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US 6,358,174 B1Granted
Hydraulic machine
AssigneeFolsom Technologies, Inc.
InventorsLawrence R. Folsom, Clive Tucker
Life of this patent
Estimating the term…
Abstract
A hydromechanical transmission has an operating assembly including an input hydrostatic unit (50) and an output hydrostatic unit (60), each having a rotating cylinder (180, 182) and piston element (210, 212) and a non-rotating yoke element (150, 151). The non-rotating elements are yoke elements (150, 151) linked together to react the separating forces internally, bypassing the housing (120).
Claims31
A continuously variable transmission comprising:
- two hydraulic units including a pump and a motor, each having a rotational element and a grounded reaction element, at least one of said hydraulic units being variable displacement;
- a control system for controlling said displacement of said one hydraulic unit;
- a variable ratio motor gearset having first, second and third meshing gear elements, and a variable ratio pump gearset having first, second and third meshing gear elements;
- an input shaft connected to said first gear element of said motor gearset;
- an output shaft connected to said second gear element of said motor gearset and to said rotational element of said second hydraulic unit;
- said third gear element of said motor gearset being connected to said third gear element of said pump gearset;
- a brake releasably connecting said first element of said pump gearset to ground;
- said second gear element of said pump gearset being connected to said rotational element of said first hydraulic unit;
- said two hydraulic units being hydraulically connected such that the displaced fluid from the first hydraulic unit flows to the second hydraulic unit and vice versa;
- whereby, input torque applied to said input shaft is transmitted therethrough to said pump, when said brake is engaged, by way of said first and third elements of said variable ratio motor gearset and thence by way of said third, first and second elements of said variable ratio pump gearset, reacting through said engaged brake to ground, to rotate said pump and pressurize a working fluid in said pump cylinders;
- said transferring of said input torque from said input shaft to said pump creating a reaction torque which is transferred through said second element of said variable ratio pump gearset to said output shaft, said pressurized fluid being conveyed through said opening in said manifold block to said motor and energizing said motor to produce motor torque that is transferred to said output shaft in addition to said reaction torque as output torque in said output shaft.
8 more elements
A method of operating a continuously variable transmission, comprising:
- applying input torque to an input shaft and transmitting said input torque through said input shaft to a pump by way of first and third elements of a first variable ratio motor gearset and thence by way of third, first and second elements of a second variable ratio pump gearset to rotate said pump and pressurize a working fluid in cylinders in said pump;
- said transferring of said input torque from said input shaft to said pump creating a reaction torque which is transferred through said second element of said variable ratio pump gearset to said output shaft, said pressurized fluid being conveyed through openings in a stationary manifold block between said pump cylinder block and a cylinder block of a motor, said fluid energizing said motor to produce motor torque that is transferred to said output shaft in addition to said reaction torque as output torque in said output shaft.
A continuously variable transmission, comprising:
- an operating assembly including a pump unit and a motor unit hydraulically related to each other through a stationary manifold and mechanically related through a planetary gear set;
- an input shaft driving a planet carrier in which are mounted planet gears engaged with a sun gear and a ring gear of said planet gear set;
- an output shaft driven by said ring gear;
- said pump having a pump cylinder block operatively driven in rotation by said sun gear of said planetary gear set;
- a housing enclosing said operating assembly;
- a stationary actuator fixed to said housing and linked to at least one of said hydrostatic units for adjusting the displacement of said one of said hydrostatic units;
- two yokes mounted in said housing for tilting about pivotal axes perpendicular to said input shaft, one of said yokes having a surface for slidably engaging an element of said pump as said pump rotates, and the other of said yokes having a surface for slidably engaging an element of said motor as said motor rotates;
- links connecting said yokes to directly resolve separating forces exerted by internal fluid pressure in said pump and said motor;
- said pump and said motor are both bent axis units having rotating cylinder blocks supported by said yokes;
- whereby said cylinder blocks tilt with said yokes and rotate in a balanced manner about their own centers of mass regardless of the angle of tilt of said yokes.
7 more elements
A transmission mechanism, comprising:
- first and second hydraulic units coupled together hydraulically such that fluid displaced from one unit flows into the other unit, and vice versa, said units each having a rotational element and a reaction element, at least one of said hydraulic units being of the variable displacement type;
- said reaction elements of both hydraulic units being connected to ground;
- a variable ratio gearset having at least first, second and third gear elements related together by meshing gear teeth;
- an input shaft mechanically coupled to said first gear element;
- an output shaft mechanically coupled to said second gear element;
- said rotational element of said first hydraulic unit mechanically coupled to said third gear element;
- and
- said rotational element of said second hydraulic unit being connected to said output shaft.
5 more elements
A process for converting rotating input power in an input shaft at an input speed and torque to rotating output power in an output shaft at a variable output speed and torque, comprising:
- applying input torque to said input shaft;
- transmitting said input torque through said input shaft to a pump via first and third gear elements of a variable ratio gearset to rotate said pump and pressurize a working fluid in said pump cylinders, transfer of said input torque from said input shaft to said pump creating a reaction torque which is transferred through said second element of said planetary gearset to said output shaft, said pressurized fluid being conveyed from said pump cylinders through said pump piston bores and through said opening in said manifold block and through said motor piston bores to said motor cylinders to energize said motor to produce motor torque that is transferred to said output shaft in addition to said reaction torque as output torque in said output shaft.
A continuously variable transmission, comprising:
- an operating assembly including first and second hydraulic units coupled together hydraulically such that fluid displaced from one unit flows into the other unit, and vice versa, said units each having a rotational element and a reaction element, at least one of said hydraulic units being of the variable displacement type;
- said reaction elements of both hydraulic units being connected to ground;
- a variable ratio gearset having at least first, second and third gear elements related together by meshing gear teeth;
- an input shaft mechanically coupled to said first gear element;
- an output shaft mechanically coupled to said second gear element;
- said rotational element of said first hydraulic unit mechanically coupled to said third gear element;
- said input shaft and said variable ratio gearset comprising an input drive train to said rotational element of said first hydraulic unit;
- said rotational element of said second hydraulic unit being connected to said output shaft;
- a clutch interposed in said input drive train for selectively decoupling said first hydraulic unit from said input shaft to allow said transmission to free-wheel when said clutch is operated.
6 more elements
A continuously variable transmission, comprising:
- a fixed housing;
- an input shaft having a longitudinal axis about which said input shaft rotates relative to said housing;
- an output shaft having a longitudinal axis about which said output shaft rotates relative to said housing;
- a pump having a rotating element and a reaction element, said pump rotating element including a pump cylinder block having pump cylinders opening in an axial face of said pump cylinder block, said pump rotating element having an axially facing surface engaged with said reaction element;
- said pump reaction element including an input yoke mounted in said housing, fixed against rotation about said input shaft longitudinal axis and free to tilt under control of a yoke tilt actuator about an input yoke tilt axis that is perpendicular to and intersecting said input shaft axis, said input yoke having a surface facing inwardly toward and in load-bearing relation to said outwardly facing surface of said pump element;
- a motor having a rotating element and a reaction element, said rotating element including a motor cylinder block having motor cylinders opening in an axial face of said motor cylinder block, said motor rotating element having an axially facing surface engaged with an inwardly facing surface of an output yoke;
- said output yoke being mounted in said housing for tilting movement about an output yoke tilt axis that is perpendicular to and intersecting said output shaft axis, said inwardly facing surface of said output yoke being in load bearing relation to said outwardly facing surface said motor rotating element;
- a manifold block fixedly mounted centrally in said housing and having flat axially outwardly facing surfaces on opposite input and output sides of said manifold block;
- a pair of opposed curved recesses on each of said outwardly facing surfaces of said manifold block and at least one opening in each of said curved recesses extending axially completely through said manifold block so as to provide fluid flow from each curved recess to a corresponding curved recess on the opposite side of said manifold block;
- said pump including an input torque ring having a ring of sockets for receiving piston heads of said pump pistons, and having a contact surface in contact with a flat, non-rotating flat surface;
- motor pistons in said motor cylinders, through-bored for fluid transmission, and extending outwardly from said motor cylinders into torque transmitting engagement with an output torque ring of said motor;
- said motor output torque ring having a ring of sockets for receiving piston heads of said motor pistons, and having a contact surface in contact with a flat output side surface of said manifold block and in torque transmitting engagement with said output shaft;
- pump pistons in said pump cylinders, through-bored for fluid transmission, and extending outwardly from said pump cylinders into torque transmitting engagement with said pump torque ring;
- a planetary gear set having a sun gear element, a ring gear element, and an intermediate planet carrier element holding a plurality of planet gears engaged between said ring gear element and said sun gear element, a first of said elements being in torque transmitting engagement with said input shaft, a third of said elements being in torque transmitting engagement with said pump, and a second of said elements being in torque transmitting engagement with said output shaft;
- whereby, input torque applied to said input shaft is transmitted therethrough to said pump via said first and third gear elements to rotate said pump and pressurize a working fluid in said pump cylinders, transfer of said input torque from said input shaft to said pump creating a reaction torque which is transferred through said second element of said planetary gearset to said output shaft, said pressurized fluid being conveyed from said pump cylinders through said pump piston bores and through said opening in said manifold block and through said motor piston bores to said motor cylinders to energize said motor to produce motor torque that is transferred to said output shaft in addition to said reaction torque as output torque in said output shaft.
12 more elements
Dependencies are inferred from the claim text.