Abstract: An auxiliary hydraulic pressurization system for use with a vehicle including a transmission having a hydraulic reservoir, a hydraulic circuit, and a main pump may include an auxiliary pump and a controller. The auxiliary pump has a low side adapted to be coupled to the hydraulic reservoir and a high side adapted to be coupled to the hydraulic circuit. The controller is electrically connectable to the auxiliary pump and is configured to turn on the auxiliary pump in response to receipt of a signal indicating that the vehicle is in a stop condition to maintain hydraulic pressurization of the hydraulic circuit of the transmission when the vehicle is in the stop condition.

Abstract: A control system for electric vehicle is provided. The control system is applied to an electric vehicle (Ve) having a motor (2, 3) and an electric oil pump (19) driven by a pumping motor (20). The control system is configured to activate the electric oil pump (19) with a predetermined duty cycle when a main switch is turned on to bring the vehicle (Ve) into a ready-on state where the vehicle (Ve) is ready to travel.

Abstract: There is disclosed a continuously variable ratio transmission assembly (“variator”) comprising a roller which transmits drive between a pair of races, the roller being movable in accordance with changes in variator ratio, a hydraulic actuator which applies a biasing force to the roller, at least one valve connected to the actuator through a hydraulic line to control pressure applied to the actuator and so to control the biasing force, and an electronic control which determines the required biasing force and sets the valve accordingly, wherein the valve setting is additionally dependent upon a rate of flow in the hydraulic line.

Abstract: An exemplary control device includes an input torque detection unit that detects an input torque input to the input shaft; and a controller that: determines torque distribution of two of the friction engagement elements that form the shift speeds; and calculates a transmission torque of the two friction engagement elements based on the input torque and the torque distribution and sets the engagement pressure to obtain a torque capacity that can transmit the transmission torque, wherein the controller sets the engagement pressure such that slippage does not occur in the two friction engagement elements in a state where engagement of the two friction engagement elements forms the shift speeds and such that, even if an additional friction engagement element engages based on the line pressure while the two friction engagement elements are engaged, one of the three friction engagement elements is caused to slip.

Abstract: A method of operating a transmission (1) with at least one interlocking shift element (F) having at least two shift element halves that can be brought into interlocked engagement with one another. When a command is received to close the interlocking shift element (F), a current rotational speed difference between the shift element halves of the interlocking shift element (F) and the current positions of the shift element halves are determined. If the rotational speed difference is smaller than a first speed difference threshold value and if a tooth-on-tooth position has occurred at the interlocking shift element (F), then to release the tooth-on-tooth position, the actuation force is changed to a release level at which a rotational speed difference above a second speed difference threshold value is produced between the shift element halves.

Abstract: An exemplary control device includes an input torque detection unit that detects an input torque input to the input shaft; and a controller that: determines torque distribution of two of the friction engagement elements that form the shift speeds; and calculates a transmission torque of the two friction engagement elements based on the input torque and the torque distribution and sets the engagement pressure to obtain a torque capacity that can transmit the transmission torque, wherein the controller sets the engagement pressure such that slippage does not occur in the two friction engagement elements in a state where engagement of the two friction engagement elements forms the shift speeds and such that, even if an additional friction engagement element engages based on the line pressure while the two friction engagement elements are engaged, one of the three friction engagement elements is caused to slip.

Abstract: A hydraulic control system for a automatic transmission includes a plurality of solenoids and valves in fluid communication with a plurality of shift actuators. The shift actuators are operable to actuate a plurality of torque transmitting devices. Selective activation of combinations of the solenoids allows for a pressurized fluid to activate at least one of the shift actuators. The solenoids are configured to provide a forward gear ratio and a reverse gear ratio when the solenoids are deengerized.

Abstract: An electrically variable transmission (EVT) selectively establishes various EVT modes and a neutral mode. The EVT includes a source of pressurized fluid, fluid-actuated clutches, various solenoid-actuated valves including trim valves and blocking valves adapted to control a flow of pressurized fluid to the clutches to establish the transmission operating modes, and an electronic control unit (ECU). The ECU actuates different combinations of the solenoid-actuated valves to establish the different transmission modes. The solenoid-actuated valves are configured in such a manner as to provide the EVT with one or more default operating modes in the event the ECU temporarily loses electrical power. Depending on the particular configuration, the default modes can be the neutral mode alone, or the neutral mode combined with one or more of the EVT modes, with the EVT modes enabled by providing one or both of the blocking valves with a latching feature.

Abstract: A hydraulic control device for an automatic transmission includes a first solenoid valve, a second solenoid valve, a third solenoid valve, a preliminary shift speed switching valve, and a hydraulic pressure supply switching valve. A second friction engagement element is engaged at high speed side shift speeds, a low speed that is one of low speed side shift speeds is achieved by engagement of a first friction engagement element and a third friction engagement element, and a high speed that is one of the high speed side shift speeds is achieved by engagement of a second friction engagement element and the third friction engagement element.

Abstract: A hydraulic control apparatus includes a switching device that switches between a hydraulic servo of the plurality of hydraulic servos of the first friction engaging element and a hydraulic servo of the plurality of hydraulic servos of the second friction engaging element so as to supply a control pressure from the one pressure regulating solenoid valve to each of the plurality of hydraulic servos, wherein the switching enables a control of an engagement and disengagement of the first friction engaging element and the second friction engagement element using the one pressure regulating solenoid valve.

Abstract: An automatic transmission includes a plurality of planetary gears disposed between an input shaft and an output shaft and having a plurality of rotational elements. A plurality of frictional elements are selectively engaged and released for controlling rotations and connections of the plurality of rotational elements in accordance with instructions so as to realize a plurality of gear positions. A rotational speed detecting section detects a rotational speed of a predetermined one of the plurality of rotational elements other than the input shaft and the output shaft. A frictional element release section releases all of the plurality of frictional elements when it is judged that the rotational speed of the predetermined one of the plurality of rotational elements is higher than a predetermined rotational speed.

Abstract: An automatic transmission control device with a hydraulic control system controlled by an electric transmission control device. The system including several pressure control valves, actuated electrically by the transmission control device, and several switching valves and pressure regulation valves, actuated by hydraulic pilot pressure, which is adjustable with the pressure control valves. Each shift element is associated with one of the pressure control valve. An engagement prevention valve is actuated by one of a control pressure of the first shift element and a pressure signal equivalent to the control pressure of the first shift element to engage the reverse drive gear. A pressure supply line of the second shift element for obtaining the reversing gear is blocked when the engagement prevention valve is in its first switch position and open when the engagement prevention valve is in its second switch position.

Abstract: An automatic transmission includes: a frictional engagement element arranged to be switched from an engagement state to a disengagement state at a switching from a running range to a neutral range, and including: frictional plates; a first piston arranged to push the frictional plates; a second piston arranged to push the frictional plates; a first hydraulic chamber arranged to receive a hydraulic fluid for pushing the first piston; and a second hydraulic chamber arranged to receive a hydraulic fluid for pushing the second piston; a first discharge speed switching section arranged to switch only a discharge speed of the hydraulic fluid of the first hydraulic chamber; and a control unit configured to increase the discharge speed of the hydraulic fluid of the first hydraulic chamber during a predetermined time period by the first discharge speed switching section at the switching from the running range to the neutral range.

Abstract: A powertrain has an electrically variable hybrid transmission having an electro-hydraulic control system, plurality of electrical power units, and a plurality of torque transmitting mechanisms selectively engageable by the electro-hydraulic control system to provide four forward speed ranges, a neutral condition, an electric low speed mode, an electrically variable low and high speed mode, and two electrical power off drive home modes. The electro-hydraulic control system of the present invention has a multiplexed trim system for an electrically variable hybrid transmission. The multiplexed trim system allows engagement control of four torque transmitting mechanism and individual control of fluid flow to effect cooling of two motor/generators by multiplexing three trim valves with two logic valves.

Abstract: A hydraulic control apparatus for an automatic transmission including two frictional coupling devices of a first group and a plurality of frictional coupling devices of a second group, the control device including a second-group-engaging switching valve arranged to receive second engaging hydraulic pressures generated to engage the coupling devices of the second group and operable, upon reception of at least one of the second engaging hydraulic pressures, to generate a second-group-engaging pilot hydraulic pressure, and a fail-safe valve to receive at least one of first engaging hydraulic pressures generated to engage the two coupling devices of the first group and operable, upon simultaneous reception of the first engaging hydraulic pressure generated to engage one of the two coupling devices of the first group and the second-group-engaging pilot hydraulic pressure, to prevent application of the first engaging hydraulic pressure to the other of the two coupling devices of the first group.

Abstract: According to an aspect of the present invention, an automatic transmission includes plural friction engaging elements configures plural shift ranges based on combinations of each friction engaging element being in engaging or disengaging condition, a controlling unit for controlling the friction engaging elements to be in engaging or disengaging condition by controlling a hydraulic pressure applied.

Abstract: A shift control method for an automatic transmission having a primary shift portion and a secondary shift portion is provided that comprises: starting, if a shift signal is output, a shift in the secondary shift portion, and then starting a shift in the primary shift portion; performing feedback control of duty ratios of friction element solenoids for the primary shift portion with a goal of approaching a change rate of a difference between an input speed and an output speed of the primary shift portion to a first target speed change rate, and simultaneously performing feedback control of duty ratios of friction element solenoids for the secondary shift portion with a goal of approaching a change rate of a turbine speed to a second target speed change rate; and completing the shift in the primary shift portion, and then completing the shift in the secondary shift portion.

Abstract: An automatic transmission for a hybrid electric vehicle where an engine is shut down during vehicle stops to improve fuel economy. The automatic transmission includes a main pump that is driven off of a transmission input shaft, and an electronically driven auxiliary pump. A shut down shuttle valve switches a hydraulic circuit connection from the main pump to the auxiliary pump for a low-reverse clutch and a forward clutch when the vehicle stops in drive or low gear. A pressure transducer, controller and steady state relay allow for closed loop feedback to control the auxiliary pump in order to assure sufficient hydraulic pressure while minimizing power consumption.

Abstract: A replacement 1-2 shift valve for an automatic transmission, which restores a smooth shift from first to second gear thereby correcting a shudder shift or a complete failure to shift from first to second gear is disclosed. The present 1-2 shift valve comprises a valve piston including at least one bi-directionally tapered valve stem that changes the direction of transmission fluid flow within the valve such that a rebound force is generated which acts to propel the valve piston in an axial direction toward the second gear position of the valve. The piston lands which comprise the valve piston are provided with a plurality of annular grooves that function to retain transmission fluid and to center the valve piston in its mating bore to resist to side loading during operation. In addition, the present valve piston is provided with an anodized surface finish, which increases service longevity.

Abstract: A hydraulic control system for an automatic transmission, in which four forward speeds and one reverse speed are realized by the use of a reduced number of friction elements compared to the prior art such that overall structure is simplified, the weight of the automatic transmission is decreased, and the cost of production is reduced. In the hydraulic control system, hydraulic pressure generated in an oil pump is controlled to a predetermined level by a regulator valve, and part of this pressure is supplied as operational pressure of a damper clutch and to a reducing valve, and another part of this pressure is supplied to a hydraulic pressure control section for the selective supply of operational pressure to friction elements that are engaged in each shift range and speed, the hydraulic pressure control section including a shift control assembly, a hydraulic pressure control assembly, a switching assembly, a fail-safe assembly, and a N-R control assembly.

Abstract: A hydraulic control system for an automatic transmission includes a 3-4 shift valve that outputs a source pressure through a first path for shift speeds lower than a fourth shift speed established by directly connecting an input shaft with an output shaft of the automatic transmission, i.e., third shift speed. The hydraulic control system further includes a clutch apply control valve that outputs a source pressure through a second path at a shift speed higher than the fourth shift speed, i.e., fifth speed. The 3-4 shift valve and the clutch apply control valve serve to interrupt supply of the source pressure through the first path and the second path, respectively, in the fourth speed or the lock-up stage.

Abstract: A hydraulic control system in which hydraulic pressure generated pressure generated by an oil pump is supplied to a pressure/damper clutch controller, a pressure reducer, and a shift controller, wherein the pressure reduced by the pressure reducer and the hydraulic pressure supplied as a result of port conversion of the sift controller are supplied to the hydraulic pressure controller, and hydraulic pressure controlled by the hydraulic pressure controller is supplied to a hydraulic pressure distributor and directly to some friction elements.

Abstract: A hydraulic control apparatus for an automatic transmission including a hydraulic pressure source, hydraulic paths, hydraulic servos for operating friction elements which are coupled with the hydraulic source an the hydraulic paths, a control device arranged on the hydraulic paths for operating engagement release through supply/removal of hydraulic pressure to the hydraulic servos and valves which are arranged on the hydraulic path for cutting off hydraulic pressure from the hydraulic pressure source to the hydraulic servo with hydraulic pressure in the downstream side of the control device as signal pressure.

Abstract: A hydraulic control system for a transmission including: a first transmission mechanism for transmitting a torque between rotary members and a transmission member by clamping the transmission member between the rotary members with a clamping pressure based on an oil pressure; and a second transmission mechanism for changing the transmission state of the torque by applying/releasing frictional engagement elements with an oil pressure, comprises: an oil pressure source; a first pressure regulator mechanism for regulating an oil pressure outputted from the oil pressure source, to a first oil pressure for establishing the clamping pressure for the transmission member by the rotary members; and a second pressure regulator mechanism for regulating the first oil pressure, as regulated and outputted by the first pressure regulator mechanism, to a second oil pressure for applying the frictional engagement elements.

Abstract: To make it possible to maintain speeds during failures in an automatic transmission that does not have exclusive friction elements corresponding to the attainment of each speed. The hydraulic control apparatus of an automatic transmission, provided with control means 71-74 for supplying regulated pressure to each of the hydraulic servos 81-84 that are first through fourth friction elements to which hydraulic pressure is supplied from the oil path L1, and provided with switching valves (1)-(5) for cutting off the supply of hydraulic pressure to friction elements other than the friction elements that engage in each speed, on the upstream side of the supply paths L31, L32, L10, L11 and L12. Each switching valve is switched by hydraulic pressure (C1-C3, B1 pressures) regulated by the control means that achieve regulated pressure operating conditions during failures, and selective application of signal pressure (Sol, SolB, SoIC pressures) output by the control means as operating means.

Abstract: A hydraulic control system includes a pressure/damper clutch controller, a pressure reducer, and a shift controller. The shift controller includes a manual valve indexed with a driver-controlled select lever to supply hydraulic pressure to the hydraulic pressure controller, the hydraulic pressure distributor, and the friction elements.

Abstract: An output bearing assembly of a transmission includes a housing, and a pair of bearings. At least one speedometer sensor is mounted between the bearings. The arrangement allows the output bearings to be spaced axially by a relatively great distance.

Abstract: A hydraulic control system for an automatic transmission includes a first clutch acting as an input element at first, second, and third forward speed ranges, a second clutch acting as the input element at third and fourth forward speed ranges, a third clutch acting as the input element at an R range, a fourth clutch operating at P, R, N, and L range for performing an engine brake function by stopping a one-way clutch at the first, second, and third forward speed ranges, a first brake acting as a response element at the P, R, N, and L ranges, a second brake acting as a response element at second and fourth forward speed ranges, a first switch valve for distributing hydraulic pressure controlled by a first solenoid valve to a damper clutch in a torque converter and to clutch control valves for the first clutch, and a second switch valve for distributing hydraulic pressure controlled by a second solenoid valve to the second clutch and the first brake.

Abstract: Methods and systems for improving the operation of a transmission for an automotive vehicle, and in particular the transmission as installed by the original automobile manufacturer. Are provided for modifying the original hydraulic fluid circuits of the automotive transmission provided by the automobile manufacturer to enable the transmission to select first gear at any time, and to enable the transmission to produce quick applies during upshifts and fast releases during downshifts for high performance operation with only minimum ratio sharing or overlap during gear changes. The modification of the original automotive transmission to achieve these goals includes modification of the hydraulic fluid circuits of the factory installed transmission; by enlarging the size of pre-existing orifices and by plugging other orifices; and by adjusting pre-existing spring and pressure values for adjusting the fluid flow and operation of the original factory installed automotive transmission.

Abstract: A hydraulic control apparatus of automatic transmission comprising a hydraulic pressure source, hydraulic paths, hydraulic servos for operating friction elements which are coupled with the hydraulic source and the hydraulic paths, a control device arranged on the hydraulic paths for operating engagement release through supply/removal of hydraulic pressure to the hydraulic servos and valves which are arranged on the hydraulic path for cutting off hydraulic pressure from the hydraulic pressure source to the hydraulic servo with hydraulic pressure in the downstream side of the control means as signal pressure.

Abstract: There are respectively provided control valves 15, 16 in hydraulic oil paths L11, L12 for inputting governor pressure PV into shift valves 11.sub.1, 11.sub.2, 11.sub.3. In the control valves 15, 16, there are provided first pressure chambers 15g, 16g pushing the spools 15a, 16a of the control valves 15, 16 onto the closing position side. At position "D.sub.3 " or "2", hydraulic pressure is inputted into the first pressure chambers 15g, 16g, so that the spools 15a, 16a can be changed over to the closing position, and the input of governor pressure PV into the shift valves 11.sub.1, 11.sub.2, 11.sub.3 is stopped so that the shift valves can be changed over to the low speed position. In the control valves 15, 16, there are provided second pressure chambers 15h, 16h pushing the spools 15a, 16a onto the opening position side, and governor pressure PV is inputted into the second pressure chambers 15h, 16h.

Abstract: A circuit for controlling hydraulic pressure of an automatic transmission includes a first shift device, a second shift device and a third shift device which make line pressure lead-through by selecting the predetermined combination of supply and exhaust of hydraulic pressure in accordance with the transmission stage in order to set the transmission stage of the automatic transmission in response to the driving condition of the vehicle. A switching device detects that a hydraulic pressure is supplied to an output line of the first shift device or an output line of the third shift device so that the third-speed and the fourth-speed are switched. The switching device also detects that the hydraulic pressure is supplied to an output line of the second shift device and an output line of the third shift device so as to shut out a line which is conducted to one of engaging elements being engaged at each time of the first-speed and the third-speed.

Abstract: Power transmissions incorporate gear ratios including a plurality of forward ratios, a neutral condition and at least one reverse ratio. The establishment of each ratio is controlled by selectively engageable hydraulically operated friction devices, such as clutches and brakes. The interchange between forward ratios is controlled by the interchange of at least one friction device. The control elements to accomplish the establishment and interchange of the ratios include a pressure source, shift valve, solenoid control valves and pressure control valves. The solenoid valves are electrically actuated and the hydraulic portion of the control includes elements that permit continued operation of the transmission in selected ratios in the event of electrical discontinuance.

Abstract: An integrated hydro-mechanical transmission having the capability of achieving continuous variability from zero to maximum in both the forward and reverse vehicle directions and having the additional capability of automatically locking up for direct mechanical drive in at least one operator selectable drive range corresponding to typical city, suburban and highway driving. Intended for use in all types of highway vehicles.

Abstract: A control system for an automatic transmission, includes a first hydraulic servo adapted to be fed with oil for effecting a shift to a target gear stage; a second hydraulic servo adapted to be fed with the oil for effecting a shift to the target gear stage; a limit oil feed circuit formed through an oil limit flow limiting device; a quick oil feed circuit bypassing the oil flow limiting device; and an oil passage switch for switching and connecting the limit oil feed circuit and the quick oil feed circuit to the first hydraulic servo and the second hydraulic servo. The oil passage switch feeds oil from the quick oil feed circuit to the first hydraulic servo and the second hydraulic servo, when the engine load is high, and feeds oil from the limit oil feed circuit to at least the first hydraulic servo when the engine load is low.

Abstract: A hydraulic control for an automatic transmission is composed of a gear shift mechanism having first and second frictional engagement elements, a hydraulic control unit for the engagement elements, and an electronic control unit for the hydraulic control unit. The first element is engaged to achieve a first speed stage and the second element is engaged to achieve a second speed stage faster than and closest to the first speed stage. The hydraulic control unit has a first directional control valve for switching the feeding and discharge of hydraulic pressure between the first and second engagement elements, responsive to a first solenoid signal from the electronic control unit. A second directional control valve is adapted to be switched by a second solenoid signal from the electronic control unit to achieve a third speed stage yet faster than the second speed stage. The first engagement element has a discharge line connected to a drain line via the second directional control valve.

Abstract: A control apparatus for an automatic transmission has a control unit which, when a selector lever is shifted from a forward drive gear range to a reverse gear range when the vehicle speed is not lower than a first predetermined speed, prevents the gear stage from being changed to that corresponding to the reverse gear range until the vehicle speed has fallen to a speed not greater than a second predetermined speed lower than the first predetermined speed. The control unit allows the gear stage to be changed to that corresponding to the reverse gear range if the selector lever is shifted to the reverse gear range when the vehicle speed is lower than the first predetermined speed. This control apparatus, therefore, ensures that the gear stage can be changed to that corresponding to the reverse gear range only when the driver intentionally shifts the selector lever from one of the forward drive gear ranges to the reverse gear range.