Abstract: An inclined-axis variable displacement unit has an output shaft (1), mounted in a housing (4) of the unit, and a cylinder block (10), these being connected via a synchronizing articulation (13), and via working pistons (11) which can be displaced axially in the cylinder block (10), the cylinder block (10) being mounted axially in a pivoting body (5) which can be pivoted in relation to the axis of the output shaft (1) and has two symmetrical cylinder segments (51, 52) which are mounted for hydrostatic sliding action in mutually opposite concave cylindrical hollows (41, 42) in the inner surface of the housing (4).

Abstract: A closed cavity piston includes an elongated piston body and a separately formed piston cap having an elongated stem and head thereon. The body includes a closed end and an open end with a cavity having a bottom wall adjacent the closed end and an outer wall terminating in a rim at the open end. The stem of the piston cap is friction inertia welded to the bottom wall of the piston body and the head of the piston cap welds to the rim of the piston body so as cover the open end and sealingly enclose the cavity. The piston components can both be formed by conventional and relatively inexpensive cold forming techniques. The stem of the cap is inserted into the cavity of the body until it engages the bottom wall. Then the cap is friction inertia welded to the body at the stem/bottom wall and head/rim interfaces.

Abstract: A lathe cut sealing ring includes a substantially cylindrical ring of elastomeric material formed about a central axis. The ring includes a rectangular cross-section and has an inner diameter, an outer diameter, opposite planar upper and lower surfaces, and a plurality of angularly spaced positioning ribs protruding inwardly from the inner diameter. This sealing ring and the groove in which it is located can advantageously be formed with simple and cost-effective lathe cutting operations.

Abstract: A method to provide a smooth shift during mode changes of an HMT when using mechanical clutches by reducing the power into the transmission momentarily when a shift is initiated by cutting fuel to the engine, and also reducing power in the hydrostatic transmission by crossporting the fluid circuit, and then reapplying power to both the engine and the transmission after the clutch has been shifted.

Abstract: The present invention discloses a system and method of determining the density of pavement material. The invention includes positioning a capacitive proximity sensor, adjacent to but not in direct contact with a pavement material, projecting an electrostatic capacitive field from the sensor in the direction of the pavement material, measuring the strength of the electrostatic capacitive field as detected by the sensor, and correlating the strength of the electrostatic capacitive field to the density of the pavement material. The invention further discloses determining a location and associating the location with a pavement material density.

Abstract: A hydraulic motor (1), has an output shaft (3), a block cylinder (6), and high-pressure pistons (7) guided therein, and a block cylinder spring (9) and a valve plate (5). The block cylinder (6) exerts a contact-pressure force on the valve plate (5) by way of the charging pressure of the hydraulic oil in the block cylinder (6) and of the spring force of the block-cylinder spring (9). The contact-pressure force is counter-acted, when the hydraulic motor (1) is at a standstill, by a hydraulic pressure field which is built up on a surface (13) between the block cylinder (6) and the valve plate (5) via a valve device (12).

Abstract: A method and apparatus for creating a finite clearance space between two parts under blind assembly conditions involves threading an elongated sensor into a housing containing the part to be sensed by first placing a spacer element on an operative surface of the sensor wherein the spacer element has a radial thickness equal to the finite clearance space. The sensor is screwed unto the housing in a radial direction towards the operative surface of the sensor until the spacer element engages the operative surface, thereby specifically locating the operative surface a precise radial distance from the operative surface.

Abstract: A method of manufacturing male bimetal slippers includes the steps of forming a stem having opposite first and second ends; rigidly affixing a ball on the first end of the stem to form a male slipper body; and capacitance discharge welding a wear pad to the second end of the stem. To manufacture female bimetal slippers the method includes forming a slipper body of a first material, the body having opposite first and second ends, the first end having a ball socket formed therein; and capacitance discharge welding a wear pad of a second material to the second end of the body.

Abstract: A hydrostatic variable displacement pump has a swash plate (3), which is used to adjust the stroke of displacement pistons in a cylinder block. The swash plate has its angle position pivoted in relation to the stroke direction of the displacement pistons by means of a servosystem. The servosystem is fitted on the housing (6) of the variable displacement pump. The servosystem (4) has a pressure cylinder (18) and a servopiston (7), which together form a servocylinder pressure chamber (8). The servopiston (7) operates in the pressure cylinder (18), is subjected to compressive loading by means of a spring assembly (9,10) and has a piston with at least two servopiston surfaces (11, 12) subjected to the action of pressure.

Abstract: A hydromechanical transmission includes a hydrostatic transmission with coaxially arranged fixed and variable displacement hydrostatic units connected to a planetary gear set. The input shaft of the variable unit extends coaxially through the hollow shaft member of the fixed unit to drive the ring gear of the planetary gear set. The hollow shaft member drives the sun gear of the planetary gear set. An input clutch can be provided to allow the hydromechanical transmission to achieve zero output speed. A charge pump driven by the input shaft of the variable unit can be utilized to insure that the hydraulic units are primed whenever the input shaft turns. The input torque can be applied from either end of the variable unit. A power takeoff shaft option is available from the end of the transmission opposite the input.

Abstract: A control system for swing cylinders to position a boom on a backhoe or the like includes a pair of double acting hydraulic cylinders on the backhoe frame operatively connected to the boom for swinging the boom with respect to the frame, a closed circuit pump arranged in a closed circuit with the hydraulic cylinders such that the control on the pump is the sole means of controlling the cylinders.

Abstract: An inclined-axis variable displacement unit comprises an output shaft (1), mounted in a housing (4), and a cylinder block (10), the cylinder block (10) being connected to the output shaft (1) via a synchronizing articulation (18), and via working pistons (11) which can be displaced in the cylinder block (10), the cylinder block (10) being mounted in a pivoting body (5) which can be pivoted in relation to the axis of the output shaft (1) by an adjusting means, it being the case that the adjusting means is arranged on that side of the pivoting body (5) on which the output shaft is located.

Abstract: A hydrostatic variable displacement pump of swash plate construction has a cylinder block 2, in a housing 1, with displacement pistons 3 guided therein, a swash plate 4 and at least a first bearing 5 and a second bearing 6, which supports the angle adjustable swash plate 4. The housing 1 has a first opening, through which the swash plate can be introduced. The first bearing 5 has a removable outer race 13 which is designed such that, following installation of the second bearing 6 of the swash plate 4 in the bearing seat 8, it fixes said swash plate in the bearing seat 7 of the first bearing 5. The servomechanism 9, 10 is integrated in a cover 10 which closes off the housing 1 on the side of the first bearing 5.

Abstract: A control device apparatus for a proportionally adjustable hydraulic pump of a closed hydraulic circuit, including an axial piston pump adjustable from a zero position in two pivoting directions, with an electro hydraulic valve configuration for the activation of a piston of the hydraulic pump from both sides and with a feedback device, connected to the piston and whereby the angular pivoting position of the piston can be fed back to the valve configuration as a control signal, the valve configuration having a valve for each pivoting direction of the piston, and the feedback device comprising two mechanical feeler elements, each connected to one of the valves and in sliding engagement with the piston in such a way that the feeler elements are actuated when it leaves the zero position.

Abstract: An axle assembly has a housing. A hydrostatic transmission separate from the housing is mounted therein. Horizontal axle shafts are rotatably supported in the housing. The hydrostatic transmission includes a center section separate from the housing with fluid conduits connected to hydrostatic rotatable cylinder blocks. A drive shaft extends from one of the blocks and is operatively connected to the axle shafts. Check valves are associated with the conduits to affect fluid flow and are positioned to move in a vertical path at right angles to the axle shafts.

Abstract: An axle driving apparatus comprising a housing being defined by two separable elements joined together along a parting plane; the housing rotatably supporting a pair of axle shafts, each of the axle shafts having a longitudinal axis; the parting plane of the housing being parallel to the longitudinal axes of the axle shafts; and a hydrostatic transmission disposed in the housing and including a pump, a motor, and a member having pump and motor mounting surfaces thereon.

Abstract: A center section for separate mounting within the housing of an integrated transaxle comprising, a member having first and second hydrostatic unit mounting surfaces thereon, at least a pair of fluid ports in each of the mounting surfaces, and internal passageways in the member connecting at least one of the fluid ports on one of the mounting surfaces with at least one of the fluid ports on the other of the mounting surfaces.

Abstract: An electronic bore pressure optimization mechanism for dynamically varying the cylinder block piston bore pressure profile in a multiple piston hydraulic unit includes a valve means having a variable orifice disposed in the end cap for metering fluid between leading and trailing pistons in a transition region or between a piston in a transition region and a high or low pressure source; and means for generating a control error signal to the valve means so as to adjust the size of the variable orifice based upon the control signal.

Abstract: An electronic connection cover for a hydraulic component has a housing structure having an interior compartment and an electronic control element in the interior compartment. The housing structure has a face for interfacing a hydrostatic component housing. A printed circuit board is affixed to the face of the housing structure with a printed circuit thereon on a side thereof opposite to the housing structure. The printed circuit is connected to the electronic control element. Electrical contacts extend from the printed circuit through the printed circuit board and the electronic connection cover for external connection to an exterior circuit. A seal element is located between the printed circuit board and the electronic control circuit which surrounds the area where the electrical contacts extend through the printed circuit board.

Abstract: An inclined-axis variable displacement unit has an output shaft (1), mounted in a housing (4), and a cylinder block (10), the cylinder block (10) being connected to the output shaft (1) via a synchronizing articulation (13), and via working pistons (11) which can be displaced in the cylinder block (10), and the cylinder block (10) being mounted in a pivoting body (5) which can be pivoted in relation to the axis of the output shaft, it being the case that the pivoting body (5) is in the form of an open vessel, and the cylinder block (10) is arranged in the opening of the pivoting body.