CN101293288B - Composite miss-match symmetrical arc toothed portion cylindrical gear and expansion processing method - Google Patents

Abstract

The invention provides a compounded mismatched symmetric arc gear line cylindrical gear and a generating machining method thereof. When the processing is carried out, the gear can actively control the mismatches in the two directions of the gear outline and the gear line. A cutting tool of a straight blade alternate blade cutter with a cutter inclination is adopted, the concept of an imaginary generating gear of the straight blade is introduced, the straight blade of the cutter is regarded as a tooth of the imaginary generating gear and does meshing movement with a processed gear, by controlling the radius of the imaginary produced gear, the mismatch in the direction of the gear outline can be controlled; by adjusting the cutter tilt, the curvature radius in the direction of the gear line of the matched gear can be changed tinily, thus realizing the control of the mismatch in the direction of the gear line. Therefore, according to the actual performance requirement of gears, the compounded mismatched point-contact cylindrical gear with the best contact region can be obtained. The gear is simple in the relation of working movement, convenient in control and adjustment and high in efficiency.

Description

A kind of symmetrical arc tooth trace roller gear and expansion machining method of fine-pitch thereof of compound mismatch

Technical field

The present invention relates to a kind of symmetrical arc tooth trace roller gear and processing method thereof, particularly a kind of expansion machining method of fine-pitch of symmetrical arc tooth trace roller gear of compound mismatch.

Background technology

Along with science and technology and development of modern industry, particularly aerospace industry and national defense construction develop to high speed, high accuracy, heavily loaded direction, all had higher requirement in aspects such as gear-driven bearing capacity, transmission stability, functional reliability, service life, structurally claimed structure compactness, in light weight then.Theoretically, common Involutes Gears Transmission has stationarity, but in the actual gear transmission system, tends to produce comparatively strong vibration and noise problem.Therefore, an urgent demand people develop new profile of tooth, study new gears engaged theory, method for designing and corresponding manufacturing technology, to satisfy high speed, high accuracy, heavy-duty machinery device to gear-driven requirement.

Summary of the invention

The purpose of patent of the present invention provides a kind of symmetrical arc tooth trace roller gear and expansion machining method of fine-pitch thereof of compound mismatch, this method has realized CNC processing completely, can initiatively adjust the compound amount of mismatch of curved tooth line roller gear according to condition of work, satisfy of the requirement of various machineries high-speed gear, high accuracy, low noise and compact conformation.

For achieving the above object, the technical solution used in the present invention is:

1) gear structure, intensity and the serviceability requirement of processing at first as required determined the basic geometric parameters of gear and the cutter tilt of straight sword alternate blade cutter, i.e. pressure angle α, addendum coefficient h _a ^*And tip clearance coefficient c ^*, and centre-to-centre spacing a, gearratio i, modulus m, tooth number Z;

2) then the gear blank of straight sword alternate blade cutter and periphery is installed in respectively on the main shaft and workbench with multi-axis linkage numerical control lathe, the inside and outside vertial knife edge of said straight sword alternate blade cutter is asymmetrical trapezoidal cutter tooth;

3) straight sword alternate blade cutter rotates around axis, forms the main motion of cutter tooth to the gear blank cutting, and secondly gear blank is fed into the generate position with the speed that changes; Then gear blank is around self axis rotation, the straight sword alternate blade cutter of Zhuan Donging begins around its axis of rotation swing simultaneously, constitute the motion of gear and gear meshing, and generate goes out the whole gear teeth flank of tooth, finish the cutting of a teeth groove, the tooth base carries out calibration then, straight sword alternate blade cutter and gear blank counter-rotating, cut next teeth groove, obtain required gear until processing all teeth groove;

Straight sword alternate blade cutter angle of revolution

At initial angle And end angle

Between change initial angle

And end angle

Can obtain by following formula:

Wherein Be the angle that reference point place workpiece turns over, r ₁, r _fRepresent the gear compound graduation radius of circle and the straight sword alternate blade cutter cutter tooth reference circle radius of gyration respectively; r _1a, r _FaRepresent the gear teeth tips radius of circle and the straight sword alternate blade cutter cutter tooth outside circle radius of gyration respectively.

According to the symmetrical arc tooth trace roller gear of method processing of the present invention, has the some contact symmetrical arc tooth trace roller gear of compound mismatch.

Because gear of the present invention is a kind of some contact roller gear with compound mismatch, obtains best contact zone easily, can improve the comprehensive strength and the transmission performance of its gear.This processing method can initiatively be adjusted the compound amount of mismatch of curved tooth line roller gear according to condition of work, realizes CNC processing completely.Satisfy of the requirement of various machineries, satisfy heavy-duty machineries such as oil, mine especially, and the naval vessels on the national defence, heavy transport etc. are to the requirement of gear high-performance, heavy duty high-speed gear, high accuracy, low noise and compact conformation.

The present invention changes the radius of curvature of the gear trace direction that matches by the minor alteration to cutter tilt, thereby reaches the purpose of the bearing length of adjusting trace direction, realizes the control of trace direction amount of mismatch; By control, realize the amount of mismatch control of flank profil direction to the cutterhead generate radius of gyration (promptly imagination is produced the generating gear radius).The present invention compares with existing roller gear generating, has the straight sword alternate blade cutter structure of cutter tilt owing to adopt, and employing and the rotating generating motion mode of gear blank do engagement, therefore amount of mismatch that can ACTIVE CONTROL symmetrical arc tooth trace roller gear in processing, acquisition has the some contact roller gear of the compound mismatch of best contact zone, thereby improves the comprehensive strength and the transmission performance of gear.

Description of drawings

Fig. 1 is the installation site schematic diagram of expansion machining method of fine-pitch of the present invention.

Fig. 2 is a generate process schematic diagram of the present invention.

Fig. 3 is the three-dimensional model diagram of machining simulation of the present invention.

The specific embodiment

Below in conjunction with accompanying drawing the present invention is described in further detail.

Referring to Fig. 1, the used cutting tool of generating of the present invention is a dish type end mill(ing) cutter 1, is uniform-distribution with some asymmetric trapezoidal cutters tooth on its cutterhead circumference, and is identical with the pressure angle that guarantees node place, teeth groove two sides; Cutter axis and tooth base 2 axis normal, and be positioned on the middle section of tooth base width, to process the gear teeth of symmetry.

At first according to the user to gear structure, intensity and serviceability requirement, determine the basic geometric parameters of gear, as pressure angle α, addendum coefficient h _a ^*And tip clearance coefficient c ^*, and centre-to-centre spacing a, gearratio i, modulus m, tooth number Z etc.; According to requirements such as transmission accuracy and alignment errors, select corresponding cutter tilt γ for use then, with the amount of mismatch of control trace direction; According to transmission speed, load, distortion, and requirement such as error, determine the rational cutterhead generate radius of gyration (promptly imagination is produced the generating gear radius), again to control the amount of mismatch of flank profil direction.

According to above-mentioned selected parameter, allow rotary head 1 do generating motion with workpiece blank 2 with tilt, because the blade of cutterhead 1 is the straight flange sword, in the process of generating motion processing, the straight flange cutterhead just can reach the purpose of flank profil direction correction of the flank shape at the unnecessary trace meter that cuts of tooth root and tooth top portion of the flank of tooth; Owing to have cutter tilt, solved the problem of the inside and outside edge radius difference of alternate blade cutter, can make the gear tooth trace directional curvature radius generation minor alteration that matches, reach the purpose of trace direction correction of the flank shape; And radius and cutter tilt that imagination is produced generating gear all can adjust as required, thereby realize the control of flank profil and trace direction amount of mismatch, with the symmetrical arc tooth trace roller gear of the compound mismatch that obtains to have best contact zone.

Among Fig. 1: o is the workpiece coordinate initial point, and i, j, k are X, Y, and the unit vector of Z axle, a, b, c are A, B, the unit vector of C axle.M is the pitch circle reference point, o _cBe cutterhead pivot, o _fBe cutter rotary center, l _fBe the distance of cutterhead pivot to the cutter rotary center, l is the position vector of cutterhead pivot to the workpiece coordinate initial point, r _fBe the radius vectors of cutter rotary center to the workpiece reference point, r ₁Be the vector of workpiece reference point place radial direction, H ₀, Y ₀Represent the vertical and horizontal initial calculation distance of cutterhead pivot respectively, ω to the workpiece coordinate initial point ₁, ω _fRepresent workpiece and cutterhead angular velocity of rotation respectively,

The angle that turns over for reference point place cutterhead pivot, The angle that turns over for reference point place workpiece,

The expression workpiece is the instantaneous angle that turns over arbitrarily, and the relative position of then any instantaneous workpiece and cutter and motion can be definite fully by following formula.

In the formula

$H_0={\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="H2008100183011E00011.png"\; state="\{\{state\}\}">r</figure-callout>}}_1+[(r_c\&PlusMinus;\frac{\mathrm{<figure-callout\; id="2"\; label="w"\; filenames="H2008100183011E00011.png,H2008100183011E00021.png"\; state="\{\{state\}\}">w</figure-callout>}}{2}\cos \mathrm{\&gamma;})\&PlusMinus;\frac{(h_a^{*}+c^{*})}{\cos \mathrm{\&alpha;}}m\sin \left(\mathrm{\&alpha;}\stackrel{\&OverBar;}{+}\mathrm{\&gamma;}\right)]\sin \mathrm{\&gamma;}$

$Y_0=[(r_c\&PlusMinus;\frac{\mathrm{<figure-callout\; id="2"\; label="w"\; filenames="H2008100183011E00011.png,H2008100183011E00021.png"\; state="\{\{state\}\}">w</figure-callout>}}{2}\cos \mathrm{\&gamma;})\&PlusMinus;\frac{(h_a^{*}+c^{*})}{\cos \mathrm{\&alpha;}}m\sin \left(\mathrm{\&alpha;}\stackrel{\&OverBar;}{+}\mathrm{\&gamma;}\right)]\cos \mathrm{\&gamma;}$

As shown in Figure 2, the generate process of symmetrical arc tooth trace roller gear is to carry out according to the principle that gear is meshed with gear.At first cutterhead 1 rotates around axis, forms the main motion of cutter tooth to the cutting of tooth base, is equivalent to a tooth of imaginary curved tooth line roller gear; Secondly tooth base (2) is fed into the generate position with the speed that changes; Then tooth base (2) rotates around self axis, and the cutterhead of Zhuan Donging (1) also begins the axis rotation around imaginary arc tooth trace roller gear simultaneously, thereby has constituted gear and gear meshing is moved, and generate goes out the whole gear teeth flank of tooth, finishes the cutting of a teeth groove.The tooth base carries out quick index then, and cutterhead and blank counter-rotating are cut next teeth groove, until processing all teeth groove.

The cutter rotary angle

At initial angle

And end angle Between change initial angle

And end angle

Can calculate by following formula.

Among Fig. 2:

Be the angle that reference point place workpiece turns over, r ₁, r _fRepresent the gear compound graduation radius of circle and the cutterhead cutter tooth reference circle radius of gyration respectively; r _1a, r _FaRepresent the gear teeth tips radius of circle and the cutterhead cutter tooth outside circle radius of gyration respectively.

Fig. 3 is the three-dimensional model diagram by the machining process simulating gained.From scheming the architectural feature of this gear as can be seen:

The flank of tooth of a. symmetrical camber line roller gear is made up of protruding, recessed two spatial complex curved surfaces, but this gear is the involute profile of correction of the flank shape on the central symmetrical section of facewidth direction, because profiling quantity is very little, so this gear is not but still have the advantage (as separability etc.) of the transmission aspect of involute gear, can also central symmetrical section as its design, make the datum level with measurement.

B. this gear is in engagement process, in theory, protruding, recessed two mesh tooth faces are the some contact Tooth, and in fact the flank of tooth under the load effect strain can take place, and the wearing and tearing of the running-in behind the gear operation certain hour, make the face contact Tooth of actual contact Tooth for certain zone.Load strengthens, and then the contact zone strengthens, and protruding, recessed two mesh tooth face curvature differences are less, contains mutually.Therefore, this gear both had bigger overlap coefficient, no axial force, running steadily, characteristics that noise is little, can also improve contact, bending, comprehensive strength such as anti-bonding.

Claims (2)

1. the expansion machining method of fine-pitch of the symmetrical arc tooth trace roller gear of a compound mismatch is characterized in that:

1) gear structure, intensity and the serviceability requirement of processing at first as required determined the basic geometric parameters of gear, i.e. pressure angle α, addendum coefficient h _a ^*And tip clearance coefficient c ^*, and centre-to-centre spacing a, gearratio i, modulus m, tooth number Z, and determine the cutter tilt of straight sword alternate blade cutter (1);

2) then the gear blank (2) of straight sword alternate blade cutter (1) and periphery is installed in respectively on the main shaft and workbench with multi-axis linkage numerical control lathe, the inside and outside vertial knife edge of said straight sword alternate blade cutter (1) is asymmetrical trapezoidal cutter tooth;

3) straight sword alternate blade cutter (1) rotates around axis, forms the main motion of cutter tooth to gear blank (2) cutting, and secondly gear blank (2) is fed into the generate position with the speed that changes; Then gear blank (2) is around self axis rotation, the straight sword alternate blade cutter (1) of Zhuan Donging begins around its axis of rotation swing simultaneously, constitute the motion of gear and gear meshing, and generate goes out the whole gear teeth flank of tooth, finish the cutting of a teeth groove, gear blank (2) carries out calibration then, straight sword alternate blade cutter (1) and gear blank (2) counter-rotating, cut next teeth groove, obtain required gear until processing all teeth groove;

Straight sword alternate blade cutter (1) angle of revolution

At initial angle

And end angle

Between change initial angle

And end angle

Can obtain by following formula:

Wherein

Be the angle that reference point place workpiece turns over, r ₁, r _fRepresent the gear compound graduation radius of circle and the cutterhead cutter tooth reference circle radius of gyration respectively; r _1a, r _FaRepresent the gear teeth tips radius of circle and the cutterhead cutter tooth outside circle radius of gyration respectively.

2. the symmetrical arc tooth trace roller gear of method processing according to claim 1 is characterized in that: said gear (3) is for having the some contact symmetrical arc tooth trace roller gear of compound mismatch.

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