Group 26 - Pressure Washer

Revision as of 16:21, 7 December 2009

Introduction

A requirement for MAE277, taught by Erich Devendorf, the Reverse Engineering Project is designed to help students familiarize themselves with the assembly of a product. Over the course of the semester, the students will work on five gates which will showcase the ongoing analysis of their products. This project will reinforce key skills that engineers utilize everyday.

Groups 25 and 26 were assigned a pressure washer. Rather than share entire product between two groups, the product was divided into two, with group 25 analyzing the compressor and with group 26 analyzing the engine.

Gate 1: Request for Proposal

This portion of the Reverse Engineering Project is designed to help the group become familiarized with the product, a pressure washer. A general work outline for the semester will be developed and will contain the following items: a work proposal, a management proposal, and an initial product assessment.

Work Proposal
Management Proposal
Initial Product Assessment

Gate 2: Preliminary Project Review

Causes for Corrective Action
Product Dissection Plan

Gate 3: Coordination Review

Component Summary
Design Revisions
Solid Modeled Assembly
Engineering Analysis

Gate 4: Critical Project Review

Product Reassembly Plan

The process for reassembling the pressure washer is almost the same process as disassembling although it in reverse. If one can disassemble it, one can reassemble without much hassle.

Step #	Process	Tools Necessary	Difficulty	Image
1	Attach the crank shaft and then the flywheel to the engine.	None	1
2	Affix the metal guard and the plastic cover to the flywheel.	None	1
3	Connect the flywheel to the crankshaft by attaching the 22mm nut located on the outside of the engine.	22mm socket wrench	1
4	Slide the piston into the engine from the top, into the crankshaft. Attach the piston to the crank by attaching two 10mm bolts.	10mm socket wrench	2
5	There are two lifters that connect to the rods; put in them into the engine directly above the camshaft.	None	2
6	Slide the cam shaft into the engine.	None	1
7	Put on the engine cover after attaching its gasket.	None	1
8	Attach six 10mm bolts to the engine cover to connect it to the engine.	10mm socket wrench	2
9	Connect the valves and the rods to the head.	None	3
10	Attach the valve springs by pushing down on their spots and affixing them to the valve.	None	2
11	Make sure that one end of the rocker arm is connected to the rod and the other end is resting on the valve spring.	None	1
12	Connect the rocker arm.	10mm socket wrench	1
13	Attach the head to the engine.	None	1
14	Attach four 12mm bolts to connect the head to the engine (There are two places located inside the head and two places located outside of the head).	12mm socket wrench	1
15	Put on the valve cover after attaching its gasket.	None	1
16	Attach four 8mm bolts to connect the valve cover to the top of the engine.	8mm socket wrench	1
17	Attach two 8mm bolts to connect the heat shield to the side of the engine.	8mm socket wrench	1
18	Slide the gaskets, the carburetor, and air cleaner onto the studded bolts.	None	1
19	Attach two 10mm bolts to connect the air cleaner, the carburetor, and gaskets to the intake manifold.	10mm socket wrench	1
20	Slide the gasket and exhaust onto the studded bolts.	None	1
21	Attach two 13mm nuts to connect the exhaust to the engine.	13mm socket wrench	1
22	Connect the springs that are attached to the carburetor.	None	1
23	Put on the fly wheel shield to the engine and attach four 8mm bolts.	8mm socket wrench	1
24	Reconnect the electrical wiring that is connected to the spark plug, sensor in the engine, and the power switch.	None	1
25	Attach the hose by squeezing the pressure clamp and placing it back onto its spout.	None (pliers are optional)	2
26	Attach the 8mm bolt to the gas tank.	8mm socket wrench	1
27	Attach two 10mm bolts on the gas tank.	10 mm socket wrench	1
28	Attach the engine to the compressor.	N/A	2
29	Affix the engine and the compressor to the power washer using the remaining bolts.	10mm socket wrench	1

Does your product run the same as before you dis-assembled it?

• After re-assembly the engine continues to move with hand cranking as it did when we received it. There are some minor issues which would prevent it from running at this time. Damage to several gaskets (which appeared to be aged to begin with) and a lack of oil which was removed and disposed of during dis-assembly. As well several hoses were misplaced. Getting the product into a working state should be as simple as adding new oil into it, new gaskets and replacement hoses.

What were the differences between the disassembly/reassembly processes?

• The disassembly/reassembly processes were mostly the same for our group. When the product was being disassembled, our members took precaution to write down the correct sequence of events if they made any mistakes so that others would not have the same problems.

• Almost the same set of tools was used during the reassembly process. The only tool that was not needed was the rubber mallet. The tools necessary are a basic metric socket set (only the 8mm, 10mm, 12mm, 13mm, and 22mm sockets are needed), and open-end wrenches. The optional pair of pliers can also be used but the funnel is not needed any more to drain the oil from the engine.

• Our group was able to reassemble almost the entire product. The engine is reassembled and mounted back onto the frame. We are just missing a couple of hoses.

Are there any additional recommendations your group would make at the product level (operation, manufacturing, assembly, design, configuration, etc.)?

• One design change which would increase the life of the pressure washer would be to have any exposed metals either covered with plastic shielding, or coated with a highly durable paint. This would reduce rusting and other damage to the engine and washer in general, extending its operational lifetime. This would require a fairly minimal cost increase weighed against a good potential lengthening of the products life.

• During dis-assembly of the product, we noticed that several of the gaskets were in poor condition. A sturdier material for the gaskets may be in order, as well as a slight increase in the width of walls to better prevent them falling apart. Again this would increase costs slightly, but should also improve the functional life of the product.