Impact Fitting Tool BFT 36 for cold mounting of rolling bearings
Most premature bearing failures may be attributed to poor workshop practices when the bearing was fitted.
Misalignment, damage to the surrounding structure (shaft or housing), applying force so that it gets transmitted from one ring through the rolling elements to the ring being fitted, use of the wrong tools, dirty conditions leading to contamination inside the bearing and a multitude of other causes can lead directly to premature bearing failure.
About cold mounting
Small bearings with a bore diameter up to 55 mm (or outside diameter up to 100 mm) can be cold mounted onto the shaft or into the housing for normal interference fits.
Before proceeding, the shaft should be examined for imperfections or burrs and these removed. The bearing should be positioned exactly at right angles to the shaft, and the shaft should be lightly lubricated with thin oil.
To prevent bearing damage, force must always be applied to the ring being fitted; that is to say:
- The force must be applied only to the inner ring when the bearing is being fitted on the shaft
- The force must be applied only to the outer ring when the bearing is being fitted in the housing
- The force must be applied simultaneously to both rings if the bearing is being fitted on the shaft and in the housing at the same time
Usually a mandril is used to fit a bearing, either on the shaft or in the housing, by striking it with a soft hammer. It is vitally important that the correct mounting tools are used, otherwise the bearing may easily be destroyed before the machine is even switched on.
About Bearing Fitting Tool BFT 33
Application
The ZVELCO Bearing Fitting Tool BFT 33 is designed for safe, precise and quick cold mounting of bearings with bore diameter from 10 to 50 mm and for other parts such as coupling hubs and gears. The right combination of impact ring (mandril) and sleeve allows effective transmission of mounting force to the bearing ring with the shaft or housing interference fit, minimising the risk of damage to the raceways or rolling elements.
Description
The fitting tool set consists of a soft hammer, 3 impact sleeves and 33 different impact rings packed in a carrying case.
- The impact rings are made of an impact-resistant polymer. The diameter of the impact ring perfectly fits the inner and outer diameter of the bearing. The impact ring is fitted on the sleeve by a click connection, which provides stability when the tool is handled. All rings are placed in upright position in the carrying case and clearly marked for identification of the ring´s size to avoid mistakes and for easy selection. The ring design allows the use of a press instead of the sleeve and hammer. The rings are also available individually as replacements should any get lost or damaged.
- The metal impact sleeve is capped with an impact-resistant polymer in the area where hammer blows are applied. Each mounting sleeve can be pushed over the shaft end as far as 220 mm. The surface of the impact sleeve is designed to provide a positive grip and prevent slippage. The sleeve head is designed for effective transmission of force by having a small impact area. The curved design of the sleeve´s head diverts the blow from the user´s hand in case of a mis-hit, minimising the risk of injury. Impact sleeves are also available individually as replacements for any that are lost or damaged.
- The soft hammer has nylon double–sided head that prevents mechanical damage of the bearings through transmission of the mounting force while absorbing the shock. It produces no sparks. The comfortable rubber-grip absorbs shock and vibration and enables positive handling.
 | Most bearings are fitted either on the shaft or housing with an interference fit; in some cases both shaft and housing have an interference fit. |
 |  Incorrect mounting: Mounting force should never go through the rolling elements |
 |  Correct mounting: Mounting force must always be applied to the ring being mounted with an interference fit |
Technical data
| Designation | BFT 33 |
| Description | Fitting tool kit |
| Impact rings | Bore diameter: 10 – 55 mm |
| Outer diameter: 26 – 120 mm | |
| Sleeves | Bore diameter: 18,5, 37,5, 57,5 mm |
| Outer diameter: 25, 45 and 66 mm | |
| Hammer | weight 1 kg |
| Dimensions of the case | 525 × 420 × 130 mm |
| Number of rings | 36 |
| Number of sleeves | 3 |
| Kit weight, Incl. carrying case | 4 kg |
| Case dimensions: | 440 x 350 x 95 mm |
ZVELCO BFT 33 selection table
