An enhanced control system for an electronic automatic transmission enables the transmission to operate in a full neutral idle, a reverse lockout, and an inching mode. These functions improve the mileage and durability of the operation of the transmission. They also enable the inching mode for use especially in industrial applications.

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.

Inventive embodiments are directed to components, subassemblies, systems, and/or methods for infinitely variable transmissions (IVT) having a variator provided with a plurality of tilting spherical planets. In one embodiment, a variator is provided with multiple planet arrays. In another embodiment, a hydraulic system is configured to control the transmission ratio of the IVT. Various inventive idler assemblies and planet-pivot arm assemblies can be used to facilitate adjusting the transmission speed ratio of an IVT. Embodiments of a transmission housing and bell housing are adapted to house components of an IVT and, in some embodiments, to cooperate with other components of the IVT to support operation and/or functionality of the IVT. Various related devices include embodiments of, for example, a control feedback mechanism, axial force generation and management mechanisms, a control valve integral with an input shaft, and a rotatable carrier configured to support planet-pivot arm assemblies.

A control for a multi-speed automatic vehicle transmission includes electrical and hydraulic components, such as pressure control valve systems in fluid communication with shift valves and electrohydraulic actuators. The control includes electrohydraulic features configured to enable the transmission to respond to an electrical failure whether the transmission is in neutral, a reverse range, or one of a plurality of forward ranges.

A valve system for controlling a system pressure control system, in particular a hydraulic control unit of an automatic transmission, includes a multi-stage system pressure valve, a pilot valve and a control valve with a control piston downstream from the pilot valve that governs the pressure at a differential area of the system pressure valve, depending on the pilot pressure. The pilot pressure/system pressure characteristic curve features a continuous development, and whereas, from a predefined pilot pressure, on the basis of a sudden change to the dependency of the change to the system pressure as a function of the change to the pilot pressure, the gradient of the system pressure as a function of the pilot pressure is significantly steeper than that prior to the predefined pilot pressure.

A transmission device with a hydraulic system includes a pump device, a primary pressure circuit, and at least one additional pressure circuit supplied with hydraulic fluid by the pump device. The pump device is coupled to and driven by a transmission input shaft. A first pump unit of the pump device is connected to and driven by the transmission input shaft. A second pump unit of the pump device is connected to and driven by a transmission output shaft. A pressure side of the first pump unit is connected to the primary pressure circuit, and is connectable to the additional pressure circuit, while a pressure side of the second pump unit is connected to the additional pressure circuit, and is able to be coupled with the primary pressure circuit.

A hydraulic system for actuating an interlocking shifting element of a transmission which comprises two piston chambers and a piston element that delimits the piston chambers. The piston element can be acted upon in one piston chamber by a pressure to open the shifting element and, in the other piston chamber, by another pressure to close the shifting element. Pressure can be delivered by a valve to two piston chamber and the valve can be actuated by an actuator by a pilot pressure. The valve and the electro-hydraulic actuator are designed and functionally connected to one another such that, in the event of a pressure drop, a total hydraulic force, acting to close the shifting element, is applied to the piston element and, if the current supply to the actuator fails, a total hydraulic force acting, in the opening direction of the shifting element, acts upon the piston element.

An enhanced control system for an electronic automatic transmission enables the transmission to operate in a full neutral idle, a reverse lockout, and an inching mode. These functions improve the mileage and durability of the operation of the transmission. They also enable the inching mode for use especially in industrial applications.

A method of controlling an automated transmission with positioning cylinders (6, 8, 20) controlled by shift valves or venting valves (10, 12, 16, 18, 22, 24). At least one cut-off valve (4) is positioned in front of the shift or venting valves and a control device controls the valves while pressure pipes, which follow the cut-off valve (4), are connected with one another following the cut-off valve (4). Due to the fact that the cut-off valve (4), for reasons of design simplicity and cost, is generally designed as a simple 2/2 way valve which only allows pressure increase but not pressure reduction, the method provides control of the shift valves or ventilation or venting valves (16, 18), of a non activated positioning cylinder (8), so that the pressure pipe system is connected with an outflow pipe (14) for a pressure reduction in the pressure pipe system (30, 32, 34).

The present disclosure relates to a method of controlling a vehicle. The method includes receiving a signal indicative of the vehicle being in a stop condition or in the process of stopping. The method also includes activating an auxiliary hydraulic pressurization system in response to the signal and regulating a hydraulic pressure in a hydraulic control system of a transmission. A drive unit is disabled such that a main pump of the hydraulic control system discontinues providing hydraulic pressure to the hydraulic control system. The hydraulic pressure is maintained at a hold pressure in the hydraulic control system by the auxiliary hydraulic pressurization system.