Group 25 - Snow Blower (Gasoline Powered)/Gate3

Revision as of 18:40, 28 October 2012

purpose

Project Management: coordination review

cause for corrective action

Product Archaeology:Product evaluation

component summary

engine

#	Component/subsystem	Image	Description	Material	Component connected
1	Gas Tank		The gas tank stores the gasoline that powers the engine of the snow blower. The fuel line is connected to the bottom of the tank and leads to the carburetor.	Plastic	Carburetor
2	Carburetor		The carburetor is bolted onto the intake manifold of the engine body and it imports fuel through the fuel lines from the gas tank and mixes it with air it imports from the atmosphere. Once the intake valve is actuated by the cam shaft, the fuel mixture gets sucked into the cylinder.	Various metals Rubber Plastic	Gas tank Governor Engine body Piston
3	Valves		Exhaust valve- opens to remove exhaust gas from the cylinder Intake valve- opens to let fuel/air mixture into cylinder Both valves consist of a valve stem, spring, lifter, valve seat and two spring retainers. The valve stem sits in the engine body vertically and is held shut against the valve seat by the spring and retainers. Below the valve stem, the bottom of the lifter sits on the camshaft.	Steel	Camshaft Engine body Piston Cylinder head
4	Camshaft		Rotated by the crankshaft to actuate the intake and exhaust valves using two cams that are set on the shaft. The camshaft rotates and periodically opens the intake and exhaust valves in extremely synchronous timing with the crankshaft.	Forged steel	Valve lifter Crankshaft Engine body
5	Piston		The piston subsystem consists of the piston head, connecting rod and piston rings. The piston head has three grooves in it where the piston rings sit. These rings seal off the bottom of the piston from the top. The piston head and rings are situated inside of the cylinder of the engine body. The connecting rod is attached to a pin on the bottom of the piston head so that it is free to rotate on one axis. Below the cylinder, the other end of the connecting rod is bolted to the crankshaft. When the piston moves vertically in the cylinder this linear motion is converted to rotational motion through the connecting rod.	Aluminum-Piston head, Connecting rod Steel-Piston rings	Engine body Cylinder head Camshaft Spark plug Intake and Exhaust valves Flywheel Pulley
6	Crankshaft		The crankshaft sits horizontally in the engine body. The eccentric vertical force from the connecting rod creates a moment which rotates the shaft. The teeth of the gear on the crankshaft mesh with the gear in the camshaft. The gear on the governor is also meshed with the gear on the crankshaft.	Forged steel	Camshaft Connecting rod Engine body Governor Flywheel Pulley
7	Governor		The governor provides a negative feedback system between the crankshaft and the carburetor. It sits on the engine body cover and when in place, the gear on the governor meshes with the gear on the crankshaft. When the crankshaft rotates too quickly, two small spring loaded weights on the governor move outward due to centrifugal force. This causes the governor to move a pin on the outside of the engine body cover which is connected to the carburetor. Once the pin moves, the carburetor reduces the amount of fuel it is dispensing into the cylinder until the crankshaft slows down enough for the spring loaded weights to move back into place. This process is constantly happening in the motor to regulate the flow of fuel into the cylinder.	Steel-Weights and Spring Plastic-Gear	Carburetor Crankshaft Engine body cover
8	Flywheel		The purpose of the flywheel is to store the rotational energy coming from the crankshaft. It is mounted to one end of the crankshaft that is tapered using a keyway. The flywheel also houses two magnets that pass very close to the spark distributor when the crankshaft rotates.	Cast iron	Crankshaft Distributor Electric starter Pull start
9	Spark Distributor		The spark distributor slides onto the crankshaft (underneath the flywheel) and is bolted to the engine body. When the flywheel rotates, two magnets pass very close to a portion of the distributor and cause an electric current to flow. The electric current runs out of the distributor though a wire to the spark plug.	Various metals Plastic Rubber	Flywheel Engine body Spark plug
10	Spark Plug		The spark plug is what creates the spark in the combustion chamber to ignite the fuel. The top of the spark plug is connected to the wire running from the spark distributor. The wire feeds electric current into the spark plug which creates a spark at the bottom of the plug. The spark plug is bolted into the cylinder head and the sparking section if it sits right above the piston.	Various metals Plastic	Cylinder head Spark distributor Piston
11	Cylinder Head		The cylinder head is bolted to the top of the cylinder portion of the engine body. The cylinder head houses the spark plug and the underside of the head is where the combustion of fuel takes place.	Cast aluminum	Spark plug Engine body Intake and exhaust valves Piston
12	Muffler		The muffler is attached to the exhaust port on the engine body. It directs the exhaust out and away from the engine as well as muffling some of the noise coming from the engine.	Iron	Exhaust valve Engine body
13	Engine Body(crankshaft and connecting rod visible in picture)		The engine body provides a base for all of the engine subsystems and components to be supported and fastened to. The top portion of the engine body is the cylinder while the bottom of the engine body is the crank-case.	Cast iron	All components/subsystem
14	Pull start		The pull start is bolted onto one of the body panels. When someone pulls the cord on the pull start, a tooth on the pull start grabs onto a receiving cup that is bolted directly to the flywheel and spins the flywheel. This is one way to start the engine if electricity is unavailable.	Nylon Steel Plastic	Flywheel Body panel
15	Electric Starter		The motor of electric start is screwed onto the engine body while the plug receiving end is screwed to the cylinder head. When plugged into an electrical source the electric starter can be activated using a button on the plug receiving end. When the button is pushed, the electrical motor spins causing the gear on the tip of it to engage with the teeth on the flywheel. Once you stop pressing the button the electric motor stops spinning and the tip of it retracts to its original position.	Various metals Plastic Rubber	Flywheel Engine body Cylinder head
16	Pulley		The pulley is what transfers the power from the engine to the belts that drive the auger and drivetrain. It is fastened onto the crankshaft using a keyway and two set screws.	Iron	Crankshaft Auger and drive train belts

Product Analysis

solid modeled Assembly

Engineering Analysis

Design Revision