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Axial Clearance For Bearings
Gage
Parameters
GAGING SYSTEM: Electronic (LVDT)
OPERATION: Semi-Automatic
NUMBER OF CHECKS: 1
READOUT: CAGTM
CLASSIFICATION: Good/Reject
FEATURES: Semi-Automatic measuring of "clearance" commonly know as
Axial Clearance between the inner race, and the outer race and ball
or roller compliment.
The Challenge
Every bearing in existence has some amount of clearance in the races
for the balls or roller to be able to perform correctly under load.
That "clearance" commonly know as Axial Clearance for its direction
in line with the axis of the shaft, needs to be measured very
accurately in order to verify the bearing quality. But the vast
range of sizes of different bearings makes this a formidable task.
And if the variability of size is not enough of a challenge, try
considering achieving this measurement with the races under load,
even while rotating!
The Solutions
A unique arrangement between a simple PLC and an Edmunds CAGQCM
gaging amplifier automate the measurements and settings that are
achieved on a Manual Axial Clearance Gaging Bench system. The task
is performed by monitoring the independent motions of the inner race
within a typical cycle, as the outer race is held motionless.
To begin, an operator loads the bearing assembly over a relaxed
clamping plug within the inner race. He/she then clamps the outer
race in fixed position and presses 2-hand start buttons to initiate
the cycle. A pneumatic clamping motion holds the inner race in place
before pneumatic motions work in tandem to push the inner race back
and forth in opposite axial directions. After a series of this
repeated motion of the inner race back and forth, the real
measurement action takes place.
At
last the opposing motions are periodically idled in one direction as
the PLC initiates the CAGQCM to reset its display to "0" zero. Next
the motion is advanced in the opposite direction and an LVDT reads
the amount of movement of the outer race. That movement is displayed
on the amplifier as the T.I.R. value of axial play. That value is
compared to the user defined tolerance limits, and a color coding of
bearing class is provided to the operator. The motions are all
relaxed and the operator removes the part form the fixture.
In an automated line, Axial Play is often checked without any
operator influence or initiation. In these situations, Edmunds
incorporates all the clamping motions automatically. However, to
check Axial Clearance correctly, the bearings must be seated. So, in
our automated units, we actually rotate the bearings, under the
customers prescribed load, to seat the rollers or balls before
measurement. And because of the nature of this measurement occurring
in opposite directions, we must load and rotate the bearings in the
same opposite directions to achieve the true Axial Clearance.
The Result
The benefits of Edmunds Axial Clearance Gaging are three-fold, each
contributing to increased production capability and/or customer
satisfaction. The automation of the measurement process, clear and
concise determination of size, and the flexibility to handle a wide
variety of part sizes with simple modular change tooling.
The compact packaging of this custom designed and built system
allowed the customer to offer product performance and overall
quality to his customers. And, perhaps of greatest impact to the
bottom line of the Edmunds Axial Clearance system - increasing
production measuring rates without compromising accuracy.
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