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Machine Tool Balancers
Hofmann Magnetic Balancer AB 9000 MT

AB 9000 MT
Balancers for High-Speed,High-Precision Grinders

Designed balancing systems for high-speed, high-precision grinders. The response of the system enables balancing corrections to be performed in seconds, and can be used on machines with automatic wheel changes.

The balancing system is comprised of five parts: balancer, actuator coil, sensors, controller and software. The balancer is mounted permanently onto the spindle of wheel hub; sensors continuously monitor the 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 machine PLC, either of which can instruct the balancer to make an automatic balance correction.

The Balancers have been designed to address the following:

1. Grinding wheel wear

2. Chatter caused by vibration

3. High-speed spindles

4. Precision two – plane balancing

5. Machine Tool PLC interface

6. Reduced cycle times

7. Improved surface finish and dimensional accuracy

8. Extended wheel and spindle bearing life

The Electro-Magnetical Ring-Balancer

The electro-magnetical balancer contains a balance ring, which mounts directly onto the spindle shaft or wheel hub. Inside the balance ring are two symmetrical counterweighted rotor assemblies which, when directed, move to create a net correction vector that will offset the measured unbalance. The counterweighted rotors are held in place using permanent magnets that are fixed to the rotors. These magnets create a holding torque, which prevents the rotors from slipping during normal operation, ramp-up or coast down. When a balance correction is required, actuator coil power pulses are sent to magnetically step the rotors to the desired position in a few seconds.

Balancer Sizes
Balancing System Features

1. Balances at spindle speeds up to 25,000 RPM and higher

2. Balances the entire spindle assembly in seconds after each wheel change

3. Protects spindles by monitoring vibration continuously and shutting down automatically if vibration is excessive

4. Rugged construction withstands the harshest environment

5. Optimum rotor integration through ring design

6. High balancing speeds

7. Short balancing time

8. Determined positioning

9. Neutral position

10. Position feedback

11. Pre-balancing

The Stator

The stator typically mounts inside or at the front of the spindle The stator pulses power to the balancer assembly. The counterweighted rotors are thus moved to the desired counter-balance position. The actuator coils  stator contains sensors for monitoring spindle RPM as well as the angular location of each counterweighted rotor.

AB9000Controller
The AB 9000 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 Ethernet connection) either of which can instruct the balancer to make an automatic balance correction. 

Modular design for max. four measuring channels, simultaneous monitor for all measuring channels.

Adaptive balancing methods with a Real dual-plane balancing,

The Software

Software
The full-featured graphical user interface software provides the ability to view real-time amplitude and phase information in both numerical and graphical format. Additionally the software provides the ability to view the balancer correction vector, which provides valuable information regarding the available correction capacity.

The ability to remotely access the software via Ethernet and configure the balancer while initiating the balance correction is a popular feature of the software package.

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How Does The AB 9000 Automatic Balancer Work

The balancer installation typically consists of a controller, a vibration sensor, a balancer ring fitted to the shaft or spindle and a fixed stator assembly. The system monitors the vibration at the shaft rotational frequency (imbalance), once an increase in imbalance vibration is detected which breaches pre defined alarm limits the controller pulses power to the balancer ring through the stator which commands the balancer rings to move to counter imbalance forces of the rotating shaft assembly. Once the vibration has reduced below a lower pre defined vibration limit the system ceases the balancer movements and continues to monitor for changes.

FAN APPLICATION.

Hofmann Fan Installation

 MACHINE TOOL APPLICATION.

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THE BALANCING PROCESS

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Hofmann HydroBalancer HB 6000

HB6000
Automatic (active) balancing of grinding wheels and grinding spindles or other rotors.

The compensation of the unbalance is made by using fluids (water, oil, coolant). A four-chamber ring container is integrated into the fixing flange. Magnitude and location of unbalance are determined by the balancing electronic and processed accordingly for control of the balancing operation. The fluid is supplied to the four injection nozzles of the four correction chambers. The quantity required is controlled via four solenoid valves. Compensates the rotor unbalance by controlled injection of liquid into the ring container using the component method.

The HB 6000 has a pre-balancing function. Whenever the initial unbalance of the grinding wheel is bigger than the maximum balance capacity of the ring container, the balancing electronic will only calculate the compensation mass and its position. The software of the HB 6000 allows determination of unbalance compensation, even under operational conditions.

 

HB6000Detail

The balancers have been designed to address the following:

1. Grinding wheel wear

2. Chatter caused by vibration

3. Machine Tool PLC interface

4. Reduced cycle times

5. Improved surface finish and dimensional accuracy

6. Extended wheel and spindle bearing life

7. Unbalance monitoring

8. Balancing during rotation without having to stop the machine

9. Balancing with the help of fluids, e.g. cooling lubricants of a grinding machine

10. High precision balancing through extremely fine fluid metering up to very high rotational speeds

11. Space-saving integration of the ring container in the machine spindle or rotor

12. Pre-balancing software for manual correction of basic unbalance; HB 6000 then only balances the new operational unbalances

13. Also suitable for retrofitting existing machines

14. Compatible replacement for Hofmann HK 5000 balancing systems incl. type BM sensors

15. Cost effective solution

 

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Machine Tool Balancers
Hofmann MecBalancer MB 4002

 

Hofmann MB 4002

The balancers have been designed to address the following:

  1. Grinding wheel wear
  2. Chatter caused by vibration
  3. Machine Tool PLC interface
  4. Reduced cycle times
  5. Improved surface finish and dimensional accuracy
  6. Extended wheel, and spindle bearing life
  7. Balancers for Low-Speed Grinders

Our balancing system for low-speed, high-precision grinders is comprised of four parts: balancing head, tranmitter, sensor and controller. The balancing head 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 MecBalancer Principle

The compensation of the unbalance is made by two balancing weights. A very rugged electromechanical balancing head is mounted on the flange or directly integrated into the spindle. The balancing weights are positioned with the spread angle method by use of two positioning motors.

MB4002

The Non-Con Transmitter

The Non-Con transmitter 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 (energy transfer distance up to 5 mm). The transmitter also works on oscillating or reciprocating spindles, and will operate at speeds up to 5,000 RPM for external heads and 15,000 RPM for internal heads.

The MB 4002 Controller

The controller continuously monitors vibration levels. The Magnitude and location of unbalance are determined by the balancing electronic and processed accordingly for the control of the balancing operation. When a change occurs which exceed a preset level, the controller determines the optimum balance correction required.
The controller send an advisory message to the operator and the machines PLC (via either PLC I/O either of which can instruct the balancer to make an automatic balance correction.

The MB 4002 has a pre-balancing function. Whenever the initial unbalance of the rotor is bigger than the maximum balance capacity of the balancing head, the balancing electronic will only calculate the compensation mass and its position. The MB 4002 allows determination of unbalance compensation, even under operational conditions.

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Hofmann AB 9000 PRO - Active Ring Balancer

Hofmann AB9000Our balancing systems have been installed in a number of industries including:

  1. Cement
  2. Chemical
  3. Foundries
  4. Glass
  5. Paper
  6. Steel
  7. Utilities
  8. Waste Water

The use of our balancing systems has helped to improve our customer's reliability, production capability and quality, while reducing maintenance and manufacturing costs.


Features & Benefits

  1. Improved Production Uptime
  2. Reduces unplanned downtime/emergencies due to balance related vibration problems
  3. Extends planned maintenance intervals
  4. Reduces start-up time
  5. Optimisation of Equipment Life
  6. Compensates for variable balance conditions: RPM, thermal changes, and material build-up
  7. Eliminates multiple starts by easing equipment through criticals during start-up and shutdown
  8. Reduces wear-and-tear on equipment
  9. Maximise Asset Availability
  10. Continuous monitoring/diagnostics
  11. Proactive analysis of potential balance problems
  12. Remote analysis capabilities

 

Fan Product Information

Active Ring Balancer
Balancers for Centrifugal Induced Draft/Forced Draft and Axial-Van Fans
Balancing systems are comprised of sensors, a controller and one or more balancers that make trim balance corrections to reduce fan vibration while the fan is running, at any operating speed or load. The system is able to compensate for variable balance conditions due to material build-up, temperature variations and changing process conditions. Balance corrections are made automatically or manually, minimising vibration caused by unbalance in seconds.

 

Features & Benefits

Cost Effective – reduces downtime and increases productivity. Trim balances equipment while operating, without a forced shutdown. Eliminates multiple starts and stops necessary for manual balance correction. Provides rapid payback on balancing system and installation cost.

Efficient – optimizes equipment life (bearings, motors, seals, etc.).

Adaptable – fits with existing condition monitoring systems. Operates in either automatic or manual modes.

Versatile – maximizes asset availability.

Reliable – performs continuous monitoring and diagnostics, on-site or remote. Eliminates unscheduled maintenance.

balancer fan types

Fail-Safe – maintains last correction, even if power is lost.

How the Balancing System Works

One or more balancers are permanently fixed on the rotating shaft, and each balancer is surrounded by a stationary coil used to transmit power into the balancer(s). Sensors monitor vibration levels and transmit information to the controller. When vibration levels exceed a preset high-limit, the controller signals the coil(s) to pulse power to the balancer(s) to make a balance correction. The correction is made by the repositioning of two counterweighted rotors relative to each other, located inside the rotating balancer(s). Vibration levels are reduced as the rotors are moved, until the controller senses that vibration levels have dropped below a preset low-limit. The rotors are repositioned in seconds to complete the trim balance correction, while the fan continues operating without a forced shutdown.

Balancer Benefits

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Wordwide perspectives

Through our wide ranging partnerships and distributor agreements we are able to cater to all markets and customer requirements.