摘要:
A power train having a gas turbine engine, a direct coupled multiratio transmission and an automatic trimmed shift control system having a manual valve, shift valves responsive to a torque demand signal provided by gas turbine engine compressor discharge pressure and an output speed signal and timed pressure increasing trimmer valves for establishing the ratio drives and a throttle controlled neutral to first drive pressure regulating and shift control providing when the manual valve is in drive position and the throttle is in an off position, idle fuel feed and zero pressure for a positive neutral, during throttle movement from off position to a low throttle position, continuing idle fuel feed and then a small fuel feed increase and a gradually increasing pressure in a low pressure range controlling the rate of low power engagement of first drive and during further throttle movement from low throttle to full throttle, low to full fuel feed trimmer valve timed increasing pressure in a higher pressure range for high power engagement of first drive and full high pressure for maintaining high power first drive fully engaged and increasing. The throttle pedal controlled pressure regulator is disabled to prevent low pressure range regulation and supply full pressure to the trimmed shift control system by pressure above a low speed to maintain high power drive for overrun braking, during reverse drive as gradual low power engagement of reverse is not required and above a low torque demand or compressor discharge pressure for low pressure regulation only at low engine torque and power engine output.
摘要:
In a multiratio transmission providing a low ratio drive and a plurality of higher ratio drives having a manual selector control to select the low ratio drive or automatic control of the plurality of higher automatically controlled ratio drives. On manual selection of automatic control, a plurality of automatic shift valves operate under the control of an output speed governor pressure and a torque demand pressure for automatic shifting between the low and high automatically controlled ratios in response to speed and torque demand. On manual selection of the lowest ratio drive, after the automatic control is in the lower or first automatic ratio drive, a selector valve pressure will be supplied by a low signal valve, if both the inverted modulator pressure is high, indicating less than 15% throttle advance and the governor pressure is low indicating low vehicle speed. The predetermined low throttle advance and low speed at which a manual shift to low may be made is independently controlled and adjusted by independently adjustable springs.
摘要:
A control for a multi-speed transmission adapted to be driven by a two spool gas turbine engine. The control has valving to control the shifting of ratios within the transmission including an engagement control valve responsive to compressor discharge pressure and vehicle speed. The engagement control valve permits the operator to control the engagement of a drive establishing device, for both low forward drive and reverse drive, at predetermined engine power conditions as represented by compressor discharge pressure.
摘要:
An automatic transmission includes a multi-speed transmission gear mechanism having an input shaft, an output shaft and a plurality of friction coupling elements. A hydraulic control system selectively supplies a hydraulic pressure to the friction coupling elements, thereby selectively applying the friction coupling elements to cause the transmission gear mechanism to shift to a speed which is determined according to a predetermined shift pattern. The control system sets a target hydraulic pressure to be applied to the friction coupling elements according to the kind of the shift to be effected and the engine load, and, when it is detected that the transmission gear mechanism is to make a backout upshift due to reduction in the engine load, increases the target hydraulic pressure by an amount which is determined according to the throttle opening and the turbine speed.
摘要:
A multispeed transmission having an automatic shift control system having an automatic shift valve which is biased for upshift by a force increasing with output speed of the transmission and is biased for downshift by a force increasing concurrently with torque demand, to provide upshifts at speeds increasing with torque demand and downshifts at lower speeds. The shift valve controls the supply of shift fluid pressure to the ratio-engaging devices to establish low and high ratio drives. A regulator valve increases the shift fluid pressure with an increasing lagging torque demand signal. A modulator valve is controlled by an engine fuel feed or throttle to provide a concurrent torque demand signal pressure concurrent with throttle movement for the shift valve. The lagging torque demand signal is more concurrent with engine torque and power, such as the gasifier pressure of a gas turbine engine, or the supercharger pressure of an internal combustion engine. The transmission is shifted immediately in response to torque demand, and the shift pressure is proportional to the engine torque and speed at the time of the shift.
摘要:
A transmission having selectively engaged fluid actuated friction drive establishing devices and an engagement timing control system having a trimmer regulator valve for each drive establishing device, a trimmer bias regulator valve and accumulator. The oncoming trimmer valve has a spring biasing device responsive to engagement pressure to increase oncoming ratio drive engagement pressure at a controlled rate, initially at a high rate up to a minimum slack take up pressure, then to gradually increase the drive pressure from the minimum pressure at a low rate in a predetermined trimming time period for establishing the drive and then to increase the pressure at a very high rate to high line pressure. A trimmer bias system pressure is supplied to a bias chamber of the trimmer valves and acts in the oncoming trimmer valve bias chamber to increase the pressure level of the gradually increasing drive engagement pressure proportional to torque demand. A limited volume flow trimmer bias supply pressure is supplied to the trimmer bias system having an accumulator and the trimmer valve bias chambers which change volume during a shift relative to the limited volume supply flow to control the trimmer bias system pressure and the resulting drive ratio pressure so the engagement pressure is reduced to the minimum at the beginning of the trimmer time period at all torque demand values and the increase with torque demand is delayed and gradual for smooth shifting.
摘要:
A power train having a gas turbine engine with a controlled power transfer clutch between the compressor turbine and the load turbine driving a power shift transmission. The engine control system includes a fuel control and a power and torque program control responsive to compressor and auxiliary torque and speed controlling the power transfer clutch to provide engine output power and maintain constant high turbine inlet temperature in a wide range of operation for optimum efficiency. The power shift transmission control has shift control valving to selectively supply control pressure to the fluid operated drive motors to selectively establish neutral and a plurality of drives. A flow valve responsive to flow filling a motor for establishing a drive controls a power transfer clutch cut off valve to disconnect the power transfer clutch providing normal engine idle during establishment of a drive. Energizing the starter circuit requires first manually placing the transmission control in neutral and then discontinues fluid feed to the engine and transmission controls, unloads the engine and transmission pumps, disengages the power transfer clutch, provides a low idle throttle stop and further ensures positive neutral in the transmission. When the engine is started and the transmission control is in neutral, the engine power clutch is disengaged, the throttle stop is in low idle, the transmission is in positive neutral and only lubrication pressure is supplied to the transmission.