CN100365322C - Microsegment gear - Google Patents

Abstract

The present invention relates to a gear, more specifically to a micro-segment gear which is characterized in that the tooth profile curve is formed by smoothly connecting micro-segment curves or micro-segment straight lines; the minimum tooth number is three. Compared with the present common involute gear, the micro-segment gear is suitable for the general transmission occasion and especially suitable for motion and power transmission under the occasions of high speed, or heavy load or miniaturized requirements.

Description

Microsegment gear

Technical field

The present invention relates to a kind of microsegment gear that is applied to mechanical transmission and transmission of power field.

Background technique

Gear is all machineries such as various industrial machines, automobile, boats and ships, locomotive, aircraft and installs indispensable important spare part, be one of principal mode of transmitting movement and power in the machinery, its performance quality is determining the quality and the level of engineering goods to a great extent.

What use was maximum at present is involute gear, involute gear has many advantages, as make simple, interchangeability is good, easy displacement etc., but its shortcoming is obvious too, and low especially lower, the minimum number of teeth of contact strength is big as intensity, thereby makes volume bigger etc., its not the minimum number of teeth of undercut be 17, after taking measure such as displacement, minimum teeth number also is difficult to less than 12, thus can not satisfy at a high speed, the requirement of heavy duty and miniaturization.At present, also there is the problem of this respect in other tooth-profile of gear that obtained to use in production practices, as: circular tooth gear, cycloidal gear etc.Though circular tooth gear has solved the not high problem of involute gear contact strength substantially but flexural strength exists deficiency again, and must make helical gear.

Summary of the invention

The objective of the invention is: provide that a kind of minimum number of teeth can be 3 teeth, the gear contact strength is high, the microsegment gear that is easy to process.

The technical solution that realizes the foregoing invention purpose is as follows:

Microsegment gear, tooth curve is by little section curve or little section smooth being formed by connecting of straight line, and described little section length of curve is below 1 micron, and the tooth root place flank profil of described gear is the indent tooth curve, it is characterized in that: its minimum teeth number is 3 teeth;

When the number of teeth was 3-8 tooth, the addendum coefficient scope was 1.1-1.4, and the dedendum of the tooth coefficient is 0.6-0.9, and transverse tooth thickness increases to 0.55 π m-0.7 π m, and spacewidth is 0.3 π m-0.45 π m, and wherein m is a modulus.

Described little section curve is involute curve, and available little section straight line substitutes.

Described gear is a straight-tooth gear, or is angular gear.

The structure of microsegment gear basic rack tooth profile curve of the present invention: be the principle of compositionality figure of few number of teeth microsegment gear basic rack as shown in Figure 1, among Fig. 1, little line segment m ₁S ₁For with o ₁Be the center of circle, o ₁o ₁'/2 is the involute on the basic circle of radius, little line segment S ₂m ₁For with o ₁' be the center of circle, o ₁o ₁'/2 is the involute on the basic circle of radius, little line segment S ₂m ₂For with o ₂Be the center of circle, o ₂o ₂'/2 is the involute on the basic circle of radius, so goes down, and promptly forms the basic tooth profile of little line segment tooth bar.

That determine this curve character is three independent parameter: r _B0, α ₀, δ, be called, initial Base radius, initial pressure angle and pressure value angle, its value does not have certain restriction, can select as required.

The formation of microsegment gear tooth curve:, can derive corresponding gear-profile curvilinear equation with being meshed by basic rack with gear by accompanying drawing 2 according to basic Principles of Gear Connection:

In the formula: d=x ₁+ y ₁/ tg α _i

x ₁, y ₁: the little line segment rack tooth of standard corridor curve point coordinate;

 ₂: microsegment gear is from the corner of initial position;

D: corresponding microsegment gear rotates  ₂During the angle, the distance that the little line segment tooth bar of standard moves;

r ₁: the microsegment gear reference radius;

x ₂, y ₂: with (x on the little line segment tooth bar of standard ₁, y ₁) point coordinates on the microsegment gear tooth corridor curve that is meshed of point;

α _i: the pressure angle of contact points.

The microsegment gear that constructs like this is the mesh form of male-female on the whole, and promptly the tooth top of each gear partly is the double wedge corridor, and tooth root partly is recessed tooth corridor.According to selected initial parameters, every section tooth corridor generally is made up of thousands of even up to ten thousand sections little section curves, and each length of little section is 1 micron even shorter.

Greater than few number of teeth microsegment gear of 8, structure need not adjusted, and for the few number of teeth microsegment gear of the minimum number of teeth between 3 and 8, need do structural adjustment for minimum teeth number, and concrete measure is:

A, reduce the dedendum of the tooth coefficient, increase addendum coefficient, but both sums remain unchanged.Equally,, also should do corresponding variation with the gearwheel of its engagement accordingly, promptly increase the dedendum of the tooth coefficient, reduce addendum coefficient for guaranteeing correctly to mesh.

The transverse tooth thickness of B, increase small gear promptly reduces the transverse tooth thickness of small gear tooth bar cutter, and transverse tooth thickness and spacewidth sum remain unchanged.Also should do corresponding variation with the gearwheel of its engagement, promptly reduce the transverse tooth thickness of gearwheel and increase its spacewidth.

Useful technique effect of the present invention is embodied in following several aspect:

Compare with involute gear at present commonly used, microsegment gear is not only applicable to general transmission occasion, is particularly useful at a high speed, heavy duty or require motion and power transmission under the occasion of miniaturization.

1. compare with involute gear, microsegment gear not only has very high contact strength, also has higher flexural strength.Because the flexural strength of gear is main relevant with thickness at root of tooth, and contact strength is main relevant with composite curve radius, and the profile of tooth of microsegment gear that we construct not only has thicker thickness at root of tooth, and adopted protruding to recessed mesh form, synthetic curvature is zero on the structure point, therefore, this gear has higher contact strength and flexural strength.The relevant experiment that we carried out has also confirmed this point.

Accompanying drawing 3 is flexural strength contrast experiment's data of two kinds of gears, and therefrom as can be seen, the crooked bearing capacity of microsegment gear will be apparently higher than involute gear.

The contact fatigue strength experiment that we did shows that also under identical operating mode, the contact strength of microsegment gear also will be apparently higher than involute gear.

2. transmission efficiency height.The transmission efficiency experimental research shows that under identical operating mode, the transmission efficiency of microsegment gear is higher by about 3% than involute gear, and this has crucial meaning for the high-power transmission under the mechanical transmission especially high speed, heavily loaded situation.Contrast experiment's curve of two kinds of gear-driven efficiencies when Fig. 4 is 1000 rev/mins (matched curve of dotted line for doing among the figure) according to laboratory data.

3. minimum teeth number is few, is suitable for miniaturization.Studies show that the minimum teeth number of microsegment gear is 3, like this, under identical modulus situation, the size of microsegment gear can be more much smaller than involute gear.At present, we to have processed minimum teeth number be 3 microsegment gear.Therefore microsegment gear is specially adapted to require the occasion of miniaturization.

Description of drawings

Fig. 1 is the formation schematic diagram of little line segment tooth bar profile of tooth;

Fig. 2 is microsegment gear tooth bar engagement system of coordinates figure;

Fig. 3 is the flexural strength contrast and experiment figure of involute gear and microsegment gear;

Contrast experiment's datagram of two kinds of gear-driven efficiencies when Fig. 4 is 1000 rev/mins.

Fig. 5 is 3 number of teeth meshed transmission gear figure.

Embodiment

Below in conjunction with accompanying drawing, the present invention is done explanation in further detail by embodiment.

Embodiment 1:

Gear ratio is 11: 51 microsegment gear transmission.Small gear is that structure does not adjust the gear with little teeth number of (promptly except that the profile of tooth factor, other parameters such as addendum coefficient spacewidth etc. need not done special processing), with the gearwheel number of teeth of its engagement be 51, also be microsegment gear.Can be straight-tooth gear, also can be angular gear.

Embodiment 2:

The a pair of microsegment gear of engagement driving, the small gear number of teeth are 3, and the gearwheel number of teeth is 12, and modulus is 6.The addendum coefficient of small gear is 1.4, and the dedendum of the tooth coefficient is 0.6, and the standard pitch circle transverse tooth thickness is 0.7 π m, and spacewidth is 0.3 π m; The addendum coefficient of gearwheel is 0.6, and the dedendum of the tooth coefficient is 1.4, and the standard pitch circle transverse tooth thickness is 0.3 π m, and spacewidth is 0.7 π m.(see figure 5)

Embodiment 3:

The a pair of microsegment gear of engagement driving, the small gear number of teeth are 8, and the gearwheel number of teeth is 20, and modulus is 2.The addendum coefficient of small gear is 1.1, and the dedendum of the tooth coefficient is 0.9, and the standard pitch circle transverse tooth thickness is 0.55 π m, and spacewidth is 0.45 π m; The addendum coefficient of gearwheel is 0.9, and the dedendum of the tooth coefficient is 1.1, and the standard pitch circle transverse tooth thickness is 0.45 π m, and spacewidth is 0.55 π m.

Claims (1)

1. microsegment gear, tooth curve is by little section curve or little section smooth being formed by connecting of straight line, and described little section length of curve is below 1 micron, and the tooth root place flank profil of described gear is the indent tooth curve, it is characterized in that: its minimum teeth number is 3 teeth;

When the number of teeth was 3-8 tooth, the addendum coefficient scope was 1.1-1.4, and the dedendum of the tooth coefficient is 0.6-0.9, and transverse tooth thickness increases to 0.55 π m-0.7 π m, and spacewidth is 0.3 π m-0.45 π m, and wherein m is a modulus.

Images