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The cutter used is virtually gear manufacturing methods pdf download gear provided with cutting edges. In the case of spur gears, this is achieved by pancaking to cause lateral flow of the metal in a die containing the desired tooth configuration gear manufacturing methods pdf download its periphery.
This process can be used with a variety of steels, bronzes, and aluminum alloys. As a general rule, however, machining is applied to achieve the final dimensions, shape and surface finish in the gear.
Most of the processes listed are suited for gears with low wear requirements, low power transmission, and relatively low accuracy of transmitted motion . Fine blanking also known as fine-edge blanking is actually more akin to geaar extrusion than to a dowbload operation such as stamping.
In a single stroke, standard mechanical forging presses, ranging from 14, to 53, kN to tonfform near-net shape gears with the complete allowable stock allowance. Table 2 shows recommended stock thicknesses for various pitches that are commonly used and require no special care in die maintenance. Precision forging is sometimes described as close-tolerance forging, in order to emphasize the goal of achieving, solely through the hot forging operation, the dimensional and surface finish tolerances required in the finished manufacturnig.
Its most apparent value lies in the making of accurate gear teeth from materials so hard that teeth cannot be readily produced by machining . After passing through the dies, they are known as pinion rods, and often are put into screw machines that finish the individual gears.
It is then allowed to cool to ambient temperature, which usually takes up to gear manufacturing methods pdf download hours.
Casting, Forming, and Forging
The specifications for various gear configurations include:. Stamping is restricted by the thickness of the workpiece and is used primarily for spur gears and other thin, flat forms . Cut gears have also been produced from continuously cast bars. The near-net shape gears can be produced in diameters up to mm 17 in. This envelope is subsequently removed by the forging house or the customer gear manufacturing methods pdf download the gear manufacturing methods pdf download gears.
Most have been made with 0. In gear generating, the tooth flanks are obtained as an outline of the subsequent positions of the cutter, which resembles in shape the mating gear in the gear pair.
In some instances gears for farm machinery, stokers, and some hand-operated devices have used cast teeth. In gear form cutting, the cutting edge of the cutting tool has a shape identical with the shape of the space between the gear teeth.
A surface finish of 0.
Gear manufacturing – Wikipedia
The term net indicates that no subsequent machining or finishing of a forged surface is downlad. These have ranged in gear manufacturing methods pdf download diameter gear manufacturing methods pdf download 64 to mm 2.
Table 1 shows that sand cast gears have the lowest AGMA quality levels of the major gear manufacturing methods. Table 1 lists the tolerances in terms of AGMA quality numbers for various gear manufacturing processes . Gear Hobbing is a continuous generating process in which the tooth flanks of the constantly moving work piece are formed by equally spaced cutting edges of the hob. The grain flow in cut gears is determined by the hot rolled orientation of the bar stock and has no relationship to gear tooth contour.
The exact weight is critical because the amount of steel must completely fill the die to produce the complete gear profile. Where desired, a light turning cut is used to provide a smooth top land and correct addendum diameter. This gear gear manufacturing methods pdf download forged to the finished dimensions.
Views Read Edit View history. Fewer teeth cause the work to roll poorly. Therefore, gfar would be difficult to maintain a good surface finish on gear teeth without grinding.
This involves a special type of machine for gear manufacturing methods pdf download variety of the bevel gear to be manufactured. Spur gear systems Worm drive Rack and pinion Epicyclic planetary gearing Sun and planet gear Harmonic drive Cycloidal drive Non-circular gear. As produced by any of the process described, the surface finish and dimensional accuracy may not be accurate enough for certain applications.
Figure 11 compares the fatigue properties of cut and forged gears .
The method involves the use of a form cutter, which is passed through the gear blank to create the dowwnload gap. Broaching can also be used to produce gear teeth and is particularly applicable to internal teeth.
01 | Gear | Machines
They are heat gear manufacturing methods pdf download to strength levels of MPa ksi and machining is not required on these gears.
Because of the metal flow that occurs, the manufacturinh lands of roll-formed gear manufacturing methods pdf download are not smooth and perfect in shape; a depressed line between two slight protrusions can often be seen.
This computerized approach is applicable to precision hot forging of spiral bevel, spur, and helical gears in conventional presses in that it allows the die designer to examine the effects of various process variables loads, stresses, and temperature on the die design. The die inserts originally used to forge this gear were made of H11 or H13 tool steel.