Industry Overview - The report from Shanghai Securities highlights the technical barriers of universal joints, which include materials and heat treatment, precision processing and manufacturing, bearing and sealing technology, and a stable quality assurance system. These components are critical for strength, vibration, wear life, and reliability, often referred to as the "fuse" of the transmission system, indicating their vulnerability as safety components [1][3]. Universal Joint Applications - Universal joints, also known as universal couplings, are essential for angular power transmission in applications requiring directional changes in drive shafts. They are categorized into three types: rigid (non-constant velocity), flexible (quasi-constant velocity), and constant velocity universal joints. Rigid universal joints are used for high torque transmission with less concern for speed uniformity, while flexible joints are designed for medium to small power transmission with high damping and noise control requirements. Constant velocity joints ensure smooth power transfer during vehicle steering, commonly found in passenger car half shafts [2]. Robotic Applications - Universal joints are being adapted for use in humanoid robots, particularly in wrist and neck joints. The specifications for automotive universal joints, which include larger sizes, higher torque, and longer lifespans, contrast with the smaller, high-precision, thin-walled structures required for robotic applications. A universal joint provides two degrees of freedom, enhancing the flexibility of robotic joints compared to standard bearings that typically offer only one degree of freedom [3]. Company Developments - Wanxiang Qianchao focuses on the research and manufacturing of automotive components, including universal joints and drive shafts. The company is also developing products for robotics, such as precision axes and cross-roller bearings, targeting leading robotic users [4][5]. - Guansheng Co., specializing in automotive aftermarket components, has recognized the potential of universal joints in humanoid robot joints and is conducting feasibility studies and technical exchanges in this area [5]. - Zhengqiang Co. is a national high-tech enterprise concentrating on cross-axis universal joint assemblies and related components, primarily for fuel and new energy vehicles [5]. Investment Recommendations - Companies to watch include Zhengqiang Co., Wanxiang Qianchao, and Guansheng Co. due to their involvement in the development of universal joints for humanoid robots and their established positions in the automotive parts industry [6].