The Unitree M107 Joint Motor is an integrated joint motor developed in-house by Unitree, used in the H1 / H1-2 humanoid series. Unitree's official page identifies it directly as the "Unitree M107 Joint Motor," highlighting its high power, agility, speed, load capacity, and durability.
In public H1 / H1-2 materials, Unitree describes the drive core of this class as a low-inertia, high-speed internal rotor PMSM with industrial crossed roller bearings. Representative torque values for the joint units on this platform include approximately 360 N·m for the knee, approximately 220 N·m for the hip, and approximately 75 N·m for the arm joints; on the H1-2, approximately 120 N·m for the shoulder and elbow and approximately 30 N·m for the wrist are also specified.

Joint Motor · serves as: Joint Actuation, Locomotion Drive, Balance and Posture Control. · compatible with: Humanoid.
Which group Unitree M107 Joint Motor belongs to and how it is built
A subcategory covering joint actuators — integrated drive units combining a motor, gearbox, encoder, and control electronics in a single module, used in the joints of robot limbs and torsos.
A joint motor is a drive motor placed directly at a robot's articulated joint, responsible for generating torque and achieving precise angular positioning of each degree of freedom. Typically implemented as brushless BLDC motors or servomotors, they are commonly integrated with harmonic or planetary gearboxes and encoders. Joint motors are fundamental to robotic manipulators, exoskeletons, and humanoid robot limbs.
An Internal Rotor PMSM (Permanent Magnet Synchronous Motor) is a motor design in which permanent magnets are mounted on a rotor positioned inside the stator. This configuration offers high torque density, excellent dynamic response, and efficient cooling of the stator windings. It is widely used in robotics for joint actuators in manipulators, drive wheels in mobile robots, and other applications requiring precise torque and velocity control.
Basic physical properties of Unitree M107 Joint Motor — dimensions, weight and materials