In depth analysis of the principle, parameters, and selection guide of SH basic type three ring reducer

In industrial transmission selection, the adaptability of the reducer directly determines the operating efficiency and service life of the equipment. As the core product of YB/T79-1995 standard, the SH basic type three ring reducer (referred to as SH type) has become the preferred choice for heavy-duty and high-efficiency transmission scenarios with its unique "parallel axis dynamic axis" transmission principle. This article deeply disassembles it from three aspects: principle, parameters, and selection.

1、 Working principle: minimal tooth difference meshing, efficient power transmission

SH type belongs to the category of planetary transmission with few tooth differences, which combines the dual characteristics of parallel axis cylindrical gear reducer and planetary reducer. The power is input by two high-speed shafts, which drive three internal gear ring plates to perform eccentric planar motion. The internal gear ring of the ring plate forms a multi tooth mesh with the external gear of the low-speed shaft, and the large transmission ratio reduction is achieved through the principle of less tooth difference. The power is ultimately output by the low-speed shaft. Two high-speed shafts can input power separately or simultaneously, suitable for multi-source power scenarios.

2、 Core parameters: Accurate matching, covering all operating conditions requirements

The parameter system of SH basic type three ring reducer is complete, and the core parameters are as follows:

Model specifications: Center distance of 80-1070mm, covering the entire series of models such as SH110-SH1200;

Transmission ratio: single-stage 11, 15, 21, 25, 33, 45, 55, 64, 75, 88, 99, with dense grading;

Output torque: 0.124-469KN · m, suitable for all scenarios from light load to heavy load;

Input speed: High speed shaft ≤ 1500r/min, suitable for conventional motor speed;

Installation form: Horizontal seat installation, supporting 23 assembly types, suitable for different installation spaces.

3、 Selection points: Four dimensions to avoid selection errors

1. Condition matching: SH type is preferred for heavy-duty impact and continuous operation scenarios; The key focus of space constrained working conditions is on their advantages of "small size and light weight".

2. Torque calculation: Select based on the maximum load torque of the equipment multiplied by a safety factor of 1.2, ensuring that the instantaneous overload does not exceed 2.7 times the rated torque.

3. Speed adaptation: Input speed ≤ 1500r/min. If it exceeds the range, a variable frequency speed control device should be equipped to avoid high-speed wear.

4. Environmental adaptation: Lubricating oil needs to be preheated for low temperature (<0 ℃) environments, heat dissipation needs to be strengthened for high temperature environments, and sealing protection should be done for humid and dusty environments.

4、 Compared with traditional reducers: clear advantages at a glance

The SH basic three ring reducer, with its innovative principles and parameter advantages, breaks the performance limitations of traditional reducers and is the "king of cost-effectiveness" in industrial transmission selection.