In 2018, a customer who was a government engineer contacted us to develop a new lock for the government. They had already built a prototype lock and tested several different types of DC gear motors, both locally and abroad, but were not satisfied with the results.
Upon evaluating their specifications, we found them to be clear and precise. The customer was looking for two torque values: 34kg.cm and 69kg.cm. Since the motors would stall in most locks, we were concerned whether the motors would stall in the customer’s new lock design. After learning that the customer had sensors in their locks to prevent gear motors from stalling, we recommended HT-WOG58C worm gear motors after conducting a thorough assessment. We customized samples and sent them to the customer for field testing.
After 25k duty cycles, we received feedback from the customer that one compound gear had broken, which seemed unreasonable and should not have happened. Upon double-checking with the customer, we found that they had removed the sensors and adopted current limitation to prevent stalling in their design, and the motors had to stall for 0.5-1s. As the gear motors were used to retract the bolt and only required a 60° run in one direction and back in the other, only a few teeth of the compound gear wore down.
Before offering a new solution to the customer, we helped them work out that the real torque required in their lock was only 18kg.cm, which was much lower than what they had consulted. Subsequently, we introduced a smaller and cheaper gear motor, the HT-WOG58B, to the customer, with a compound gear made of 45# steel instead of free-cutting steel.
The samples passed the customer’s tests smoothly, and even the lifetime goal was expanded from 100k to 500k. The lock has been in mass production for US government projects.
In summary, we were able to help our customer optimize their lock design by providing a more suitable motor solution, and ultimately help them achieve their project goals.
