Plural Pump-motor Sets Patents (Class 475/24)
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Patent number: 12209657Abstract: Methods and systems for a hydromechanical transmission. In one example, a vehicle system includes a hydromechanical transmission with a power-take off (PTO) that is designed to rotationally couple to an implement. The vehicle system further includes an engine coupled to the hydromechanical transmission and a power-management control unit configured to, during a drive or coast condition, cause the power-management control unit to: determine a net available power for the hydromechanical transmission and manage a power flow between the hydromechanical transmission, a drive axle, and the implement based on the net available power.Type: GrantFiled: November 17, 2023Date of Patent: January 28, 2025Assignee: DANA ITALIA S.R.L.Inventors: Lorenzo Dalla Palma, Fabio Gunsch, Alessandro Dilisa
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Patent number: 12162347Abstract: An electric drive for may have at least one electric machine in a housing with a rotor shaft forming the drive shaft, which can be coupled to an intermediate shaft via at least one spur gear, wherein the intermediate shaft is coupled to an output differential for driving output shafts, wherein there is at least one oil pump for pumping transmission fluid, wherein a pump shaft in the oil pump can be driven in the same direction of rotation via a first drive path, which has at least one first freewheel, and via a second drive path, which has at least one second freewheel and at least one differential, and wherein at least the first freewheel and the second freewheel, as well as the differential, are located radially inside the hollow intermediate shaft.Type: GrantFiled: February 11, 2021Date of Patent: December 10, 2024Assignee: ZF Friedrichshafen AGInventor: Alexander Markow
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Self-propelled construction machine and method for controlling a self-propelled construction machine
Patent number: 11572661Abstract: A self-propelled construction machine comprises a machine frame having a working means arranged thereon, and a drive means for driving left and right crawler tracks at respective predetermined chain speeds. A control unit is configured such that, based on a distance between a front reference point with respect to the machine frame in the working direction and a predetermined path, the chain speed(s) of the left and/or right crawler track is predetermined such that the front reference point moves on the predetermined path. The control unit is further configured such that, during cornering, the control is corrected based on a distance between a rear reference point with respect to the machine frame in the working direction and the predetermined path such that the distance between the rear reference point with respect to the machine frame in the working direction and the predetermined path is reduced.Type: GrantFiled: June 23, 2020Date of Patent: February 7, 2023Inventor: Matthias Fritz -
Patent number: 10926629Abstract: A drive assembly for a vehicle is provided, the vehicle having a frame, a prime mover and a pair of driven wheels. The drive assembly includes a transmission having a housing in which a pump and motor may be disposed. The transmission may be pivotally mounted to the frame and movable between at least two positions. The transmission may include an internal reduction gear assembly driven by a motor output shaft, a transmission output shaft disposed generally parallel to the motor output shaft and driven by the internal reduction gear assembly, the transmission output shaft extending from the transmission at both ends thereof. Each end of the transmission output shaft may drive an external reduction assembly supported in part by the frame, and the external reduction assemblies power at least a driven wheel of the vehicle.Type: GrantFiled: January 8, 2018Date of Patent: February 23, 2021Assignee: Hydro-Gear Limited PartnershipInventor: Michael L. Bennett
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Patent number: 10077828Abstract: A powertrain system in a machine includes a transmission, and a transmission drive mechanism coupled between the transmission and an engine. The transmission drive mechanism includes a split path architecture where a first input gear receives a torque input from a driveshaft and a second input gear receives a torque input from a variator. The transmission drive mechanism is thereby structured to operate the transmission at a range of speeds that is not dependent upon a speed of the engine, enabling the engine to operate at an engine speed set point or with an optimum engine speed range.Type: GrantFiled: April 18, 2016Date of Patent: September 18, 2018Assignee: Caterpillar Inc.Inventors: Michael Cronin, Kevin Meyer
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Patent number: 9919737Abstract: A steerable crawler track for an agricultural utility vehicle such as a tractor or a self-propelled harvesting machine has a left-side track roller unit, a right-side track roller unit, a differential having a transmission input driven by an engine, a first transmission output for driving the left track roller unit, and a second transmission output for driving the right track roller unit and a hydraulic transmission having a variable transmission ratio (i). The transmission outputs of the differential are coupled to one another via the hydraulic transmission such that the ratio of the rotational speeds (nl, nr) of the transmission outputs are influenced by changing the transmission ratio (i) of the hydraulic transmission.Type: GrantFiled: September 8, 2015Date of Patent: March 20, 2018Assignee: CLAAS Industrietechnik GmbHInventors: Helmut Claas, Heinrich Dueckinghaus, Robert Obermeier-Hartmann, Hendrik Schulze Zumkley
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Patent number: 9523418Abstract: A two mode CVT is provided that for a motor vehicle. The CVT includes a speed change device connected to a pulley and belt assembly. The pulley and belt assembly is connected to a planetary gear set arrangement. The planetary gear set arrangement generally includes two planetary gear sets, two brakes, and one clutch. The planetary gear set arrangement is connected to a final drive unit.Type: GrantFiled: April 25, 2014Date of Patent: December 20, 2016Assignee: GM Global Technology Operations, LLCInventors: Edward W. Mellet, James M. Hart
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Patent number: 9416519Abstract: A wheel loader includes: a mechanical drive unit; a mechanical drive clutch controlling transmission/cutoff of a power in the mechanical drive unit; an HST pump driven by an engine; a hydraulic motor driven by a hydraulic oil delivered from the HST pump; a hydraulic drive unit; a hydraulic drive clutch controlling transmission/cutoff of a power in the hydraulic drive unit; a load detecting unit detecting an amount of a load; a vehicle speed sensor detecting a vehicle speed; a switching controlling unit setting a switching vehicle speed in accordance with the amount of the load; and a vehicle-body controller switching between mechanical drive state and hydraulic drive state based on the switching controlling unit. The switching controlling unit sets the switching vehicle speed at a high-speed side when the load becomes large and at a low-speed side when the load becomes small.Type: GrantFiled: April 2, 2014Date of Patent: August 16, 2016Assignee: Komatsu Ltd.Inventor: Yasuhiro Kobiki
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Patent number: 9206885Abstract: An infinitely variable transmission includes a clutch, a brake and a first planetary gear set, including first and second components, and a double planetary gear set, including input and output components and additional third and fourth components. The first component receives power from an engine. The double planetary set sums mechanical power from the first planetary set and an infinitely variable power source (“IVP”). The third component receives mechanical power from a IVP. The second component directly transmits power to the input component. The clutch directly controls power transmission between the first and second components. The brake engages the fourth component to stop its rotation. The output component receives mechanical power directly from the input component and the fourth component. During operation of the engine, controlled actuation of the brake and the clutch causes the output component to be powered by the infinitely variable power source but not by the engine.Type: GrantFiled: December 31, 2013Date of Patent: December 8, 2015Assignee: Deere & CompanyInventors: Andrew K. Rekow, Rainer Gugel, Dennis L. Jeffries, David Mueller
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Patent number: 9109660Abstract: An automatic manual transmission for a car provided with an internal combustion engine, the automatic manual transmission having: a mechanical gearbox provided with at least one primary shaft, at least one secondary shaft, a plurality of pairs of gears and a plurality of locking devices, actuated by first actuators, a variable ratio transmission device, which is arranged upstream of the primary shaft and is adjustable to have two different transmission ratios: a first unitary direct drive transmission ratio and a second multiplying transmission ratio, and a second actuator, which is coupled to the transmission device to vary the transmission ratio of the transmission device itself.Type: GrantFiled: June 6, 2013Date of Patent: August 18, 2015Assignee: Ferrari S.p.A.Inventor: Franco Cimatti
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Patent number: 9109680Abstract: A hydrostatic mechanical power split transmission includes a housing, at least one first power branch having at least one hydraulic pump and at least one hydraulic motor, and at least one drive shaft provided with gear wheel elements, which is disposed inside the housing and can be directly or indirectly driven by at least one drive engine, in particular an internal combustion engine as a further power branch, the drive shaft being able to selectively act either directly or indirectly on the sun gear of a planetary gear system by way of at least one clutch, to be decoupled from the planetary gear system, wherein the planetary gear system can be switched to a state of constrained motion by way of further clutches as a function of the respective operating state of the power split transmission.Type: GrantFiled: December 20, 2011Date of Patent: August 18, 2015Assignee: Hytrac GmbHInventor: Detlef Tolksdorf
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Patent number: 8852043Abstract: The present invention utilizes the rotary kinetic power of a rotary kinetic power source to directly drive the epicyclic gear set, or to drive the epicyclic gear set through a transmission device, then a continuous variable transmission (CVT) is individually installed between two output shafts of the epicyclic gear set and the load driven thereby, so the wheel set of the driven load is enabled to randomly perform variation of the driving speed ratio and the driving torque, so as to drive the combined common load; between the output ends of the mentioned two continuous variable transmissions, a limited slip differential or a stabilize device composed of a dual shaft connecting device having slip coupling torque can be further installed according to actual needs.Type: GrantFiled: April 11, 2012Date of Patent: October 7, 2014Inventor: Tai-Her Yang
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Patent number: 8790205Abstract: The present invention utilizes the rotary kinetic power of a rotary kinetic power source to directly drive the epicyclic gear set, or to drive the epicyclic gear set through a transmission device, then a continuous variable transmission (CVT) is individually installed between two output shafts of the epicyclic gear set and the load driven thereby, so the wheel set of the driven load is enabled to randomly perform variation of the driving speed ratio and the driving torque, so as to drive the combined common load; between the output ends of the mentioned two continuous variable transmissions, a limited slip differential or a stabilize device composed of a dual shaft connecting device having slip coupling torque can be further installed according to actual needs.Type: GrantFiled: February 23, 2012Date of Patent: July 29, 2014Inventor: Tai-Her Yang
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Patent number: 8298106Abstract: An infinitely variable hydromechanical crossdrive steering transmission having a multiple of forward and reverse ratio ranges and a separately selectable low ratio range in both forward and reverse. The forward and reverse ratio ranges are enabled to shift between ratio ranges in a synchronous manner in both speed and torque, thus smoothly propelling the vehicle from rest through the multiple transmission ranges to maximum speed in a stepless manner.Type: GrantFiled: October 19, 2009Date of Patent: October 30, 2012Assignee: Berkshire Powertech, Inc.Inventor: Robert Francis Larkin
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Patent number: 8047941Abstract: A drive unit (1) for continuously, variably controlling rotational speed and reversing the rotational direction of at least one output shaft. The drive unit (1) having two identical transmission modules (2, 3) with a common input (4) and a way for power splitting a continuously variable rotational speed and reversing the rotational direction.Type: GrantFiled: March 10, 2008Date of Patent: November 1, 2011Assignee: ZF Friedrichshafen AGInventor: Stefan Prebeck
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Publication number: 20100113203Abstract: An infinitely variable hydromechanical crossdrive steering transmission having a multiple of forward and reverse ratio ranges and a separately selectable low ratio range in both forward and reverse. The forward and reverse ratio ranges are enabled to shift between ratio ranges in a synchronous manner in both speed and torque, thus smoothly propelling the vehicle from rest through the multiple transmission ranges to maximum speed in a stepless manner.Type: ApplicationFiled: October 19, 2009Publication date: May 6, 2010Applicant: BERKSHIRE POWERTECH INC.Inventor: Robert Francis LARKIN
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Patent number: 7476172Abstract: A brake mechanism for a motor assembly including a motor and a reduction gear assembly driving an output shaft or axle is disclosed. A brake rotor is driven by the motor shaft and a brake puck is operatively engageable with the brake rotor for moving the brake rotor toward a braking surface. A brake cam shaft is rotatably supported about an axis perpendicular to the axis of the output shaft and engages the brake puck so that rotation of the brake cam shaft about its axis forces the brake puck to move the brake rotor toward the braking surface.Type: GrantFiled: March 10, 2008Date of Patent: January 13, 2009Assignee: Hydro-Gear Limited PartnershipInventors: Thomas J. Langenfeld, Shane A. Deters
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Patent number: 7476171Abstract: A hydraulic motor assembly having a motor and gear reduction set mounted in a housing. A brake assembly may be mounted in the port block to provide braking for the output axle or it may be located externally to the axle housing portion of the assembly. The housing may be formed of separate components, including the external surface of the ring gear and the hydraulic motor port block.Type: GrantFiled: September 28, 2004Date of Patent: January 13, 2009Assignee: Hydro-Gear Limited PartnershipInventors: Thomas J. Langenfeld, Shane Deters
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Publication number: 20080113838Abstract: A hydraulic drive comprising multiple gear motors each having a gear motor output shaft, and a common gear engaged by the output shafts of the multiple gear motors. Each hydraulic motor has a characteristic sinusoidal torque ripple out of phase with the characteristic sinusoidal torque ripple of at least one other hydraulic motor for cancelling torque ripple and thereby reducing the torque ripple at the common gear.Type: ApplicationFiled: June 11, 2007Publication date: May 15, 2008Inventors: Joseph A. Kovach, Lisa K. Furches, Richard D. Kimpel, Hao Zhang, Raymond E. Collett, Lori A. Martinelli
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Patent number: 7357744Abstract: The invention comprises a hydro-mechanical continuously variable transmission (HMCVT) that uses a planetary gear system to provide a combination of hydraulic and mechanical power for a vehicle or stationary equipment. The invention further comprises various ancillary elements to improve the performance of the HMCVT.Type: GrantFiled: November 19, 2002Date of Patent: April 15, 2008Inventors: Gerald Dyck, Paul Dries
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Patent number: 6932733Abstract: A transmission has an HMT which is in parallel with an HST both driving two planetaries which are used for forward/reverse and for differential steer. A two or three mode HMT is created by having a first HST in parallel with two or three mechanical power paths defined by separate clutches. One clutch has a speed reversing gear to produce reverse output speed. A four-element planetary sums the parallel flow and delivers variable speed and torque to two output shafts. The differential steer is created by two planetaries connected with the outputs of the HMT and a second HST. The planetaries have a speed reversing gear on one power path connection. The second HST controls the differential speed between the output shafts by adding speed to one and subtracting speed from the other.Type: GrantFiled: November 22, 2002Date of Patent: August 23, 2005Assignee: Sauer-Danfoss Inc.Inventor: Frederic W. Pollman
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Patent number: 6540633Abstract: A transmission for speed changing and steering of a vehicle includes a first hydrostatic pump (52) and motor (53), a first differential (24′) for speed changing, a second hydrostatic pump (71) and motor (72), and a second differential (23′) for steering. A prime mover drives the first pump (52), and the second pump (71) is driven by the output from the first motor (53). The second motor (72) drives the second differential (23′) for steering the vehicle.Type: GrantFiled: November 21, 2000Date of Patent: April 1, 2003Assignee: Tuff Torq CorporationInventors: Toshiyuki Hasegawa, Travis S. McCloud, Keith J Andrews, Robert Abend
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Publication number: 20030050145Abstract: A transmission for speed changing and steering of a vehicle comprises a first HST and a first differential for speed changing and a second HST and a second differential for steering. The first HST is a combination of a hydraulic pump and motor. The pump is driven by an engine and the motor is drivingly changeable by operation of a speed change pedal. Output power from the motor is transmitted into a pair of first differential output shafts as axles through the first differential. The second HST is a combination of a hydraulic pump and motor. The second pump is driven by output power from the first HST and the second motor is drivingly changeable by operation of a steering wheel. A pair of second differential output shafts are rotated in opposite directions by output power of the motor, so that when turning, the first differential output shaft on the opposite side of the turning direction is accelerated.Type: ApplicationFiled: October 22, 2002Publication date: March 13, 2003Inventors: Toshiyuki Hasegawa, Travis S. McCloud, Keith J. Andrews, Robert Abend
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Patent number: 6447419Abstract: An axle driving apparatus comprising a combination of a speed-change HST for coupling a variable-capacity pump and a motor with a fluid on the one hand and a steering HST for coupling a variable-capacity pump and a motor with a fluid on the other hand, configured in such a manner that the two HSTs are accommodated in a common housing. The motor output of the speed-change HST is transmitted to a differential arrangement for differentially coupling a pair of axles, and the motor output of the steering HST is transmitted to a differential arrangement for differentially coupling a pair of steering output shafts. One of the steering output shafts and one of the axles are power-coupled to one transmission train, while the other steering output shaft and the other axle are power-coupled to the other transmission train which applies a turning effort to the other axle in the direction opposite to the turning effort applied to the first axle by the first transmission train.Type: GrantFiled: August 21, 2000Date of Patent: September 10, 2002Assignee: Kanzaki Kokyukoki Mfg. Co., Ltd.Inventors: Koji Irikura, Hiroaki Shimizu
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Patent number: 6336886Abstract: A drive unit provided with a power transmission path interlockingly connecting an engine (E) to left and right sprockets (12L, 12R), which are adapted to drive left and right crawlers (11) of left and right traveling parts (1L, 1R), via a non-stage traveling transmission unit (21) and an auxiliary traveling transmission unit (28) capable of changing the speed of a working vehicle in a plurality of stages. The power transmission path is provided with a non-stage steering transmission unit (20), left and right steering transmission units (48L, 48R) and left and right planetary gears (40L, 40R) all of which are adapted to be operated for speed change in accordance with a turning operation of a steering wheel (7). This construction enables a pivot turn and a spin turn of a working vehicle body to be made, the swinging performance of the working vehicle to be improved, the maneuvering of the vehicle to be done easily, and the construction of the drive unit to be simplified.Type: GrantFiled: November 10, 1999Date of Patent: January 8, 2002Assignee: Yanmar Agricultural Equipment Co.Inventors: Terumitsu Ohya, Takanobu Shimada
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Patent number: 6312354Abstract: A transaxle apparatus is constructed so that left and right axles, two hydrostatic transmissions (HSTs), one for driving a vehicle and the other for steering it, and a differential unit for differentially connecting said axles with each other are together contained in a housing. The driving HST is disposed so that its hydraulic pump and motor are aligned along either a left or right side of the housing. The steering HST is disposed so that its hydraulic pump and motor are aligned along either a front or rear side of the housing. The differential unit is laterally opposite to the driving HST. Either the left or right axle crosses the driving HST between its hydraulic pump and motor. The two HSTs are provided with one or two flat center sections disposed in the housing. The cylinder blocks of the hydraulic pumps and motors of the two HSTs are mounted on either a top or bottom surface of the center section or sections.Type: GrantFiled: January 24, 2000Date of Patent: November 6, 2001Assignee: Kanzaki Kokyukoki Mfg. Co., Ltd.Inventors: Koji Irikura, Norihiro Ishii, Ryota Ohashi, Kenichi Takada, Hirohiko Kawada, Robert Abend, Keith J. Andrews, Toshiyuki Hasegawa, Hiroaki Shimizu
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Patent number: 6126564Abstract: An axle driving apparatus comprising a combination of a speed-change HST for coupling a variable-capacity pump and a motor with a fluid on the one hand and a steering HST for coupling a variable-capacity pump and a motor with a fluid on the other hand, configured in such a manner that the two HSTs are accommodated in a common housing. The motor output of the speed-change HST is transmitted to a differential arrangement for differentially coupling a pair of axles, and the motor output of the steering HST is transmitted to a differential arrangement for differentially coupling a pair of steering output shafts. One of the steering output shafts and one of the axles are power-coupled to one transmission train, while the other steering output shaft and the other axle are power-coupled to the other transmission train which applies a turning effort to the other axle in the direction opposite to the turning effort applied to the first axle by the first transmission train.Type: GrantFiled: July 8, 1999Date of Patent: October 3, 2000Assignee: Kanzaki Kokyukoki Mfg. Co., Ltd.Inventors: Koji Irikura, Hiroaki Shimizu
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Patent number: 6125954Abstract: A continuously shifting-type steering system includes a pair of left and right hydrostatic continuously variable transmissions each of which is comprised of a hydraulic pump and a hydraulic motor, and a pair of left and right planetary gear mechanisms each having a first sun gear, a second sun gear, a two-step planetary gear and a carrier. A first driving gear connected to an engine, is operably connected commonly to the left and right first sun gears. Left and right second driving gears secured to motor shafts of the left and right hydraulic motors, are operably connected to the left and right carriers, respectively. Left and right output shafts are operably connected to the left and right second sun gears, respectively. Thus, it is possible to provide an increase in the shifting range of the continuously shifting-type steering system, and an enhancement in low-output performance.Type: GrantFiled: September 19, 1997Date of Patent: October 3, 2000Assignee: Honda Giken Kogyo Kabushiki KaishaInventors: Yoshitaka Oota, Jitsumi Hanafusa, Tomoaki Ishikawa
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Patent number: 5390751Abstract: The present invention is directed to a planetary steering system for a skid steered vehicle. A prime mover directs rotational motion through right and left drive shafts having planetary carriers with planet gears. The planet gears of the right and left planetary carriers rotate around a right and left sun gears that are coupled to right and left hydraulic steering motors. The planet gears rotate in right and left ring gears that are coupled to the right and left drive wheels of the vehicle. By rotating the motors the speed of the drive wheels can be independently controlled.Type: GrantFiled: November 19, 1993Date of Patent: February 21, 1995Assignee: Deere & CompanyInventors: Craig A. Puetz, Mervin P. Kizlyk, James A. Nagorcka
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Patent number: 5211610Abstract: Reduction-distribution unit for gearshift units, particularly for industrial machines, including a first hydrostatic motor and a second hydrostatic motor which are operatively associated for the transmission of the motion to the axles. The unit also comprises an epicyclic train which adds the power of the hydrostatic motors, the first motor being associated with the shaft of the sun gear and the second motor being associated with the shaft of the crown gear of the epicyclic train. A first brake and a second brake are respectively associated to the shaft of the sun gear and to the shaft of the crown gear.Type: GrantFiled: May 31, 1991Date of Patent: May 18, 1993Assignee: Hurth Axle S.p.A.Inventor: Fritz C. A. Hurth
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Patent number: 5139465Abstract: A two-path hydromechanical transmission system used in a crawler-type vehicle and a method of controlling this transmission system. Excellent maneuverability and high degree of running course steadiness at low tramming speed, as well as high power transmission efficiency at high tramming speed, are obtained by the use of hydraulic pumps and motors of capacities smaller than those of known systems. The transmission system has a power transmission line including independent left and right hydraulic pumps 2, 3 driven by an engine 1 mounted on a vehicle and motors 4, 5 and reduction planetary gear trains 200, 250 having reduction gear trains 100, 150 for transmitting the output torques of said hydraulic motors to left and right driving wheels.Type: GrantFiled: September 26, 1991Date of Patent: August 18, 1992Assignee: Kabushiki Kaisha Komatsu SeisakushoInventor: Masayuki Sato
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Patent number: 5041064Abstract: In a superimposed steering gear (3) for tracklaying vehicles in which the steering power needed for turning is superimposed on the drive system via summarizing differentials and which has a hydrostatic-mechanical power branching summed up in a summarizing transmission (31), the power losses of the hydrostatic branch that works with poor efficiency are kept as small as possible and, at the same time, an infinite steering is made possible over all radial ranges. For this purpose, the summarizing transmission (31) is shiftable into steps that cover at least two radial ranges, a speed adaptation to the transmission components taking place at any given time in the shift points for an infinite transition.Type: GrantFiled: April 6, 1990Date of Patent: August 20, 1991Assignee: Zahnradfabrik Friedrichshafen AGInventors: Hans-Jurgen Eickhoff, Peter Tenberge
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Patent number: 5030177Abstract: To increase the top speed of a multi-speed range hydromechanical steering transmission for tracklaying vehicles, the displacements of the hydraulic motors in the two hydrostatic drive units are abruptly destroked from 100% displacement to 80% displacement at the moment the infinitely variable displacements of their respective hydraulic pumps achieve zero displacement during acceleration through the highest forward speed range of the transmission.Type: GrantFiled: April 26, 1990Date of Patent: July 9, 1991Assignee: General Electric CompanyInventor: Bradley O. Reed
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Patent number: 5026333Abstract: An infinitely variable driving and steering gear for track-laying vehicles has a hydrostatic/mechanical overlaying steering gear. The mechanism includes a hydrostatic unit and a summation gear train for summing hydrostatic and mechanical input power. The summation gear train has one or more summed power outlet shafts. The drive mechanism also includes a first multiple shaft steering summation transmission that is operably coupled to the summed power outlet shafts and which has left and right steering output shafts. The drive mechanism also includes a second multiple shaft steering summation transmission having respective output shafts that are operably connected to first steering summation transmission. The shafts of the summation gear train of the driving transmission and the shafts of the first steering summation transmission are all coaxially arranged for rotation about a common axis.Type: GrantFiled: September 18, 1990Date of Patent: June 25, 1991Inventor: Michael Meyerle
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Patent number: 4997412Abstract: An infinitely variable speed hydromechanical steering transmission includes a range-changing mechanism flanked by a pair of hydrostatic units which are commonly driven by a mechanical input to produce respective mechanical and hydrostatic outputs. These outputs are combined in left and right output planetary gear sets which are interconnected by a cross-shaft extending centrally through the range-changing mechanism and hydrostatic units. The range-changing mechanism includes a plurality of clutches and brakes that are selectively engaged in pairs to incrementally change the mechanical output speed on the cross-shaft and thus to operate the transmission in a plurality of forward and reverse speed ranges. Each range change is accomplished by a step change in the hydrostatic outputs.Type: GrantFiled: December 26, 1989Date of Patent: March 5, 1991Assignee: General Electric CompanyInventor: Bradley O. Reed
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Patent number: 4995276Abstract: A drive system includes a vehicle propulsion drive having a speed change gear box which drives tracks through a pair of planetary gears and a steering drive having a pair of variable hydrostatic drives. The hydrostatic drives engage a neutral shaft which superimposes rotation on the planetary gears to provide steering control for the tracks. The neutral shaft is separable into two segments. A differental reversing gear may be employed to selectively couple the neutral shaft segments. When the vehicle travels at high speed, the neutral shaft segments are coupled for unitary rotation. At low vehicle speeds, the propulsion drive is blocked and the neutral shaft segments are uncoupled so that both propulsion and steering are provided through the hydrostatic drives.Type: GrantFiled: February 14, 1990Date of Patent: February 26, 1991Assignee: Renk AktiengesellschaftInventor: Franz X. Zaunberger