MOUNTING OF MACHINE ELEMENTS ON TRANSMISSION SHAFT (PULLEY & BEARING) Prof. H. D. Mhatre MOUNTING OF MACHINE ELEMENTS ON TRANSMISSION SHAFT (PULLEY & BEARING) Prof. H. D. Mhatre Prof. H. D. Mhatre

PART 1 :- MOUNTING OF MACHINE ELEMENTS ON TRANSMISSION SHAFT (PULLEY) Prof. H. D. Mhatre

Introduction:- What are pulleys:- Pulley is wheel on an shaft for transferring power between belt and shaft pulleys can be found everywhere to make tasks easier. In addition to lifting things, pulleys can be used singly or with many pulleys working together in order to transport people or things. Pulleys mostly changes the direction of force to make work easier. Prof. H. D. Mhatre

Construction:- Parts:- 1) cords 2) Ropes 3) cables 4)Belt’s Main parts:- A pulley wheel that can spin around. A rope that goes around it. Prof. H. D. Mhatre

Prof. H. D. Mhatre Prof. H. D. Mhatre Prof. H. D. Mhatre

Applications:- Crane and the sailboat. The blinds of a curtain are moved with the help of a pulley. To take out water from a well is one application that almost everyone see. It is used in machine or mechanism. Pulleys are also used in vehicles to ensure that the parts of the vehicle work smoothly. A Gym is one place where one can find a lot of machines using the pulley system. Prof. H. D. Mhatre

labeling Paper machinery Marine engineering Conveyors Prof. H. D. Mhatre Marine engineering Conveyors

INSTALLATIONS Prof. H. D. Mhatre

INSTALLATIONS 1. Polish the motor shaft to remove all burs. 2. Remove dirt from the motor keyway. 3. Remove any burs on the key with a flat file as well (see Fig. 2). 4. Test fit the key in the motor keyway. 5. Ream pulley collar to remove burs. 6. Clean motor shaft, pulley, and key with a solvent (carburetor cleaner). Prof. H. D. Mhatre

Without the key in the keyway, slide the pulley onto the shaft. Note 1: Pulley should slide on easily by applying only hand pressure. Note 2: Do not use any lubricant on shaft. 9. Repeat steps 1-7 if pulley does not fit. 10. Remove the pulley from the shaft and insert the key into the keyway. Prof. H. D. Mhatre

11. Gently slide the pulley onto the motor shaft. Note : The pulley should fit on the shaft without any play. 12. Align the pulley to the proper position and tighten the pulley set screws. Note: Pulley set screw should tighten down on top Prof. H. D. Mhatre

Forces involved:- The Weight of the load does not change, it is the same for each trial. the Output force will be the force required to hold load steel it does not change since weight remains the same. As more strings are added, the input force required to achieve the same output force decreases. Prof. H. D. Mhatre

Mechanical Advantages:- Work required to complete particular task is fixed Machine provides us mechanical advantage by decreasing input force and increasing distance. Mechanical advantage = Output force/Input force Mechanical advantage of 1 means Input force is equal to output force MA =1 means work with less force but it is for greater distance MA = F0 Fi Prof. H. D. Mhatre

PART 2 :- MOUNTING OF MACHINE ELEMENTS ON TRANSMISSION SHAFT (BEARING) Prof. H. D. Mhatre

Introduction:- /Cage A bearing is a machine element that constrains relative motion to only the desired motion, and reduces friction between moving parts. There are many types of Ball & Roller bearings. Each of these bearings have a different advantages based on its construction and design. The selection of the type of bearing in a particular application depends upon the requirement of the application and the characteristics of different types of bearings. Prof. H. D. Mhatre

General Overview of Bearing Mountings :- Design engineers established the following terms :- 1. Cleaning the bearings and related parts. 2. Checking the dimensions and finish of related parts. 3. Mounting. 4. Inspection after mounting. 5. Supply of lubricants. Prof. H. D. Mhatre

MOUNTING PROCEDURES :- Depending on the size of the bearing and the application, there are different methods for mounting roller bearings. In all methods, certain basic rules must be followed. CLEANLINESS :- • Choose a clean environment, free from dust and moisture. • The installer should make every effort to ensure cleanliness by use of protective screens and clean cloths. PLAN THE WORK :- • Know in advance your plans and have the necessary tools at hand. This reduces the time for the job and decreases the chance for dirt to get into the bearing. Prof. H. D. Mhatre

How to Mount Bearings When bearings are mounted incorrectly the balls will cause brinelling (dents) on the raceway due to this bearing performance as well as life of bearing also decreases. Several general rules apply to mounting bearings. When assembling a bearing on its shaft or in a housing, the care should be taken that no force to be applied to the balls. When mounting a bearing to a shaft always press the inner ring whereas when mounting into a housing press the outer ring. Never apply force to the outer ring when mounting to a shaft or to the inner ring when mounting into a housing. 1. When manually fitting a shaft into a bearing through its bore do not force the shaft because it may cause brinelling to the bearing. Prof. H. D. Mhatre

2. After gluing a bearing to a housing using a guide through the bearing bore take the guide out very carefully or it may cause brinelling to the bearing. 3. When motors are being assembled bearings may be attracted by the magnet and hit something that will causing brinelling.  4. To avoid this, hold the motor shaft in your palm and carefully insert the rotor.  5. Brinelling would also occur when bearings are automatically press-fitted to a rotor shaft if the shaft and bearing bore are not kept accurately in line through their bore. For dismounting i.e to remove the bearing, bearing tools to used. Generally Bearing Pullers may used to remove bearing. Prof. H. D. Mhatre

Generally Fitting with a press that means press fit is widely used for small bearings. A mounting tool is placed on the inner ring as shown in Fig. 1 and the bearing is slowly pressed on the shaft with a press until the side of the inner ring rests against the shoulder of the shaft. Prof. H. D. Mhatre

Prof. H. D. Mhatre

Corrective Bearing Fitting :-  Mounting bearings using a hammer causes damage due to sharp impacts. So the effective way is to mount press fit bearings using a pressing arbor or other designed to provide a uniform face. Prof. H. D. Mhatre

Bearing Care :- Bearings are very susceptible to impacts and shock loads! Prof. H. D. Mhatre

Mounting of bearing on Transmission shaft The precautions to be taken during the mounting operation are as follows: - (i) Mounting should be carried out in a dust free and dry environment. Machines which produce metal particles, chips or sawdust should not be located in the vicinity of the mounting operation. (ii) Before assembly, the shaft and the housing bore should be inspected. The burrs on the shaft and the shoulders should be removed. The accuracy of the form and dimensions of the shaft and bearing seat in the housing should be inspected. Prof. H. D. Mhatre

Mounting of bearing on Transmission shaft Prof. H. D. Mhatre

Mounting of bearing on Transmission shaft (iii) The bearing should not be taken out from its package until before it is assembled. The rust-inhibiting compound on the bearing should not be wiped except on the outer diameter and bore surface. These inner and outer surfaces are cleaned with white spirit and wiped with clean cloth. (iv) Small bearings are mounted on the shaft with the help of a small piece of tube or ring. Blows are applied by means of a hammer on this tube or ring. Direct blows should never be applied to the bearing surface, otherwise the race or the cage may get damaged. The tube or the metallic ring is placed against the inner race and the blows are applied with an ordinary hammer all around the periphery of the ring. Prof. H. D. Mhatre

Mounting of bearing on Transmission shaft Prof. H. D. Mhatre

Mounting of bearing on Transmission shaft (v) Medium size bearings are mounted on the shaft by pressing the tube or the metallic ring by means of a hydraulic or mechanical press. Large size bearing is mounted by heating it to 80° to 90°C above the ambient temperature by induction heating and then shrinking it on the shaft. The bearing should never be heated by direct flame. The interference fit between the outer race and the housing is obtained by similar methods, viz., by applying hammer blows on a metallic ring or tube which is in contact with the outer race or by using hydraulic or mechanical press or by heating the housing. Prof. H. D. Mhatre

Mounting of bearing on Transmission shaft Prof. H. D. Mhatre

Thank You ! Prof. H. D. Mhatre