CN102371473A - Method for machining standard spherical involute spur bevel gear - Google Patents

Abstract

The invention discloses a method for machining a standard spherical involute spur bevel gear. The method comprises the following steps of: (I) teeth blank machining: manufacturing a teeth blank of a gear by using a forging process; (II) tooth form machining: machining the standard spherical involute spur bevel gear as required by using a gear shaper cutter on a spur bevel gear shaper according to a principle of generating a gear of a gear; (III) thermal treatment of the gear: performing thermal treatment on the gear subjected to initial machining; and (IV) finish machining of the gear: performing finish machining on the gear subjected to thermal treatment to obtain the gear meeting requirements. The gear machined by using the method for machining the standard spherical involute spur bevel gear, provided by the invention has the advantages of high precision in tooth form and tooth profile, transmission stability and high comprehensive performance.

Description

A kind of processing method of standard sphere Involute Straight-teeth Bevel Gear

Technical field

The present invention relates to a kind of processing method of driving parts, particularly a kind of processing method of standard sphere Involute Straight-teeth Bevel Gear.

Background technology

The spherical involute spur bevel gear is that mechanical field is used to transmit one of parallel axes motion and the most basic part of power, is widely used in various plant equipment such as mine, metallurgy, building and transportation.At present, the spherical involute spur bevel gear usually on straight bevel (gear) generator, the profile of tooth of processing the spherical involute spur bevel gear with the dedicated tool gear shaper cutter by " product generating gear " principle with two standard gear shaper cutters that are packed on the knife rest.Add man-hour, the upper and lower knife rest of straight bevel (gear) generator is made the cutting movement of linear reciprocation, and whole knife rest is contained on the cage chair; And do the swing of certain angle with cage chair, and constituting generating motion with the positive and negative gyration of the respective angles of workpiece, cage chair swing up and down reciprocatingly whenever is once; Just accomplish the cutting movement of a tooth, at this moment workpiece withdraws from saddle, turns over certain angle and carries out the branch tooth; Saddle enters the operating position again then, begins to cut second tooth.The blade of gear shaper cutter is a skew lines, and the profile angle of gear shaper cutter is 20 °, in the cutting movement process, forms a tapered plane, promptly produces the flank of tooth of generating gear, and through generating motion, the tapered plane flank of tooth envelope that produces generating gear goes out the flank of tooth curved surface of processed straight bevel gear.

Because processing equipment and installation errors, can the tangible error of generation near the tooth top of the gear teeth and the tooth root, addendum thickness is inhomogeneous, all less than the addendum thickness of spherical involute spur bevel gear, i.e. topping.In this way processing the straight bevel gear precision not high, be not in fact on the normal meaning the spherical involute spur bevel gear.

Summary of the invention

Technical problem to be solved by this invention is the processing method of a kind of standard sphere Involute Straight-teeth Bevel Gear of design; The precision that it can reduce at present to be produced by " product generating gear " principle processing spherical involute spur bevel gear is not high; Actual what obtain is not the shortcoming of standard sphere involute gear, but designs a kind of method of accurate processing spherical involute straight bevel gear.

Technical scheme

A kind of processing method of spherical involute spur bevel gear, it comprises following step:

(I) tooth base processing utilizes Forging Technology to make the tooth base of gear;

(II) tooth Profile Machining utilizes gear shaper cutter to process required standard sphere Involute Straight-teeth Bevel Gear according to " product generating gear " principle on the spur bevel gear gear shaper;

(III) gear heat treatment is heat-treated the gear through preparatory processing;

(IV) fine finishining of gear to carrying out fine finishining through heat treated gear, obtains satisfactory gear;

It is characterized in that: used gear shaper cutter is a kind of novel gear shaper cutter in the said step (II), and its tooth surface satisfies parametric equation:

both the profile angle of gear shaper cutter is 19 ° 53 '.

Beneficial effect

The spur bevel gear profile accuracy that the processing method of a kind of standard sphere Involute Straight-teeth Bevel Gear of the present invention's design is manufactured is high; Stable drive; It is low to vibrate less noise; Improve straight bevel gear registration, improve flank of tooth contact and force-bearing situation, avoid the latch phenomenon to occur, improved the precision of transmission system.

Description of drawings

Accompanying drawing 1 is existing gear shaper cutter processing spherical involute spur bevel gear schematic cross-section.

Accompanying drawing 2 is the schematic cross-section of novel gear shaper cutter among the present invention.

Accompanying drawing 3 is first embodiment of the invention acceptance of the bid director sphere Involute Straight-teeth Bevel Gear sketch map.

Accompanying drawing 4 is second embodiment of the invention acceptance of the bid director sphere Involute Straight-teeth Bevel Gear sketch map.

The specific embodiment

Below in conjunction with accompanying drawing and specific embodiment, further set forth the present invention.

The processing method of first kind of a kind of standard sphere of embodiment Involute Straight-teeth Bevel Gear of the present invention, it comprises following step:

(I) tooth base processing utilizes Forging Technology to make the tooth base of gear;

(II) tooth Profile Machining utilizes gear shaper cutter to process required spherical involute spur bevel gear according to " product generating gear " principle on the spur bevel gear gear shaper;

Shown in accompanying drawing 1; The flank of tooth of the product generating gear of traditional processing straight bevel gear is the inclined-plane; And the theoretical flank of tooth

of the product generating gear of processing spherical involute straight bevel gear is the curved surface on-plane surface, and its tooth surface equation is:

$\stackrel{\→}{P_r}=R\left(\begin{array}{c}\sin {\mathrm{\α}}_0\sin \mathrm{\ψ}\\ \cos {\mathrm{\α}}_0\cos \mathrm{\φ}\sin \mathrm{\ψ}-\sin \mathrm{\φ}\cos \mathrm{\ψ}\\ \cos {\mathrm{\α}}_0\sin \mathrm{\φ}\sin \mathrm{\ψ}+\cos \mathrm{\φ}\cos \mathrm{\ψ}\end{array}\right);$

The position vector of any on the theoretical flank of tooth of

-product generating gear;

R is a pitch cone radius in the formula, φ=ψ/cos α ₀, α ₀Be pressure angle, standard value α ₀=20 °,, make z so pitch cone radius R and angle ψ are two basic parameters _r=C, i.e. z _rCoordinate is a constant, or

$R=\frac{C}{\cos {\mathrm{\α}}_0\sin \mathrm{\φ}\sin \mathrm{\ψ}+\cos \mathrm{\φ}\cos \mathrm{\ψ}},$

C-is a constant;

The substitution following formula can be obtained and produce generating gear and perpendicular to the cross section tooth curve of nodel line be:

$\left(\begin{array}{c}{x}_P\\ y_P\\ z_P\end{array}\right)=\frac{C}{\cos {\mathrm{\α}}_0\sin \mathrm{\φ}\sin \mathrm{\ψ}+\cos \mathrm{\φ}\cos \mathrm{\ψ}}\left(\begin{array}{c}\sin {\mathrm{\α}}_0\sin \mathrm{\ψ}\\ \cos {\mathrm{\α}}_0\cos \mathrm{\φ}\sin \mathrm{\ψ}-\sin \mathrm{\φ}\cos \mathrm{\ψ}\\ \cos {\mathrm{\α}}_0\sin \mathrm{\φ}\sin \mathrm{\ψ}+\cos \mathrm{\φ}\cos \mathrm{\ψ}\end{array}\right);$

x _P, y _P, z _PThe coordinate of any on the tooth curve of-cross section.

Obviously, the cross section flank profil is a curve, and non-rectilinear, processing spherical involute straight bevel gear produces generating gear as the cutting cutter, promptly produces the generating gear cutter, is equivalent to gear shaper cutter, and obviously, these two kinds of tool-tooth profiles are different, traditional standard gear shaper cutter profile angle α ₀=20 °.Processing spherical involute straight bevel gear produces the generating gear tool-tooth profile and near nodel line, overlaps basically, but far away more apart from nodel line, the deviation of these two kinds of tool-tooth profiles is big more; Tooth top and tooth root place are maximum, and modulus is big more, and the deviation at tooth top and tooth root place is just big more; Deviation between two kinds of tool-tooth profiles is big more; Deviation between the corresponding two kinds of tooth surfaces of bevel gears that process is just big more, and in order to make the tooth surfaces of bevel gears that processes more near spherical involute flank of tooth curved surface, we need design a kind of α ₀≠ 20 ° straight line profile of tooth.

By spherical triangle sine formula, addendum angle θ _aOr dedendum angle θ _f, θ _a=θ _fCan be expressed as sin θ _a=sin α ₀Sin ψ _a, in addition,

$\tan {\mathrm{\θ}}_a=\frac{h_a}{R}=\frac{2}{z_1\sqrt{1+i^2}}$

Wherein,

z ₁-the number of teeth is generally got z ₁=13～30,

The gearratio of i-single gear is generally got i=1～6,

So θ _a=0.1-3.2 °, ψ _a=0.29 °～9.4 °;

We establish spherical involute and produce the generating gear tool-tooth profile, and need satisfy the simple regression linear equation is y=a+bx

The a-constant term, the b-regression coefficient, and

$b=\frac{l_{\mathrm{xy}}}{l_{\mathrm{xx}}}$

$a=\stackrel{\‾}{y}-b\stackrel{\‾}{x}$

Wherein is the arithmetic mean value, promptly

$\stackrel{\‾}{x}=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{x}_i$

$\stackrel{\‾}{y}=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{y}_i$

Order

$l_{\mathrm{xx}}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{(x_i-\stackrel{\‾}{x})}^2$

$l_{\mathrm{xy}}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}(x_i-\stackrel{\‾}{x})(y_i-\stackrel{\‾}{y})$

$l_{\mathrm{yy}}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{(y_i-\stackrel{\‾}{y})}^2$

Coefficient correlation then

$r=\frac{l_{\mathrm{xy}}}{\sqrt{l_{\mathrm{xx}}{l}_{\mathrm{yy}}}}$

x _iThe abscissa of-sample point

y _iThe ordinate of-sample point.

Obviously | r|≤1, when | r| is more near 1, and linear correlation is big more, can try to achieve the point on the spherical involute gear shaper cutter profile of tooth by producing generating gear perpendicular to the cross section tooth profile curve equation of nodel line, and is modern according to the method for getting particular value, at ψ _aGet the n=11 point in=0 °～9.4 ° scopes, this can try to achieve b=2.765, and obviously, the size dimension of b and bevel gear is irrelevant; A=-0.0001R, a is relevant with the pitch cone radius R of bevel gear, and is directly proportional, substitution simple regression linear equation; At rectangular coordinate system oxy, see accompanying drawing 2, get the linearity of regression equation

$y=\±0.0001R\stackrel{\‾}{+}2.765x$

Get positive sign for first of right side profile of tooth, get negatively for second, and first of left side profile of tooth got negative sign, gets positive sign for second, correlation coefficient r=0.99999, and height correlation then, this equation can be used.By tan ^-1° 7 (2.765)=70 ', gear shaper cutter obtained at profile angle α ₀The accuracy of gear that=19 ° of 53 ' times manufacture is the highest, and then new gear shaper cutter profile of tooth is for satisfying equation

Be profile angle α ₀=19 ° 53 ' gear shaper cutter.

For the straight bevel gear of pitch cone radius R≤100mm, ignore ± the 0.0001R item, at this moment get skew lines As tool-tooth profile, promptly node overlaps with the node of traditional standard cutter, and still, the tool-tooth profile angle is α ₀=19 ° 53 ' processing obtains standard sphere Involute Straight-teeth Bevel Gear shown in accompanying drawing 3 on gear shaper.

(III) gear through preparatory processing is heat-treated;

(IV) fine finishining of gear is to carrying out fine finishining through heat treated gear;

Utilize profile angle α ₀=19 ° 53 ' new gear shaper cutter spur bevel gear gear shaper on utilize gear shaper cutter to process that required standard sphere Involute Straight-teeth Bevel Gear can be avoided gear shaper processing and alignment error and the uneven shortcoming of addendum thickness that takes place according to " product generating gear " principle;

Another embodiment of the present invention is the straight bevel gear for pitch cone radius R＞100mm, and at this moment reservation ± 0.0001R item gets skew lines

As tool-tooth profile, promptly node does not overlap with the node of traditional standard cutter, and promptly the tool-tooth profile angle still is α ₀=19 ° 53 ', standard sphere Involute Straight-teeth Bevel Gear shown in accompanying drawing 4.

Claims (1)

1. the processing method of a spherical involute spur bevel gear, it comprises following step:

(I) tooth base processing utilizes Forging Technology to make the tooth base of gear;

(II) tooth Profile Machining utilizes gear shaper cutter according to " " principle processes required spherical involute spur bevel gear to produce generating gear on the spur bevel gear gear shaper;

(III) gear heat treatment is heat-treated the gear through preparatory processing;

(IV) fine finishining of gear to carrying out fine finishining through heat treated gear, obtains satisfactory gear;

It is characterized in that: used gear shaper cutter is a kind of novel gear shaper cutter in the said step (II), and its tooth surface satisfies parametric equation:

be that the profile angle of gear shaper cutter is 19 ° 53 ';

The abscissa of any on the x-flank of tooth; The ordinate of any on the y-flank of tooth;

The R-pitch cone radius.

Images