中文版本

Opportunity

The field of robotics, particularly in industrial manufacturing, demands motors that are compact, lightweight, and capable of delivering high torque with precision to enable direct drive of robotic arms without the need for bulky and complex gear systems. Traditional electric motors, whether based on axial or radial principles, often fail to provide sufficient torque density within the size constraints required for on-board robotic applications. Consequently, robotic systems typically rely on integrated gearing mechanisms, such as planetary gears, to amplify torque. However, these gear systems introduce significant drawbacks, including added weight, increased mechanical complexity, higher maintenance requirements, and potential points of failure. This creates a pressing need for a motor that can achieve high torque output directly, eliminating or reducing dependency on gearboxes, thereby enhancing the efficiency, reliability, and compactness of robotic systems.

Technology

This patent introduces a novel motor design that ingeniously combines both axial and radial magnetic principles to overcome the traditional trade-off between torque density and motor size. The core innovation lies in a rotor structure that incorporates permanent magnets on both axial and radial portions surrounding the stator windings. Specifically, the motor comprises a stator with a core and windings, and a rotor with permanent magnets arranged such that a first set is placed on at least one axial rotor portion adjacent to the axial sides of the windings, and a second set is placed on at least one radial rotor portion adjacent to the radial side of the windings. When the windings are energized, torque is applied to the rotor simultaneously through both the axial and radial rotor portions. This dual-action significantly increases the torque density for a given motor volume by effectively utilizing multiple sides of the windings for electromagnetic interaction. A preferred embodiment features two axial rotor portions and one radial rotor portion, forming a recess that encloses the stator on three sides, with the magnet arrangements on the two axial portions being mirror copies to cancel out imbalanced axial forces and prevent rotor tilting. Further enhancements include the use of Halbach arrays for the permanent magnets, which concentrate magnetic flux towards the windings, produce a more sinusoidal magnetic field to reduce harmonics and torque ripple, and improve overall efficiency. The design also incorporates reinforcement structures, such as bolts, to mechanically stabilize the axial and radial rotor components. By integrating these features, the motor achieves a high level of winding and core utilization, enabling it to function as a high-torque-density direct-drive unit suitable for robotic applications without the need for intermediate gearing.

Advantages

• High Torque Density: Generates significantly higher torque for a given size and volume by simultaneously utilizing axial and radial magnetic fields.
• Direct-Drive Capability: Provides sufficient torque to directly drive robotic joints, eliminating the need for reduction gearboxes.
• Compact and Lightweight Design: Ideal for integration into robotic arms where space and weight are critical constraints.
• Reduced Mechanical Complexity and Maintenance: By removing gear systems, it lowers part count, potential failure points, and associated maintenance costs.
• Improved Mechanical Stability: Mirror-symmetric axial rotor magnet arrangements and reinforcement structures cancel unbalanced axial forces, preventing rotor tilt and enhancing structural integrity.
• Reduced Torque Ripple: The use of Halbach arrays creates a more sinusoidal magnetic field, minimizing torque pulsations for smoother operation.
• High Utilization of Windings and Core: Electromagnetically engages multiple sides (e.g., upper, lower, inner) of the toroidal windings, increasing efficiency and mitigating end effects.
• Scalability and Flexibility: The core principle of combined axial-radial action can be adapted to various motor geometries and pole configurations.

Applications

• Industrial Robotics: Direct-drive motors for robotic arms, joints, and actuators in manufacturing, assembly, and material handling.
• Precision Automation: Equipment requiring high torque and precise motion control in compact spaces.
• Electric Vehicles: Potential use as an in-wheel motor or other traction motor where high torque density is beneficial.
• Aerospace and Defense: Actuators for control surfaces or mechanisms where weight and reliability are paramount.
• Medical Robotics: Surgical robots and assistive devices requiring smooth, powerful, and compact actuators.
• Consumer Electronics and Appliances: High-performance motors for drones, advanced tools, or compact machinery.
• General Industrial Machinery: Mixers, drills, conveyor drives, and other applications needing high torque in a limited footprint.