LORD Corporation’s balancing system for low-speed, high-precision grinders is comprised of five parts: balancer, actuator coil, sensor, controller and software. The balancer is mounted permanently onto the wheel hub and sensors continuously monitor vibration levels while running. When an increase in vibration is detected above a pre-determined level, the controller sends an advisory message to the operator and the machines PLC, either of which can instruct the balancer to make an automatic balance correction.
The balancers have been designed to address the following:
- Grinding wheel wear
- Chatter caused by vibration
- Machine Tool PLC interface
The Balancer
Consisting of no moving parts, the fluid balancer houses four connecting chambers each containing a high-density fluid and heating element. When an imbalance is detected, the controller when initiated activates the on-board microprocessor to direct power to the insert heaters of the heavy chamber. This power vaporizes the high-density fluid, forcing it to the opposite cooler chamber where it condenses into liquid, correcting the unbalance.
Balancing System Features
- Closed loop system, impervious to contamination
- Ability to balance at levels as low as the background noise of the grinder
- No moving parts reduces maintenance
- Rugged construction withstands the harshest environments
The Actuator Coil
The actuator coil has no moving parts. It consists of a stationary primary coil and a rotating secondary coil, which allows power and data to transfer across an air gap between the two coils. The actuator coil also works on oscillating or reciprocating spindles, and will operate at speeds up to 5,000 RPM.
The Controller
The controller continuously monitors vibration levels. When a change occurs which exceed a preset level, the controller determines the optimum balance correction required. Depending upon the mode of operation selected the controller will send an advisory message to the operator and the machines PLC (via either PLC I/O or an RS232 serial port) either of which can instruct the balancer to make an automatic balance correction.
Controller Features
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Data storage (vibration and balance coefficients)
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EEPROM storage of setup parameters
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Automatic self-calibration
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Reduces cycle time
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Improves surface finish and dimensional accuracy
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Extends wheel and spindle bearing life
The Software
The full-featured graphical user interface software provides the ability to view real-time amplitude and phase information in both numerical and graphical formats. Additionally the software provides the ability to view the fluid transfer operation, keeping you informed as to what is happening within the balancer.
The data history files store information regarding the machine's process and performance including: maximum/minimum vibration levels, balance frequency, wheel changes and machine sensitivity at various spindle speeds.
The software captures machine signature ad spectrum readings, providing valuable frequency response information through the entire spindle operating speed range. This information assists in identifying problems associated with structural components, machine resonance and foundations.