Product Analysis -(Group 10)
- The component is what is moved by the explosion in the piston chamber. This is also what moves the piston linkage in order to turn the crankshaft.
- Its only function is to move the piston linkage in order to turn the crankshaft.
- Combustion energy from the explosion that causes expansion moves the piston downward and in turn moves the linkage down which, once connected to the crankshaft is turned into rotational energy.
- The piston functions in a lubricated chamber enclosure, called the piston chamber. On one side of the piston there is oil and on the other is the explosive side.
- The piston is a symmetrical 3 dimensional cylindrically shaped object with one side being slightly hollowed out.
- The height is 1.75 inches
- The diameter is 2.75 inches
- Since it is a cylinder, the diameter suffices for both length and width
- The component is shaped so there is a tight seal to the sides of the chamber so that gas doesn’t escape.
- The piston weighs 1.25 pounds.
- The piston is made from stainless steel.
- Stainless steel is stronger than aluminum but lighter than iron but manufacturing decisions didn’t effect this decision.
- The material choice needs to be lightweight but strong to withstand the explosive force.
- Environmental and economic factors effected this decision. Being stainless steel allows the piston to not rust and also have the strength that comes with steel as opposed to aluminum so there is less a chance of breaking and is better on the environment due to the lack of waste. Being that stainless costs about the same as aluminum but is stronger, it is a better deal cost wise to use it rather than aluminum.
- The piston has zero aesthetic qualities and therefore has a bare finish, no paint, stain or coloration needed since it’s a purely physical component.
- The piston is press-punch forged, lathed, precision ground and milled.
- The precision grinding is evident due to the precision finish in the holes where the pin fits into.
- Milling is evident due to the fact that there are holes, and for the slots that the rings fit into.
- Lathe work is evident from the lines on the top of the piston that come from the facing operation performed by a lathe.
- Forging is evident due to the lack of parting lines, and the internal shape that would be very difficult to mill. There are also stamped numbers in the bottom.
- It would be more cost effective to forge stainless steel rather than completely mill or investment cast it.
- Being a cylindrical shape it effected the choice to perform multiple lathe operations. The need for a snug fit to the pin required precision grinding and milling was needed for minor holes and slotting.
- The need for a strong yet light, product with minimal waste and the ability to withstand rust or decomposition, effected material choice, manufacturing process and finish of the final product.
- This is a fairly simple component and would get a rating of #2 for its complexity.
- The categories above serve as a representation of all of the components of the piston, in detail and therefore is what determines its complexity.
- The interactions are very simple and would get a rating of #1
Horizontal Disk (Part Number 135)
- The Horizontal Disk gets power directly from the engine via the belt and pulley system.
- The Linear Movement Pulley (Part 107) is mounted to the drive shaft which is connected directly to the Horizontal Disk. This provides the rotational kinetic energy to engage the Vertical Drive Disk (Part 137) into motion.
- The shape of the Horizontal Disk is a flat disk shape with a hole in the center. The drive shaft is mounted in this space and run through the mounting bracket. The general shape of the mounting bracket is a cylinder with a large flat base and supporting arms. All of these parts are largely axis-symmetrical with the disk being more so one dimensional, the shaft is two dimensional, and the mounting bracket is three dimensional.
- The disk is 6 inches in diameter and ¼ inch thick, the shaft is ¾ in diameter and 6½ inches long, and the mounting bracket is 5 inches in height, 7¼ inches at its widest and 4¾ inches long. The shapes are completely appropriate for the functions they perform. The disk only needs to spin and have another wheel running on it at a 90 degree. The bracket houses the drive shaft so the cylindrical shape is the perfect form for that; the drive shaft is just a simple shaft the needs to spin in a confined space so this is also the idea shape.
- The weights of the components are estimated to be 1lb for the Disk, 1lb for the drive shaft, and 10lbs for the mounting bracket.
- Both the Disk and the drive shaft are made of aluminum while the mounting bracket is made of caste iron.
- The GSEE factors played a role in the decision on the materials. Global reasons would be that both iron and aluminum are readily available materials so manufacturing can take place all around the world. Societal factors come into play when considering the conditions that the product is used in. The parts need to be strong, reliable, and not susceptible to becoming brittle in the cold. Economic factors are focused more on the mounting bracket witch is the heaviest part by far and is made from the cheapest material. This keeps the price down for manufacturing and in turn for the customer.
- There are no real aesthetic purposes for the parts since they will generally not be seen by the user. The only painted part is the mounting bracket which is coated grey to help prevent rust.
- The surface finish of the disk is rough on the back and smooth on the face that contacts the Vertical Drive Disk.
- The mounting bracket is entirely rough and the drive shaft is entirely smooth. The reasoning the shaft is smooth and the face of the disk is smooth is to reduce friction and power loss. The other parts being left rough are more of an economic reason.
- The most likely method for manufacturing the Disk and Shaft are Die Casting since die casting is generally used for non-ferrous metals and with a somewhat rough texture on the back of the Disk. The Disk on the smooth side was most likely machined with a vertical mill to get the smooth finish.
- The shaft was possible subject to the subtractive process of turning to provide the smooth finish. For the mounting bracket the most logical method is sand casting because of the rough texture and the cheap cost. The shapes are all relatively simple so these methods are not necessarily needed but they are quickest and most cost effective.
- A global factor that influences manufacturing methods for these components is the age of this technology. Sand casting and die casting are some of the oldest methods used for this type of manufacturing.
- A societal factor that influences manufacturing is that these pieces can be mass produced cheaply so if a piece is broken then it can be replaced very quickly.
- An economic factor that has an impact on these manufacturing choices is the cost of production. These methods are cheaper than milling or investment casting.
- Environmental factors that pertain to these methods are that there is less waste produced. With Die casting there is a permanent mold which gets reused also with all three methods there is less need for total material used for each part.
- This is a moderately simple component overall with rankings as follows:
- Part Complexity: 2 for having more than one surface finish Interaction Complexity: 1 only has on simple function
- Part Complexity: 2 for having a moderately complex geometric shape Interaction Complexity: 1 only has on simple function
- Part Complexity: 1 simple shape and one finish Interaction Complexity: 1 has one simple function
Vertical Drive Disk (Part Number 137)
- The main function of the Vertical Drive Disk is to transfer the rotational kinetic energy from the Horizontal Disk to transfer it to the Gear and Chain (Parts 138) which then transfers the energy directly to the wheels and drives the snow blower.
- The Vertical Disk can also slide left and right over the Horizontal Disk in order to change the RPM’s or speed at which the snow blower moves. It can also slide to the other side of the Horizontal Disk and have the same function but moving the snow blower in reverse. Since the operating environment is outdoors in the snow the part must be rugged and reliable.
- The component is a disk in shape so it also is axis-symmetric through its center. This Disk largely one dimensional since it is comprised of two flat disks mounted together by 5 bolts.
- The outside larger disk is 6 inches in diameter and ¾ inch thick but is hollowed out like a shell.
- The smaller inner disk is 4½ inches in diameter and 3/8 inch thick.
- The Shape being a circular disk is absolutely necessary to perform the required function; since is rotates along the Horizontal disk no other shape would perform without error.
- The rough weight of the disk is 1.5lbs and the material it is composed of is caste iron and rubber.
- The most logical reasoning for this material being chosen is that it needs to be strong and durable enough to withstand the cold and elements and be exposed to high g forces. Global factors which contributed to the materials being chosen are the abundance of iron throughout the world allows for manufacture in more areas. The Surface finish of the disk is rough and coated in grey paint. This is pure function and not aesthetic as no general user will see this component. The rubber around the edge is smooth most likely to create the most friction between the Horizontal and the Vertical Disk.
- The method used to create the Vertical Disk was Sand Casting. This is the most likely method because of the rough surface finish that sand casting will result in. The rubber may have been heated up in order to expand it to fit around the disk and then an adhesive would be applied so as it cooled it would shrink fit and become permanently stuck to the disk.
- The shape of the disk is very simple and could easily have been done through milling but the GSEE factors influenced the method used. Sand casting is one of the oldest methods for molding metals into the required shape, meaning that this technology would be able to be widely used throughout the world.
- Societal factors that influenced this method are that parts can be mass produced very quickly and cheaply so if parts need to be replaced it can be a very quick and cheap process for the consumer.
- Economic factors are probably the largest reason for this method being chosen. It is probably the cheapest method available because it uses the least material and the mold can be reused numerous times since it is made of sand.
- Environmental factors that play a part in this method being selected are that there is much less material needed and virtually no wasted material.
- This is a relatively simple component responsible for a lot of function represented as follows:
Vertical Drive Disk:
- Part Complexity: 1 very simple shape and one surface finish Interaction Complexity: 2 responsible for speed adjustments in the machine and the direction in which the machine is moving