Unipat Ag

Other

Unipat Aktiengessellschaft

Christian Helmut Thoma

George Duncan Arnold

Arthur Atholl Blair

George D Arnold

Roland L Von Kaler

Dale I Havens

Roland Von Kaler

An apparatus for heating a liquid includes a housing having an internal chamber and a rotor disposed in the chamber. The rotor is preferably cylindrical and operates inside a bore provided by the housing without touching, the shape of the bore preferably being parallel with the exterior surface of the rotor, and a series of openings disposed over the rotor surface. At least one internal passageway in the rotor and elements for: pre-heating some or all the incoming fluid in the chamber; priming the chamber initially; cooling certain temperature sensitive components; injecting fluid into a partially evacuated volume; developing a vacuum state during operation expeditiously.

Apparatus and method for heating fluids

An axle assembly for use in lawn tractors, pedestrian walk-behind mowers and snow blowers in the form of a housing having an internally disposed hydrostatic transmission and speed reducing gearing. An input shaft supported in the housing for driving a variable-displacement hydraulic pump of the hydrostatic transmission, the pump fluidly coupled to a fixed-displacement hydraulic motor of the hydrostatic transmission, and where the motor is drivingly connected through the speed reducing gearing to an output axle shaft or shafts. A mechanical differential disposed within said housing for applications requiring differential speeds of said axle output shafts. The housing being formed by three housing members and joined together along a substantially planar and horizontally peripheral seam formed there between such that two of said housing members are to one side of said seam and join with the third housing element. Two internal chambers formed by the three housing elements where one chamber contains the hydrostatic transmission and the other chamber contains the speed reducing gearing. A connecting shaft spanning between the chambers to provide the power transmission link between the hydrostatic transmission and the speed reducing gearing.

Hydrostatic transaxles with 2 chambers defined by three housing parts

A radial piston hydrostatic machine having a first fluid displacement stage and a second fluid displacement stage, the machine having an outer housing structure for defining an internal chamber, a drive-shaft supported in the housing and operatively connected to a cylinder-barrel located within the internal chamber, the cylinder-barrel having a number of radial cylinders and each cylinder containing a piston operatively connected to a surrounding annular track-ring, the cylinder-barrel and pistons defining a rotating-group and where the rotating-group is positioned in a sub-chamber generally defined axially by the width of the track-ring and radially by the radial distance between the cylinder-barrel and surrounding track-ring. The volume space between adjacent pistons defined as cells and fluid distribution means in the housing comprising two or more ducts lying axially adjacent the rotating-group and generally radially inwards of said track-ring to communicate with the sub-chamber to provide a first stage pumping motion when the track-ring is eccentric in position in relation to the cylinder-barrel in order to 'prime' the second stage piston reciprocating assembly in the cylinder-barrel. The invention further allows more than one hydrostatic machine to be driven by the same drive-shaft whereby the drive-shaft can be extended to pass through the machine without problems arising because the low-pressure fluid passages are restricted in size.

Radial piston hydrostatic machine with a first sweeping-displacement

A hydrostatic transmission having a housing for an internally disposed variable-displacement hydraulic pump and fixed-displacement hydraulic motor, a framework for supporting the hydraulic pump and motor components within said housing in a manner whereby the loads generated by the pressure medium flowing between pump and motor are absorbed into the framework. The framework to support a pintle-valve which as the fluid coupling means between pump and motor.

Radial piston hydrostatic transmission of the type incorporated into a

Hydraulic radial piston machines

A hydrostatic transaxle axle assembly for a vehicle such as a grass mowing lawn or garden tractor comprising a housing for an internally disposed hydrostatic transmission having a variable-displacement hydraulic pump fluidly connected to a fixed-displacement hydraulic motor, the hydraulic motor being connected by differential gearing to axle shafts supported in the housing. The housing is formed by three housing members, two of which are preferably separable on a parting plane coincident with the longitudinal axes of the axle shafts. One of the housing members being provided with an opening to allow a portion of one of the other housing members to extend through, and where the extending housing member contains within its interior a number of internal fluid passages for fluidly connecting the hydraulic pump to the hydraulic motor. This construction allows for improved cooling of the power transmitting fluid flowing between the pump and motor and simplifies manufacture of the transaxle such that the bulk or all the machining operations can be carried out in only one of the three housing elements, this housing member being the smallest of the three which can be completed using a comparatively smaller sized CNC machining-center than would otherwise be the case. The two remaining housing elements may be used in an as cast or supplied condition.

Hydrostatic transaxle

A housing structure for a hydrostatic machine comprising two shells of part-cylindrical form. The shells are connectable together at their junction surfaces on a parting-plane. A drive-shaft is supported in the housing structure and its axis of rotation lies on the parting-plane, this being the axis of symmetry of the shells. The shells are identical in cast shape, and have symmetrically arranged recesses and surface features to either side of said axis of symmetry. In the interior chamber between the shells, working component elements of the machine are located and driven by the drive-shaft to convert mechanical power into hydraulic power passing through openings or fluid-passageways provided in the housing structure.

Simplified housing structure for a hydrostatic machine

A radial piston hydrostatic machine having an outer housing structure and defining an internal chamber, a drive-shaft supported in the housing and operatively connected to the cylinder-barrel, the cylinder-barrel having a number of radial cylinders, each cylinder containing a piston such that the pistons bear on the track-ring, the track-ring eccentrically position within the internal chamber by means of fixed abutment means in the housing, the abutment means disposed radially adjacent the track-ring for resisting the action of the pistons on the track-ring and thereby suppressing vibration emanating from the track-ring.

Radial piston machines

A radial piston hydrostatic machine having an outer housing structure comprising at least two housing elements connectable together along a parting-plane arranged perpendicular to the rotational axis of said drive-shaft to define an internal chamber, a drive-shaft supported in the housing to drive the cylinder-barrel, the cylinder-barrel having a number of radial cylinders, each cylinder containing a piston such that the pistons can bear on the track-ring, fixed abutment means in the housing and disposed radially adjacent the track-ring for resisting the action of the pistons on the track-ring and suppressing vibration emanating from the track-ring.

Hydrostatic piston machines

A housing for a hydraulic piston machine comprising two shells of part-cylindrical form, the shells connectable together along a parting plane in which the rotating axis of the drive-shaft lies to contain within internal working elements of the machine. Either or both housing shells may be provided with a opening connecting the interior to the exterior of the shell(s) to provide means for fluid distribution of the machine. A non-deformable liner-element located within one or more of said openings for isolating pressurized fluid passing through the machine from coming into direct contact with the housing shells.

Hydraulic piston machines

A radial piston hydrostatic machine contained within a housing and comprising a cylinder-barrel mounted to rotate on a pintle-valve fixed to said housing. Two hydraulic-rams operatively acting on a track-ring to provide eccentric displacement relative to the pintle-valve to change the rate of fluid output from the machine. The hydraulic-rams being of unequal size and subjected to the same level of machine discharge pressure during periods when the level of discharge pressure is insufficient to cause an internally disposed pressure relief-valve to 'open'. A throttle-valve disposed in a fluid channel linking the cylinders of said hydraulic-rams and arranged to introduce a pressure differential across two said two cylinders during periods when the machine discharge pressure is sufficiently high to cause said pressure-relief-valve to 'open'.

A radial piston hydrostatic machine disposed in a housing, a drive shaft supported in the housing and connecting through bevel pinion and gear to transmit rotation of the shaft to a cylinder barrel. The cylinder barrel provided with generally radial cylinder bores supporting pistons and mounted to rotate on a stationary ported pintle valve fixed to said housing. The cylinder barrel having an axially extending projection to support the bevel gear in spaced relationship with the end of said cylinder barrel, the bevel gear rotating with said cylinder barrel and drivingly connected to said bevel pinion. Fluid bearing means provided on the outer cylindrical surface of said pintle valve to provide a pressure field under said axially extending projection in order to counter any deflection of said bevel gear.

Bevel gear support with fluid bearings for radial piston hydrostatic

A transaxle driving apparatus for a self-propelled vehicle such as a grass-mowing lawn tractor, the transaxle comprising a two-piece housing structure forming an internal chamber for encapsulation of a hydrostatic machine and associated reduction gearing. The hydrostatic machine may comprise in one form a single hydrostatic pump driven by an input shaft rotatably supported in the housing, and fluidly coupled to two hydrostatic motors. In a modified form, the hydrostatic machine may comprise two hydrostatic motors fluidly coupled to a pumping source remotely mounted outside the transaxle.

Variable speed transaxle

A friction drive unit for use within a transaxle driving assembly in self-propelled vehicles such as grass-mowing lawn tractors, the transaxle comprising a two-piece housing structure forming a number of internal chambers for the encapsulation of the friction drive unit, associated reduction gearing and a mechanical differential. The friction drive may comprise as input members, a pair of driver wheels operatable against a larger driven disc wheel acting as the output member, such that only one driver wheel can be engaged to the driven wheel at any one time, and where the direction of vehicle motion depends on which one of the two driver wheels is in contact with the driven wheel. Each of the driver wheels is subjected to continuous rotation from an input drive shaft and are operatively displaced along the shaft by means of respective sliding yoke means. The output from the driven wheel is connected to the transaxle output shafts by means of high ratio gear reduction means.

Growing community of inventors

Jersey, United Kingdom

Christian Helmut Thoma