The summary introduced a kind to be machined with standard gear cutting tool nonstandard the new method of gear. Because the base pitch of cutting tool and gear is unequal, the gear of treatment is put in the error. Be like this error not out of tolerance, gear can be used directly. Should increase otherwise stay grind surplus, via be being used after roll flute. The keyword is nonstandard gear cutting Machining Non-standard Cylindrical Gear With Standard Gear CutterWang Huapei, what Et Al imports equipment to go up is nonstandard after gear damages, need make repairs and supply replacements. It is normally import gear fittings from equipment country of origin or make cutting tool technically machine this gear. These two kinds of methods are wasteful and take time. Best choice is to use existing machine tool and cutting tool treatment to be not mark gear. Document  put forward to use the rack cutting tool with adjustable pitch to age in Ma Ge moulding plane the treatment on machine is not mark gear, but this kind of machine tool is rare in the factory. The means that the article offers, all can come true in general plant. Roll flute machine is the relatively common device in the factory, the principle that extends law roll flute and the principle that machine gear with rack cutting tool are same, can use at any modulus that be not mark and the treatment that are not gear of mark pressure angle. But the gear wheel with very little modulus just can be ground directly on roll flute machine piece. The gear with largish modulus this kind of method is unsuited, need prior operation gives tooth form. With standard cutting tool (hob, the knife that insert tine) very difficult treatment gives the accurate gear that be not mark. If use,boil, insert as working procedure of gear prior operation, increase surplus grind a proper tooth form finally by roll flute machine, although treatment efficiency is inferior, but can assure gear precision. Well-known, involute gear and rack (gear) the postulate of clench the teeth is basic circle pitch must equal, when hob and gear of treatment of the knife that insert tine such also. Namely the M0 in 1 type of Pb0=Pb1 (1) or α of M1cos of π of 0= of π M0cos α , m1 -- the modulus of cutting tool and gear, mmPb0, pb1 -- the base pitch α of cutting tool and gear 0, α 1 -- the pressure angle on the tooth form horn of cutting tool and gear reference circle, (° ) the product of the modulus that wants to the product of the modulus of cutting tool and tooth form horn is close to or be equal to the gear that be cut only and pressure angle, can machine gear with this cutting tool. If both base pitch difference is less than tolerancepublic errand limits, gear can be used directly, if the error is too big, be about the surplus with enough put apart, get right gear wheel with roll flute. Use normally when angrily detect L of length of public law line controls transverse tooth thickness, stay grind a quantity to want to consider to eliminate base pitch error, a few bigger than be being obtained normally. The Sb1 in because length of public law line is solid,summing mood of L=(n-1)Pb1+Sb1(2) of transverse tooth thickness of a basic circle for a few base pitch -- basic circle transverse tooth thickness, mmn -- length of line of public law of the number that cross tine increases a quantity to be Pb1 of the Δ in type of Pb1 of Δ of L=(n-1) of Δ of -- the base pitch with cutting tool and both gear is poor, mm is final even checking computations tine is deep: The transverse tooth thickness on pitch circle of the gear when angrily should be equal to the alveolar width on line of cutting tool section. Have ′ of =r of S ′ namely [0) of α of S/r+2(inv α 1-inv] cutting tool moves ′ of M0=(S-S of ζ of of of the that be apart from a value) / (′ of Rf=r of of of of round radius of root of tine of of 2tg α 0) - the R in type of M0 of ζ M0-h ″ -- gear divides round radius, mmr ′ -- radius of gear pitch circle, mmS -- gear divides round transverse tooth thickness, mm ζ -- move be apart from coefficient H ″ -- coefficient of gear height of teeth root presses type (3) if the tine root round radius of cipher out is worth close with gear blueprint, to can be used. If use, is the knife that insert tine, its analyse computational method likeness. To helical gear, also can realize standard cutting tool to machine the gear that be not mark with afore-mentioned methods, compare in differential drive only in adjusting formula, modular numerical value should be workpiece modulus M1, m0 of modulus of cutting tool of and rather than. Computational example sets gear wheel of one blame mark, tine of; of ° of 1=15 of pressure angle α of diameter section DP=4; counts Z=40, try decide its machine a method. Through comparing, with M=6.
5, the hob of α 0=20 ° is machined, both base pitch is most adjacent. Pb0=3.
1416 × 6.
=19 of ° of 5 × Cos20.
1416 × 6.
=19 of ° of 35 × Cos15.
269 Δ Pb1=-0.
The gear base pitch that of of of of of of of of of of 08 machines the gear that go out actually to ask than the design is small, basic circle is lesser also. ′ of D of diameter of the pitch circle when treatment (the length of public law line that Mm) is roll flute of of D ′ =m0 Z=260 stays grind a quantity to should be compared increase L of a Δ normally, namely × of L=(5-1) of Δ of 0.
Tooth depth of 32 checking computations: Beg a S=9.
975;S ′ =7.
930; ζ M0=3.
00, with blueprint requirement Rf=119.
06 close. If base pitch error is bigger, be obliged put apart is enough surplus passes roll flute. If differ very big, make special cutting tool only. CNC Milling