Vibration Specifications Standards For Machine Tool Spindles
And Heads With Alarm Limits
Spindle And Head Requirements
All single spindle and multi-spindle units will be (where
possible) mounted on a test stand in their normal operating
attitude, properly secured in a STRESS FREE CONDITION and
be either direct coupled or belt driven. Integral motor
spindles (motorized spindles) will be tested as a self-powered
unit.
The Spindle or Head will be run-in until it reaches temperature
stability at operating speed.
Measurement Locations
Vibration measurement locations shall be;
· at a point as close to the spindle bearing as possible
and in line with the spindle center line
Figure 1 (a) Measurement Locations for Single Precision
Spindle
Figure 1 (b) Measusrement Locations for Spindle Cluster
Figure 1 (c) Measurement Locations for Multi-Spindle Gear-type
Head
Operating Speed:
If a spindle unit is designed to operate at one speed,
the unit is to be tested at that speed.
If a spindle unit is designed to operate at multiple speeds,
the unit is to be tested at the each rated speed.
If a spindle unit is designed to operate at all speeds
in a given speed range, the unit must be tested at its'
maximum rated speed, unless this coincides with a resonance
or resonance-like condition. In this case, the test speed
shall be the maximum speed possible without encountering
the resonance or resonance-like condition.
VIBRATION LIMITS
LIMITS FOR BOX AND CARTRIDGE-TYPE
SPINDLES
The maximum velocity amplitude (Inch/sec-Peak) of vibration
at bearing locations in any direction shall not exceed the
Line Amplitude Band Limit values specified and graphed when
determined in accordance
The maximum acceleration amplitude (g's Peak) of vibration
at bearing locations in any direction shall not exceed the
Band-Limited Overall Amplitude Acceptance Limits specified
and graphed when determined in accordance
TABLE 1 MAXIMUM ALLOWABLE VIBRATION LEVELS FOR GEARLESS
TYPESPINDLES 600 to 12,000 RPM (<= 400,000 DN)
LINE-AMPLITUDE BAND LIMITS
BAND FREQUENCYRANGE (CPM) VELOCITY(INCH/SEC - PEAK)
1 0.3 x RPM0.8 x RPM 0.01
2 0.8 x RPM1.2 x RPM 0.01
3 1.2 x RPM3.5 x RPM 0.01
4 3.5 x RPM120,000 CPM 0.005 - Angular Contact Bearings0.0075
- Roller Bearings
BAND-LIMITED OVERALL AMPLITUDE LIMITS
BAND FREQUENCYRANGE (CPM) ACCELERATION(g’s PEAK)
1 0.3 x RPM - 120K CPM 0.5 - Angular Contact Bearings1.0
- <= 1000 RPM - Roller Bearings1.5 - > 1000 RPM -
Roller Bearings
Figure 2 Line Amplitude Acceptance Limits for Gear less
Type Spindles 600 to 12,000 RPM
Figure 3 Band-Limited Overall Amplitude Acceptance Limits
for Gear less Type Spindles 600 to 12,000 RPM
TABLE 2 MAXIMUM ALLOWABLE VIBRATION LEVELS FOR GEARLESS
TYPE SPINDLES <600 RPM
LINE-AMPLITUDE BAND LIMITS
BAND FREQUENCYRANGE (CPM) DISPLACEMENT(MILS - PEAK-TO-PEAK)
1 0.3 x RPM0.8 x RPM 0.1
2 0.8 x RPM1.2 x RPM 0.1
VELOCITY(INCH/SEC - PEAK)
3 1.2 x RPM3.5 x RPM 0.01
4 3.5 x RPM30,000 CPM 0.005 - Angular Contact Bearings0.0075
- Roller Bearings
BAND-LIMITED OVERALL AMPLITUDE LIMITS
BAND FREQUENCYRANGE (CPM) ACCELERATION(g’s PEAK)
1 0.3 x RPM - 60K CPM 0.5 - Angular Contact Bearings0.75
- Roller Bearings
Figure 4 Line Amplitude Acceptance Limits for Gear less
Type Spindles <600 RPM
Figure 5 Band-Limited Overall Amplitude Acceptance Limits
for Gear less Type Spindles <600 RPM
LIMITS FOR INTEGRAL MOTOR
(MOTORIZED) SPINDLES
Integral Motor (Motorized) Spindles shall be tested as
a complete assembly (motor & spindle).
The complete assembly must meet the vibration limits specified
"LIMITS FOR BOX AND CARTRIDGE-TYPE SPINDLES."
LIMITS FOR MULTI-SPINDLE
(CLUSTERS) NON-GEAR TYPE ASSEMBLIES
Belt driven Multi-Spindle Clusters shall be tested as a
complete assembly.
The complete assembly must meet the vibration limits specified
"LIMITS FOR BOX AND CARTRIDGE-TYPE SPINDLES."
LIMITS FOR GEAR-DRIVEN SPINDLE
ASSEMBLIES
For gear driven spindle assemblies the number of lines
of resolution from 0.3 x Lowest Shaft Running Speed to 3.5
x Highest gear mesh frequency (GMF) or otherwise specified
Fmax shall be sufficient to resolve the 1st Order Gear Mesh
Sideband frequency (e.g. + 1 x Shaft RPM).
In the Velocity Spectra and the Acceleration Spectra, the
line amplitude of the Gear Mesh Frequency Sidebands must
be less than (<) 0.5 times the line amplitude of the
Gear Mesh Frequency. The line amplitude of sidebands of
Harmonics of the Gear Mesh Frequency must also be <.5
X the line amplitude of the GMF Harmonics.
In the Velocity Spectra and the Acceleration spectra, the
line amplitude of GMF Harmonics must not exceed 0.2 x GMF
line amplitude.
The maximum velocity band-limited overall amplitude (Inch/sec
- Peak) of vibration at locations specified and illustrated,
in any direction (as defined) shall not exceed the Band-Limited
Overall Amplitude Acceptance Limits specified
TABLE 3 MAXIMUM ALLOWABLE VIBRATION LEVELS FORGEAR-DRIVEN
SPINDLE ASSEMBLIES
BAND-LIMITED OVERALL AMPLITUDE LIMITS
BAND FREQUENCYRANGE (CPM) VELOCITY(Inch/sec - Peak)
1 0.3 x Lowest Shaft RPMto3.5 x Highest GMF 0.08
Figure 6 Band-Limited Overall Amplitude Acceptance Limits
for Gear-Driven Spindle Assemblies
Where the number of machining components or high speeds
cause a head to exceed acceptable limits, a decision to
correct or accept shall be mutually agreed upon by purchaser
and machine builder.
PRECISION MACHINE TOOLS
Precision Machine Tools shall not exceed the Vibration
Limits specified and graphically illustrated
TABLE 4 MAXIMUM ALLOWABLE VIBRATION LEVELS FORPRECISION
MACHINE TOOLS
LINE-AMPLITUDE BAND LIMITS
BAND FREQUENCYRANGE (CPM) VELOCITY(INCH/SEC - PEAK)
1 0.3 x RPM0.8 x RPM 0.02
2 0.8 x RPM1.2 x RPM 0.02
3 1.2 x RPM3.5 x RPM 0.01
4 3.5 x RPM120,000 CPM 0.005 - Angular Contact Bearings0.0075
- Roller Bearings
BAND-LIMITED OVERALL AMPLITUDE LIMITS
BAND FREQUENCYRANGE (CPM) ACCELERATION(g’s PEAK)
1 0.3 x RPM - 120K CPM 0.5 - Angular Contact Bearings1.0
- <=1000 RPM - roller Bearings1.5 - >=1000 RPM - Roller
Bearings
Figure 7 DEFAULT Line Amplitude Acceptance Limits for Precision
Machine Tools
Figure 8 DEFAULT Band-Limited Overall Amplitude Acceptance
Limits for Precision Machine Tools
