摘要:
A fan drive with high torque release embodying the concepts of the present invention is adapted to disengage the fan drive under high torque conditions. The fan drive includes an input shaft member and an output shaft member. A torque transfer device operatively connects the input shaft member with the output shaft member. A spring apply mechanism is provided for engaging the torque transfer device at low speeds and under low torque loading, and a centrifugal apply mechanism is provided for maintaining engagement of the torque transfer device under higher operating speeds and at properly anticipated torque loading. A release mechanism substantially disengages the torque transfer device upon the application of higher than desired torque loading conditions.
摘要:
A mechanical/hydraulic brake system has an operator input pedal to initiate braking and brake cooling. The brake return springs establish a reaction force to provide the operator with a "brake feel" or feed-back force. The hydraulic apply forces have a tendency to reduce the feed-back force. A plurality of balance pistons are pressurized simultaneously with the hydraulic apply forces to maintain the feed-back force felt by the operator undiminished.
摘要:
A hydrostatic steering arrangement and control having the high speed steering capability of an output-driven system and the low speed steering capability of an input-driven system. The engine drives the vehicle through a fluid coupling and a multiple ratio hydraulic transmission, and the hydrostatic pump of the steering system is driven by the output (turbine) of the fluid coupling. Increased steering capability at vehicle speeds which would otherwise limit the steering capability, is achieved by controllably slipping the active torque transmitting device of the transmission. In this mode, the hydrostatic pump speed is permitted to increase, and the steering system operates essentially as though it were input-driven.
摘要:
A brake apply system has a rotary input member and two rotary output members which are operable to actuate individual brake mechanisms. Disposed between the input and output members is a differential mechanism which permits differential rotation of the output member so that the brake mechanisms can undergo separate movements during brake application to achieve full braking action. The differential mechanism is comprised of a pair of driven cam members which are rotatable in response to a cam driver which is driven by the input member. The cam driver is movable longitudinally while enforcing differential rotation of the driven cam members to initiate the differential action between the output members.
摘要:
A hydrostatic transmission, especially for a steer drive of a propulsion and steer drive transmission, having a variable displacement pump, a fixed displacement motor, and a pump displacement control, and including a low pressure fluid source supplying the charging and lubrication systems of the hydrostatic transmission and a high pressure source. The high pressure source, in a normal range of low hydrostatic power pressure values, provides control pressure regulated in proportion to high hydrostatic power pressure to meet the pressure requirements of the pump displacement control which increase with high hydrostatic power pressure. In an abnormal and lower range of low hydrostatic pressure values, the control pressure is regulated to decrease to zero as the low hydrostatic power pressure decreases to a minimum operating pressure value. In the abnormal range, the reduction of control pressure reduces load capacity and thus steer capacity, with decreasing low pressure supplied to the charging and lubrication systems to advise the operator of the abnormal pressures and to discontinue hydrostatic transmission operation to prevent operation with insufficient charging and lubrication pressures.
摘要:
A multi-speed power transmission has two simple planetary gear sets interconnected to provide a multi-speed planetary arrangement. The planetary arrangement has input members selectively connectible by a plurality of friction clutches to a prime mover through two distinct input ratio gear sets. One member of the one of the simple planetary gear sets is selectively connectible individually with both input ratio gear sets via two of the clutches. Two additional clutches and two friction brakes are also included, whereby eight forward speeds and two reverse speeds are attainable by engaging selective combinations of the clutches or clutch and brake.
摘要:
A planet carrier for a compound planetary gear arrangement has four side plates supporting six pinion gears. One pair of side plates, supporting three of the pinion gears, have one of the other pair of side plates disposed axially between them. This allows the pinions to be in meshing relation between adjacent side plates which are each supporting three pinions, respectively. To complete the planetary arrangement, the outer side plates are sized to permit central access at respective sun gears and outer axial access at respective ring gears. The ring gears and sun gears do not encroach upon the meshing location of the pinion gears. With the judicious use of friction clutches and brakes and two input gear sets providing ratios, the compound planetary arrangement can be controlled to provide powertrains having from five forward speeds (the four friction devices) to seven forward speeds and two reverse speeds (with eight friction devices). Thus, the planetary arrangement can be utilized to provide a plurality of speed ratios, wherein the number of friction devices is one less than the total number of speed ratios.
摘要:
A torque transmitting mechanism has a hydraulically actuated piston that is slidably disposed in a cavity. An apply chamber, formed by the piston and cavity, is filled with hydraulic fluid when the torque transmitting mechanism is to be engaged. One or more gas permeable—liquid impermeable mats are secured in a passage between the chamber and a non-liquid area in a transmission. During initial engagement of the torque transmitting mechanism, any entrapped air is forced out of the chamber through the mat while the leakage of liquid is inhibited. In a rotating torque transmitting mechanism (clutch), the mats are installed near the innermost periphery of the chamber. In a stationary torque transmitting mechanism (brake) the mats are installed near the top outermost periphery of the chamber.
摘要:
A trim valve controls the pressure rise and pressure gain in a torque transmitter. The trim valve controls the distribution of a system pressure to the torque transmitter in a controlled manner such that the apply pressure of the torque transmitter has a desired gain rate. A spool valve controls the admission of system pressure through a sleeve valve for distribution to the torque transmitter in response to a control pressure. The trim valve has bias spring elements that control a sleeve member of the trim valve in response to the apply pressure at the torque transmitter. The rate at which the apply pressure rises in relation to the control pressure is established by the bias spring elements which can be a single variable rate member or a plurality of parallel members. If parallel members are used, they are positioned to be sequentially engaged by the sleeve valve during linear movement in response to a change in the apply pressure.
摘要:
A vehicular braking system embodying the present concept utilizes multi-plate brake packs in conjunction with a mechanical actuating system that comprises first ramps secured to ground and second ramps presented from an annular apply cam member as well as a brake apply annulus, the latter being disposed adjacent the brake pack with rollers between the ramps and between the brake pack and the brake apply annulus. The annular apply cam member is connected to the brake pedal by a suitable linkage so that actuation of the pedal transmits brake apply torque to the apply cam member which results in the application of an apply force to the brake pack by virtue of the rollers which effect axial translation of the brake apply annulus in response to rotation of the annular apply cam member. The system also includes an anti-lock brake system which is actuated in response to depression of the brake pedal. The anti-lock brake system actuates a hydraulic piston which acts against the brake apply annulus in an axial direction opposite the mechanical apply force to control the braking force and produce the required deceleration rate until the brake pedal is released.