Pdf an infinitely variable transmission ivt is a continuously variable transmission with an infinite ratio range, which means that the transmission. Infinitely variable transmission ivt using oscillating torque lestran l. A geared infinitely variable transmission for automotive. Infinitely variable transmission autopowrivt system. A drive system adapted for use in motor vehicles comprises an infinitely variable speed. Infinitely variable transmission types ratcheting cvt ratcheting cvt the ratcheting cvt is a transmission that relies on static friction and is based on a set of elements that successively become engaged and then disengaged between the driving system and the driven system, often using oscillating or indexing motion in conjunction with one. A compact, infinitely variable transmission for robotics.
Infinitely variable transmission the john deere ivt is an easytouse transmission with simple and intuitive controls allowing you to move smoothly from 0. A continuously variable transmission cvt is a light weight, gear reduction system that utilizes a few regulatory mechanisms to achieve the same end as a conventional automatic transmission. Advanced continuously variable transmissions for electric and. Mar 07, 2010 infinitely variable transmission ecpoladian. Modeling of the dynamics for an automotive application will demonstrate its high performance characteristics. Positive infinitely variable transmission piv drive piv, or positively infinitely variable chain, is a roller chain designed for transmission gearboxes that are used in a variety of industrial applications, such as. Energy consumption of a battery electric vehicle with. The company, currently part of technology transfer organisation btg, is to demerge as part of a move to raise about pounds 50million to develop its infinitely variable transmission system, a gearless transmission used in vehicles that can use up to 20 pe r cent less than conventional systems currently in use. In general the power split device is an infinitely variable transmission ivt that can be mechanical 18,19 or electrical with one toyota prius, lexus ct200h, ford cmax or two chevrolet tahoe hybrid electric motors 20. An infinitely variable power transmission comprising an input shaft, a layshaft driven by the input shaft via internalexternal gearing, a toroidal variator, and gearing and clutches which implement a lowreverse variable ratio mode and a high range variable ratio mode. In general the power split device is an infinitely variable transmission ivt that can be mechanical 18,19 or electrical with one toyota prius, lexus ct200h, ford c.
Infinitely variable transmission transmission, driveline. The john deere infinitely variable transmission autopowrivt utilizes a combination of mechanical and hydrostatic power, providing stepless and continuous power across an infinitely variable range of speeds. The hmx range of track transmissions provides infinitely variable, hydrostaticregenerative, bidirectional steering with the optional steer by wire. Infinitely variable transmission utilizing oscillating torque. Abstractan infinitely variable transmission ivt is a continuously variable. The mechanism adapted for infinitely variable output between range 0 to14th of input speed. Due to the limited power transmission capacity and speed ratio range of the cvt, researchers attempted to combine the cvt with a planetary gear train and a fixed ratio mechanism. In this paper, the linear infinitely variable transmission in automobile engine use particular drive a cam and number of follower rotary mounted a carrier plate to generate an auxiliary motion in equal number of planet gear the energy.
Compared to the adjustment of speed in steps, the continuously variable transmission. A continuously variable transmission cvt, also known as a shiftless transmission, stepless transmission, pulley transmission, or, in case of motorcycles, a twistandgo, is an automatic transmission that can change seamlessly through a continuous range of effective gear ratios. Edyson ivt is a stepless speed variator using only toothed gears sprockets, which can be used on any traditional engine gasoline, diesel, cng, electric motors, steam or wind turbines, bicycles human power, as well as a large number of industrial or agriculutre applications, replacing the current transmission also toothed belt or chain. Therefore, the cvt allows the engine to operate at its fueloptimal speed. An infinitely variable transmission ivt is a transmission that can smoothly and continuously vary the speed ratio between an input and output from zero to some other positive or negative ratio. Torotrak believes that its infinitely variable transmission, now approved by gm and ford, represents the next generation of automatic transmissions. Variable speed pulleys torque transmission s variable speed pulleys provide reliable variable speed service with a time proven design, at an economical cost. Reverse mode provides infinite vehicle speeds from 50 metershr to 17 kmhr. Infinite variable transmission ivt is a type of cvt with added restriction that a speed ratio of zero must be available. An infinitely variable transmission ivt is a continuously variable transmission with an infinite ratio range, which means that the transmission ratio may. Study of a noncircular gear infinitely variable transmission. An additional clutch and gearing implement an optional fixed ratio mode. A unique infinitely variable transmission utilizing oscillating torque to transmit mechanical power will be presented.
Nominal travel speeds mph kmh low range 011 mph 017 kmh, high range 026. In an infinitely variable transmission ivt, which is a specific kind of continuously variable transmission, the transmission ratio includes a zero point that can be approached from either a. Development of a novel cambased infinitely variable transmission. Infinitely variable transmission ivt using oscillating. Study of conversion of continuous variable transmission to. It maintains a uniform output for a given uniform input. In this paper, a new transmission principle, named pulse drive, is proposed for potentially realizing a highly compact, highefficiency, infinitely variable transmission, such as that used in switching electrical power supply systems, by transmitting the driving power intermittently through periodic vibration control. A continuously variable transmission cvt, also known as a shiftless transmission, stepless. Pdf infinitely variable transmission of racheting drive type. Variable speed pulleys torque transmissions variable speed pulleys provide reliable variable speed service with a time proven design, at an economical cost. Torotrak infinitely variable transmission articles. This mechanism is called infinitely variable transmission ivt. An infinitely variable transmission ivt consists of three elements.
Nov 17, 2016 therefore, the cvt allows the engine to operate at its fueloptimal speed. These tractors provide infinite vehicle speeds in the forward mode from 50 metershr to 40 kmhr or an optional 50 kmhr. A drive system adapted for use in motor vehicles comprises an infinitely variable speed drive transmission coupled to a dc motor, and the speed ratio of the transmission is controlled by a speedresponsive flyweight or governor so as to maintain the dc motor at its most efficient operating level. In this paper, a geared infinitely variable transmission ivt is analyzed for efficiency through static analysis. Infinitely variable transmission ivt, continuously variable transmission, positive transmission.
On the plus side, this scheme would seem to allow you to use a constantspeed engine, say a diesel engine, plus an. The system includes a fourbar linkage mechanism, an epicyclic gear train, and a. This ivt is based on a noncircular gear concept described in 1, 2. The range of ratios of outer shaft speed to inner shaft speed includes a zero output speed. Edyson ivt is a stepless speed variator using only toothed gears sprockets, which can be used on any traditional engine gasoline, diesel, cng, electric motors. Hydromechanical ivt kd solutions transmission design. Contact stress reduction mechanisms for the cambased. Study of conversion of continuous variable transmission. Analysis indicates that the upper design load limit is nearly unlimited. Infinitely variable transmission power takeoff performance power crank hp shaft kw speed galhr lbhp.
Using a hybrid hydromechanical infinitely variable transmission allows vehicle designers to harness the hydraulics features for retardation braking as well as engine control. Introduction this transmission contains six unique components. Pires, a geared infinitely variable transmission for automotive applications, society of automotive engineers paper presented at the sae international congress and exposition, pp. The advantages of an infinitely variable transmission for gasoline powered automobiles over slidinggear types was recognized by inventors at a very early date. A typical automatic uses four or five such gears, while a manual normally employs five or six.
This ivt consists of multiple function generators with each function generator comprising two sets of noncircular gear sets whose outputs are combined with a. Singlespeed lever is used for intuitive and accurate control of ground speeds as slow as 50 mh 0. Infinitely variable transmission article about infinitely. A continuously variable transmission cvt transfers power through a range of speedtorque ratios from engine input to output, continuously without interruption contrast with either manual or conventional automatic transmissions that use discrete ratios and normally disengage when changing ratio. Infinitely variable transmission ivt of john deere 7000. A variable transmission includes various powerpath layouts consisting in either. Cam has a continuously varying profile along its length. Torotrak infinitely variable transmission finds business in outdoor power, targets hybrids for the future 15 december 2005 torotrak, the uk developer of a fuelefficient toroidal infinitely variable transmission ivt, has formed a 5050 joint venture with mtd holdings inc to apply technology to the outdoor power equipment ope market. But if you have a variable speed motor, such as an electric motor, then you dont much need a variable speed transmission anyway. The heart of this transmission is a centrally located three dimensional cam. A subset of cvt designs are called infinitely variable transmissions ivt or ivts, in which the. Speed range is infinitely variable within standard ratio limits. Infinitely variable ratio gearbox with neutral using only sprockets toothed gears pinions this is not an epicicloidal transmission. Development of a novel cambased infinitely variable.
Us4391156a electric motor drive with infinitely variable. Power flows and efficiency in infinitely variable transmissions. In addition, this transmission can be designed as a. The cambased infinitely variable transmission ivt is a new type of ratcheting ivt based on a three dimensional cam and follower system which provides unique characteristics such as generating specific functional speed ratio outputs including dwells, for a constant velocity input. Apr 16, 2017 infinitely variable transmission a specific type of continuously variable transmission cvt. Infinitely variable transmission greglocock automotive 22 sep 19.
The term infinitely variable transmission ivt means basically the same as cvt, with the added restriction that a speed ratio of zero must be available, i. John deere 7710 and 7810 series tractors are the first of the 7000 ten series tractors offering an infinitely variable transmission ivt. The continuously variable transmission replaces discrete gear ratios with infinitely adjustable gearing through one of several basic cvt. Infinitely variable transmission with orbital pulleys. Infinitely variable transmission types ratcheting cvt. It is used in transportation machines, lathes, instruments, and so forth.
To prove its torque capacity, epilogics demonstrated a prototype of its patented transmission concept in a class vii diesel truck in june, 1989. Hydromechanical infinitely variable transmission innovations for value and performance. Infinitely variable transmission a specific type of continuously variable transmissioncvt. Dec 19, 2014 in this paper, a geared infinitely variable transmission ivt is analyzed for efficiency through static analysis. Continuous variable transmission cvt, infinitely variable transmission ivt, power split, powertrain, efficient transmission. Powersuppressed continuously variable transmission system. The continuously variable transmission replaces discrete gear ratios with infinitely adjustable. The comparative size and complexity of a common cvt system is shown in fig. A cambased infinitely variable transmission system allows a user to vary the speed. Pdf an infinitely variable transmission ivt, based on the use of oneway action clutches, belonging to the family of ratcheting drives is described find. Lestran 3104 riverwood drive fort worth, texas 76116. The infinite variable transmission with orbital pulleys is controlled under different conditions. Jun 23, 2002 torotrak infinitely variable transmission finds business in outdoor power, targets hybrids for the future 15 december 2005 torotrak, the uk developer of a fuelefficient toroidal infinitely variable transmission ivt, has formed a 5050 joint venture with mtd holdings inc to apply technology to the outdoor power equipment ope market.
Application of multispeed gearbox in infinitely variable. The operation and kinematic analysis of a novel cambased. Continuously variable transmission a mechanism for smoothly changing a gear ratio, that is, the ratio between the frequency of rotation of the driving element and the rate of the driven element. The unique characteristics of each inversion can be matched to the particular application. A fully mechanical, infinitely variable transmission ivt based on the use of an oscillating inertia is described. It can be continuously approached from a definite higher ratio.