Backlash Calculations pg 2
| TABLE 3.2 BACKLASH EXAMPLE CALCULATIONS | |||||||||
| Maximum Backlash (Radial Value) | |||||||||
| Mesh 1 | Mesh 2 | Mesh 3 | Mesh 4 | ||||||
| Backlash Source | Design Data: | Gear | Pinion | Gear | Pinion | Gear | Pinion | Gear | Com- ponenet Pinion |
| Shaft No. Pitch Dia. |
S-1 3.333 |
S-2 .4167 |
S-2 1.250 |
S-3 .2812 |
S-3 1.250 |
S-4 .2656 |
S-4 .9375 |
S-5 .1562 |
|
| Group I. Design Backlash Allowance *1. Center Distance allowance 2. Gear size allowance |
0 0 |
- 0 |
0 0 |
- 0 |
0 .0005 |
- .0005 |
0 .0005 |
- .0005 |
|
| Group II. Major Tolerance *1. Center distance 2. Gear size |
.001 .0007 |
- .0007 |
.002 .0012 |
- .0012 |
.002 .0015 |
- .0015 |
.002 .0015 |
- .0011 |
|
| Group III. Secondary Sources 1. Fixed - bearing eccentricities: a. Ball-bearing fixed race b. Sleeve - bearing runout 2. Radial clearances: a. Ball - bearing radial play. b. Clearance: Shaft and bearing bore (1) Shaft diameter tolerance (2) Bearing bore tolerance (3) Allowance c. Clearance: Bearing OD and housing bore (1) Bearing OD tolerance (2) Housing bore diameter tolerance. (3) Allowance 3. Component error sources: a. Clearance: component mounting (1) Component - mounting pilot dia. tolerance. (2) Housing - mounting bore dia. tolerance (3) Allowance b. Component's mounting pilot eccentricity c. Component mounting pilot flatness and perpendicularity. d. Component shaft radial play |
|
.0001 .0003 .0001 .0001 .00005 .0001 .00015 0 |
.0001 .0003 .0001 .0001 .00005 .0001 .00015 0 |
.0001 .0003 .0001 .0001 .00005 .0001 .00015 0 |
.0001 .0003 .0001 .0001 .00005 .0001 .00015 0 |
.0001 .0003 .0001 .0001 .00005 .0001 .00015 0 |
.0001 .0003 .0001 .0001 .00005 .0001 .00015 0 |
.00025 .00025 .00015 .0005 .0005 |
|
| Group IV. Sources Variable with Rotation (one - half total value) 1. Total composite error a. Runout b. Tooth-to-tooth composite 2. Clearance: Gear mounting to shaft a. Gear bore diameter tolerance b. Shaft diameter tolerance c. Allowance 3. Shaft runout at gear mounting 4. Ball - bearing rotating - race eccentricity 5. Miscellaneous runouts a. Component shaft b. Composite gear assembly 6. Other Sources |
.00015 .0001 .00005 .0001 .0001 |
.00015 .0001 .00005 .0001 .0001 |
.00015 .0001 .00005 .0001 .0001 |
.0001 |
.00015 .0001 .00005 .0001 .0001 |
.0001 |
.00015 .0001 .00005 .0001 .0001 |
||
| Group V. Miscellaneous Sources 1. Thermal 2. Deflections 3. Other sources |
|||||||||
Sub - Total |
.0031 | .0021 | .0046 | .002 | .0054 | .0030 | .0054 | .00325 | |
Mesh Total |
.0052 | .0068 | .0084 | .00865 | |||||
*These are values for a pair and are arbitrarily put into gear columns.
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