The number of gears commonly used in production is generally less than 100, which is the most commonly used gear for the Y3150E gear hobbing machine. However, in some special occasions when using a prime number gear of more than 100, the Y3150E type gear hobbing machine has a gear of Uxc)/(6xd), and the number of teeth of one gear must be this prime number or its integer. In order to process this prime number of gears. However, since the Y3150E hobbing machine only has a prime number of hanging wheels with a number of teeth less than 100, it is impossible to select a suitable hanging wheel. The ordinary method cannot process a prime number gear with a number of teeth greater than 100. In addition, the helical gear has a helix angle. When the hob is in the vertical feed motion during the machining, the workpiece makes an additional rotary motion, so that the machining of the helical helical gear with the number of teeth greater than 100 becomes more complicated. This paper will analyze this problem and give examples of feasible processing methods with examples.
Machining the gear on the gear hobbing machine can make such a straightforward statement: the hob is used for the axial feed movement during the machining process. When the hob RZi is turned, the workpiece is accurately turned over the scale (X is the number of the cutter head), and the obtained gear It is a spur gear; if the workpiece does not turn enough A: turn or turn over the head, the resulting gear is a helical gear.
When processing a number of helical gears larger than 100, due to the large number of teeth Z can not select the appropriate 6, d hanging wheel, using a slightly different from the Zi 4 to match the chain of the hanging wheel, to ensure (axc) / (6x (i ) = 24 heart 7. or (axc) / (6xd) = 48X / Z. Optional to the shared hanging wheel, so in the Fancheng motion transmission chain, the hob turns, the workpiece turns to ZiA7Z. Turn, produce = ( Z.-Zd/C% error, if this error is exactly the additional motion required to form the helix angle of the helical gear? At this time, the tool holder has made the axial feed motion of r (mm), then it is needed The large number of helical gears. If the additional motion required for the helix angle of the helical gear has a difference of Y, the synthetic mechanism on the Y3150E can be used to compensate the difference of the remaining W with the differential motion transmission chain. This makes it possible to machine any number of helical gears larger than 100. The former method is called the differential-free method and the latter is called the differential machining method.
Third, the transmission chain adjustment calculation using the non-differential method to process the number of helical gears greater than 100, without the use of a synthetic mechanism, the main drive chain is the external connection drive chain, and the processing under normal conditions is no different, no special calculations are required The axial feed chain is actually involved in the formation of the helical angle of the helical gear. In fact, the axial feed chain of the Y3150E shares a set of hanging wheels with the Fan Cheng chain. The axial feed amount / "mm" is known, then the key to the problem is the calculation of the Fancheng motion drive chain. The main point is to change the motion relationship between the hob, the workpiece and the tool holder: the hob Zz/foot A workpiece 1 is rotated to a tool holder / (mm), and changed to: the hob turns a workpiece 1 to a tool holder / Q (mm).
On the one hand, the change is to enable Fan Chengxing to select the matching hanging wheel suitable for Z. At the same time, it must also ensure the requirement of additional rotation of the workpiece helix angle.
For the convenience of calculation, the above relationship is transformed into: hob Zj / especially a workpiece 1 ± 厶 turn a knife holder / 丨 (mm) where d is the additional amount of rotation required to form the helical angle of the helical gear, the specific value of the slogan It is judged according to the relationship between the rotation of the workpiece and the steering of the table, and since //1=1/eight f is the helical gear lead, r=tt%'/ is obtained. "The movement balance type of the fan chain on the Y3150E hobbing machine is: (1 turn) hob x20x¥x¥x¥x¥xu synthetic workpiece with =1 generation of people's scoring gear hanging wheel replacement formula: the result is: will be large The number of prime numbers and the helix angle of the workpiece are combined at +"; when the workpiece is opposite to the direction of the hob, the number is taken.
2. Adjustment calculation of the differential machining method When the helical gear is machined without the differential method, the additional amount of rotation required to form the helix angle cannot be obtained or the resulting additional rotation is not accurate enough. If the differential machining method is used, the differential mechanism can be used to compensate the remaining difference by using the synthetic mechanism on the Y3150E, so that any number of helical gears larger than one can be processed. The total motion relationship between the hob, the workpiece and the tool holder is: the cutter Z/tool turns a workpiece 1* to a knife holder/; + soap, wherein the number of additional rotations obtained by the soap is a differential chain is the differential chain The number of additional rotations obtained, wherein the calculated displacement relationship between the end pieces determined by the Fancheng motion train is: the hob Z/turn to a workpiece 1 ± soap turn.
The calculated displacement relationship between the end pieces determined by the differential motion drive chain is: workpiece 1 + 4 to a tool holder /, (mm) - workpiece soap transfer.
The adjustment calculation of Fan Chengxing is similar to the analysis of the non-differential method, except that the transmission ratio of the synthetic mechanism is -1, and the motion balance type is: the replacement formula of the -1 generation of the scoring tooth hanging wheel: 4 is an arbitrary number, can be positive, Negative, the main consideration is to select the fan-shaped hanging wheels a, 6, c, d. 2) The adjustment of the differential motion transmission chain calculates the calculated displacement of the two end pieces of the differential motion transmission chain: the workpiece armor, " After the 2'5, the replacement formula of the differential hanging wheel is: ±": the ratio of the hanging wheel of the orientation feeding movement when the workpiece and the hob are the same; the axial direction of the machine tool Give the sport a hanging wheel.
Optional hanging wheel is: 2. Calculation example using differential method: Right-hand helical gear is machined with a right-hand hob, the number of hobs is less than 1, 7 is = 103, and =20., normal modulus % 捩 =1, Fan Cheng chain hanging wheel configuration is as follows: Optional hanging wheel is: Example: right-handed hob with right-hand hob, the number of hobs is 1 = 1, this paper summarizes the field production experience of helical gear processing On the basis of this, a new understanding of the concept of helical gear machining is presented and a visual statement is made to guide the adjustment calculation of the transmission chain in the processing of large-mass helical gears, compared with some methods adopted in the past. The ideas are clearer, the calculations are easier, and the accuracy gained is even worse. Through the example calculation, the correctness of the algorithm is verified and successfully applied in actual production.
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