1047 results about "Gear ratio" patented technology

A clutch mechanism is disclosed for use with a hybrid electric vehicle wherein the electric motor-generator and engine are arranged in a series configuration. The clutch mechanism is positioned between and in communication with the electric motor-generator and engine to allow for either direct drive or a predetermined gear ratio between the electric motor-generator and engine. The electric motor-generator is preferably an integrated electric motor and generator. The engine is preferably a combustion engine.

Power roller-side concave grooves are opposed to disk-side concave grooves 19, 19 so as to have angles therebetween in a rolling contact area between a peripheral surface of the power roller and a one-side surface 17 of a disk 16 in an axial direction regardless of a transmission gear ratio of a toroidal continuously variable transmission. Accordingly, the disk-side concave grooves 19, 19 are formed so as to have angles with respect to a circumferential direction of the disk 16 when viewed from a normal direction relative to the one-side surface 17 in the axial direction. Meanwhile, the power roller-side concave grooves are formed into a concentric shape (or a spiral shape) about a central shaft of the power roller. As a result, it is possible to prevent a decrease of a contact area in the rolling contact area regardless of the transmission gear ratio.

A variety of methods and arrangements for controlling the operation of an internal combustion engine in a skip fire variable displacement mode are described. In general, a firing control unit determines working chamber firings during operation of the engine that are suitable for delivering a desired engine output. In one aspect, the firing control unit is arranged to isolate the generation of firing sequences having frequency components in a frequency range of concern and to alter the firing sequence in a manner that reduces the occurrence of frequency components in the frequency range of concern. In another aspect, a filter is arranged to filter a feedback signal to provide a filtered feedback signal that is used in the determination of the working chamber firings. In preferred embodiments, the frequency characteristics of the filter are variable. In various embodiments, the frequency characteristics of the filter vary as a function engine speed and/or a transmission gear ratio.

PCT No. PCT/JP97/03887 Sec. 371 Date Jun. 25, 1998 Sec. 102(e) Date Jun. 25, 1998 PCT Filed Oct. 27, 1997 PCT Pub. No. WO98/19083 PCT Pub. Date May 7, 1998There is disclosed a vehicle control system that controls an automatic transmission by utilizing road information stored in a navigation system unit. In response to the road information stored in a data memory, the upper-limit of a shiftable gear ratio range is determined, thereby allowing change of the gear ratio only within the restricted range. The actual downshift is carried out in response to initiation of a decelerating operation by the driver, such as release of the accelerator pedal, which prevents unnecessary upshift and provides favorable transmission control in conformity with the driver's intention.

An automatic transmission is capable of obtaining appropriate gear ratios for six forward shifts and one reverse shift. The automatic transmission includes a first planetary gear, a second planetary gear, a planetary gear unit including a third planetary gear, and a fourth planetary gear. Also provided are first, second, third and fourth shaft elements, first and second first clutch elements, first, second, and third brake elements, the first clutch element is capable of selectively interconnecting the input shaft and the fourth shaft element. The second clutch element is capable of selectively interconnecting the input shaft and the carrier of the single planetary gear. The first brake element is capable of selectively fixing the first shaft element. The second brake element is capable of selectively fixing the second shaft element. The third brake element is capable of selectively fixing either the sun gear or the carrier of the double pinion planetary gear.

A powertrain system is provided that includes a prime mover and a change-gear transmission having an input, at least two gear ratios, and an output. The powertrain system also includes a power shunt configured to route power applied to the transmission by one of the input and the output to the other one of the input and the output. A transmission system and a method for facilitating shifting of a transmission system are also provided.

A closed loop shift control apparatus and method based on estimated torque in friction elements controls a torque transfer phase when shifting from a low gear configuration to a high gear configuration for an automatic transmission system. When pressure actuated friction elements are selectively engaged and released to establish torque flow paths in the transmission, estimates of torsional load exerted on the off-going friction element are used to predict the optimal off-going friction element release timing for achieving a consistent shift feel. The estimated torque is preferably calculated by using estimated torque signals generated as a function of speed measurements represented either the engine speed and turbine output speed or transmission output speed and wheel speed under dynamically changing conditions.

Methods and systems are provided for controlling a vehicle engine coupled to a stepped-gear-ratio transmission. One example method comprises, in response to a first vehicle moving condition, shutting down the engine and at least partially disengaging the transmission while the vehicle is moving; and during a subsequent restart, while the vehicle is moving, starting the engine using starter motor assistance and adjusting a degree of engagement of a transmission clutch to adjust a torque transmitted to a wheel of the vehicle.

A vehicle transmission includes a differential gear set having five coaxial gear elements and an output member. Two of the gear elements are controllable via torque transmitting mechanisms such as electric motors to establish a plurality of speed ratios between the input shaft and the output shaft. Two of the other gear elements are selectively operatively connectable to an output shaft via a gear arrangement that allows for a plurality of speed ratios between the gear elements and the output shaft. Additional torque transmitting mechanisms such as clutches are selectively engageable to provide continuously variable speed ranges between the input shaft and the output shaft, fixed gear ratios and an electric drive mode. The various speed ratios enable a plurality of compound split operating modes as well as an input split mode.

A speed change system for work vehicle having a continuously variable transmission device selects a first change gear ratio which is set larger than a smallest change gear ratio, when an engine rotational speed is a first set rotational speed which is set equal or close to an idling rotational speed of an engine; retains the change gear ratio of the continuously variable transmission device at the smallest change gear ratio, when the engine rotational speed is equal to or above a second set rotational speed set on a high-speed side relative to the first set rotational speed; and makes the change gear ratio of the continuously variable transmission device larger between the first change gear ratio and the smallest change gear ratio, as the engine rotational speed at that moment becomes lower, when the engine rotational speed is between the first and second set rotational speeds.

A continuously variable transmission includes: first to third power transmission components; a rolling component; a support shaft for the rolling component; a first guide member that includes a first guide portion for guiding a first protrusion portion of the inserted support shaft; a gear shift member that includes a gear change portion; a first actuator which tilts each rolling component by moving each second protrusion portion along the gear change portion with rotation of the gear shift member at a time an input-output gear ratio is changed; a second guide member that includes a second guide portion for guiding a second protrusion portion of the inserted support shaft; and a second actuator which prohibits rotation of the second guide member during reverse rotation of the first and second power transmission components and allows rotation of the second guide member during normal rotation of the first and second power transmission components.

Methods are provided for controlling the fueling of a motor vehicle and specifically for controlling the cut off of fueling of a hybrid electric motor vehicle during deceleration of that motor vehicle. In a hybrid electric motor vehicle having an internal combustion engine, a motor/generator, and a continuously variable transmission, one embodiment of the method comprises the steps of sensing throttle position of the internal combustion engine and slewing the continuously variable transmission to a higher gear ratio in response to sensing a closed throttle position. The method further comprises the steps of, cutting fueling of the internal combustion engine during the deceleration, and coupling the motor/generator in parallel with the internal combustion engine with the motor/generator operating as a generator.

In vibration suppression apparatus and method for a hybrid vehicle, the hybrid vehicle comprises at least one main power source, a plurality of auxiliary power sources, and a planetary gear mechanism to modify a gear ratio when an output of the main power source is transmitted to a drive output member and two power sources whose torque controls are enabled to be performed are selected and a vibration suppression control signal is superposed onto each of torque commands supplied to the selected two power sources to suppress two-degrees-of-freedom vibrations of the planetary gear mechanism.

An outboard motor for a marine vessel application, transmission devices for such an outboard motor, and related methods of making, operating, and modifying attributes of same, are disclosed herein. In at least one embodiment, the motor includes a horizontal-crankshaft engine in an upper portion of the motor, positioned substantially above a trimming axis of the motor. In at least another embodiment, first, second and third transmission devices are employed to transmit rotational power from the engine to propeller(s). In at least a further embodiment, the motor is made to include a rigid interior assembly formed by the engine, multiple transmission devices, and a further structural component. In further embodiments, the motor includes numerous cooling, exhaust, and/or oil system components, and/or other transmission features. In at least some additional embodiments, a transmission device of the motor is configured to facilitate gear ratio variation and/or includes an integrated oil pump.

A system for controlling a vehicle drivetrain in a fuel-efficient manner includes a control computer operable to define a contour from substantially zero engine load to substantially full engine load, wherein the contour may correspond to a fuel-efficient path from no-load to full-load engine operating conditions. With change gear transmissions, the control computer is operable to control transmission shift points about the contour. With continuous variable transmissions the control computer is operable to modify the effective gear ratio thereof to maintain engine operation on or about the contour. In either case, fuel efficient operation may be optimized.

A hybrid powertrain system is provided that includes a first prime mover having a rotational output, a second prime mover having a rotational output, and a transmission having a main shaft supporting at least two main shaft gears thereon. The transmission includes a first independent countershaft drivingly connected to the first prime mover and including at least one ratio gear supported thereon that meshes with a respective main shaft gear. A second independent countershaft is drivingly connected to the second prime mover and includes at least one ratio gear supported thereon that meshes with a respective main shaft gear. The ratio gears on the first and second countershafts cooperate with the main shaft gears to provide at least one gear ratio between the first and second countershafts and the main shaft. A shift control mechanism selectively engages and disengages the first and second countershafts for rotation with the main shaft.

A gear ratio shift control and control method controls gear ratio upshifts in a multiple-ratio transmission for an automotive vehicle. Pressure actuated friction elements establish torque flow paths in transmission gearing as they are selectively engaged and released. A net torque reduction at a transmission torque output shaft during an upshift event is reduced by increasing transmission input torque prior to the start of the inertia phase of the upshift event.

A control device is provided for a vehicular drive apparatus, having a differential mechanism and a transmission, for miniaturizing the differential mechanism and/or providing improved fuel economy while preventing a busy shift. With the provision of a switching clutch C0 or a switching brake B0, a transmitting mechanism 10 can be placed in a continuously variable shifting state and a step-variable shifting state whereby the vehicular drive apparatus has combined advantages including a fuel saving effect of the transmission, enabled to electrically change a gear ratio, and a high transmitting efficiency of a gear type transmitting device enabled to mechanically transmit drive power. With a total speed ratio γT set to a lower vehicle speed gear ratio than that for a given running state, if a required drive force or a drive force source brake is unavailable or if load torque of an electric motor is deviated from an allowable range, switching control mean 50 switches a differential portion 11 to the step-variable shifting state for thereby obtaining larger drive force or drive force source brake than those for the given running state without causing load torque of the electric motor from deviating from the allowable range while preventing the busy shift.

A vehicle comprises a steering operation device, a pair of running-driving wheels, which differentially drive when the steering operation device is manipulated, a pair of steerable running wheels interlocking with the steering operation device, and a steering mechanism interposed between the steering operation device and the pair of running-driving wheels. The steering mechanism includes a pair of drive gears interlocking with the steering operation device and a pair of follower gears interlocking with the respective steerable running wheels. The drive gears mesh with the respective follower gears so as to control lateral turning of the respective steerable running wheels. A gear radius of the drive gear may be greater than that of the follower gear meshing with it. A gear ratio between the mutually meshing drive and follower gears may be variable. The lateral turning centers of both the steerable running wheels may coincide with each other, and further coincide with a lateral turning center of the vehicle body caused by differential rotation of the running-driving wheels.

A hybrid propulsion system for a vehicle. The hybrid propulsion system including a multiple step fixed-gear transmission device for transmitting torque to a first at least one drive wheel, a first electric energy conversion device coupled to an input of the multiple step fixed-gear transmission device, and a control system, during a deceleration condition, the control system increasing negative torque output of the first electric energy conversion device to meet a desired wheel braking torque in response to the multiple step fixed-ratio transmission transitioning from a first gear ratio to a second gear that is higher than the first gear ratio.

A contactless rotary shaft position sensor provides for precision computation of shaft angle for a wide range of input shaft rotational angles. The sensor includes two annular two-pole magnets which are connected by a precision, motion-transmitting gear train. An optional second gear train between one of the magnets and the input shaft can provide additional angular rotation scaling to accurately measure either fractional or a large number of multiple turns of the input shaft. The gear ratios are selected such that one of the magnets does not rotate more than one revolution. Pairs of ratiometric Hall-effect or magnetoresistive sensors provide differential voltage signals which are used for sensing angular position of each magnet over a full 360 degrees of rotation. The single-turn magnet provides an absolute, coarse indication of input shaft rotation with a typical accuracy of 2%. The gear ratio between the magnets produces several turns of the second magnet for each turn of the single-turn magnet. Since the gear ratio between the magnets is fixed, the angle sensed for the multi-turn magnet can be predicted from the position of the single-turn magnet. This is compared to the multi-turn magnet's actual sensed rotation. The result is an improvement in accuracy directly proportional to the gear ratio between the magnets. Computation of the individual magnet rotation angles and the input shaft angle is performed using a microprocessor and appropriate signal conditioning circuits. Utilizing two magnets, input shaft rotation can be accurately measured to within 0.1% of maximum range.

An automotive internal combustion engine control system transmits the output of a starting motor capable of operating as a generator to an internal combustion engine in starting the internal combustion engine, and transmits the output of the internal combustion engine to accessories while the internal combustion engine is in operation. The automotive internal combustion engine control system includes a transmission mechanism that transmits the output of the starting motor to the accessories while the internal combustion engine is stopped for a predetermined condition, transmits the rotation of the drive shaft of the starting motor to the crankshaft of the internal combustion engine at a high first gear ratio in starting the internal combustion engine, and transmits the rotation of the crankshaft of the internal combustion engine to the drive shaft of the starting motor at a low second gear ratio while the internal combustion engine is in operation to operate the starting motor as a generator. The transmission mechanism enables driving the accessories by the starting motor while the internal combustion engine is stopped, smoothly starting the internal combustion engine and efficient energy regeneration while the internal combustion engine is in operation.

A powertrain having a controller for limiting the torque and power inputs to a transmission as determined by operating parameters and design features of the transmission. These parameters and design features include torque limits for various components in the transmission, torque ratio of the torque converter, the design K factor of the torque converter, gear ratios of the transmission, operating condition of the torque converter clutch, and input power limits for the transmission. A programmable digital computer includes a subroutine that evaluates and establishes torque limits and input speed limits from the design features and operating parameter. The controller sets the limits for each transmission ratio including reverse such that a family of transmission can be coupled to a single engine design without overpowering the transmission should the engine be capable of greater output power than the transmission can accept.

The invention relates to an electromechanical brake booster for a master brake cylinder of a hydraulic vehicle braking system. The invention provides to configure the brake booster such that it preferably includes a switchable freewheel, which enables an actuation of the master brake cylinder without any movement of the electric motor of the brake booster. The invention further provides to configure the brake booster such that it includes a mechanical gear having a variable transmission ratio, which has a high path transmission at the beginning of an actuation of the master brake cylinder, and a force transmission that rises with increasing actuation. A variable gear ratio is possible using a rack and pinion gear, the toothed rack of which has a soothing with a pitch that changes across the length of the toothed rack. A further possibility of a mechanical gear having a variable ratio is a toggle lever mechanism.

A rotary refractive laser scanner head uses two sets of lenses and prisms aligned along a common optical axis. Each prism is paired with one of the lenses. The lens-prism pairs are separately mounted rotatable on a common axis coaxial with the optical axis. A motor drives two gear sets. Each gear set is separately coupled to one of the two lens-prism pairs and rotates them at selected, typically different speeds. An input laser beam is directed along the optical axis at one of the lens-prism pairs. The first pair collimates and refracts the input beam into an intermediate deflected beam according to Snell's law and the characteristics of the laser beam and optics. The second pair receives the intermediate beam and further deflects it to form an output beam. By selecting the motor speed, gear ratios, optics spacing, characteristics and prism wedge (deflection) angle, the scanner head effectively can scan an output laser beam over a desired pattern area.

A multi-channel fiber optic rotary joint (FORJ) includes an external housing, a stationary collimator array, a rotating collimator array, an all-reflective de-rotating prism and a gear ratio. The external housing contains an internal cavity having a longitudinal rotation axis. The stationary collimator array is affixed to the external housing approximate a first end of the internal cavity. The rotating collimator array is rotatably attached to the external housing approximate a second end of the cavity. The second end of the cavity is opposite the first end of the cavity. The rotating collimator array is configured to rotate about the rotation axis. The de-rotating prism is located along the rotation axis within the internal cavity between the stationary collimator array and the rotating collimator array. The prism is retained in a prism housing, which is rotatably attached to the external housing and the prism housing is configured to rotate about the rotation axis.

An automatic transmission control apparatus is provided with a control scheme that focuses on the rotational speed differences of the frictional engaging elements and the distribution of torque transferred by the frictional engaging elements. When the automatic transmission is upshifted while in a power-off state, the individual torque capacity of a frictional engaging element being released and the individual torque capacity of a frictional engaging element being connected are corrected by adding a prescribed torque capacity amount to each of the individual torque capacities during an inertia phase of the shift control in which a compensation is executed for inertia related to changing the gear ratio. In this way, frictional losses are induced in the frictional engaging elements so as to absorb the inertia torque and lower the input rotational speed more quickly.

A vehicle drive-train includes a drive-motor having an output shaft and a transmission having an input shaft, an output shaft, a plurality of discrete forward gear ratios and a corresponding plurality of synchronizers. Each of the synchronizers is configured to mechanically synchronize rotation of the drive-motor output shaft with the transmission output shaft according to a value of a selected gear ratio, during shifting of the transmission to the selected gear ratio. The output shaft of the drive-motor and the input shaft of the transmission are coupled together such that, during normal operation of the drive-train, rotation of the output shaft of the drive-motor results in a proportionate and uninterrupted rotation of the input shaft of the transmission.

In a double clutch transmission in which an input shaft can be coupled by two load clutches selectively with a central intermediate shaft and a concentric intermediate shaft and each of the intermediate shafts can be operatively connected by gear stages selectively to a first or a second jackshaft arranged in the power output path to a driven vehicle axle, wherein the jackshafts are arranged parallel to the transmission input and intermediate shafts, the intermediate shafts each have at least one gear firmly mounted thereon which forms the input gear for more than one of the gear stages provided for different transmission gear ratios so as to form a compact transmission arrangement, particularly for transverse engine applications.

A multiple-speed transmission provides a wide gear ratio coverage for an automotive vehicle by using a basic structure of a six-speed transmission. The multiple-speed transmission is comprised of a combination of three planetary gearsets, three clutches, and three brakes. Each speed is established by applying two of six elements of three clutches and three brakes.