The World best hydraulic Products, JEIL PMC.
Hydrostatic Transmission(HST) cover a wide range of applications. It has an excellent durability for hydraulic pumps used in agricultural machine, fork-lifter and construction machine, etc.
HST is a hydraulic power transfer unit composed of hydraulic pump and motor in a single body. Pump displacement is varied with the swash plate angle. The pump is equipped with a varying displacement swash plate type piston and the motor is designed as a fixed displacement type. Motor rotation either for clockwise or counterclockwise direction can be changeable from stop to maximum number of rpm according to the change of swash plate angle of pump. The forward, reverse and stop modes of HST are performed using simple lever control and velocity proportional to lever handling range makes an easy use of transporting system for an agricultural machine and a transportation machine.
|Max Input Speed
|Max Output Speed
|Max Output Torque
|Charge Pump Displacement
|Cool and Cold Region||Warm and Hot Region|
|-10 ~ 25℃||0 ~ 35℃|
|ISO VG 32||ISO VG 46|
|Classification||Viscosity Cst||Oil Temperature|
|ISO VG 32||ISO VG 46|
|Proper Range||25 ~ 90||15 ~ 45℃||27 ~ 57℃|
|Usable Range||25 ~ 90||-3 ~ 50℃||5 ~ 63℃|
- Usable range : 10 - 80℃
- Limited range : -20 - 90℃
- A light shock may be caused by the shift of the valve in operation.
- It is required to chock knockings in ascending and descending at the time of low-speed rotation.
- Descending speed at the neutral position slows down particularly on gently sloping road. Braking distance may be affected by the valve's set pressure.
- Choose the valve according to the kind and use of the vehicle.
- Oil level below the standard
- Polluted and/or aged oil
- Driving with noises caused by cavitation at temperature or aeration by the inflow of air
- Acceleration of the engine while the overloaded vehicle stops running and the relief is in operation(loss of heat occurs because of HST's rapid heating.)
- Continuing work with the relief working
- Polluted(abnormal increase of charge pressure → damage to the charge pump or the filter → inflow of alien substances through the main passage → wearing out of parts)
- Blending of different working oils
- Continual working of the relief with the mechanical brake on (Avoid excessive working of the relief.)
- Change in the setting of HST's relief valve pressure
- Starting the engine when the speed pedal is in other than the neutral position. Avoid cutting the clutch off from or connecting it abruptly to the engine when the speed pedal is in other than the neutral position.(possibility of engendering danger, such as surge pressure, abnormal wearing out of the shaft, and turnover of the vehicle by abrupt shut-off, start, or stop)
- Cutting the clutch off to stop while the vehicle is driving with a working machine of big inertia being attached to HST's PTO shaft, which makes the vehicle uncontrollable because the continuous rotation of HST's pump and shaft duo to the working machine's inertia leaves HST's driving power in operation
- When the vehicle stops with HST's lever being in other than the neutral position, the engine may backfire as the vehicle runs backward on a sloping road because of the wheels' back-driving.
- In order to prevent the vehicle's turnover by an abrupt start or stop, make a structure in which HST's lever does not operate rapidly. Make mention about the danger of the abrupt start and stop in the manual.
- When the worker leaves the vehicle, put the mechanical brake in operation so that the vehicle may not run backward. In case the vehicle stops on a sloping road, working oil in HST's high-pressure passage(about 200cc) may leak, causing the motor to idle and the vehicle to slide down.
- To prevent sliding make a structure in which HST's tilt-angle control lever should return to its original position after it is put in the neutral position. (When a spring is used for the return, take into consideration HST's control power and control shaft, and friction and damping force in the link system. Consider also prevention of rust and pollution in the link system.)
- Do not make a sub-transmission shift when HST's lever is in other than the neutral position.
- Do not make a sub-transmission shift also while the vehicle is running. For it may cause a rapid speed-up or slow-down of the vehicle.
|HYDROSTATIC TRANSMISSION||HPVMF SERIES||DOWN PDF|