CN1058081A - Involute conic worm pair with straight generatrix contact transmission and technological equipment for making thereof - Google Patents

Abstract

Involute conic worm pair with straight generatrix contact of the present invention and technological equipment for making thereof, belong to Der Grundsatz der Maschinen and mechanical manufacturing field, the gear teeth two flank of tooth A of worm gear 2 and T and perpendicular to the intersection on the plane of worm gear axis are two involutes, and the base circle diameter (BCD) of these two involutes is respectively D _A2, D _T2, worm gear flank of tooth A, T are respectively that diameter is D _A2, D _T2Two the formed involute spiral of base cylinder faces.Flank of tooth A, the T of worm screw 1 is to be d by diameter _JA, d _JTTwo base cylinders form.A, T two sides are that pitch is t _A, t _TArticle two, the tangent line L of helix _A, L _TFormed tangent surface.The present invention has designed the frock and the technology of spiroid and the processing of the worm gear flank of tooth.

Description

Involute conic worm pair with straight generatrix contact transmission and technological equipment for making thereof

The invention belongs to Der Grundsatz der Maschinen and manufacturing technology, relate to gear engagement theory and worm drive.

The development of Procedure for Spiroid Gearing starts from five abroad, the sixties (O.Saari, The Mathematical Background of spiroid Gear, " Industr.Math. " NO7,1959.; W.D.Nelson, Spiroid Gearing, " Machine Design " Vol 33, NO4,5,6,1961.; D.W.Dudey, Gear Handbook, 1962.) and at farm machinery, Hoisting Machinery, lathe is used in guided missile and the various military machinery.The development work that China has carried out spiroid in the eighties has obtained a collection of achievement (Taiyuan Heavy Machinery College, Procedure for Spiroid Gearing, " gear " 1977, the third phase; Northwestern Polytechnical University, Procedure for Spiroid Gearing, the 3rd, 4 phases of " Machine Design " nineteen eighty-two).Aforementioned spiroid is Archimedes's helical line worm screw, compares with normal cylindrical worm gear drive, and it has Transmission bearing big, and lubricating condition is good, and the worm gear material can be used copper take place of steel, and sideshake is convenient to control and transmission efficiency advantages of higher.But Archimedes's helical line Procedure for Spiroid Gearing has the nonsymmetry of transmission, and worm screw, the worm gear flank of tooth again can not grindings, and this has just limited the further raising of bearing capacity, and the worm gear cutter is difficult in addition makes, and when the snail material is used steel, also need use the top gem of a girdle-pendant bar honing worm gear flank of tooth.This technologic difficulty makes that Procedure for Spiroid Gearing still is difficult to promote at home at present.The design of involute spiroid and Research on processing technology be existing report (theory of engagement of involute Procedure for Spiroid Gearing, Zhao Yihan, Shao Junsong, " Machine Design " first phase in 1988 in recent years; Turning involute Procedure for Spiroid Gearing, high blog article " the 7th national mechanology academic discussion collection of thesis ", 1990.）

The objective of the invention is according to mesh theory analysis, physical dimension is calculated, and designs practicable involute conic worm pair with straight generatrix contact transmission in machining, has overcome the shortcoming of above-mentioned Archimedes spiral Procedure for Spiroid Gearing.

According to mesh theory analysis (Zhao Yihan etc. " Machine Design " first phase P15-in 1988), appropriate worm screw, the worm gear geometric parameter selected, just can make worm screw involute surface straight edge line become the conjugate surface Line of contact of endless screw-worm gear pair, this not only makes the involute Procedure for Spiroid Gearing can have the advantage of Archimedes' worm transmission, and can overcome its shortcoming, especially the processing of the worm gear gear teeth can adopt single angle milling cutter to cut on common universal milling machine with half generate half mould milling without hob cutting.This worm drive, worm tooth-surface can grindings, and the worm gear flank of tooth also can adopt the simple process equipment to carry out grinding.These are not only the innovation of worm gear processing technology, have also created condition for choose reasonable worm drive geometric parameter.

Involute straight edge line of the present invention worm drive, calculate conjunction with figs. according to the physical dimension of its transmission of the theory of engagement and be described below:

1. the physical dimension of involute Procedure for Spiroid Gearing is calculated.

On the basis of mesh theory analysis, consider to improve transmission performance, improve the transmission component anufacturability, the present invention has drafted formula, and its main formula is as follows:

(1) worm screw modulus

Worm screw has three moduluses

The A over glaze is to modulus

$m_A=\frac{t_A}{\mathrm{\π}}=2\frac{\mathrm{tg}{\mathrm{\λ}}_A\mathrm{tg\δ}}{\mathrm{tg}{\mathrm{\λ}}_A-\mathrm{tg\δ}}\frac{A}{Z_1}---\left(1\right)$

The T over glaze is to modulus

$m_T=\frac{t_T}{\mathrm{\π}}=2\frac{\mathrm{tg}{\mathrm{\λ}}_T\mathrm{tg\δ}}{\mathrm{tg}{\mathrm{\λ}}_T-\mathrm{tg\δ}}\frac{A}{Z_1}---\left(2\right)$

Worm screw conical surface modulus

$m_0=\frac{S}{\mathrm{\π}}=\frac{1}{2}{m}_{n}1+{\mathrm{tg}}^{2}a---\left(3\right)$

A is a transmission centre distance (see figure 4) in the formula, t _A, t _TBe worm screw axial pitch (Fig. 5), λ _A, λ _TBe the axial angle of sections of worm-shaped tooth, tg δ=1/i ₁₂, i ₁₂=ω ₁/ ω ₂Be velocity ratio, S is a worm gear conical surface tooth pitch, α ₁Be the worm screw cone angle.m _h=m _A+ m _T, Z ₁Be worm thread head number.

(2) worm screw cone angle

Work as λ _T=λ _ADuring=λ

$a_1=\mathrm{arctg}(\frac{\mathrm{tg\δ}}{{\mathrm{tg}}^2\mathrm{\λ}}---\left(4\right)$

(3) worm screw involute surface Base radius

A face Base radius

$r_{\mathrm{IA}}=\frac{\mathrm{tg\δ}}{\mathrm{tg}{\mathrm{\λ}}_A-\mathrm{tg\δ}}A=\frac{Z_1{m}_A}{2\mathrm{tg}{\mathrm{\λ}}_A}---\left(5\right)$

T face Base radius

$r_{\mathrm{JT}}=\frac{\mathrm{tg\δ}}{\mathrm{tg}{\mathrm{\λ}}_T-\mathrm{tg\δ}}A=\frac{Z_1{m}_T}{2\mathrm{tg}{\mathrm{\λ}}_T}---\left(6\right)$

(4) worm gear cone angle

$a_2=\mathrm{atctg}\left(\frac{X_{K2}-X_0}{r_{P2}}\right)---\left(7\right)$

During engagement, snail root awl and worm gear addendum cone are at P point tangent (Fig. 6), K ₁, K ₂Straight line is that two awls are selected the normal of public tangent plane, K at P ₁, K ₂Point is K ₁K ₂The intersection point of straight line and two axis of cone lines is in the formula (7)

T _P2: the worm gear P point turning radius

X _K2: K ₂Point coordinates

X _P1: the P point coordinates.

By above-listed formula calculating worm and worm gear size can (Fig. 7, this figure be processing m with single angle milling cutter _SThe cutter of=4mm) cutting on universal milling machine.

2, the involute Procedure for Spiroid Gearing (seeing Fig. 1,2,3) of the present invention design, the gear teeth two flank of tooth A of its worm gear 2 and T and perpendicular to the intersection on the plane of worm gear axis are two involutes, the base circle diameter (BCD) of these two involutes is respectively D _A2, D _T2Worm gear flank of tooth A, T are respectively that diameter is D _A2, D _T2Two formed involute helicoids of base cylinder.The flank of tooth A of worm screw 1, T(Fig. 3 are to be d by diameter a) _JA, d _JTTwo base cylinders form (Fig. 3 b), A, T two sides are that pitch is t _AT _TArticle two, the tangent line L of helix _AL _TThe tangent surface that forms.

3, the mechanical processing technique equipment of Procedure for Spiroid Gearing of the present invention

(1) processing of spiroid

The cutting of spiroid can be finished on the engine lathe with master plate or hydraulic copying attachment annex.When not possessing the said equipment, the ball pivot dop 3 and the eccentric counter center 4(Fig. 8 that can utilize the present invention to design).Car device chuck 5 of device blocks eccentric counter center 4 on the chuck on lathe tailstock, and head of a bed three jaw chuck blocks anti-thimble 8 and the on-the-spot centre hole of revising.Workpiece 6 is placed between two steel balls, the centering level, nationality helps ball pivot dop 3 can make tilting workpiece average rate revolution, finishes thread turning work.Should guarantee the center 0 of ball pivot dop during installation, at (π-α ₁) bisector plane (this face is perpendicular to the lathe bed guide surface) P in the motion.

(2) worm gear gear teeth processing

The single angle milling cutter of the present invention, common universal milling machine and special-purpose mill teeth frock (Fig. 9) are finished worm-gear tooth mill teeth operation.Figure 10 is a mill teeth frock kinematic sketch of mechanism.This frock is by base 16, slide 15, and critical pieces such as saddle 14 and main shaft frame 9 are formed.Milling cutter tightens with the cantilever knife bar during mill teeth, milling machine table does not move, base 16 is fastened on the worktable, right side at slide 15 connects tooth bar 19, gear g is engaged with, via pulley frame change gear a, b, c, d and gear f and quadrature tooth bar (on tooth bar two vertical planes tooth being arranged) 17 engagements of being fixed on the saddle 14.This nibble bar 17 again with main shaft cog 10 the engagement.When rotating handwheel 21, promoting saddles 14 through leading screw 22, nut 23 advances or retreats along worm gear tooth trace (direction of arrow), and gear g is rotated, make gear 10 and fixed cover 11 on the main shaft drive main shaft gyration through gear a, b, c, d, f and tooth bar 17, so just finished the compound motion that main shaft changes not only but also moves relative to cutter (cutter does not move along its axis).Matched change gear than ac/bd can make cutlery sword face with the relative movement of worm gear base in the envelope cutting mill out the worm gear flank of tooth.

After a roller seating space was finished in cutting, saddle 14 and main shaft resetted, and plugged latch 12, unclamp the bolt on the fixed cover 11, rotatable handle 18 is finished calibration one time by position, hole on the porose disc, unplug latch 12 then, the bolt on fastening 11 repeats the next roller seating space of cutting campaign cutting.Should be noted that must be according to transmission parameter λ before the cutting ₄(λ _T), α ₁, Υ _JAAnd A utilizes rotating shaft H, K(hinge), aligned the angle (Figure 10) between tool axis and axis of workpiece and tooth bar 19 nodel lines, fastening then rotation H, K, after this utilize again the milling machine elevating screw mix up between cutter and axis of workpiece apart from a(Fig. 9).

Accompanying drawing of the present invention such as following:

Fig. 1 involute Procedure for Spiroid Gearing engagement figure

Fig. 2 worm-gear tooth line chart

Fig. 3 worm tooth-surface figure

Fig. 4 mesh schematic representation

Fig. 5 worm screw sectional view

Fig. 6 worm gear size computational geometry graph of a relation

Fig. 7 list angle milling cutter figure

Fig. 8 worm screw turning ball pivot dop installation diagram

Fig. 9 mill teeth tool structure figure

Figure 10 mill teeth frock kinematic sketch of mechanism.

Advantage of the present invention

The product of manufacturing of the present invention-involute straight edge line contact spiroid gear transmission has following advantages:

Compare with cylindrical worm gearing transmission that to have bearing capacity big, the efficient height, compact conformation, and available steel replaces copper to do the worm gear material.

Compare with hourglass worm and to have the insensitive advantage of axial error.

Compare with Archimedes's helical line spiroid, it has transmission symmetry, but and the advantage of the equal grinding of the worm and wormwheel gear teeth.

When utilizing the cutting worm gear gear teeth of the present invention, need not the high special-purpose hob cutter of complicated valency, only use common single angle milling cutter, and one can process the worm gear of different moduluses and gearratio to milling cutter. This reform of worm gear processing technology not only can reduce manufacturing cost, has also created condition for reasonable selection of design parameters.

The technology of the present invention is not difficult to grasp, and medium or small factory, the technical staff of township enterprise and workman through short-term cultivation, all can grasp production technology.

Claims (4)

1, involute Procedure for Spiroid Gearing is characterized in that the gear teeth two flank of tooth A of worm gear 2 and T and perpendicular to the intersection on the plane of worm gear axis, is two involutes that the base circle diameter (BCD) of these two involutes is respectively D _A2, D _T2, worm gear flank of tooth A, T are respectively that diameter is D _A2, D _T2Two formed involute helicoids of base cylinder; Flank of tooth A, the T of worm screw 1 is to be d by diameter _JA, d _JTTwo base cylinders form, the two sides is that pitch is t _A, t _TArticle two, the tangent line L of helix _A, L _TThe tangent surface that forms.

2, the mechanical processing technique of involute Procedure for Spiroid Gearing according to claim 1 and device is characterized in that:

1. the flank of tooth of spiroid processing cutting is finished on the engine lathe with master plate or hydraulic copying attachment annex, also can be with the ball pivot dop 3 and the eccentric counter center 4 of the present invention design, four jaw chuck 5 of device on lathe tailstock, block eccentric anti-top 4 on the chuck, head of a bed three jaw chuck blocks anti-thimble 8 and the on-the-spot centre hole of revising, and workpiece 6 is placed between two steel balls centering level, nationality helps ball pivot dop 3 to make tilting workpiece average rate revolution, finishes thread turning;

2. the processing of the worm gear gear teeth uses the special-purpose mill teeth frock of single angle milling cutter and the present invention design to carry out on common universal milling machine.Milling cutter tightens with the cantilever knife bar during mill teeth, milling machine table does not move, the base 16 of frock is fastened on the worktable, right side at slide 15 connects tooth bar 19, gear 9 is engaged with, via the pulley frame change gear a that is fixed on the saddle 14, b, c, d and gear f and quadrature tooth bar (there is tooth on the perpendicular two sides of tooth bar) 17 is meshing, tooth bar 17 again with main shaft cog 10 the engagement, when rotating handwheel 21, through leading screw 22, nut 23 promotes saddles 14 and advances or retreat along worm gear tooth trace (direction of arrow), and gear g is rotated, through gear a, b, c, d, f and tooth bar 17 make gear 10 and the fixed cover 11 on main shaft drive main shaft gyration, finish the compound motion that the relative cutter of main shaft (cutter is fixed) changes not only but also moves, the good row's wheel of apolegamy than ac/bd make cutlery sword face with the relative movement of worm gear base in the envelope cutting mill out the worm gear flank of tooth, after a roller seating space is finished in cutting, saddle 14 and main shaft reset, plug latch 12, unclamp the bolt on the fixed cover 11, rotatable handle 18, finish calibration one time by position, hole on the porose disc, unplug latch 12 then, the bolt on fastening 11 repeats the next roller seating space of cutting action cutting.

3, technology according to claim 2 is characterized in that the spiroid cutting should guarantee the center 0 of ball pivot dop when installing, at (π-α ₁) bisector plane (this face is perpendicular to the lathe bed guide surface) P in rotate.

4, technology according to claim 2, it is characterized in that must be according to transmission parameter λ before the cutting of the worm gear gear teeth ₄(λ _T), α ₁, γ _JAAnd A utilizes rotating shaft H, K, aligned the angle between tool axis and axis of workpiece and tooth bar 19 nodel lines, and fastening then rotating shaft H, K utilize the milling machine elevating screw to mix up distance alpha between cutter and axis of workpiece again.

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