These are the instructions for a centrifugal pump a team of product design engineers made for a project to pump water a height of 60cm efficiently.
Pump is still in the prototype stage so any input would be welcomed.
24V Power supply
ABS Plastic Impeller Housing
Motor - RS Components.
Power Supply - Weir Instrumentation Ltd
Meccano No:94 sprocket chain
Ball Bearings - RS components
Step 1: Creating the Frame
The frame was manufactured using 4mm thick laser cut acetate.
Files were created in Solidworks and exported as a DXF file - the format appropriate for laser cutting.
5 Sections were cut and using dichloromethane attached together.
spec and pictures to follow.
Step 2: Creating the Gears
The gears are also laser cut from 4mm thick acetate.
4 different sizes of gears were cut to broad give scope for testing, one with 56 teeth, one with 42 teeth, one with 28 and one with 14 teeth.
Step 3: Creating the Impeller
The impeller was firstly designed on Solidworks saved as a STEP file and run through a program called Alphacam to convert file to G code which is suitable for modelling in a Mini Mill.
A test run is stimulated and then the Mini Mill cut the impeller from aluminium.
First picture depicts Solidworks model of impeller, second picture is the milled aluminium impeller.
Step 4: Creating the Impeller Housing
Three housings prototypes were created to maximise testing and increase efficiency.
The housing is shaped to hold the blades with very small clearing between housing
One was rapid prototyped while two were laser cut from acetate.
Picture below shows Solidworks model and laser cut acetate model.
With the acetate model a bush (displayed in picture) is required to connect to the tubing while the rapid prototype does not.
Step 5: Creating the Axles
Axles were milled out of aluminium.
Spec outlined in image.
The small hole in the left hand end of the axle is space to fit a grub screw to connect the motor.
Design modified to incorporate a 10mm thread to connect to the impeller.
Step 6: Assembly
1. Press the axles through the bearings, there should be no clearance between the axle and the inner ring of the bearing to secure the tightest fit possible.
2. Assemble fram, glue using dichloromethane and slide the axles into place firmly so that there is no possibility of slip.
3. Connect the motor to the upper axle with the grub screw. This connection should also be tight enough to eliminate the chance of slip.
4. Slide gears onto axle end making sure to align the groove, smallest gear on upper axle and larger gear on lower axle and attach the meccano chain ensuring it is taught.
5. Thread impeller pump to lower axle and connect tubing to outlet on pump.
6. Connect the motor to the power supply.