Chain drive design Essay Example

Chain drive design

Introduction

The chain drive system is to be designed to transmit 25kw power produced by a motor to an aluminum can compressing machine. The motor shaft revolves at a speed of 1200rpm, and it is desired that the shafts distance to less than 1m. The desired speed ratio should be 3:1. To achieve this designs, the task will be split into two sections. The first section we will design the chain transmission system. In this section, the belt type will be selected as well as the design of the sprocket. In the second section, a guard for the chain will be designed.

Section I

Design calculations

1. Number of teeth

The transmission system should reduce the speed of the motor by the ratio 1:3 and

1. Input power

The input power is already specified as 25 kW

1. Design power

Safety factor will be determined from the loading condition of the system. In this system a motor drive is utilized, and it drives a compressing machine moving in a reciprocating motion, therefore, the loading condition is a heavy shock load hence a safety factor of 1.5 is desired. This can be read from Table 1.

1. Required power

The required power is determined as follows;

1. Belt selection

From table3 searching for a combination of 1200rpm and 24.85hp it appropriate to utilizes a chain with the ANSI chain number 60 Type B (that is oil stream lubrication). This chain type has the following specifications.

Minimum tensile strength
Average weight
Roller diameter
Multiple strands spacing

1. Diameter of the driving sprockets d=

Diameter of the driven sprocket D=

1. Calculation of minimum center distance

Therefore, a center distance of 900mm was selected

1. Number links based on the above-selected center distance

1. Actual center distance

The following tables are utilized in the determination of the parameters above

Section II

Due to cost factors, the design of the guard will utilize a square wire mess that will be welded to the support plate as shown below. This guard will be mounted on the machine by means of bolts and nut to allow easier disassembly during maintaince.

Discussion

Due to the high amount of that is transmitted from motor to the machine a chain transmission system with three strands is utilized. This increases the amount of the stresses that can be carried by the chain. In addition to this the load condition or, in other words, the working condition involves the system to high shocks. This calls for a very strong chain system.

The center distance between the two shafts has been determined to be 906.3 mm which is, of course, less than the 1000mm. This design will therefore work as required.

The belt that is select in this design is type b, which requires continues lubrication. This can be achieved by bath method of lubrication where the part of the chain is allows dipped in the lubricating medium as it rotates.

The parameters determined in this document are loaded in a 3d modeling software that produces the model as shown in the figures above.

Conclusion

The design parameters calculated above yielded positive results when they were input in 3-dimensional modeling software that indicates that the above procedure is a powerful tool in the design of a chain drive system. The designer does not require to create every component on its own they only need to determine a few components that are input to the software and software evaluate the rest of the parameters.in this way the design process is significantly reduced and, therefore, the less time is taken in the design process. The final design achieved a belt that can withstand high power than the applied power, therefore, reducing chances of the belt’s mechanical failure and thus this model is viewed to be satisfactorily for the application specified above. This procedure can be utilized in the design of any belt provided that the loading conditions are clearly specified and that both the input speed and output speeds are known.

References

KHURMI, R. S., & GUPTA, J. K. (2005). Theory of machines: [a textbook for the students of B.E. / B. Tech., U.P.S.C. (Engg. Services) ; Section ‘B’ of A.M.I.E. (I)]. Ram Nagar, New Delhi, Eurasia Publishing House.