Modulus of gear of current much axle box decides modular machine tool really

Summary: Analysing modular machine tool gear of current much axle box is specific on the foundation of the design, those who recommend modulus of a group of affirmatory gear is special simplify the design is formulary, in order to improve artificial design quality. Keyword: Current much axle box; Gear modulus; Design 1 foreword at present, current much axle box designs modular machine tool in, when deciding gear modulus artificially, decide with analogy law commonly, or estimate by formula, namely M ≥ (30 ～ 32) , the P in type is the power that gear place transfers, the unit is KW, z is teeth of a cogwheel of the denticulation in gear of a pair of clench the teeth to count, n is the rotate speed of pinion, the unit is R ／ Min. Next, after waiting for protocol of whole transmission system, undertake test and verify to the gear modulus of place make choice of again, whether does school nucleus satisfy working requirement. Because checking computations is more irritated, be opposite only commonly bear among them the gear with the the biggest, most fragile load undertakes checking computations. In old design practice job, the author thinks above method is put in defect. Its rationality lacks the gear modulus with analogy certain way apparently mensurable assessment, and the result that applies afore-mentioned estimation formula to reach and result of checking computations of specific school nucleus sometimes error is bigger, with use a result actually abhorrent also. In addition, afore-mentioned estimation are formulary, applying convenient sex actually to go up to also need to improve. Analysing modular machine tool gear of current much axle box is specific on the foundation of the design, those who recommend modulus of a group of affirmatory gear is special simplify the design is formulary, in order to improve artificial design quality, what can absolve school nucleus checking computations is troublesome, can use what design artificially at current much axle box to examine evaluate. In the meantime, also can provide reference of a bit experience for active CAD. 2 special simplify the design is formulary 2.

1 about estimation is at present formulary M ≥ (30 ～ 32) the ≥ of M of formula of gear modulus estimation that brief analyse introduces on the data at present (30 ～ 32) , was to simplify roughly the general and mechanical gear after a lot of parameter simplifies the design is formulary, the accuracy of computational result is poorer; And cube of formulary formally continue to use root relation, also be to suffer general and mechanical gear to simplify the influence that devises formula; Additional, the power that transfers with P(gear place in type) for parameter, do not facilitate actual design applies, this are designed to the gear on transmission shaft particularly apparent. 2.

2 special simplify place of current much axle box uses the choice modular machine tool that devises formula gear is hard tooth flank gear of straight tine cylinder, intensity of surface contact of tine teeth of a cogwheel is high, tine root flexural strength is relatively a few lower, and lubricant and cooling condition is better when gear works, produce bit of corrode not easily, main and the turn that the most dangerous invalidation form is teeth of a cogwheel is broken zigzag, when designing gear artificially accordingly, the choice ages computation regards a bend fatigue intensity as design basis as a result, relatively appropriate. By FP of σ of ≤ of school nucleus formula, convertibility, have design formula apparently M ≥ , the K in type is load coefficient; T is the torque that gear place delivers, the unit is N*mm; YFS is coefficient of complex tooth form; B is gear facewidth, the unit is Mm; Z is tine teeth of a cogwheel to count; What σ FP uses data for gear place is allowable curve stress, the unit is MPa (or N ／ Mm2) . 2.

3 computation parameter is decided really according to modular machine tool the working characteristic of gear of current much axle box differs, can divide for two kinds of big 4 group. Namely: One kind is bore with a reamer of the boring that get enlarge many kinds axle box gear; Another kind is tap many kinds axle box gear. Gear of two kinds of many axle box is divided severally again for general gear (one-way get power) with intermediate gear (two-way) getting power. Accordingly, when parameter of affirmatory concerned computation, must classify choose affirmatory. 2.

3.

K of 1 load coefficient gets enlarge boring bore with a reamer kind coefficient of load of gear of box of general main shaft: ＝ of α of K of β of K ＝ KAKPNTKVK 1. 1 × of 1 × 1. 05 × 1. 2 × 1. 15 ＝ 1. 5939 attack whorl many kinds the load coefficient of axle box gear: ＝ of α of K of β of K ＝ KAKpntKVK 1. 1 × of 25 × 1. 05 × 1. 2 × 1. 15 ＝ 1. 81125 2.

3.

The limits of Z of number of tine of gear of current much axle box is modular machine tool of YFS of coefficient of 2 complex tooth form 16 ～ 70, general actor chooses limits to be 18 ～ 50, specific and corresponding numerical value is: Z ＝ 18, YFS ＝ 4. 45 Z ＝ 20, YFS ＝ 4. 37 Z ＝ 25, YFS ＝ 4. 20 Z ＝ 30, YFS ＝ 4. 12 Z ＝ 35, YFS ＝ 4. 07 Z ＝ 40, YFS ＝ 4. 03 Z ＝ 45, YFS ＝ 4. 01 Z ＝ 50, YFS ＝ 4. 00 analyse through contrast knowable, YFS value and Z value size become inverse ratio; And as Z the value increases, the rate of YFS value decrescent is minor. Because this joins sex of several data disperse big, reason uses YFS ＝ 4. 45 ～ 4. 00. 2.

3.

B of 3 gear facewidth should choose 1T0741, when 42 gear train are listed, b ＝ 24 Mm should choose 1T0741, when 41 gear train are listed, b ＝ 32 Mm 2.

3.

4 allowable curve stress σ FP place of gear of much axle box of modular machine tool is 45 steel with material, the technology asks the ministry that it is tine is high frequency quench G54, precision 7 class. Reference concerns a material, combinative production is actual, take a value to be as follows respectively: General gear (one-way get power) σ FP ＝ 1. Among 476MPa of ＝ of 4 σ Flim gear (two-way get power) ＝ of Flim of σ of σ FP ＝ 340MPa 2.

4 special simplify the design derives each groups of afore-mentioned computation parameter is worth era to enter M formularily ≥ , notice to be worth the T in type the unit by N.

Mm conversion becomes N.

M, what reach the watch lists all sorts of circumstances 1 times to fall not hard is special simplify the design is formulary: Express the 1 circle that is facilitating formula data to rectify, with former estimation formula contrast studies, will go up the watch simplifies design formula turns a watch into 2 forms. Kind of the place in expressing 2 watches is special simplify the limits coefficient in devising formula, count a decision with tine teeth of a cogwheel by place, age the extraction with little number is worth greatly, the extraction with tine much number is small value, specific application characteristic is referred to 2. 3. Entry of YFS of coefficient of 2 complex tooth form. Watch 33 about attacking whorl many kinds the characteristic specification that modulus of axle box gear designs certainly is designing tap many kinds when axle box, should consider the impact of tap passivation, right special simplify the T in devising formula is worth (or P is worth) make amend accordingly, combine characteristic of protocol of system of transmission of much axle box of modular machine tool, general and desirable: T amends ＝ (1. 5 ～ 2. 5) T. The tap that T is worth correction coefficient and drive of this gear place concern between number, if the watch is shown 3 times,the article is recommended. CNC Milling