Technological breakthrough

Recently, the laboratory of the Wanxiang Qianchao Technology Center received good news from the Drive Shaft Company: the static spline wear testing technology for heavy-duty drive shafts with high torque has been successfully applied to the production verification of D-brand drive shafts. As one of the “9+N” customers of the Drive Shaft Company, the D brand has product standards that are significantly higher than those in China. The Drive Shaft Company has developed multiple series of drive shaft products specifically for this customer, with an anticipated annual sales volume of 38,000 units and sales revenue exceeding 40 million yuan, yielding remarkable economic benefits. The static spline wear testing rig for heavy-duty drive shafts, developed by the Technology Center, has enabled the Drive Shaft Company to successfully meet customer requirements and enter this supplier’s system for the first time, laying a solid foundation for future project development.

From the very beginning, when we “didn’t feel confident at all,” to numerous rounds of verification and revision, thanks to everyone’s joint efforts over more than half a year, we’ve finally achieved a breakthrough—reaching “zero” in this technological field—and are now seeing promising results. All our colleagues in the lab feel deeply gratified.

To ensure the smooth advancement of the product integration project, it is crucial to establish the capability for keyway wear testing. However, at the time, the Technology Center did not have any equipment capable of conducting keyway wear tests for this particular brand. After extensive research, we found that none of several domestic testing institutions met the required standards. With no local solutions available, should we consider importing equipment from abroad? Everyone made a rough estimate: from initial research to equipment delivery, the entire process would likely take two years—and the cost of imported equipment would be extremely high. To keep the project moving forward swiftly and smoothly and overcome this technical hurdle, Li Bohua, Deputy Manager of the Technology Center’s laboratory, resolved to lead his colleagues in tackling this “tough challenge” together.

Guided by the principle that “customer needs are our ultimate goal,” everyone worked together wholeheartedly to develop the design from scratch. Li Bohua admitted frankly that at first he felt somewhat uncertain, as there were no reference cases in this niche field within China. As the lead designer of the project, he could only “feel his way forward, step by step.” It was precisely his many years of industry experience that gave him the confidence to take bold design initiatives. Since joining Wanxiang in 1998 and dedicating over two decades to the field of experimental technology, Li Bohua has witnessed Wanxiang’s journey—from importing technologies from abroad to engaging in exchanges and learning from others, and finally to independent R&D. With the continuous strengthening of its talent pipeline and the ongoing upgrading of its collaborative clients, Wanxiang has provided a broad platform for technical professionals to showcase their abilities and continuously improve themselves. This is not the first independently developed project that he and his colleagues have undertaken; each R&D endeavor has allowed them to accumulate valuable experience, making them increasingly mature and confident. Before finalizing the conceptual framework, the spline experiment team thoroughly reviewed extensive domestic and international literature and actively engaged in exchanges with equipment suppliers and manufacturers in the industry, ultimately arriving at a well-structured approach.

Once the overall direction has been established, every single detail—no matter how minor—becomes critically important for successful implementation. During the testing phase, there were numerous possible approaches for applying torque and for generating axial thrust through shaft extension and contraction. After extensive comparisons among various options, the project team decided, in order to save costs, to pursue an independently developed solution: using a vertical actuator cylinder to apply force at the lever arm, thereby inducing radial torque in the transmission shaft. For this particular project, the experimental conditions for spline wear required both torque and axial push-pull forces. However, since the shaft was movable, it proved extremely challenging to coordinate these two forces simultaneously. After repeated adjustments and creative problem-solving, the team ingeniously introduced a sliding-stage mechanism that perfectly balanced the two experimental requirements. Thus, the prototype of the independently developed static spline wear test bench for heavy-duty transmission shafts began to take shape.

From initially proposing the concept from scratch to finally bringing the project to fruition, the process involved numerous rounds of repeated debugging—constantly identifying and resolving issues along the way. Although the equipment design had taken shape, minor problems kept cropping up. In the experiments, how could we accurately measure and determine the magnitude of torque? At first, Li Bohua planned to use a domestically produced torque sensor. After consulting with experts, he learned that domestic torque sensors have relatively low push-and-pull capacity, making this approach unfeasible. The project team then explored the possibility of procuring imported instruments. While imported sensors did meet the theoretical calculation range for push-and-pull force, their price exceeded 100,000 yuan, making them prohibitively expensive. Later, drawing on collective wisdom, the team came up with an ingenious solution: by using the formula relating lever arm and applied force, they were able to calculate the torque magnitude directly, thereby smoothly overcoming the challenge.

During the phased testing, the project team discovered that, when the test conditions were carried out according to the customer’s requirements, the product’s service life was significantly shorter than expected. At first, the team suspected there might be a problem with the equipment itself; however, after multiple adjustments and tests, they confirmed that the equipment was functioning properly. After several rounds of meetings and discussions, and having ruled out various potential interfering factors, the team pinpointed the root cause as being related to temperature control. Verification revealed that the wear life of the splines was closely linked to temperature—a critical factor that the customer had not previously noticed. Creatively, the project team added an air-cooling system to the original equipment, thereby making the entire setup even more robust and complete.

This R&D effort, which took seven months to complete, has successfully overcome key technical hurdles, providing crucial support for the implementation of the drive shaft project and enabling Wanxiang products to enter the supplier system of Brand D for the first time. Li Bohua, the project’s chief leader, said: “It’s incredibly rewarding to see our ideas come to life. Despite the challenges we’ve faced, we’ve worked closely together, continuously pushing the boundaries of our technical capabilities. Contributing to the company’s market expansion and strengthening its core competencies is our shared mission. We’ll stay true to our original aspirations and keep striving forward!”