How to Selection Harmonic Reduction Gear?

This article explains how to select harmonic reduction gears based on specific equipment, covering aspects such as average load torque, input speed, start-stop peak torque, comparison of impact torque, permissible number of impact torque cycles, and service life. It concludes with a mention of Honpine's star products, harmonic reduction gears.

What are the steps for selecting a Harmonic Reduction Gear?

1. Confirm the core operating parameters of the equipment.

The load torque mode (referring to the relationship between load torque and output speed over time in a complete working cycle) is the basis for selection calculation. It clarifies the torque and speed requirements of the equipment at each stage. The specific mode is shown in the figure below.

Based on the diagram, assume the following equipment operating parameters are used: Normal operating mode

At startup:

T1＝150N·m t1＝0.2sec n1＝10 r/min

At constant speed:

T2＝82N·m t2＝3sec n2＝20 r/min

At stop (deceleration):

T3＝130N·m t3＝0.3sec n3＝10 r/min

At shutdown:

T4＝0 N·m t4＝0.2sec n4＝0 r/min

Maximum speed (limited by motor, etc.)

Maximum output speed:

no max ＝ 20r/min

Maximum input speed:

ni max ＝ 2000r/min

Impact torque

When impact torque is applied:

Ts＝200N·m ts＝0.15sec ns＝20 r/min

2. Calculate the average load torque of the equipment to preliminarily verify the feasibility of the model.

The average load torque (Tav) is the equivalent continuous load borne by the equipment during its working cycle. It is directly related to the long-term heating and mechanical fatigue life of the reducer, and it must be ensured that it does not exceed the reducer's allowable value.

The calculation formula and process are as follows:

The calculation results show that Tav = 89 N·m, which is less than the maximum allowable average load torque of FSG-25 (140 N·m). Therefore, the initially selected model passes this verification step.

3,Calculate and compare whether the input speed is within the allowable range of the reducer.

The input speed (including average and peak values) must be strictly controlled within the rated range of the reducer. Exceeding the speed limit will lead to abnormal temperature rise and accelerated gear meshing wear, thereby directly shortening the service life.

The average and maximum input speeds were within limits; the verification passed.

4. Compare whether the peak torque during start-up and stop is within the reducer's allowable range.

The peak torque during start-up and stop is a periodic load; it is necessary to verify whether the reducer's structural strength can withstand it to avoid damage caused by long-term impact.

The peak torque during start-up and shutdown did not exceed the limits, and the verification was successful.

5,Check if the impact torque is within the reducer's allowable range.

Impact torque is a sudden, extreme overload that may occur during equipment operation. Due to emergency stops or external, unpredictable impacts, a relatively large load torque may be applied to the reducer. When the reducer is subjected to torque reaching its instantaneous maximum allowable torque, it will cause irreversible damage. Therefore, it is necessary to ensure that the impact torque does not exceed the reducer's instantaneous load limit.

6,The impact torque did not exceed the limit; the verification passed.

Calculate and determine whether the permissible number of impact torque applications meets the requirements.

The permissible number of applications (Ns) needs to be calculated based on the output speed ns and the application time ts under the impact torque, and it needs to be confirmed that this limit meets the usage conditions.

The allowed number of times must be limited to 1000, which does not exceed the limit of 1.0 × 10⁴ (redirects), meeting the design and usage requirements, and the verification has been passed.

7,Calculate and compare whether the service life exceeds that of the wave generator.

The overall service life (Lh) of the harmonic reducer is usually determined by the service life (Ln) of the wave generator bearings. Ln is generally determined using the general rated service life standard L10 for bearings (10,000 hours in this example). That is:

8. Calculated value = 10638 ≥ 10000h (L10 lifespan), verification passed.

After the above seven verification steps, the FSG-25-100-I-E model meets the equipment operating conditions and usage requirements in terms of load, speed, and lifespan under simulated equipment operating conditions, and this model can be finally selected.

What are some of HONPINE's star products in the harmonic drive reducer category?

Hollow Shaft Harmonic Drive Reducer

The large central through-hole design allows for easy passage of cables, air tubes, optical fibers, or mechanical shafts, simplifying wiring. Suitable for collaborative robots, medical surgical robots, and industrial automation turntables.

Ultra Thin Pancake Harmonic Drive Reducer

The ultra-thin design helps improve the dynamic response speed of the entire device. It is commonly used in robot joints, gimbal systems, and medical exoskeletons.

Cup Shape Harmonic Gerbox with Cross Slider

The cross-slider mechanism enhances the mechanism's ability to absorb load impacts and improves transmission smoothness. It is suitable for equipment with high stability requirements, such as precision CNC machine tools.

Cup Shape Miniature Harmonic Gearbox

It can provide stable high torque output in small spaces, making it suitable for space-constrained mechanical equipment, such as sewer robots.