LORD has a full range of spindle balancing
systems designed for high-speed spindle, high
precision grinder balancing. The response of the
system enables balancing corrections to be
performed in seconds, and can be used on
machines with automatic tooling changes.
The system is comprised of five parts:
balancer, rotary transformer, sensors,
controller and software. The balancer is mounted
permanently onto the spindle; sensors
continuously monitor the vibration levels while
running. When an increase in vibration is
detected above a pre-determined level, the
controller can be programmed to make an
automatic balance correction or send an advisory
message to a plant control system.
Benefits of the Balancing System include:
- Increases spindle speeds resulting
in increased thru put of product
- Improves part tolerance variation
- Eliminates vibration caused by run
out
- Increases tool life
- Eliminates manual balancing at setup
and tool changing
- Increases spindle/bearing life of
the machine tool
- Improves part surface finish
The Balancer
The electro-mechanical balancer consists of a
balance ring, which mounts directly onto the
spindle shaft. 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.
Features of the Balancing System include:
- Balances at spindle speeds up to
40,000 RPM
- Balances to levels below G-1.0 at
speed prior to grinding or truing
- Balances the entire spindle and
tooling assembly in seconds
- Protects spindles by monitoring
vibration continuously and shutting down
automatically if vibration is excessive
- Rugged construction withstands the
harshest environments
The Actuator Coil
The actuator coil typically mounts to the
static portion of the spindle housing. With no
moving parts, the actuator coil pulses power to
the balancer assembly. The counterweighted
rotors are thus moved to the desired
counter-balance position. The actuator coil
contains sensors for monitoring spindle RPM, as
well as the angular location of each
counterweighted rotor.
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.
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 th ability to view the
balance 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 this software package.
