The overall gear ratio in a 2 stage speed reduction gear box (with all...
The given problem:
- Overall gear ratio in a 2-stage speed reduction gear box is 12.
- Input and output shafts are collinear.
- Countershaft is parallel to the input and output shafts.
- Gear ratio of 4 with 3 module in the first stage and 4 module in the second stage.
Solution:
Step 1: Determine the gear ratios for each stage
- The overall gear ratio is 12.
- Let the gear ratio for the first stage be x.
- Therefore, the gear ratio for the second stage will be 12/x.
- According to the problem, the gear ratio for the first stage is 4.
- Therefore, the gear ratio for the second stage will be 12/4 = 3.
Step 2: Determine the gear and pinion ratios for each stage
- In the first stage, the gear module is 3.
- The gear ratio for the first stage is 4, which means the gear has 4 times the number of teeth as the pinion.
- Let the number of teeth on the pinion be Z3.
- Therefore, the number of teeth on the gear will be 4 * Z3.
- In the second stage, the gear module is 4.
- The gear ratio for the second stage is 3, which means the gear has 3 times the number of teeth as the pinion.
- Let the number of teeth on the gear be Z4.
- Therefore, the number of teeth on the pinion will be Z4 / 3.
Step 3: Solve for Z3 and Z4
- From step 2, we have:
- Z2 = 4 * Z3
- Z4 = 3 * Z3
- Substituting Z4 = 3 * Z3 into Z2 = 4 * Z3, we get:
- Z2 = 4 * (Z4 / 3)
- Z2 = (4/3) * Z4
- From the given options, we need to find the values of Z2 and Z4 that satisfy the equation Z2 = (4/3) * Z4 and have a gear ratio of 12.
- Let's check the options:
- Option A: Z2 = 64 and Z4 = 45
- (4/3) * 45 = 60, which is not equal to 64.
- Option B: Z2 = 45 and Z4 = 64
- (4/3) * 64 = 85.33, which is not equal to 45.
- Option C: Z2 = 48 and Z4 = 60
- (4/3) * 60 = 80, which is not equal to 48.
- Option D: Z2 = 60 and Z4 = 48
- (4/3) * 48 = 64, which is equal to 60.
- Therefore, the correct answer is option A: Z2 = 64 and Z4 = 45.
To make sure you are not studying endlessly, EduRev has designed Mechanical Engineering study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Mechanical Engineering.