| Patent application number | Description | Published |
|---|
| 20080294318 | FEEDBACK ADJUSTMENT FOR OPEN-LOOP TORQUE CONTROL MAP - A variator torque control system and method utilize a hydraulic actuator to control the variator output via a torque control map, wherein the values of the torque control map are evaluated and modified during use of the map to improve map accuracy. In an example, errors in the map are evaluated to determine whether a system fault has occurred. | 11-27-2008 |
| 20080300103 | OPEN-LOOP TORQUE CONTROL WITH CLOSED-LOOP FEEDBACK - A variator torque control system adjusts a variator output so that the actual output torque of the variator closely matches an expected output torque. In an example, pressure values of an existing torque control map are supplemented in real time with calculated pressure supplement values based on the current operation of the variator. The pressure supplement value for each mapped pressure value may be derived based on a prior application of the same or another map value. | 12-04-2008 |
| 20090005914 | FEEDBACK ACCELERATION REDUCTION FOR FLUID SUPPLY VALVES - A system and method for controlling a variator operate to detect variator torques and/or internal pressures and generates a preliminary corrective command. The preliminary corrective command is transformed via a dynamic transform to account for system characteristics during transient operating conditions such as machine acceleration, such that the acceleration of the system during transient periods is not torque-limited by static torque-control map values. In an embodiment, the acceleration may be positive or negative, and in a further embodiment, braking is automatically applied in the case of negative requested power or desired machine retarding. | 01-01-2009 |
| 20090005941 | ANTI-HUNT SYSTEM AND METHOD FOR PARALLEL PATH VARIABLE TRANSMISSION - A system and method for largely controlling transmission gear ratio oscillation is disclosed. When shifts are executed substantially at synchronous points rendering hysteretic anti-hunting schemes impractical, the disclosed techniques in any combination thereof may allow for oscillation control via an overridable lock-out timer. For oscillation control during incline navigation and other similar loading scenarios, the transmission may be selectively locked if certain operational criteria are met. | 01-01-2009 |
| 20090011901 | Oil warming strategy for transmission - A method is provided for increasing a temperature of oil in a continuously variable transmission during engine start-up, the transmission including a fluid pump and motor, and a mechanical transmission. The method includes starting the engine, maintaining the fluid pump at substantially zero displacement, and heating the transmission oil by relative rotation of a first clutch disc and first clutch hub of a first clutch assembly and by relative rotation of a second clutch disc and second clutch hub of a second clutch assembly. The method further includes maintaining a substantially zero net torque from the transmission during the heating of the oil by the first and second clutch assemblies. | 01-08-2009 |
| 20090199814 | POWER-BASED UNDERSPEED CONTROL - A method of adjusting the operation of an engine-driven machine to avoid engine under-speeding entails converting a received speed or torque command into a power command. When an engine under-speed condition is sensed, the system performs underspeed correction in the power domain before converting the underspeed processed power command back into the units of the original domain. The converted underspeed processed power command is issued to the transmission or other component to alleviate the engine under-speeding condition. | 08-13-2009 |
| 20090298635 | Electric motor actuation of a hydrostatic pump - A hydraulic motor system for improved frequency response includes a hydraulic variator having a pump and a motor, wherein the pump includes a variable angle swash plate, and the system further includes an electric actuator for controlling an angle or torque of the swash plate, thereby controlling the motor output characteristics. The electric actuator for controlling the variable angle swash plate may comprise a linear electric motor, ball screw drive or a rotary electric motor. In an example, the rotary electric motor tilts the swash plate by applying a torque to the swash plate at a point away from its tilt axis. In a further example, the rotary electric motor tilts the swash plate via a worm drive or ball screw drive. | 12-03-2009 |
| Patent application number | Description | Published |
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| 20080202112 | Method and system for feedback pressure control - A method of controlling a motor includes monitoring a pressure in a circuit supplying a pressurized fluid to the motor, determining a difference between the monitored circuit pressure and a desired circuit pressure, and determining an actuator command for an actuator that is capable of adjusting a pressure of the pressurized fluid supplied to the motor. The actuator command is determined based on the difference between the monitored circuit pressure and the desired circuit pressure, and is independent of a position of the actuator. The method also includes operating the actuator based on the actuator command. | 08-28-2008 |
| 20090282904 | Multiple transmission test system and method - A test system for a plurality of transmissions is disclosed. Each of the plurality of transmissions may have a transmission input member and a transmission output member. The test system may have a prime mover. The prime mover may have a prime mover output member configured to connect to the transmission input member of each of the plurality of transmissions. Additionally, the test system may have a plurality of inertia devices. Each of the inertia devices may be configured to connect to the transmission output member of one of the plurality of transmissions via a drive shaft. The test system may also have a controller. The controller may be configured to communicate with the prime mover and the plurality of transmissions to control a transfer of power between the plurality of transmissions. | 11-19-2009 |
| 20100095665 | Hydrostatic pump and motor with improved torque reversal characteristics - A system and method for variator control employs positively directed electronic make-up and flushing relief valves for more precise torque control of a hydraulic variator, especially during torque reversal, as well as improved cold weather operation. This can improve machine response during periods of severe torque change. The ability to more tightly control variator torque allows more precise torque management algorithms for power control and engine matching purposes. Moreover, the ability to positively control venting of the hydraulic circuit for purposes of fluid cooling allows for more consistent machine response regardless of ambient temperature. | 04-22-2010 |
