I am very satisfied with the services. Happy to create long term business relationship with your company.
—— Ashley Scott---USA
Thanks for the good quality, good design with reasonable price
—— Anna Diop---United Kingdom
I'm Online Chat Now
Company News
Parallel Shaft Gear Transmission in Gear Drive: A Comprehensive Explanation
Overview
Gear transmission is one of the most prevalent methods in mechanical engineering, boasting high efficiency, stable transmission ratios, and strong load-carrying capacity. Among its variants, parallel shaft gear transmission is tailored for scenarios where two shafts are arranged in parallel, finding extensive applications in industrial equipment, automobiles, aerospace, and beyond. This guide elaborates on its working principles, design methodologies, and engineering applications, serving as a practical reference for professionals.
1. Working Principles of Parallel Shaft Gear Transmission
1.1 Basic Transmission Mechanism
Parallel shaft gear transmission relies on the meshing of two gears with parallel axes to transfer motion and power. Common types of parallel shaft gears include:
Spur Gear: Teeth are parallel to the gear axis, featuring a simple structure. Ideal for low-speed, light-load applications.
Helical Gear: Teeth are helically shaped, ensuring smoother meshing and higher load capacity. Suitable for high-speed, heavy-load transmission.
Double Helical/Herringbone Gear: Consists of two symmetric helical gear rows, offsetting axial forces. Used in heavy-load, precision transmission systems.
Meshing Requirements:
Identical module (m)
Identical pressure angle (α)
Advantages
Disadvantages
High efficiency (up to 98%)
High manufacturing precision requirements
Constant transmission ratio
Vibration and noise (more pronounced in spur gears)
Strong load-carrying capacity
Requires precise lubrication
1.2 Transmission Ratio Calculation
The transmission ratio i is defined as the ratio of input speed to output speed:(i = frac{n_1}{n_2} = frac{z_2}{z_1}) Where:
(n_1, n_2) = input and output speeds (r/min)
(z_1, z_2) = number of teeth on driving and driven gears
For multi-stage transmission, the total ratio is the product of individual stage ratios:(i_{text{total}} = i_1 times i_2 times dots times i_n)
2. Key Design Parameters and Calculations
2.1 Basic Gear Parameters
Module (m) Selection: Estimated using torque and speed:(m geq sqrt[3]{frac{2000T}{psi_d z_1 [sigma_F]}}) Where:
T = torque (N·m)
(psi_d) = tooth width factor
(z_1) = number of teeth on the pinion
([sigma_F]) = allowable bending stress (MPa)
Preferred standard modules: 1, 1.25, 1.5, 2, ..., 18 (mm).
Tooth Count Determination:
Closed transmission: Pinion teeth = 20–40
Open transmission: Pinion teeth ≥ 17
Minimum teeth to avoid undercutting: (z_{text{min}} = frac{2}{sin^2 alpha}); for (alpha = 20^circ), (z_{text{min}} = 17).
Transmission Ratio Distribution: For multi-stage systems, follow the "small first, large later" principle. Adjacent stage ratios should range from 1.3 to 1.5.