Undergraduate Senior Project - GCPUD Lifting Device

Description

This project was conceived, analyzed and designed at both Central Washington University and Grant County Public Utilities District. Grant County PUD has outsourced the construction of the device to Busby International, Co.

Parts list and labels

Lifting Device:

B1:          Lifting Device Bill of Materials

B1A:       Modified Lifting Device Assembly

B2:          Dovetail Guide to Adapter

B3:          Lifting Lug to Top Plate

B4:          Bottom Plate

B5:          Top Plate

B6:          Lifting Lug

B7:          Dovetail Adapter

B8:          Dovetail Guide

B9:          Wood Blocks

Turning Device:

B10:       Turning Device Bill of Materials

B11:       Bottom Plate to Side Plates

B12:       Bars to Middle and Side Plates

B13:       Dovetail Guide and Stopping Plate

B14:       Bottom Plate

B15:       Dovetail Guide

B16:       Side Plate

B18:       Handles

B19:       Middle Plate

B17:       Threaded Rod  

B20:       Lifting Device Side Plates

B21:       Side Plate to Rod Welds                                                               

Manufacturing issues

The manufacturing of this device occurred at Busby International, Co in Moses Lake, WA following the guidelines laid out in the technical specification found in Appendix E. Extensive equipment and expertise is available at this facility.

Manufacturing issues were mainly trouble with constructing the device as the engineer (who is fairly inexperienced) had designed it. This included the weld size between the side plates and the bottom plate of the turning device. Creating a 5/8 inch weld on a ¼ inch plate is not common practice. It was decided that this weld could be down sized to ¼ inch because the 5/8 inch weld was based on a safety factor of 5, which is not necessary for the turning device because it will never be lifted overhead. Most other issues were simply that the drawings needed either more information or clarification.

After the device was delivered to Priest Rapids Dam it was load tested and then an attempt to use the device was made. Although the load test went very well, during the attempt to use the device it was found that the bottom plate was too large to pull the pole straight up without hitting the poles on either side of the pole being removed. This issue required a complete redesign because simply making the bottom plate smaller would create a loss of material to hold the rods. The redesign changed the rods to plates that bolt to the outside ends of the bottom plate.

Operation

Horizontal to Vertical –

The first thing to do is secure the device around the rotor pole. This will take two people to accomplish. The two should hold the device around the pole and tighten the nuts to 75 ft*lb. Then the turning device should be slid onto the pole. The crane can then begin to lift the pole. The turning device will allow it to come to a vertical position without damaging the pole. Once the pole is vertical, someone needs to hold onto the turning device while the crane lifts the rotor pole up. The turning device should always remain on the ground.

Putting the pole on the rotor (inside or outside unit) –

The pole should be lifted above the generator rotor. With someone guiding the pole, the crane can slowly lower the pole into place. Once the pole is about half way down the rotor, the dovetail adapter piece can be removed by unscrewing the bolts and sliding the piece upward. The pole can then be lowered the rest of the way into the rotor. If the rotor is outside the unit, the nuts can be loosened and the device can be moved horizontally away from the pole. If the rotor is inside the unit, the bottom plate must be detached completely and then the crane can lift the rest of the device up and out of the unit.

Taking the pole off the rotor (outside unit) –

The device, without the dovetail guide attached, can be lifted by the crane to a place where the device can be slid horizontally onto the rotor pole. Once the device is in position, the nuts should be tighten to 75 ft*lb. The crane can then begin to pull the pole up. Once the pole is halfway

out of the rotor, the dovetail guide should be secured to the device. The pole can then be pulled off of the rotor.

Taking the pole off the rotor (inside unit) –

The device, without the dovetail guide or the bottom plate attached, can be lifted above the generator. The side plates should be lined up so that they are lowered in between the poles. Once the top plate is resting on the pole, the bottom plate can be secured to the device. The crane can then begin to pull the pole up. Once the pole is halfway out of the rotor, the dovetail guide should be secured to the device to prevent the pole from sliding out one side of the device. The pole can then be pulled off of the rotor.

Vertical to Horizontal –

As the rotor pole approaches the floor, someone should be guiding the pole into the turning device. Once the pole is resting on the turning device, the pole can be lowered to a horizontal position.

Discussion of Parts Manufacturing

Busby International, Co has the freedom to construct the device in the order and manner that they see fit, as long as the device is delivered on time. The dovetails will be outsourced to a secondary supplier because Busby does not have the resources to complete this part themselves.