FABRICATION OF PNEUMATIC MOBILE CRANE
Abstract : This project deals with the fabrication of pneumatic mobile crane. The aim of this project work is to acquire practical knowledge in the field of material handling equipment. The project work is concerned with the fabrication of the portable jib crane. This machine is very useful for lifting and transporting heavy jobs up to two tons for all types of jobs such as automobile repairs and service shops of central workshops, production industries, material handling units etc.
Rotary bearings hold rotating components such as shafts or axles within mechanical systems, and transfer axial and radial loads from the source of the load to the structure supporting it. The simplest form of bearing, the plain bearing, consists of a shaft rotating in a hole. Lubrication is used to reduce friction. In the ball bearing and roller bearing, to reduce sliding friction, rolling elements such as rollers or balls with a circular cross-section are located between the races or journals of the bearing assembly. A wide variety of bearing designs exists to allow the demands of the application to be correctly met for maximum efficiency, reliability, durability and performance.
The self-aligning ball bearing has two rows of balls and a common concave sphered raceway in the outer ring. The bearing is consequently self-aligning and insensitive to angular misalignments of the shaft relative to the housing.
The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this by using at least two races to contain the balls and transmit the loads through the balls. Usually one of the races is held fixed. As one of the bearing races rotates it causes the balls to rotate as well. Because the balls are rolling they have a much lower coefficient of friction than if two flat surfaces were rotating on each other.
It has a good capacity to support the radial loads and also the axial loads in the two directions. It presents a swivelling and exists in an instrumented version making it possible in particular to determine the rotational speed of the shaft
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