Gearbox selection

Several coefficients that need to be considered during the selection of a reducer: 1. Operating condition coefficient; 2. Safety factor; 3. Ambient temperature coefficient; 4. Load rate coefficient; 5. Nominal power utilization coefficient. The parameters that users need to provide include: motor power, motor speed, required power, speed of the machine connected to the reducer, daily operating hours, operating environment, and temperature. The steps for selecting a reducer are as follows: 1. Determine the reduction ratio of the reducer, using the formula: motor speed/workpiece speed; select a nominal reduction ratio that is close to the value required by the user. 2. Determine the nominal input power of the reducer. The calculated power of the reducer = the power required by the machine connected to the reducer * the operating condition coefficient of the machine * the safety factor. The nominal input power is greater than or equal to the calculated power. The operating condition coefficients and safety factors that appear in the formula must be obtained by referring to the specifications for each series of reducers. After calculating the power, the corresponding table is consulted to determine the nominal input power, thereby establishing the nominal center distance of the reducer. 3. Verify the starting torque: The nominal input power must be greater than or equal to (motor’s rated torque * input speed * peak torque coefficient) / 9550. 4. Check whether the thermal power of the reducer can be managed; thermal power = load power * ambient temperature coefficient * load power coefficient * nominal power utilization factor, and this value must be less than or equal to the reducer’s power (in the absence of any cooling measures). For cylindrical gear reducers, only when disc-cooled is used does the calculated power of the reducer (either with disc-cooling or circulating oil lubrication) exceed the thermal power. Therefore, the available model of reducer features oil bath lubrication, with disc-shaped water pipes used to circulate water for cooling the lubricating oil. If disc-coil cooling is not used, a larger-sized reducer must be selected. Based on the principle of transmission, reducers can be divided into two main categories: conventional reducers and planetary reducers. Those that use a fixed-axis gear train for transmission are referred to as conventional reducers, while those that utilize a planetary gear train are called planetary reducers ； Based on the type of gear transmission, they can be classified into: worm gear reducers, spur gear reducers, bevel gear reducers, worm-spur gear reducers, etc ； Based on the number of transmission stages, they can be classified into two-stage reducers, single-stage reducers, and multi-stage reducers ； Based on the gear arrangement, they can be classified into three types: coaxial type, split type, and extended type ； Based on the installation method, they can be divided into horizontal and vertical types. Based on the casting type, it can be divided into cast iron type and aluminum alloy type. Reducers are typically installed between the prime mover of a machine and the working machine; their main function is to reduce speed and increase torque to meet the requirements of the operation. In some cases, reducers can also be used to increase rotational speed, and in such situations they are referred to as speed increase gears.

Today, I heard from the supplier that the rotational speed of the cycloidal type is below 30 revolutions per minute

The speed of reducers using planetary cycloids is even lower; those with gear reduction can also reach a few revolutions per minute. Motors with high power, such as 55 KW models, can achieve a minimum speed of 80 revolutions per minute

It is recommended that the original poster download a gearbox manual to take a look; moreover, the most important factor when choosing a gearbox is the application scenario.