Technical Report 5Bearing Assembly1. For each arrangement:- number the different parts and list the names of the different parts (spacers, shafts, covers, washers, flanges, etc)

The parts are numbered 1- 11 for arrangement under figure A (1).

R A R8116 7 9 4 2 5103121

Bearing A Tapered Roller Bearing; Bearing B CARB Bearing1. Shaft2. Taper Roller Bearings3. CARB Bearings4. Centering Flange(Spigot)5. Screw (For Pre-loading)6. Spacer7. Shims8. Ring Nut9. Hole for Lubrication10. Casing11. Shims

The parts are numbered 1- 11 for arrangement under figure A (2).

96

A R R123 21

Bearing C Tapered Roller Bearing; Bearing D Cylindrical Roller Bearing1. Shaft2. Taper Roller Bearings3. Cylindrical Roller Bearings4. Centering Flange (Spigot)5. Screw (For Pre-loading)6. Spacer7. Shims8. Ring Nut9. Hole for Lubrication10. Casing11. Shims12. Spring for preload

2. For each bearing point out if it is locating or not locatingFor figure A (1), the taper roller bearing (Bearing A) is in locating and the CARB bearings (Bearing B) are non-locating. A locating bearing is one which reacts to the external forces by taking in axial and radial forces whereas a non-locating bearing is one which reacts to the external forces by taking in only radial forces. There is some amount of axial displacement also allowed in the current non-locating configuration. The same stands true for Figure A (2) where the taper roller bearings (Bearings C) are locating and the cylindrical roller bearing (Bearing D) are non-locating.

3. Highlight if the bearing rings are mounted with shrink fit or with slide fit and why;

For figure A (1), the inner ring of the bearings A and B are shrink fitted (Red Line) with the shaft in order to prevent any free motion in between the shaft and the inner ring of the bearing. The outer ring for bearing A is slide fit (green line) in order to allow motion in between the outer ring and the housing during the pre-load action. The outer ring of bearing B is also slide fit ((green line)) in order to minimize assembling difficulties, but it can change depending on the operational requirement.

For figure A (2), the inner ring of bearing C is slide fit in order to allow motion in between the inner ring and the shaft during the pre-load action. The outer ring for one pair (i.e. left bearing) of bearing C is also slide fit in order to take the movement in between the outer ring and the housing as the result of the spring action which helps in maintaining a constant pre-load at all time. The other pair (i.e. right bearing) has an interference fit to prevent any sliding motion. This further allows for the pre-load action to take place for this part of the bearing pair. The bearing Ds both inner race and outer race are shrink fitted.

4. Draw on the figure arrows indicating external axial loads and radial loads and arrowsindicating the forces exerted by each bearing.

The forces are marked on the figure with the red arrows. For figure A (2), the blue dotted arrow shows the constant spring force. The shaft forces are also shown in blue.

5. describe the function of each separated part (covers, spacers, springs)

Spacers: Spacers helps to maintain a constant distance in between the bearings when they are being assembled onto the shaft. The help in locating the bearing onto the shaft during assembly.Spacers or shims help to maintain a minimum axial clearance between the bearings when they are mounted. This also helps to cope with the temperature differential between the shaft and the casing. They are further assembled in such a way that the right amount of pre-load is achieved during adjustment. Springs: Springs are used to provide a pre-load force to the inner or the outer race or both. The preload force remains practically constant even when there is axial displacement of the bearing as a result of thermal expansion.Covers: Covers are provided to protect bearing arrangements at the ends of shafts and to avoid accident risks with free shaft ends. In certain cases, the ring nuts used for pre-load are accessed through the cover.

6. Compare the two solutions proposed for each Figure highlighting the differences andadvantages of one with respect to the other;a. The use of CARB bearings in solution A (1) helps take in angular misalignments caused by off-centre point of action of the tooth forces with no reduction in life. Another advantage is that it does not require the flanges to exactly parallel during mounting. This is not true in the case of cylindrical roller bearing used in figure solution A (2). b. The tapered roller bearings in solution A (2) are always under load irrespective of the direction of the load. As a result, this arrangement is less sensitive to vibrations. This is not true for the case in figure A (1) since one roller is always completely unloaded depending on the direction of the load. Hence, these are more sensitive to vibrations. c. Solution A (2) proposes some mounting difficulties and is more complex compared to Solution A (1). Outer ring of one of the tapered roller bearing are shrink fitted to the flange. As a result it required heating of the flange. Another problem is that the there is no intermediate ring between the taper roller bearings which have to be adjusted on mounting. The radially free outer ring of the taper roller bearing at the cover side is prevented fromturning by an O-ring.

1. For each arrangement:- number the different parts and list the names of the different parts (spacers, shafts, covers, washers, flanges, etc)

A A R RBearing A Tapered Roller Bearing; Bearing B Tapered Roller Bearing (FF arrangement)

1. Shaft2. Tapered Roller Bearing3. Casing4. Cover5. Shims

One of the bearing pair takes the load depending on the direction R R A

Bearing A Tapered Roller Bearing; Bearing B Tapered Roller Bearing (FF arrangement)

1.2.3.4.5.

2. For each bearing point out if it is locating or not locating.

Solution B (1) consists of taper roller bearings. Both the bearings are locating since both types can take axial and radial loads in response to the external load.Solution B (2) consists of paired angular contact bearing at one end which is of locating type since it can take both the radial as well as the axial load. The cylindrical roller bearing on the other end is of non-locating type owing to its capacity to take only radial loads.

3. Highlight if the bearing rings are mounted with shrink fit or with slide fit and why;For solution B (1), the inner ring is interference fit and the outer ring is slide fit to allow for the preload adjustments.4. Draw on the figure arrows indicating external axial loads and radial loads and arrowsindicating the forces exerted by each bearing.

The forces on the bearing are indicated in the draw with the help of red arrows and external forces from the shaft to bearing are indicated with the help of blue arrows.

5. Describe the function of each separated part (covers, spacers, springs).a. Covers: In solution B (1), the left tapered roller bearing is adjusted by the cover in order to give adequate preload.b. Spacers: Not Used.c. Springs: Not used.

6. Compare the two solutions proposed for each Figure highlighting the differences andadvantages of one with respect to the other;

a. Solution B (1) consists of both the bearings as tapered roller bearings. As a result, care must be taken while performing the adjustment since they are very sensitive to excessive preload which will lead to failure of the bearings.b. The bearings used under solution B (2) are paired angular contact bearings which in this configuration have a higher load carrying capacity than the single row tapered roller bearings in solution B (1). Another advantage is related to the fact that since these bearings are in pairs, individual adjustment is not required. This solution is comparatively expensive when compared to solution B (1).