Reduce the attrition force between crankshaft end panel and crankcase end panel
On machine of pneumatics of straight couplet type, crankshaft front uses positive drive means, and the branch that gear has straight tine and inclined a tooth-like part of anything, and when using inclined tine transmission, an axial power will produce in axial, the product that gives to assure to design is OK and long-term move reliably normally, contact crankshaft and crankcase photograph normally and appear the positional design of attrition stops push washerbed down the livestock to reduce the attrition force between crankshaft end panel and crankcase end panel. Graph 1 stop to the subassembly of pneumatics engine casing that pushs washerbed down the livestock pursues and be used to take stop the knot composition of a picture that turns washerbed down the livestock.
This is a completely proper design, what did not discuss again is necessary. But all of us thinks, increase a spare parts to be able to raise cost. Does that have other construction to replace stop turn the design of washerbed down the livestock?
In ” mechanical design manual ” copy introduces in the sliding friction coefficient about material: The when having lubricant sliding friction coefficient between steel and bronze is 0.15, the sliding friction coefficient when having lubricant is 0.1 ～ 0.15; Steel and cast-iron a sliding friction coefficient when having lubricant for 0.18, the sliding friction coefficient when having lubricant is 0.05 ～ 0.15. From above data can see, below the case that has lubricant presence, steel and cast-iron the attrition between the steel of attrition deputy excel between and bronze deputy. And the place when be being designed is to have what lubricate compulsively, this provided strong academic basis to improve a design. Graph 2 stop to the subassembly of pneumatics engine casing that pushs washerbed down the livestock pursues and be not taken to be not taken stop the knot composition of a picture that turns washerbed down the livestock.
Look now stop the construction that postpones back-up ring, to lubricate 2 square chamfer left to slip with Yu Run above its, can consult this one principle is in the end panel that when crankcase is designed, will chafe with crankshaft photograph uses cast means casting to give 3 wide for 4mm, it is the lubricant oil groove of 2mm high, its action stops together the square chamfer on circle of half volley with push is identical, can achieve same lubricant function.
Cost of the reducible after such improvement includes: (1) save to stop circle of half volley with push, the price is 2.52 yuan; (2) two process reduced when crankcase is machined (installation stops half volley with push encircles Konghe to drill half hole) ; (3) the cast-iron dosage of position of axle sleeve opening decreases.
But maintainability problem
As the development of the times, the architect’s idea also should be changed. Because user economy actual strength is no good,go, the architect wants to consider a product when the design but maintainability problem. User economy actual strength increased now, when pneumatics machine uses occurrence issue, not be to change specific spare parts, use whole to change however the means of pneumatics machine will undertake maintaining. For this, the product takes no account of when the architect can be being designed according to actual condition but maintainability problem, can reduce the cost of the product significantly thereby.
The knot composition of a picture before improving is like graph 3a: To satisfy design requirement, we use the circle of crankcase, 0 form, bolt and gasket, rear cover, connect that answer oil, copper the combination of these spare partses comes to static seal achieve into oil and the function that return oil, and the purpose of the design assures to enter oil and the unobstructed that answer oil namely. Because be,pass the function that combination will come to to finish at the same time, because possible still presence assembles the quality hidden trouble with occurrence undeserved and oily leakage.
See the knot composition of a picture after improving be like graph 3b again: Combine afore-mentioned parts together through cast means, reduced spare parts amount, decreased to machine working procedure. Want to undertake hitting approaching an experiment in producing a course as a result of crankcase at the same time, can from go up at all put an end to leakage oily problem. And the crankcase after changing is machining a respect and did not increase treatment difficulty.
Afore-mentioned improvement but managing cost is quite considerable truly: (1) the connect that answer oil is 2.8 yuan; (2) static seal is copper 0.66 yuan; (3) back end lid is 3.4 yuan; (4) 0 model the circle is 0.5 yuan; (5) 4 M8x20 bolt is 0.68 yuan; (6) 4 bedspring gasket is 0.06 yuan. Value of above spare parts adds up to 8.1 yuan.
Bolt joins the structure is designed
When products plan, often use spacer to add cover board to undertake designing through bolt connective structure to unused aperture face.
The back end structure before the analysis improves is like graph 4a: Bolt of smooth gasket of the spacer after can seeing the end panel after be being blocked up to seal needs, rear cover, φ8, M8×20 adds up to ability of 4 kinds of spare partses fulfils its design function. Because this structure is put in whorl to assemble a relation, in certain shake become enamoured condition falls to still appear to become loose and reveal a problem likely.
The change devises a method, see the back end structure after improving be like graph 4b: Lid and crankcase block up after new structure used merely be filled with too assemble the design intent that can achieve us, and nonexistent whorl becomes loose and appear reveal hidden danger. Still can reduce manufacturing cost on the other hand.
Afore-mentioned improvement but managing cost is quite considerable truly. The spare parts value of original structure: (1) rear cover mat is 0.41 yuan; (2) rear cover is 3 yuan; (3) 4 φ8 smooth gasket is 0.07 yuan; (4) 4 M8×20 bolt is 0.68 yuan. Value of above spare parts adds up to 4.16 yuan. And of new structure hind block a lid up to be 0.6 yuan, value of both optical spare parts is managing 3.56 yuan.
Look from treatment, craft of treatment of the structure after changing is simple, finished cost also is reduced, and material of crankcase back end is used makings decreased to also reduce product cost. Above structure already was used in the design of normal product, produced the economic benefits that comparative and social beneficial result.
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Will improve a design through changing train of thought, can reduce product cost significantly, enhance the market competition ability of the product, help enterprise obtains considerable economic benefits.