Liuzhou AAM opts for electromechanical joining systems from Kistler to manufacture its components

Liuzhou AAM is an American-Chinese company that manufactures drive axles and components for both conventional and electric vehicles. Thanks to NC joining modules from Kistler, the engineers can achieve excellent product quality and maximum integration into the company's highly automated factory. The benefit: flexible and efficient production of a diverse range of parts.

The shift to electromobility is under way all over the world: in China, manufacturers as well as consumers have seen an acceleration in the pace of this transition since 2015, fully justifying the nation's claim to be an industrial pioneer. 'Use green energy and Chinese technology to move into the fast lane': this is the name of the agenda published by the government that encourages automobile manufacturers to focus more attention on innovative approaches. They are building smart factories, setting up platforms to bundle resources, and entering into joint ventures and partnerships.

Liuzhou Wuling Automobile is a leading automotive company based in the south of China; in 2018, it joined forces with American Axle & Manufacturing (AAM), a world-renowned supplier to the automotive industry, to launch a joint venture: Liuzhou AAM Automotive Driveline System Co., Ltd. (or Liuzhou AAM for short). The collaboration between these two industrial corporations aims to build up local expertise not only in R&D but also in the production of rear wheel drives, complete powertrains and transmission shafts.

Electromobility is surging ahead

Liuzhou AAM currently employs a 71-strong workforce. Production was initially launched with components for drive systems of fuel-powered vehicles, used in cars such as the Wuling Hongguang S3 and other vehicle types built by its customers. But the company's medium-term aims are not only to consolidate its production of core components for combustion engines but also to gradually expand its market share for electric vehicles. Liuzhou AAM already invested considerable resources in this business segment at an early stage: the first electric powertrains went into production in March 2020, and the Baojun E300 small car that is equipped with them has attracted enormous attention ever since then.

Monitoring and controlling press-fit processes in real time

For its production lines, Liuzhou AAM relies on NC joining systems from Kistler – the solution of choice for assembly processes thanks to their accuracy, controllability and universal compatibility. 'Hydraulic press-fit modules were used at Wuling Industrial,' according to Senior Process Engineer Chen Chuanliang, a former employee of Wuling Industrial who can draw on five years' experience of industrial production. 'There was no real-time process monitoring and the control level of the press-fit process was low, so we were always confronted with quality problems in assembly – bent surfaces, dented edges, and parts damaged by excessive forces. In the worst-case scenario, there could even be machine downtime or complaints from customers – and economic losses of that sort really have to be prevented.'

These experiences triggered the quest for a press-fit solution with precise force-displacement monitoring for Liuzhou AAM's new factory. 'We wanted an easy-to-operate system to control press-fit speed, with real-time visualization of all the parameters in relation to the entire production line. What's more, we wanted to reduce installation and servicing time, and cut training efforts.' And that is exactly what the combination of the electromechanical joining module and maXYmos NC (Numeric Control) from Kistler delivers: continuous force-displacement monitoring and control of the joining process based on accurate sensor data. The result: virtually 100% quality assurance – as Chen confirms: 'We've seen a massive decrease in our scrap rates for manufacturing products as oil seals and bearings.'

Maximum quality and flexibility in assembly

There are even more benefits, such as better system integration and flexible application. Liuzhou AAM operates highly automated and highly integrated production lines that require precise observation of the cycle times for all the systems involved. And to achieve increased efficiency and productivity, press-fit systems must also be adaptable to the requirements for a varied range of products and work sequences. These reasons persuaded Liuzhou AAM to equip its drive and axle system production lines with the NCFH, NCFN and NCFE electromechanical joining modules from Kistler. They are used to assemble components such as gear units, bearings, floating axles, bushings and many more. 'One major advantage of the solutions from Kistler is that they are generally very adaptable to different applications. That makes work a lot easier for the process engineers,' Chen points out. 'Because the joining modules are compact and uniform, they can be combined flexibly – so setup is simple, even for complex assembly processes.'

In the future, Liuzhou AAM intends to continue developing traditional as well as electric and hybrid drives in parallel. Especially in Guangxi province, electric vehicles are making enormous advances – and they are set to become even more popular. Thanks in no small measure to government support, the city of Liuzhou has become a center for the production and promotion of small electric vehicles for private use. The streets are already packed with vehicles that operate entirely on electric power, and car sharing is gaining popularity all the time. On the global scale too, China is the main driver of electromobility (followed by the USA) – back in 2019, the government introduced a quota system for automobile manufacturers operating in the Chinese market, and the regulations were tightened again in 2020.