Features
Excavator reduction gear consists of spur gear (- -stage reduction) and differential gear (two-stage reduction). It reduces high rotation speed, increases the torque output of the hydraulic motor and turns the gearbox.
(2) Operating principle ①-stage deceleration. In Figure 1-72, the rotary motion of the hydraulic motor is delivered to the input gear of the -stage reduction.
Then, the three spur gears mesh with the input gear to gradually reduce the rotation speed. The formula for calculating the gear ratio for first-stage reduction is:
In the formula, Zi refers to the number of teeth of the input gear; Zs refers to the number of teeth of the spur gear.
②Two-stage deceleration. The three spur gears are connected to three crankshafts, which are input by the two-stage reduction gear.
RV gears A and B are mounted on the eccentric crankshaft through bearings. As shown in Figure 1-73, according to the rotation of the crankshaft, the RV gears A and B rotate with the pin gear in the hub. The operation comparison is shown in Figure 1-74. Because these crankshafts are supported by the mandrel, the hub rotates while decelerating. The formula for calculating the gear ratio of the two-stage reduction is:
In the formula, Z refers to the number of pin shafts: ZR refers to the number of RV gear teeth.
The calculation formula of the total gear ratio of the reduction gear is:
