) enters the tank (17), in which a proportional pressure valve (23) is inserted which is controlled by the control electronics and is equal to the exact pressure that is necessary for the movement of the covering top (1) or the like.

Abstract: An apparatus for hydraulic actuation of a hinged cover on a vehicle having a working cylinder such that work spaces within the cylinder are respectively connected, via check valves, to a reversible pressure source. The check valves respectively contain a reciprocal unclosing facility, and the work spaces are connected, via a pilot valve, in parallel to the check valves. Between the one of the work space and one of the check valves, an emergency valve guiding off to the tank is interposed and is shut off during normal operation of the apparatus to allow a safe emergency actuation of the hinged cover.

Abstract: A hydraulic circuit for opening and closing of a folding roof has at least two (pairs of) cylinders, one of which is adapted to open and close the folding roof and the other of which is adapted to lock the roof upon closing. The hydraulic circuit also has electrically operated valves provided in the circuit in such a way that the closing pressure within the roof cylinder is released rapidly as soon as the front roof edge gets within the catching area of the lock member, after which the lock cylinder will immediately close. This prevents the roof from moving in the closing direction too far, which would involve the tendency of the roof to "spring back", and avoids the chance of "miscatching" by the lock member.

Abstract: A variable-stroke crank mechanism includes a crankshaft rotatably mounted in a casing and having an eccentric crankpin, and a plurality of fluid pressure actuators disposed substantially radially with respect to the crankshaft, for pressing the eccentric crankpin to rotate the main shaft and the casing relatively to each other. The fluid pressure actuators are selectively supplied with a working fluid. An eccentric collar is rotatably mounted on the crankpin and operatively coupled to the fluid pressure actuators. The eccentric collar having an axis which is eccentrically displaced with respect to the axis of the crankpin. The crankpin and the eccentric collar are arrested in their respective angular positions by intermeshing internal and external gears. The crank mechanism may be incorporated in a plunger-type hydraulic unit, which may also be incorporated in a hydromechanical continuously variable transmission.

Abstract: A hydraulic pump/motor in which working piston elements are arranged for radial reciprocation. A cam is arranged eccentrically to a rotor which carries the pistons. Fluid cavities are provided in feet on the pistons, in the faces of a polygon to which the feet are attacahed, and in bearing pads in the outer ends of the cylinders to provide hydrostatic balancing. The pistons are hollow and are equipped with check valves to prevent centrifugal force from expelling fluid from the polygon and foot cavities. The cam includes mating spherical surfaces which compensate for bending forces applied to the cam. An improved mechanism for adjusting the cam position uses inherent forces to eliminate the need for a power assist device for cam adjustment. Port plates on opposite sides of the rotor provide inlet to the unit near the axis of the unit and outlet near the outer edge to alleviate stresses and increase efficiency.

Abstract: This invention relates to a radial piston device with a rotatable casing useful as a pump or a motor. The device is highly efficient with an overall efficiency of 0.95 and a mechanical efficiency of 0.97, a wide rotational speed range of over 1000 rpm, and can be made with continuously variable or fixed displacement. The device is compact in size, light in weight and simple in structure making it easy to manufacture. Moreover, the device can be constructed from a variety of materials without restrictive material requirements, can operate with both filtered and non-filtered oil, and is not sensitive to environmental effects. When the device is mounted on a wheel to form a hydrostatic transmission system, the layout and performance of the vehicle are significantly improved. The displacement control means provided by the present invention is also applicable to other motors or pumps with eccentric shafts. This invention also provides a simple and reliable flat oil seal.

Abstract: In a radial piston engine, in order to reduce the friction forces appearing at the pistons, a guide part is provided which engages a hollow piston through a guide section and which includes a bearing section at its outer end, by means of which the guide part is pivotably mounted in the cylinder cover.

Abstract: In a hydraulic motor or pump comprising a casing, a shaft, means journalling said shaft in said casing, an eccentric on said shaft, a bearing block within said casing and about said eccentric and having a bore permitting relative rotation between said bearing block and said eccentric, a plurality of hydraulic cylinders formed and grouped in said bearing block radially about said eccentric in a common plane normal to the axis of said shaft, a plunger slidable in each of said cylinders, said plunger having an outer end face, flat faces of abutments formed in said casing at its internal surface for engagement with said outer end faces of said plungers, respectively, means urging said plunger in the direction of said face abutment of said casing during the operation of said motor or pump, and said bearing block having a port communicating between its bore and the interior of each of said cylinder interior, whereby pressure liquid is admitted to the cylinders in turn one after another during the operation of said