Selecting a speed reducer is a required course for all mechanical design engineers. Therefore, we will introduce the key considerations for speed reducer selection based on the speed reducer selection guide.
In selecting a speed reducer, we need to pay special attention to the selection and calculation of the following parameters: A. Calculate the torque of the speed reducer's output shaft. B. Calculate the maximum speed of the transmission mechanism. C. Select the installation method of the transmission mechanism. D. Select the transmission accuracy of the speed reducer. F. Configure the speed reducer interface. Next, we will introduce the selection criteria and methods of speed reducers in detail from the above aspects.
1. Calculation of reducer output shaft torque
The output torque of a speed reducer is the torque required by the transmission mechanism. The purpose of selecting a speed reducer is to obtain the motor's rated torque (i.e., minimize cost) + speed reducer (increased torque) = greater torque output.
In fact, the application of speed reducers in mechanical structures has many advantages, such as increasing torque, reducing inertia, reducing the impact of the electric motor on the servo motor, and automatically locking the electric motor.
Of course, its core value is to increase torque. Therefore, when determining the torque required by the drive mechanism, the torque of the selected servo motor is compared. The ratio of the two torques is the reduction ratio of the selected reducer. Generally, we allow some redundancy in the final torque of the mechanism, so the transmission ratio will be slightly higher. Oops.
Therefore, the required final torque and the rated torque of the servo motor are very important in this process. Only by knowing these two parameters can the reduction ratio of the selected geared motor be determined.
2. Calculate the maximum speed of the motor.
The maximum speed of the transmission mechanism must be confirmed by the mechanical design engineer. Because the parameters are related to the selection of the reduction ratio, the reduction ratio cannot necessarily be increased indefinitely. A larger reduction ratio results in greater torque but lower output speed, thus affecting the overall operating speed of the motor.
Therefore, a balance between torque and speed is needed. Under the premise of meeting the transmission speed of the mechanical mechanism, it is a reasonable choice to increase the reduction ratio and increase the transmission torque as much as possible.
Of course, the transmission speed of the transmission mechanism is not entirely determined by the reducer. The speed of the servo motor, the pitch of the drive screw, and the size of the gear are decisive factors. Therefore, we need to take them into consideration when designing the structure. However, the size of the reduction ratio is also a decisive factor that needs our attention.
3. Selection of installation method for transmission mechanism
In addition to the parameters mentioned above, the selection of a speed reducer should also include the type and installation method of the speed reducer, such as planetary speed reducer, worm gear speed reducer, coaxial direct connection speed reducer, or 90° vertical mounting speed reducer.
In particular, the selection of worm gear reducers is influenced by specific application scenarios. For example, the entire actuating mechanism may require locking. We often have such design requirements. For instance, the transmission device may be vertically mounted. To prevent the mechanism from falling off after a power outage, a worm gear reducer is typically chosen.
Therefore, choosing the right installation method is important, rather than choosing it arbitrarily.
4. Selection of reducer transmission accuracy
The transmission accuracy of a speed reducer depends entirely on the accuracy requirements of your designed transmission mechanism. Of course, as long as the corresponding parameters are matched according to the function, the actual cost will be higher, which is often unacceptable. This is especially true for some good brands, which are often unavailable.
5. Reducer Interface Configuration
When selecting a reducer, two reducer interfaces need to be defined through the seat. At the same time, the structure and appearance of the reducer must meet the requirements of the equipment and be able to connect with the selected servo motor.
Servo motor interface. The reducer manufacturer will customize the reducer interface based on the servo motor interface selected by the customer. Therefore, when communicating with the reducer supplier, you need to provide them with the servo motor interface information.
Generally, we select the output interface of the reducer according to the reducer supplier's standards, unless you have special requirements.
Since all customizations incur costs, we must consider costs during the design process and try to purchase standard products from suppliers unless it is mandatory.
