Servo controlled rotary table

Types of Servo Controlled Rotary Tables

A servo controlled rotary table is a work positioning device commonly used in CNC milling machines. It enables machines to cut, normally at right angles, to rotate workpieces or fixtures precisely on the programmed axis and angles. Unlike the direct drive tables that anuses worm gears and belts to offer movement, the servo-driven models use a servo motor and gearbox for accurate and repeatable results. To achieve accuracy, repeatability, and reliability, the rotary tables can feature closed-loop control and high-resolution digital encoders.

Based on the driving system, the rotatory tables can be divided into four main types - direct drive, harmonic drive, worm gear drive, and belt drive:

• Direct drive : It provides a simple, more-profound design and more, more good backlash, accuracy, smoothness of motion, and higher speed than worm gear transmissions, such as a high-precision servo motor connected directly to the rotation axis of the table. With no intermediate gears interacting, a direct drive rotary table usually possesses a predetermined backlash. Also, it has improved efficiency, so an extra power consumption isn't required to attain the same level of torque and speed.
• Harmonic Drives: A disadvantage of direct drives is that the motor's rotor needs to be of a more prominent diameter to provide a sufficient moment of inertia to ensure stable speed during the machining process. Moreover, a direct drive servo motor usually rotates at a higher speed than necessary, requiring a gear ratio to reduce the speed and increase the torque output. To achieve vast gear ratios in compact assemblies, the servo motor can be normed to a harmonic drive gear. These gears can offer very high gear ratios and an excellent accuracy of start and stop position.
• Worm Gear Drives: They utilize a worm screw to drive a worm wheel. This design allows for large reductions in gear ratio and provides great torque, which is usually required to turn heavy loads. Among the advantages of worm gear drives is the fact that they provide self-locking capabilities, allowing the table to stay in position even if the power is turned off.
• Belt Drives: They can provide huge reductions in gear ratio and high speeds, which are commonly needed in applications.

Based on the table's construction, as mentioned earlier, rotary tables can have three main types.

• Vertical Axis : To mount vertical CNC rotaries are machines that can hold workpieces on their vertical plane. Like all other CNC rotary tables, their primary purpose is to allow for machining on both vertical and horizontal planes.
• Horisontal Axis: At the same time, horizontals CNC rotary tables are machines that can hold workpieces on their horizontal perimeter.
• Tilting Axis: CNC tilting rotary tables are machines that fix workpieces within their assemblies. The support workpieces' support fixtures and jigs can be tilted at a predetermined angle and precision, locating and hold them in alignment.

Specifications and Maintenance

The basic specifications for a rotary table servo are as follows:

• Sizes

  They come in various sizes, but common sizes are 250, 300, 350, 400, 450, 500, 600, 1000, and 1200.

• Speed

  Angular velocity has a parameter range, but table speed of 0 to 242r/min is typical.

• Torque

  Whether direct drive or gear/rack pinion servo torque, the holding torque is typically 10N.m at zero position.

• Payload

  The payload is the maximum load, static or dynamic, that the rotary table can support. Static payload examples are 35Kg at a radius of 100mm, 70Kg at a radius of 200mm, etc. It can be higher at increased inertia.

Maintenance

While no grease replenishment is required, operators should periodically change the oil on lubricant seals and replace the oil at their rotary table service centers. There should not be any mechanical adjustments. Cooling water should be of drinking standard and covered with a standard non-ferrous alloy.

Application scenarios of the servo controlled rotary table

The applications of the servo rotary tables are numerous and varied. They are extensively used in the CNC machining industry due to their high precision and efficiency levels. However, they are also useful in other industrial fields.

• Industries that commonly use servo rotary tables: The packaging sector makes good use of the servo motor rotary table. It is widely used on assembly lines to package products quickly and efficiently. The food and beverage industry also uses these tables for labeling and bottle packaging.
• Healthcare and automotive industries make good use of the servo rotary table indexers: These precision devices are ideal for assembly operations where consistent and repeatable part orientation is required. Robotics is another field where servo rotary tables can be found. They are usually mounted on robot arms as a means to extend the robot's reach and allow for more flexible and agile movements.
• Entertainment industry: Servo rotary tables with cameras are mostly used for filming purposes. They create smooth and steady shots, adding entertainment value to the final film or video.
• Medical field: The medical servo rotary tables are mainly used for serving and holding medical equipment and tools during surgery. Their precision and repeatability make them ideal for delicate and intricate surgical procedures where the surgeon requires utmost ease and comfort.

Tips for choosing a servo controlled rotary table

When choosing a servo motor rotary table, it's essential to consider many factors to ensure that the final purchase is in line with application needs. First of all, it is important to determine the intended use or application of the rotary table. Identify specific needs like the desired positioning accuracy. Next, take a look at the payload capacity of the rotary table. The selected table should have enough capacity to handle the weight of the intended payload. It's also important to consider the drive system of the rotary table. Choose a drive system that complements the application and ensures smooth performance. Another important thing to consider is the size and dimensions of the rotary table. Choose a size that fits the particular setup or configuration. Also, consider the available connection interfaces of the rotary table. Choose a table with connection interfaces that work with the existing control systems. Additionally, vibration, shock, and cleanliness levels and requirements must be considered when selecting a rotary table. The parameters of the table should be in line with these system demands to ensure optimal performance. Finally, consider the environmental factors of the intended application. Determine whether or not the rotary table will be exposed to harsh environmental conditions. If yes, then a suitable protective enclosure should be considered.

FAQ

Q1: How are servo rotary tables different from traditional rotary tables?

A1: Traditional rotary tables are generally controlled by human gears or flow valves, leading to less accurate positioning and repeatability. Servo-controlled rotary tables have the advantage of high-precision positioning, repeatability, and automation.

Q2: What are some trends related to the rotary servo table?

A2: The trend is toward intelligent and integrated rotary tables. The servo-controlled rotary table is integrated with artificial intelligence, IoT, and cloud technology, achieving remote monitoring, data analysis, and intelligent decision-making capabilities. An intelligent servo rotary table can adjust operating parameters and modes according to the ambient environment and working status, thereby enhancing flexibility and adaptability.

Q3: What is the future development of the servo rotary platform?

A3: The future development of the servo rotary platform will focus on improving the performance of the rotary table, enhancing its load-bearing capacity, expanding the applicable scenarios, and promoting the popularization and application of intelligent rotary table technology.