The Solution

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.

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!

Axial Clearance For Bearings


Gage Parameters

OPERATION: Semi-Automatic
FEATURES: Semi-Automatic measuring of "clearance" commonly know as Axial Clearance between the inner race, and the outer race and ball or roller compliment.

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.

Edmunds Gages Farmington CT USA

A New Dimension In Precision Measurement


(860) 677-2813

Toll Free 877-521-5818 

(860) 677-2813

(860) 677-4243


Farmington Industrial Park

45 Spring Lane

Farmington,  CT USA 06032

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