Hollow Rotary Actuator
Discover the precision and versatility of Hollow Rotary Actuators:
Advanced solutions for seamless rotational motion control in complex engineering systems.
TH Series
THG Series
THM Series
THR Series
THS Series
THB Series
THD Series
What is Hollow Rotary Actuator（Hollow Rotating Platform）？
Hollow Rotary Actuator, also known as Hollow Rotating Platform or Rotary Positioners, is a mechanical device designed to provide continuous or indexed rotary motion. It features a hollow interior that allows cables (such as electrical lines, optical fibers, air or liquid pipes) to pass through its center, providing undisturbed power and signal transmission to the device or tool mounted on the actuator. This design is particularly suitable for occasions where space is limited or internal channels are required to keep the exterior clean.
Such devices are widely used in automation equipment, robotic joints, precision measuring instruments, semiconductor manufacturing, medical equipment, aerospace, and other fields that require precise and complex motion control. They can provide a flexible range of motion and highly accurate angular control while maintaining the compactness and integration of the system.
Features of Hollow Rotary Actuator
● Integrated product
TH series is a product that combines a hollow rotary platform and a servo motor. The internal structure of the platform is a reduction ratio, which can achieve high output drive.
● Short-time positioning
Inertial loads can be positioned in a short time.
● High-precision positioning without backlash
No backlash, helical gear, grinding machine gear; large gear module to achieve high torque repeated positioning accuracy ±5 arcsrc (soil 0.001°)
*Accuracy is the value under a certain load and a certain temperature (normal temperature)
● Reduce design time and shorten delivery time
The output platform can be directly installed on the workbench or robot arm of the equipment. Compared with the use of belts, pulleys and other mechanism parts, it can reduce the time and cost of mechanism design, parts allocation, belt tension adjustment, etc., save equipment design time, and help shorten delivery time.
● Large-diameter hollow output platform saves wiring and piping
Large-diameter hollow holes (through holes) can be used on complex wiring and piping, which can simplify equipment design.
| Installation dimensions （mm） | Hollow diameter（mm） | |
| TH60 | 60 | Φ28 |
| TH85 | 85 | Φ33 |
| TH130 | 130 | Φ62 |
| TH200 | 200 | Φ100 |
| TH280 | 280 | Φ150 |
| TH450 | 450 | Φ250 |
Internal Structure of the Hollow Rotary Actuator
①Crossed roller bearings
All series use crossed roller bearings. This type of bearing has a rotational accuracy 4-5 times higher than ordinary bearings and can withstand loads in all directions such as axial loads and torque loads.
②Precision gears
The reducer adopts a helical gear design, and its tooth meshing rate is more than twice that of general spur gears. It has the characteristics of smooth operation, low noise, high output torque and low backlash.
③Input mounting flange
Advanced connecting plate design, easy installation, and perfect combination with servo and stepper motors from various manufacturers.
④Input shaft
The entire input is an integrated design, ensuring the impulse accuracy and rigidity of the reducer. Error-free installation and balanced clamping system can achieve higher input speeds, and power transmission is gapless.
⑤Sensing device
This position is the position for assembling sensors. Used for origin positioning and effective position correction. Provide installation sensor accessories, customers only need to purchase photoelectric switches to use, thus shortening the design, processing and procurement of all parts related to sensor installation.
Applications of the Hollow Rotary Actuator
Load inertia changes
High-precision positioning using hollow holes
High-precision positioning
Apply inertia load
Free Design of Installation Direction
In addition to horizontal installation, the TH rotary platform can also be installed vertically or upside down, and the range of device design is wide.
Please note when using: A small amount of lubricating oil may occasionally leak out of the hollow rotary transmission device. If the lubricating oil leaks out and causes pollution to the surrounding environment, please confirm it during regular inspections or install devices such as oil pans.
Professional Term Analysis
- Rotating platform contact bearing: the type of bearing used in the rotating platform.
Allowable torque: the critical value of the mechanical strength of the reduction mechanism, including the acceleration torque and load inertia, must be used within this allowable torque range - Allowable speed: the disk speed of the rotating platform that can be allowed by the mechanical strength of the reduction mechanism.
- Rotational inertia: the sum of the values converted on the rotating platform by the rotor inertia of the motor part + the inertia of the reduction mechanism.
- Allowable axial load: the allowable value of the axial load applied to the rotating platform axis.
- Allowable inertia moment load: the allowable value of the inertia moment load calculated by the eccentricity of the center x load when the load is applied at a position deviating from the center of the rotating platform so that the force of the tilting of the rotating platform will act.
- Positioning accuracy: the error value between the theoretical rotation angle and the actual rotation angle when the rotating platform is positioned at any point within 360°.
- Repeatable positioning accuracy: the error value generated when the same position is repeatedly positioned from the same direction.
- Rotating platform parallelism: the parallelism of the rotating platform disk relative to the base mounting surface when the rotating platform is running.
- Concentricity of rotating platform: The concentricity error value between the inner diameter and the outer diameter of the rotating platform when there is no load.
- Allowable input speed: The input speed that can be allowed by the mechanical strength of the reducer structure.
- Backlash: The input speed that can be allowed by the mechanical strength of the reducer structure.
- Destruction torque: When the reducer is subjected to this torque, the structure will be destroyed.
- Accuracy life: The design life of the reducer to maintain accuracy under normal use.
- Protection level: For the protection structure of the machine based on IEC529, EN60034-5 (=IEC60034-5), it can be classified according to the level of dustproof and waterproof properties.
Installation Steps
Step 1:
Confirm whether the specifications and models of the motor and hollow rotating platform are correct, and clean the installation surface of the motor and hollow rotating platform.
Step 2:
Remove the buckle plug on the connecting flange of the hollow rotating platform, turn the locking ring until the locking ring screw is aligned with the plug hole; remove the original key on the motor shaft, and install the balance key if necessary.
Step 3:
Vertically install the adapted motor, confirm the motor shaft size, if it is smaller than the input hole diameter, select the appropriate sleeve and then install it upright.
When the motor is a flat shaft, align the bushing gap with the center line of the flat shaft so that the locking ring screw is perpendicular to the flat shaft surface.
Step 4:
Use a torque wrench to tighten the positioning bolt diagonally at 5% of the torque value recommended by the locking torque table (tighten the screws step by step according to the diagonal sequence table).
Step 5:
Refer to the locking torque table, use a torque wrench to tighten the locking ring and reinstall the buckle plug.
