PLANETARY GEAR BOX
| 1. |
General Information |
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1.1 |
Introduction |
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1.2 |
Construction |
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1.3 |
Special Features |
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1.4 |
Nomenclature |
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Foot Hollow
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Flange Hollow |
| 2. |
Technical Information |
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2.1 |
Radial (Overhung) Load Rating |
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2.2 |
Axial Load Capacity |
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2.3 |
Thermal Rating & Hollow I/p Sizes |
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2.4 |
Efficiency |
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2.5 |
Service Factor |
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2.6 |
Mounting |
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2.7 |
Input |
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2.8 |
Output |
| 3. |
Selection Procedure |
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3.1 |
Selection based on HP & RPM |
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3.2 |
Selection based on Torque |
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3.3 |
Selection examples |
| 4. |
Selection Chart |
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4.1 |
Selection chart based on HP & RPM |
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4.2 |
Selection based on Torque |
| 5. |
Dimensional Details |
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5.1 |
Dimensional details of Foot Mounted Units |
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5.2 |
Dimensional details of Flange Mounted Units |
| 6. |
Installation & Maintenance |
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6.1 |
Delivery Conditions |
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6.2 |
Installation Guidelines |
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6.3 |
Commissioning |
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6.4 |
Maintenance |
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6.5 |
Lubrication |
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| 1. |
General Information |
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| 1.2 |
Construction |
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Planetary gear box works on planetary motion principle. Each stage of the planetary gear box consists of a central Sun Gear meshing with accurately positioned three Planet Gears around it which in turn mesh with the internal teeth of the outer Ring Gear. Normally, the Ring gear is stationary & forms the part of the housing, input is given to the sun gear & output is derived from the three planet gears through a planet carrier. However, out of these three members any one can be held stationary, second is driven by input and the output can be derived from the third member. Due to this flexibility, planetary gear boxes have a large variety and innumerable applications. As total load is shared by three planets, the torque handling capacity of this type of gear box is very high compared to all other types of gear boxes. Hence, in all high torque applications, planetary gear box is the only economical solution and is most preferred worldwide. It also gives the highest weight /volume ratio i.e. in a given space, this type of gear box can handle the highest torque |
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| 1.3 |
Special Features |
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| 1) |
All shafts are made of special alloy steel and are hardened and tempered. |
| 2) |
Sun and Planet gears are made of case
carburizing alloy steel & are case carburized and ground. |
| 3) |
The Ring Gear is made of forged alloy steel. |
| 4) |
Full complimentary roller bearing for planets. (except for Model 019) |
| 5) |
Accurate positioning of planets and hence, best load sharing. |
| 6) |
Good quality bearings for input and output shafts. |
| 7) |
High efficiency |
| 8) |
Low noise level |
| 9) |
No oil leakages |
| 10) |
Taper roller bearings on output shafts for bigger models |
| 11) |
Long and trouble free performance |
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| 1.4 |
Nomenclature |
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Every gear box manufactured and supplied by us has got a specific code number and a unique serial
number. This combination of code number and serial number helps us in exactly identifying the unit supplied.
The code number of the gear box gives full information about the exact type of the gear box
The codification is done as under: |
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Example: FFB3206031.10 - This is a Foot Mounted Gear Box, Model 2060 i.e. 2
stage Model 060,
Ratio 31.10 : 1, with Free Solid Input Shaft, Mounted
Horizontally. |
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TABLE 1 - ORIENTATION |
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2 . |
Technical Information |
2.1 |
Radial (overhung) Load Rating |
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It is not necessary to check the overhang load on the Gear Box Shaft if the shaft is connected by a coupling to another shaft, which is separately supported on bearings. It is also not necessary to check the same for Hollow Input of our Gear Box which is meant for mounting the motor directly on the Gear Box. However, many a times, Gear Box input or output shafts are fitted with Pulleys, Sprockets, Gears etc. It is very important in such cases, to see that the actual overhang load on the shaft does not exceed the allowable overhang load of that particular gear box. The actual overhang load on the shaft can be calculated by the following formula : |
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F |
= |
(14052200 x P x Fc) / (D x N) |
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| where |
F |
= |
Actual Radial Load in N |
P |
= |
Power being Transmitted in HP |
Fc |
= |
Load Connection Factor (See Table 2) |
D |
= |
PCD for Pulley or Sprocket in mm |
N |
= |
Speed of shaft in RPM |
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Table 2 |
Table 2 |
| Type of Connection |
Fc |
| Sprocket or Timing Belt |
1.00 |
| Pinion or Gear |
1.25 |
| V Belt |
1.50 |
| Flat Belt |
2.50 |
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This Calculated Overhang Load should be less than the Allowable overhang Load Fa.
The allowable overhang load is directly related to the expected life in Working Hours. The recommended expected life values are given in Table 3. |
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Table 3 - Recommended Life Values |
| Type of Operation |
Examples |
Life in Working Hours |
| Infrequent |
Demo Units, Prototypes etc. |
500 |
| Brief Operation |
Hand Tools, Lifting Tackle, Domestic & Agricultural Machines etc |
4000 - 8000 |
| Intermittent Operation |
|
8000 - 12000 |
| One Shift operation |
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12000 - 30000 |
| Continuous Operation |
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30000 - 60000 |
| Continuous with High Production |
Power Plant Machinery, Mine Pumps, equipments with very high downtime cost. |
60000 - 100000 |
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Based on this expected life and the speed of the shaft, find Life Factor K from Table 4 given below. |
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The Allowable Overhang Load Fr is calculated by following formula : |
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|
| where |
Fr |
= |
Actual Radial Load in N. |
Fo |
= |
Radial Load capacity for the related model as per Table 5. |
K |
= |
Life Factor as per Table 3. |
Lf |
= |
Load Location factor (See Table 7). Depending on the Model & Position of the actual load, Dist. 'x' (at which you desire to calculate the radial load), see Fig.2, Select 'Lf'. |
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