Key causes of CNC spindle motors overheating

1.Main description of CNC spindle motor

A CNC spindle motor is the central electric motor in a Computer Numerical Control (CNC) machine that rotates a cutting tool or workpiece at high speeds and with precision. It is the core component that provides the necessary power and rotational force for operations like cutting, drilling, and milling by driving the spindle shaft, which holds the tool. Key aspects include its high speed and accuracy, and it can be an AC or DC motor, with options for different cooling systems and drive mechanisms like belts or direct drives. 

2.Key components and types

1.Stator and rotor: Like most electric motors, a spindle motor has a stationary part (stator) and a rotating part (rotor) that generates torque. 

2.Motor types: Common types include DC brushless motors and AC motors, each with advantages depending on the application.AC motors(Often preferred for high-power applications due to efficiency and a longer lifespan) and DC brushless motors(Popular for high-end applications that require high speeds and precision, as they have fewer parts that wear out) .

3.Cooling systems: Different cooling methods are used to manage the heat generated, especially during high-speed operation.Water-cooled( More efficient for high-speed, heavy-duty applications and industrial settings) and Air-cooled(Simpler and common for less demanding applications).

4.Drive system: The motor can be connected to the spindle shaft via a belt, gears, or an integrated direct-drive system.        

3.Key causes of CNC spindle motors overheating

1.Inadequate Cooling System:CNC spindle motors typically rely on a cooling system to maintain their operating temperature. These cooling systems can be air-based or liquid-based. If the cooling mechanism is insufficient, damaged, or improperly maintained, it will fail to dissipate the heat generated during high-speed operation. When this happens, the spindle is unable to regulate its temperature, leading to overheating.

2.High-Speed Operation for Extended Periods:CNC spindle motors are often pushed to their speed limits, especially in demanding industries. Running a spindle at high RPMs (revolutions per minute) for extended periods generates significant friction and heat. Without sufficient breaks or slower operational cycles, the spindle may exceed its thermal limits, leading to overheating.

3.Excessive Load and Cutting Forces:A common cause of spindle overheating is applying excessive load or pressure during the cutting process. When operators select aggressive feeds and speeds or work with tough materials, the cutting forces required increase, generating more heat in the spindle. Over time, this added stress can lead to thermal overload, especially if the machine is not optimized for such conditions.

4.Bearing Issues:Bearings are critical components in a CNC spindle. If they wear out or are improperly lubricated, they can create more friction and heat. Worn bearings increase the spindle’s resistance, making it work harder and generate more heat than usual. This is one of the most common mechanical reasons for overheating.

5.Clogged Filters or Poor Ventilation:For air-cooled spindles, proper airflow is critical. Filters can become clogged with dust, chips, and debris from machining, reducing airflow and trapping heat around the spindle. Poor ventilation inside the machine housing can also exacerbate this problem, leading to increased internal temperatures.

6.Imbalanced CuttingTools:An often overlooked factor is the balance of cutting tools. If the tool is not properly balanced, it can create vibrations and imbalances during operation, causing additional strain on the spindle. These vibrations increase the workload and heat generation, leading to premature spindle failure.    

4.Design features of CNC spindle motor

1.Performance and control:Designed to handle demanding cuts, allowing for higher material removal rates without sacrificing accuracy.Capable of reaching speeds up to 60,000 RPM, which is ideal for finishing operations on softer materials like aluminum and plastics.Offering exceptional control over rotational speed, allowing operators to optimize parameters for different materials, tools, and desired results. 

2.Precision and accuracy:Precision-engineered bearings and rotor designs minimize deviation and vibration, leading to better surface finishes and increased accuracy.Built for high precision, which ensures consistent and accurate results across multiple workpieces. 

3.Durability and reliability:Built to be rugged and reliable for continuous, demanding industrial applications, which reduces downtime and increases productivity.High-precision bearings are critical for supporting the rotor and enabling smooth, accurate rotation. 

4.Thermal management:Equipped with efficient cooling systems, such as air or liquid cooling, to dissipate the significant heat generated during high-speed operation.Some designs, particularly built-in high-speed spindles, integrate components like the motor, oil, gas, water, and electricity into a single unit to manage heat and improve performance within a compact space.

What are the most suitable applications for closed-loop stepper motors?

1.Main introduction of closed loop stepper motor

A closed-loop stepper motor is an advanced stepper motor that integrates a feedback mechanism, typically an encoder, to continuously monitor and correct its position. Unlike traditional open-loop systems that assume the motor reaches its commanded position, closed-loop systems use the feedback to verify performance in real time, ensuring higher accuracy, improved torque at higher speeds, and greater reliability by preventing step loss or stalls. This makes them a cost-effective and high-performance alternative to traditional servo systems for applications with higher demands for precision and torque. 

2.Key advantages of closed loop stepper motor   

1.Eliminates step loss: The feedback mechanism ensures the motor doesn't lose steps, even under heavy loads or during rapid acceleration.  

2.Increased accuracy and reliability: It provides real-time position verification, leading to higher accuracy and more reliable operation.  3.Improved torque and speed: It can maintain a higher percentage of its holding torque at higher speeds compared to open-loop steppers, while still delivering high torque at low speeds.  

4.No need for margin: Because it corrects for errors, a large torque margin (often \(30\%\) for open-loop) is not needed, which can lead to a smaller, more efficient system.  

5.Reduced micro-vibrations: They often have smoother operation with less micro-vibration when stopped.        

3.Main advantages of closed loop stepper motor

1.Enhanced Accuracy and Precision: The feedback system, often an encoder, continuously monitors the motor's position and allows for real-time adjustments to correct any errors. This eliminates the risk of lost steps common in open-loop systems, resulting in superior position accuracy and control. 

2.Improved Torque and Performance: These motors can maintain consistent torque, even under varying loads or during dynamic changes, and offer higher torque at low to medium speeds. They can operate at higher speeds than open-loop systems without losing steps. 

3.Increased Reliability: The feedback loop makes the system more robust by detecting and correcting errors, reducing the risk of stalling or missed steps, which ensures consistent and dependable operation. 

4.Energy Efficiency and Lower Heat Generation: They only draw the necessary power to meet the current load, unlike open-loop motors that run at full power constantly. This results in less energy consumption and lower heat generation, which can extend the life of the motor and reduce the need for cooling mechanisms. 

5.Reduced Vibration and Noise: The smoother operation resulting from the feedback control leads to less vibration and quieter performance compared to traditional steppers. 

6.Simplified System Integration: Closed-loop systems often require less complex tuning or calibration compared to traditional servo motors, simplifying setup and integration into applications like 3D printers, robotics, and CNC machines.    

4.Best applications for closed-loop stepper motor

1.Industrial Automation: Precision positioning in conveyor systems, pick-and-place machines, and packaging equipment.

2.Robotics: Accurate motion control in robotic arms, grippers, and automated guided vehicles (AGVs). Closed Loop Stepper Motors offers the accuracy and responsiveness required to execute tasks with utmost precision. From industrial robots to collaborative robots (cobots), these motors drive efficiency and productivity in diverse robotic applications.

3.CNC machining: Closed-loop systems are used in CNC machines to achieve precise cutting and machining operations. Whether it’s milling, turning, or grinding, these motors ensure consistent and reliable performance, leading to superior machining quality.

4.3D printing: The burgeoning field of 3D printing relies heavily on precise motion control to produce intricate designs with accuracy and repeatability. Closed Loop Stepper Motors enables precise layer deposition, resulting in high-quality prints with minimal errors or defects, thereby pushing the boundaries of additive manufacturing.

5.Textile Manufacturing: In textile machinery, closed-loop stepper motors precisely control the tension and movement of fabrics during processes such as weaving, knitting, and embroidery. This ensures consistent fabric quality and pattern accuracy, minimizing defects and waste.

6.Semiconductor Manufacturing: Closed-loop stepper motors play a crucial role in semiconductor manufacturing equipment for processes like wafer handling, lithography, and inspection. They ensure precise alignment and movement of wafers and components, essential for achieving nanoscale fabrication tolerances.

7.Food and Beverage Industry: In food processing and packaging machinery, closed-loop stepper motors control the movement of conveyor belts, filling nozzles, and sealing mechanisms with precision. This helps maintain consistent product quality, portion sizes, and packaging integrity.

8.Aerospace and Defense: Closed-loop stepper motors are used in aerospace applications such as satellite positioning systems, antenna tracking systems, and unmanned aerial vehicles (UAVs). Their precise motion control capabilities are essential for maintaining stable flight paths and accurate positioning.

9.Photovoltaic (PV) Solar Panel Manufacturing: In the production of solar panels, closed-loop stepper motors are used in equipment for cutting, handling, and assembly processes. Their accuracy ensures precise alignment of solar cells and components, maximizing energy conversion efficiency.

Methods of improving the efficiency of hollow rotary actuator

1.Details of hollow rotary actuator

A hollow rotary actuator is a rotary positioner with a large central bore designed for routing cables, pipes, or other components, providing a compact and integrated solution for precise, high-accuracy rotational movement in automation, robotics, and manufacturing. It features a table with cross-roller bearings for high stiffness and load capacity, can be driven by servo or stepper motors, and offers benefits like multi-point positioning and integration with collaborative robots. 

2.Function of components

1.Hollow Shaft: The central feature is a large-diameter hole for passing through wiring, sensors, air lines, or optical fibers, eliminating the need for external cable management. 

2.Cross-Roller Bearings: These bearings are designed for high rigidity, supporting large thrust, radial, and moment loads while ensuring high accuracy and durability. 

3.Integrated Motor: They often come with an integrated stepper or servo motor, simplifying design and setup for a complete motion control solution. 

4.Motor Mount Options: Some models offer both vertical and horizontal motor mounting configurations for flexible installation. 

5.Mechanical Absolute Encoder: Some units include a battery-less absolute encoder for precise positioning without needing external home or limit sensors.       

3.Functions of hollow rotary actuator

1.Integrated Wiring & Piping: The central opening allows for the continuous passage of air lines, electrical wires, and other components, which simplifies the equipment's design and reduces its overall size and weight. 

2.Precise Rotational Motion: These actuators are engineered for high-precision positioning and smooth rotational movement, often with features like zero-backlash and the ability to make rapid, short-distance moves. 

3.Automation: They are used to control and automate various movements in automated equipment, such as robot joints, alignment mechanisms, and the drive rollers of printing machines. 

4.Space-Saving Design: By integrating the hollow shaft, they reduce the need for external components and cable management, leading to a more compact and streamlined end effector or machine design. 

5.Reduced Design & Assembly Time: Their design streamlines the integration of components, which can significantly shorten design cycles and assembly man-hours. 

6.Complex Motion: With the right control and configuration, they can perform complex multi-axis motions or "short-cut" movements, moving to a target position via the shortest path to reduce cycle times. 

7.High Load & Torque: They can handle significant axial and moment loads, allowing for robust applications where heavy components are mounted to the output table.   

4.Methods of improving the efficiency of hollow rotary actuator

1.High-Rigidity Components: Use components like cross roller bearings to improve rigidity, reduce displacement under load, and enhance overall accuracy and efficiency, as seen in systems that require high precision. 

2.Advanced Bearing Systems: Employ cross roller bearings and combined components to reduce parts, minimize influences on mechanical accuracy, and improve deflection accuracy and parallelism. 

3.Improved Heat Management: Redesign internal housings with optimized heat flow paths to efficiently dissipate heat during continuous operation, preventing performance degradation and ensuring long-term stability. 

4.Power Density: Research and design for better power and torque density, and improved mechanical output, for example, using fewer piezoelectric ceramics in miniature actuators to reduce volume and increase efficiency. 

5.Precision Processing: Focus on precision grinding, CNC machining, and gear processing during the manufacturing stage to improve the quality and effectiveness of the actuator's assembly and use. 

6.Strict Quality Control: Implement strict quality control measures throughout the manufacturing process to ensure consistent performance and reliability. 

7.Model Selection: Carefully select the appropriate hollow rotary actuator model and parameters based on the actual application requirements to ensure optimal speed reduction, stability, and overall efficiency. 

8.Closed-Loop Control: Adopt closed-loop motor and driver packages to achieve more efficient and energy-saving operations compared to traditional open-loop systems. 

9.Intelligent Drivers: Utilize drivers with built-in controllers that store operating data, reducing the burden on the host controller and simplifying integration into automated systems. 

10.AI & IoT: Leverage AI-driven analytics and IoT connectivity to develop intelligent, self-monitoring actuators that deliver enhanced precision, reliability, and energy efficiency. 

Main types and applications of linear stepper motor

1.Basic introduction of a linear stepper motor

A linear stepper motor is an electromechanical device that converts electrical pulses directly into discrete linear (straight-line) motion. Unlike a conventional rotary stepper motor, which requires external mechanical components like lead screws or belts to achieve linear motion, the linear stepper motor has these conversion mechanisms integrated into its design. These motors offer high precision, reliability, and ease of control, making them suitable for applications in automation, robotics, and precision positioning systems.

2.Working principle of linear stepper motor

A linear stepper motor uses a motorized lead screw or a threaded nut that is attached to a rotor, which converts the stepper motor's rotary motion into precise linear motion. The motor's rotor is driven by a controller that sends digital pulses, causing it to turn in discrete, measurable steps. As the rotor spins, the threaded mechanism translates this rotation into a controlled, linear movement of a slider or moving part, allowing for accurate and repeatable positioning. 

3.Main types of linear stepper motor

1.Permanent magnet linear stepper motors:Permanent magnet linear stepper motors (PMLSMs) are a widely used type of linear stepper motor. They consist of a moving part with a permanent magnet and a stationary part with a series of electromagnetic coils. When the coils are energized, they create a magnetic field that interacts with the permanent magnet, causing the motor to move. PMLSMs offer high force density, good efficiency, and excellent holding torque.

2.Hybrid linear stepper motors:Hybrid linear stepper motors combine the features of both permanent magnet and variable reluctance stepper motors. They consist of a rotor with permanent magnet poles and a stator with toothed iron cores. When the stator coils are energized in a specific sequence, the rotor moves due to the attraction and repulsion between the permanent magnet and the toothed cores. Hybrid linear stepper motors provide high torque, precise motion control, and good dynamic performance.

3.Variable reluctance linear stepper motors:Variable reluctance linear stepper motors (VRLSMs) operate based on the principle of magnetic attraction. They consist of a rotor with teeth and a stator with multiple electromagnetic coils. When the coils are energized, the teeth on the rotor align with the magnetic field produced by the stator, causing the rotor to move. VRLSMs are known for their simplicity, low cost, and high-speed capabilities. However, they may suffer from low holding torque and vibration issues.

4.Tubular linear stepper motors:Tubular linear stepper motors are similar in design to PMLSMs but have a hollow cylindrical shape. They consist of a moving rod that fits inside a stationary coil assembly. When the coils are energized, the moving rod moves in a linear direction. Tubular linear stepper motors offer high force output, compact size, and ease of installation. They are commonly used in applications where space is limited, such as robotic arms, medical devices, and precision positioning systems.

5.Moving coil linear stepper motors:Moving coil linear stepper motors are unique compared to other types of linear stepper motors. They consist of a stationary coil assembly and a moving magnet assembly. When the coils are energized, the magnetic field pushes or pulls the magnet assembly, causing linear motion. Moving coil linear stepper motors offer high acceleration, high force output, and excellent responsiveness. They are commonly used in applications that require rapid movement and high precision, such as semiconductor fabrication and pick-and-place machines.  

4.Common applications of linear stepper motor

1.Robotics and automation:Linear stepper motors are frequently employed in robotics and automation systems. They are used for precise motion control in robotic arms, automated assembly lines, and autonomous vehicles. Linear actuators based on stepper motors are often preferred for their accurate position control and ability to perform repetitive tasks.

2.Medical equipment:In the medical field, linear stepper motors are used in various equipment and devices. They are utilized in precision surgical robots, automated drug dispensers, adjustable hospital beds, and diagnostic equipment. Linear motors' precise movement and compact design make them suitable for medical applications that demand high precision and efficiency.

3.Consumer electronics:Linear stepper motors play a crucial role in consumer electronics, particularly in devices that require controlled linear motion. They are found in printers, scanners, disk drives, camera lenses, and autofocus systems. Linear motors enable smooth and precise movements in these devices, enhancing their overall performance and user experience.

4.Industrial automation:Linear stepper motors are extensively used in industrial automation applications. They provide precise control and positioning in CNC machines, pick-and-place systems, industrial robots, and material handling equipment. Their ability to perform accurate and repeatable movements significantly improves the productivity and efficiency of industrial processes.

Development issues of right angle planetary gearbox

1.Basic definition of right angle planetary gearbox

A right angle planetary gearbox is a compact device that uses a planetary gear system to transmit power and torque from an input shaft to an output shaft at a 90-degree angle, making it suitable for applications with limited space or specific alignment needs. It consists of a planetary gear train, which includes a central sun gear, surrounding planet gears, and an outer ring gear, combined with a right-angle bevel gear set to achieve the 90-degree change in direction. 

2.The working principle of right angle planetary gearbox

A right-angle planetary gearbox works by using a planetary gear system with gears arranged to change the direction of motion by 90 degrees, allowing for compact, space-saving designs in applications where the input and output shafts are perpendicular. The core components—a sun gear, multiple planet gears orbiting it, a ring gear, and a carrier—distribute the load among the planet gears, providing high torque density, efficiency, and precision in a compact package.       

3.Key design advantages of angle planetary gearbox

1.High Torque Density:The load is distributed across multiple planet gears surrounding a central sun gear, allowing for significantly higher torque output in a smaller, more compact unit compared to traditional gearboxes. 

2.Compact and Space-Saving:Their unique coaxial and concentric gear arrangement allows for a small, efficient design that is crucial for integrating into machinery with limited space, such as automated systems and robotic arms. 

3.High Efficiency:The multiple meshing points and primarily rolling contact between gear teeth minimize friction and energy loss, leading to high operational efficiency and reduced heat generation. 

4.High Precision and Low Backlash:The symmetrical design of the planetary system, with multiple points of contact, provides excellent positional accuracy and high torsional stiffness, which is vital for applications demanding precise motion control. 

5.Durability and Reliability:Load distribution across multiple gears reduces stress on individual components, leading to increased wear resistance and enhanced overall durability and reliability. 

6.Design Flexibility:The combination of a right-angle housing and planetary design offers mounting flexibility, allowing installation in any direction to suit the specific requirements of the application. 

4.Development issues of right angle planetary gearbox

1.Design and Performance Issues:The 90-degree angle requires additional components, such as bevel gears, which increases the overall complexity and cost of the gearbox. Gear types with angled teeth, like spiral bevel gears, can have a lower torque capacity compared to other designs due to their smaller total tooth contact area. The gear teeth can generate noise and vibration, which can be problematic in applications requiring smooth and quiet operation. The angle change can limit the suitability of right-angle gearboxes for high-speed applications, potentially causing reduced rotational speed and increased wear. 

2.Maintenance and Material Challenges:Proper lubrication is critical for smooth operation but requires additional maintenance and cost. Gearbox development must consider environmental factors like shock, vibration, and washdown conditions, requiring corrosion-resistant materials or stainless steel for certain applications.Some applications, particularly in the food and beverage industry, require specific food-grade lubricants and corrosion-resistant materials. 

3.Cost and Market Issues:High-precision right-angle planetary units can be more expensive than alternative solutions, which can be a barrier in price-sensitive markets.Inline planetary or standard helical reducers can offer a cost-effective alternative for applications that do not require the right-angle configuration or high precision.Import barriers and delays can increase the total cost of gear components, particularly in markets with limited local manufacturing capabilities.

4.Manufacturing and Regulatory Challenges:A lack of domestic capability to produce highly precise right-angle planetary units can hinder scaled production and increase reliance on imports. Product development must align with regional safety standards, environmental regulations, and energy efficiency directives to ensure market access. The availability of skilled labor and technical expertise in gear manufacturing and integration is crucial for successful product development and market growth.

Core technology and structure adcantages of worm reduction gearbox

1.What is a worm gear reducer gearbox?

A worm gear reducer gearbox is a compact mechanical device that transmits rotational motion between two non-intersecting shafts at right angles, using a screw-like worm and a worm wheel. It is designed to significantly reduce speed and increase torque in a small package, often featuring a right-angle output and a self-locking (non-back-driving) effect that prevents reverse movement, making it useful in applications like elevators and conveyor belts. 

2.Working principle of worm gear reducer gearbox

1.Input Motion:The motor or engine turns the worm, causing its threaded shaft to rotate. 

2.Engagement:The worm's spiral threads engage with the teeth of the worm wheel, which is positioned perpendicular to the worm shaft. 

3.Output Rotation:As the worm turns, its threads push against the worm wheel's teeth, causing the worm wheel to rotate around its axis. This transfer of motion results in a lower speed and higher torque at the output shaft. 

4.Sliding Contact:Unlike other gear types that use rolling contact, worm gears rely on a sliding friction between the worm's threads and the worm wheel's teeth.    

3.Structure advantages of worm gear reducer gearbox

1.Compactness and High Torque:The design of the worm and worm wheel provides a large reduction ratio in a very small space, producing high output torque. This makes them suitable for applications with limited installation space. 

2.Self-Locking Capability:Many worm gearboxes have a self-locking feature that prevents the driven shaft from rotating backward when power is off. This acts as a built-in mechanical brake, increasing safety in applications like hoists and conveyor systems. 

3.Smooth and Quiet Operation:The sliding contact between the worm and the worm wheel, along with a large contact area, results in less vibration and smoother, quieter operation compared to some other gear types. 

4.Durability and Shock Resistance:The robust construction and design of worm gearboxes enable them to withstand heavy loads and shock. This ensures longevity and reliability in harsh environments and heavy-duty applications. 

5.High Reduction Ratios:A single-stage worm gear can achieve very high reduction ratios, making them efficient for reducing speed significantly and multiplying torque. 

6.Low Maintenance:Due to their simple structure and robust design, worm gearboxes require minimal maintenance, often just requiring regular inspection and lubrication. 

4.Core technology of worm gear reducer gearbox

1.Annular surface enveloping transmission technology: Adopting annular surface enveloping worm gear structure, the contact area is increased (up to 85%) through multi-tooth meshing design, and high torque density (500Nm/kg) is achieved, which is more than 3 times higher than the traditional solution.

2.Miniaturized manufacturing process: Through the compact design of 4.5-10mm center distance, the volume is reduced by 40%, the weight is only 9-49g, and the torque output is 1-3N·m. This miniaturized technology breaks the contradiction between the volume and performance of traditional reducers and provides a solution for smart machinery. ‌

3.High-precision tooth shape design: The asymmetric tooth profile design reduces the center distance by 30%, the surface roughness Ra0.4μm, and the gradient composite coating technology extends the life of the worm gear by 2.3 times. The laser processing technology further optimizes the uniformity of the tooth surface contact stress and improves the load-bearing performance by 38%. ‌

4.Self-locking characteristics: The self-locking function is achieved by relying on friction and lead angle design, and only one-way transmission is allowed, and reverse drive is impossible. This feature plays a key protective role in safety scenarios such as lifting machinery. ‌

5. Efficient heat dissipation and lubrication: The embedded heat sink and forced oil cooling system (≥12L/min) are used to accurately control the temperature rise Δ45℃ to ensure long-term stable operation. Lubricant additive technology allows the gear oil to adhere to the surface to form a protective film when the machine is stopped, reducing direct contact wear.

Selection principles of a hollow rotary actuator

1.Brief of a hollow rotary actuator

A hollow rotary actuator is an integrated device that combines a high-rigidity hollow rotary table with a motor and driver, designed for automated angular adjustment and the accurate, high-torque positioning of large-inertia loads. Its defining feature is a large-diameter central bore, which simplifies wiring, piping, and installation by allowing components to pass directly through the unit. These actuators are used in factory automation for tasks like robot joints, alignment mechanisms, and rotary tables, offering advantages such as high precision, reliability, and simplified equipment design. 

2.Key Components and functionality

1.Motor & Driver:An integrated motor (often a stepper motor) with a driver provides the energy for rotation. 

2.Hollow Output Table:The central component is a large-diameter, hollow output table with a high-precision, direct-mount design. 

3.Bearings:Cross-roller bearings are used to support high axial, radial, and moment loads, providing rigidity and durability. 

4.Mechanical Encoder:Many models include a built-in, battery-less absolute encoder, eliminating the need for external home or limit sensors.      

3.Key technologies of a hollow rotary actuator

1.Hollow Shaft/Bore:The defining feature is the large diameter hole through the center of the actuator, which simplifies wiring and tubing, reducing the need for complex routing and saving space. 

2.High-Rigidity Cross-Roller Bearings:These bearings are crucial for providing high stiffness and accuracy, allowing the actuator to withstand significant radial, thrust, and moment loads without excessive deflection. 

3.Optimized Gear Train:A carefully designed gear train provides precise speed reduction and torque multiplication while maintaining a compact form factor. 

4.Integrated Sensors:Many hollow rotary actuators feature built-in mechanical absolute encoders, eliminating the need for external sensors for homing and positioning, thereby simplifying the system design. 

5.High Torque & High Accuracy:The combination of the bearing design and integrated components allows for high torque output and high positional accuracy despite the actuator's compact size. 

6.Simplified System Design:By allowing components to pass through the shaft, the hollow design eliminates the need for separate mechanical components like belts and pulleys, reducing complexity, cost, and potential errors. 

4.Selection principles of a hollow rotary actuator

1.Understand Application Needs:Define the required torque for starting and stopping, and the desired rotational speed and acceleration/deceleration rates. For precise tasks, consider backlash (the amount of play in the system) and repeatability to ensure the actuator can consistently reach and hold target positions. Determine how accurately and quickly the actuator must stop at a specific position. 

2.Calculate Loads:Calculate the load's moment of inertia, as it indicates how difficult it is to start or stop the load. Use the load inertia and desired speed/time to calculate the acceleration torque needed. If the load exerts forces on the output shaft, calculate the axial and radial loads and ensure they are within the actuator's specifications. 

3.Evaluate Actuator Specifications:Ensure the actuator can provide the necessary torque and handle the load's moment of inertia within the required positioning time. Verify that the actuator can withstand the calculated axial and radial loads. Look for actuators with high rigidity to prevent vibration and ensure stable operation. 

4.Consider Practical Design Aspects:The large hollow center simplifies equipment design by allowing cables and tubing to pass through, reducing complex wiring and piping. Consider the mounting configuration (horizontal, ceiling, or wall mount) and whether a motor clearance hole is needed in the mounting plate, or if an accessory installation pedestal is required. Some actuators may produce a small amount of grease leakage. If this is a concern due to contamination, plan for routine inspection or install protective equipment.