In the joints of humanoid robots, bearings are facing challenges never before encountered in industrial bearing applications. Unlike industrial robots mounted on fixed bases, humanoid robots must maintain balance during dynamically unstable bipedal walking, enduring continuous impact loads from ground reaction forces and precise posture adjustments with every step. Hip joints must bear the weight of the entire upper body, knee joints must complete repeated flexion/extension and locking during walking, ankle joints must adjust foot angles to ground surfaces at every moment, shoulder joints must complete large-range arm swinging, and elbow and wrist joints must perform dexterous manipulation tasks.

 

The requirements of humanoid robot joint bearings combine multiple contradictions that industrial robots have never simultaneously faced: they must possess both the high precision and high rigidity of industrial robots and the lightweight and low inertia of collaborative robots； they must withstand dynamic impact loads during bipedal walking while maintaining micron-level repeat positioning accuracy during extended fine manipulation； they must adapt to frequent start-stop and direction changes while maximizing power density within compact joint space. When humanoid robot joint bearings develop clearance or insufficient rigidity, posture control during bipedal walking fails and the robot falls； when bearing friction fluctuates, force control precision degrades and dexterous manipulation fails； when bearing weight is excessive, robot self-weight increases, runtime shortens and dynamic response slows.

 

Japan NMT humanoid robot joint bearings are specialized product series developed specifically for the extreme requirements of humanoid robots for ultra-high precision, lightweight, low friction and long life. NMT humanoid robot joint bearings feature systematic specialized optimization in thin section design, lightweight materials, ultra-high-precision manufacturing and low-friction control——ensuring stable and reliable precision support through long-term dynamic motion of humanoid robot hip, knee, ankle, shoulder, elbow and wrist joints.

 

NMT humanoid robot joint bearings precisely address the different requirements of each core humanoid robot joint. Hip joint bearings utilize high-rigidity thin section crossed roller bearings, withstanding upper body weight and walking dynamic loads while maintaining precise hip rotation and torque transmission, with thin section design significantly saving joint axial space and leaving more installation space for hip drive motors and reducers. Crossed roller bearings, with their orthogonally arranged cylindrical rollers, achieve line-contact load distribution with rigidity several times that of ball bearings of equivalent size, maintaining micron-level rotational precision even under single-leg support instantaneous impacts. Knee joint bearings utilize ultra-high-precision thin section crossed roller bearings or angular contact ball bearings, withstanding alternating loads and impact during repeated flexion/extension and locking, maintaining precise knee angle control and locking reliability, ensuring stable knee support and natural gait during bipedal walking.

 

Ankle joint bearings utilize ultra-high-precision thin section angular contact ball bearings or spherical plain bearings, withstanding combined loads and off-center loads during foot angle adjustment and ground reaction force absorption, automatically compensating for foot-ground angle deviations, maintaining flexible ankle adjustment and precise force control, ensuring bipedal walking balance and ground adaptability. Shoulder joint bearings utilize thin section crossed roller bearings or four-point contact ball bearings, withstanding overturning moments and bidirectional axial loads during large-range arm swinging and load manipulation, maintaining smooth shoulder rotation and precise positioning, ensuring arm freedom and load capacity.

 

Elbow joint bearings utilize ultra-high-precision thin section angular contact ball bearings, maintaining low friction and high rigidity during frequent flexion/extension and load manipulation, withstanding arm weight and manipulation loads, ensuring precise elbow angle control and smooth dexterous manipulation feel. Wrist joint bearings utilize ultra-high-precision miniature thin section angular contact ball bearings or hybrid ceramic bearings, maintaining extremely low friction and extremely high angular repeat accuracy during fine manipulation and posture adjustment, withstanding end-effector weight and manipulation reaction forces, ensuring precise and flexible hand operation.

 

NMT humanoid robot joint bearings utilize high-purity bearing steel or silicon nitride ceramic ball materials, processed through vacuum degassing and ultra-purification refining to provide excellent fatigue resistance and dimensional stability under frequent start-stop and dynamic impact. Ceramic balls offer low density, low centrifugal force and high hardness characteristics——density仅为 steel's 41%, weight reduction by approximately 60%, significantly lowering joint rotational inertia, making dynamic response more sensitive, while reducing motor power consumption and extending robot runtime. Raceways undergo nanometer-level superfinishing, and rolling elements undergo ultra-high-precision grading screening to achieve extremely low friction coefficient, effectively reducing joint power consumption and temperature rise. Bearing clearance is precisely set with compensation optimization for frequent start-stop and dynamic load variations, maintaining proper internal gaps under various motion states.

 

Thin section design is a core technical advantage of NMT humanoid robot joint bearings. Regardless of bore size changes, bearing cross-section dimensions remain consistent, allowing humanoid robot designers to use the same mounting interface and lubrication solutions across joints of different diameters, dramatically simplifying structural layout and assembly processes while creating valuable space for more compact drive and sensing components. In large-diameter joints such as hips and knees, thin section design makes overall joint dimensions more compact, reduces robot lower limb weight and lowers energy consumption during walking.

 

Low friction is key to force control and walking control precision. NMT humanoid robot joint bearings achieve extremely low starting and running friction torque through nanometer-level superfinished raceways, ultra-high-precision rolling element grading and low-friction seal design, ensuring robots experience uniform, smooth motion resistance during walking and manipulation without stick-slip or hesitation, providing a reliable physical foundation for precise force control algorithms.

 

Reasons for selecting NMT humanoid robot joint bearings：

 

Thin section crossed roller bearing solutions with rigidity several times ball bearings, significantly saving joint space

 

Thin-wall structure + ceramic ball lightweight design reducing bearing weight by approximately 60%, lowering joint inertia and power consumption

 

Nanometer-level superfinished raceways for extremely low friction and minimal starting torque, precise smooth force control

 

Ultra-high-precision graded rolling elements with micron-level consistency for long-term stable rotational precision

 

Low-density low-centrifugal-force ceramic balls for sensitive dynamic response, suitable for bipedal walking high-frequency impacts

 

Precisely set bearing clearance matched to dynamic load variations and frequent start-stop

 

Ultra-high-precision miniature thin section bearing solutions for wrist and fine manipulation

 

Passed rigorous dynamic impact and durability testing for hip, knee, ankle, shoulder, elbow and wrist humanoid robot joints

 

These performance advantages establish NMT humanoid robot joint bearings as the reliable precision components for humanoid robot hip, knee, ankle, shoulder, elbow and wrist joints.

 

Application scenarios

 

Humanoid robot hip rotation and load bearings

 

Humanoid robot knee flexion/extension and locking bearings

 

Humanoid robot ankle angle adjustment and force control bearings

 

Humanoid robot shoulder large-range swing bearings

 

Humanoid robot elbow flexion/extension and load bearings

 

Humanoid robot wrist fine manipulation bearings

 

Anthropomorphic robot waist rotation and flexible support bearings

 

Bipedal robot dynamic walking and balance joint bearings

 

Precision manufacturing

 

Produced according to humanoid robot industry standards and ultra-precision bearing manufacturing specifications, NMT humanoid robot joint bearings utilize high-purity bearing steel or silicon nitride ceramic materials, processed through vacuum degassing refining, nanometer-level superfinishing, ultra-high-precision rolling element grading screening, thin section precision forming, precision assembly and clearance setting, precision dynamic balancing inspection, rotational accuracy verification, starting torque testing and dynamic impact durability validation——ensuring every product delivers ultra-high precision, lightweight, low friction and long service life.

 

Product range

 

Humanoid robot hip thin section crossed roller bearings

 

Humanoid robot knee ultra-high-precision crossed roller bearings

 

Humanoid robot ankle thin section angular contact ball bearings

 

Humanoid robot shoulder thin section four-point contact ball bearings

 

Humanoid robot elbow ultra-high-precision thin section bearings

 

Humanoid robot wrist hybrid ceramic miniature bearings

 

Humanoid robot joint module integrated thin section bearings

 

Custom non-standard humanoid robot joint bearings

 

Global industrial service

 

Japan NMT supplies high-quality humanoid robot joint bearings to global humanoid robot manufacturers, bionic robotics R&D institutions, bipedal robot companies and embodied intelligence firms, empowering breakthroughs and commercialization in the global humanoid robot industry with ultra-high-precision lightweight precision engineering and long-term stable anthropomorphic motion transmission performance.