The correct selection of the puller is crucial in order that the bearing, bushing and gear removal works are easily and quickly performed, thus protecting the machine components and the physical integrity of the user.

Puller Selection Procedures

1. Puller Type: review the application in terms of the arrangement of the component to be removed and the other machine components, selecting the suitable puller type for the application.

- External Puller: removes the mechanical components by their outer side. For bearings, the removal is made by the external ring. When the interfering adjustment is between the shaft and the bearing ring, this should not be used any more.
- Internal Puller: removes mechanical components by the internal side. For bearings, the removal is carried out by the internal ring, by using specific spare accessories (bearing-puller device) for this job.
- Journal Bearing Puller: removes bearings from the shells and installs them on the shafts, using specific spare accessories for this type of job.

2. Puller Size: review the dimension and force required for pulling the component to be removed, selecting the ideal puller size for the application.

Main Puller Dimensions (as per the figure below):
- Range: longest distance possible between the tapered tip of the hydraulic cylinder and the splined surface of the claws;
- Aperture: longest distance between claws;
- Travel: Maximum extension of the hydraulic cylinder;
- A: claw length;
- B: claw depth;
- C: claw width;
- D: distance between the claw screw centers;
- E: threaded body length;
- F: threaded body diameter;
- G: hydraulic cylinder diameter.

3. Pulling Force: The puller's force required for removal depends on the interfering adjustment, contact area and rugosity between the adjustment surfaces, in addition to other non-expected factors, such as contact corrosion, chemical lock, among others.

4. Rule of Thumb to Select the Puller Size: usually, we must select a hydraulic puller with maximum force (in tonnes) from seven to ten times greater than the shaft diameter (in inches).

Example: