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| Illustration 1 | g00880647 |
Final drive (1) Travel motor (2) Shaft (3) Casing (4) Gear (5) Drive gear (6) Hub (7) Gear | |
The final drive reduces the rotational speed of travel motor (1). Input gear (5) of the travel drive is splined to shaft (2) of the motor. When the motor rotates, input gear (5) is driven by shaft (2) .
In the final drive, the gear reduction has two stages. These stages are the first stage reduction and the second stage reduction. The two stages reduce the high rotary motion of the motor and the two stages attain the high torque that is required for rotation of the hub (6) .
Gear Reduction
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| Illustration 2 | g00880657 |
Schematic of the gear train (1) Ring gear (2) Planetary gear (3) Drive gear (4) Second stage sun gear (5) Planetary gear (6) Second stage planetary carrier | |
Drive gear (3) is meshed with planetary gear (2). Also, second stage sun gear (4) is meshed with planetary gear (5) .
Second stage planetary carrier (6) is fixed to the frame of the machine. Planetary gear (2) and planetary gear (5) are meshed with ring gear (1) .
The travel motor transmits power to drive gear (3). The gears reduce the rotational speed of the travel motor. The drive power is transmitted to ring gear (1) through planetary gear (5) of final reduction planetary carrier (6). A part of the drive power is also transmitted to ring gear (1) from first stage planetary gear (2). As a result, the rotational direction of the output side is reversed to the input side.
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| Illustration 3 | g00880731 |
Set of equations (A) Overall reduction ratio (B) First stage reduction (C) Second stage reduction (D) Output rotation | |
Use the above equations in order to calculate the overall reduction ratio and the output rotation. The variables are given in table 1.
| Definition of Variables | |
| Z1 | Number of teeth in drive gear |
| Z3 | Number of teeth in ring gear |
| Z4 | Number of teeth in sun gear |
| Z6 | Number of teeth in ring gear |
| N1 | Input speed (speed of the motor's output) |