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EST (For Environment & Energy-efficiency, Spontaneous Stepless Transmission)
EST is a variable transmission. It changes the rotary motion of the power source into the reciprocating motion and generates output in the rotary power according to on the change in the angle of the reciprocating motion. Depending on the input and output conditions, the angle of the reciprocating motion is automatically changed so without a separate gear control system, gear is automatically, steplessly changed.
Method of gear change : Stepless gear change Range : 0 ~ Infinity
Direction change : Possible to change into the right direction and the reverse direction;
     Auto stepless gear change for both directions
Energy efficiency : High efficiency  
Gear control : A gear control device is not necessary.  
Performance of transmission : Possible to transmit large power
Safety : Automatically coping with overload Automatically preventing
Voluntary gear section setting : Possible to be set by users (option)
Overview Transmitting power with hydraulic pressure energy Transmitting power with fixed reduction gear ratio Transmitting power with infinite gear ratio
Type of power transmission Working oil -> Actuator Gear Gear , Rod
Capacity of power transmission Transmitting large power Transmitting large power Transmitting large power
Startup Proper operation Fixed rpm startup Variable rpm startup
Normal operation Classified into positive displacement and variable displacement type
Working at fixed rpm all the time
Working at the set rpm within the proper load; rpm ↓, output torque ↑
at overload
Energy consumption Different by type Consuming overcurrent depending on load
Flexibly consuming proper current
Transmission of overload Different by type Startup load and overload are transmitted to the power source.
Startup load and overload are not transmitted to the power source. It copes with auto stepless gear change.
Protection of power source Different by type Impossible
Efficiency The efficiency of power transmission is low.
-Power loss in the hydraulic pump
-Power loss in the pipe
-Power loss in the control valve
-Power loss in the actuator
-Power loss by the change in the viscosity of hydraulic oil
The higher the reduction gear ratio is, the lower the efficiency of power transmission is. Highly-efficient power transmission is possible regardless of the stepless gear range.
Durability There are many factors that can lower durability.
-Change in the temperature of the hydraulic oil and its pollution
-Shortage of oil quantity and pressure
-Leaks of pipes and packings
-Broken valves
-Foreign materials mixed
-Electric and electronic precise control
-Limitation of the lifetime of other consumables
Drop in the durability caused by load change

Gear teeth wear and impact wear
Having stable durability against load change, protecting the power source, and lengthening lifetime
Output adjustment Through the control valve
Impossible Auto adjustment without gear control
Prevention of reverse rotation Possible None Auto prevention of reverse rotation
Direction change Possible Possible Possible
Size Big Average Average
Noise Big Average Average
Type Hydraulic unit system GearedMotor, Linepower GearedMotor, Linepower
Mounting In unit Vertical , Horizontal Vertical , Horizontal
Structure Oil tank, Hydraulic pump, Control valve, Actuator, Others Gear Box + Power source
Gear Box
Gear Box + Power source
Gear Box
Management Management of operating oil, consumables, filters, and the whole system General management of gearbox General management of gearbox
Application Machinery industry Machinery industry Machinery industry
Development focus For vehicles For vehicles
All the mechanical factors
Variator Belt and variable pooley Traction tooler and toroidal Cam and Rod
Type of power transmission Frictional force of belt and variable pooley Shear force of the lubricant by the rolling contact of a body of rotation Gear power transmission by the change in the rod angle
Capacity of power transmission Low High High
Efficiency High High High
Gear ratio Restricted range Restricted range 0 ~ Infinity
Gear control Gear control through the control system Gear control through the control system Auto gear control in EST itself based on the change in the rpm of the power source and the change in the output load, without a gear control system
Size Average Big Average
Weight Average Big Average
Noise Average Low Low
Durability Average Low High