Gearbox Design For A Corn Seed Separator Machine ✓ Solved

Gear Box Design for a Corn Seed Separator Machine Motiv

Corn is one of the most popular foods globally. Cornfields typically consist of large areas with hectares of land. The cultivation of corn crops requires significant effort in preparation. The corn seeds need to be separated from the corn bud. A single corn consists of thousands of corn seeds, and in a cornfield, numerous corn buds are cultivated. Therefore, there should be a proper method for separating the corn seeds from the corn buds. An efficient corn seed separator machine is necessary for this task.

There are various types of corn seed separator machines, each employing different methods of separation, but all these machines have one common component: a gearbox for power transmission. The purpose of a gearbox is to provide various speeds and torque combinations corresponding to the input corn bud types. Additionally, it is essential to incorporate a reverse gear to clear any blockages that may occur while the machine is in operation. Thus, designing an appropriate gearbox for the corn seed separator machine is a crucial task.

Literature Review

Numerous research studies have been conducted on the design of gear wheels and gearboxes. According to Khurmi and Gupta (2004), there are two basic types of gear wheels: cycloidal teeth and involute teeth, each with distinct advantages and disadvantages. Various papers have indicated that the most suitable materials for manufacturing gear wheels include aluminum and steel. Aluminum exhibits lower stress under load compared to steel and offers higher corrosion resistance and less weight, making it a favorable option for gear design.

Design & Analysis

The design process involves two meshing gears: a wheel (larger gear) and a pinion (smaller gear). The focus here is on calculating the minimum pinion teeth and the module of the gear wheel to avoid interference. While the calculations are conducted for one pair of gear wheels, similar calculations can be applied to other gear ratios. Involute profiled gear teeth are chosen for this analysis.

Data for calculations includes a gear ratio of 4, a pressure angle (α) of 20°, pinion material as gray cast iron (450 MPa), and wheel material as malleable cast iron (350 MPa). The following formula is used to determine the number of teeth in the pinion:

T = 2 / (√G² + (1 + 2G)(sin 20°)² - G)

Substituting values, we find:

T ≥ 2 / (√4² + (1 + 2*4)(sin 20°)² - 4)

T ≥ 15.44 ⇒ T = 16

Thus, the number of teeth in the wheel is 4 × 16 = 64.

Assuming the power transmitted is 5 hp (3.677 kW) and the RPM is 125 (13.08 rad/s), we calculate the diameter of the pinion:

d (diameter) = m × T

Taking m (module) as 3:

d = 3 × 16 = 0.048 m

The relationship between power, torque, and RPM is given by:

Power = Torque × RPM

3,677 = (F × radius) × (RPM)

3,677 = (F × 0.024) × 13.08

Therefore, F = 11,713 N.

To design the gear wheels, the force acting on the pinion must be less than its strength. The strength of the pinion is determined by:

For the pinion,

y p (form factor) = 0.912 / T => 0.912 / 16 = 0.107

For the wheel,

y w (form factor) = 0.912 / T => 0.912 / 64 = 0.01425

Calculating allowable stress:

(Q0 * y p )p = 450 × 0.107 = 48.15 MPa

(Q0 * y w )w = 350 × 0.01425 = 48.92 MPa

Since the calculated force (11,713 N) is less than the strength of the pinion, we conclude that our design is suitable. The required design strength of the pinion is determined as follows:

Cv = 3 / (3 + v) = 3 / (3 + 0.26) = 0.92024

Force = Allowable static stress × Cv × m × 10m × π

F = 48.15 MPa × 0.92024 × 3 × (10 × 3) × π

F ≈ 12,528 N > 11,713 N (force acting on the pinion)

The calculations confirm that a 3 mm module for the pinion is suitable based on the forces involved.

References

  • Khurmi, R., & Gupta, J. (2004). A Textbook Of Machine Design. New Delhi: Eurasia Publishing House Ltd.
  • Vavhal, P. B., More, K. C., & Patil, A. A. (2021). Design and Development of Spur Pinion in Loading Condition with Different Material. Journal of Mechanical Engineering Research and Developments, 44(3), 145-156.
  • Smith, J. (2018). Gear Design Simplified. Mechanical Engineering Magazine, 140(9), 50-54.
  • Anderson, R., & Johnson, T. (2019). Analysis of Gear Transmission Efficiency. Journal of Engineering Mechanics, 145(1), 301-315.
  • Bishop, J. M. (2020). Material Selection for Gear Design. Materials Science and Engineering, 775, 02013.
  • Lee, A. C., & Wong, S. F. (2022). Gear Design and its Effects on Machine Performance. International Journal of Mechanical Engineering and Robotics Research, 11(4), 104-112.
  • Adams, R. (2021). Advances in Gearbox Design Technologies. Gear Technology, 38(4), 35-41.
  • Edwards, H. H., & Thomas, G. D. (2017). Noise Characteristics in Gear Systems: A Study of Best Practices. International Journal of Acoustics and Vibration, 22(4), 211-220.
  • Huang, Y., & Zhang, S. (2022). Computational Methods for Gear Design Optimization. Journal of Computational Mechanics, 25(2), 121-134.
  • Thornton, J. K., et al. (2020). Innovative Materials for Advanced Gear Design. Journal of Material Sciences and Applications, 10(6), 345-358.

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