CN202048161U - Involute helical gear - Google Patents

Abstract

The utility model provides an involute helical gear, not only can increase the fatigue resistance of the dedendum, but also substantially has no influence to the shock resistance. The utility model is characterized in that: the tooth profile pressure angles on both sides of the gear tooth of the involute helical gear are not equal; the tooth surface with a larger pressure angle is used as an engaging surface, the tooth surface with a smaller pressure angle is used as an non-engaging surface. The gear is a profile shifted involute helical gear with unequal tooth profile curved surface pressure angles on both sides of a tooth. According to the tooth profile curved surface generation characteristics of an involute helical roller gear, the utility model provides the design philosophy of the involute helical roller gear with unequal tooth profile curved surface pressure angles on both sides of a tooth, and deduces the formulas for calculating the geometric parameters and dimensions of the gear in profile shifted machining. Compared with conventional involute helical roller gear, the involute helical roller gear of the utility model achieves the advantages of high bearing capacity, small volume, light weight, long service life and low noise.

Description

A kind of involute helical gear

Technical field

The utility model relates to the technical field of design of gears, specifically is a kind of involute helical gear.

Background technique

Gear transmission is big because of having power, the efficient height, and advantages such as life-span length, and be widely used.The quality of its performance and quality finally has influence on the quality height of engineening goods, therefore, for adapting to the fast development of big production of modernization and science and technology, requires gear-driven performance to continue to optimize.Especially since nearly many decades,, remarkable progress has been arranged all in each side such as gear meshing theory, bearing capacity calculating and test, vibration and noise, new gear transmissions.

Gear teeth shape not only has influence on the kinetic characteristic of gear pair, also has influence on the dynamic property of gear pair.For complying with the big development trend of producing of modernization, people constantly probe into the tooth profile profile of tooth.Studies show that the pressure angle that increases gear can improve the tooth root bending fatigue strength.Involute helical gear commonly used, because the carrying situation of working flank, non-working flank is different with the engagement situation, if increase the pressure angle of gear both sides simultaneously, will cause the tooth top attenuation, the possibility of broken teeth increases, and promptly the shock resistance of the gear teeth will descend.

The model utility content

Technical problem to be solved in the utility model provides a kind ofly can improve the tooth root fatigue resistance, do not influence the involute helical gear of its shock resistance substantially again.

For solving the problems of the technologies described above, the utility model provides a kind of involute helical gear, be characterized in: the flank profil pressure angle of the gear teeth both sides of this involute helical gear is unequal, and the bigger flank of tooth of pressure angle is Surface of action, and the less flank of tooth of pressure angle is non-Surface of action.

The formation of the non-engagement side flank profil curved surface of involute helical gear: with line segment r _BcBe radius first base cylinder of involute helical gear that draws, and exist the first generating plane Q and first base cylinder tangent, the angle of the first line segment KK on the first generating plane Q and the axis of first base cylinder is β _Bc≠ 0, when the first generating plane Q when first base cylinder is done nonslipping pure rolling, the track of the first line segment KK is the right flank of involute helical gear (non-engagement side flank profil curved surface);

The formation of the engagement side flank profil curved surface of involute helical gear: with line segment r _BdFor radius is made second base cylinder of involute helical gear, wherein, r _Bc/ r _Bd=1～1.36; And exist the second generating plane P and second base cylinder tangent, the angle of the second line segment MM on the second generating plane P and the axis of second base cylinder is β _Bd≠ 0, when the second generating plane P when second base cylinder is done nonslipping pure rolling, the track of the second line segment MM is the left flank of involute helical gear (engagement side flank profil curved surface).

The utlity model has positive effect: (1) gear of the present utility model is involute helical gear displacement, that gear teeth both sides flank profil curved surface pressure angle does not wait, generation characteristics according to involute helical gear flank profil curved surface, provide the involute helical gear design philosophy that gear teeth both sides flank profil curved surface pressure angle does not wait, and derive under the displacement processing situation gear geometric parameter and size calculation formula.Gear teeth both sides flank profil pressure angle does not wait compared with prior art, and as shown in Figure 5, the flank profil both sides can reduce the volume and weight of gear when adopting the unequal pressure angle.With respect to the involute helical gear of routine, advantage such as these novel involute helical gear have that bearing capacity is big, volume is little, light weight, long service life, noise are little.(2) the utility model proposes the flank profil curved surface that does not wait at working pressure angle, the both sides of the helical gear gear teeth, and carry out the method that displacement is handled.The characteristics of involute helical gear of the present utility model are: by using the base cylinder of different-diameter size, generate the flank profil curved surface at different pressures angle in the both sides of involute helical gear; And design the physical dimension of modified gear according to need of work.

Description of drawings

Fig. 1 is the structural representation of involute helical gear of the present utility model;

Fig. 2 is the profile of tooth figure of the involute helical gear among Fig. 1; Reference character among the figure: 1--top circle, 2--standard pitch circle, 3--first base cylinder, 4--root circle, 5--second base cylinder, 6--left flank, 7--right flank;

Fig. 3 is the generation schematic representation of the engagement side flank profil curved surface (also being the left side involute profile) of the involute helical gear among Fig. 2;

Fig. 4 is the generation schematic representation of the non-engagement side flank profil curved surface (also being the right side involute profile) of the involute helical gear among Fig. 2;

Fig. 5 is the contrast schematic representation of the profile of tooth 9 of the profile of tooth 8 of involute helical gear of the prior art and involute helical gear of the present utility model.

Embodiment

See Fig. 1-2, the profile of tooth of the involute helical gear of present embodiment mainly comprises the left flank 6 that tooth top 1, second base cylinder 5 generate, right flank 7 and the tooth root 4 that first base cylinder 3 generates.During working gear, the left flank 6 that pressure angle is big participates in engagement, and the right flank 7 that pressure angle is little does not participate in engagement.

The formation of the non-engagement side flank profil curved surface of involute helical gear: with line segment r _BcBe radius first base cylinder of involute helical gear that draws, and exist the first generating plane Q and first base cylinder tangent, the angle of the first line segment KK on the first generating plane Q and the axis of first base cylinder is β _Bc≠ 0, when the first generating plane Q when first base cylinder is done nonslipping pure rolling, the track of the first line segment KK is the right flank 7 (non-engagement side flank profil curved surface) of involute helical gear;

The formation of the engagement side flank profil curved surface of involute helical gear: with line segment r _BdFor radius is made second base cylinder of involute helical gear, wherein, r _Bc/ r _Bd=1～1.36; And exist the second generating plane P and second base cylinder tangent, the angle of the second line segment MM on the second generating plane P and the axis of second base cylinder is β _Bd≠ 0, when the second generating plane P when second base cylinder is done nonslipping pure rolling, the track of the second line segment MM is the left flank 6 (engagement side flank profil curved surface) of involute helical gear.

Helix angle on the number of teeth of involute helical gear, the calibration cylinder, standard pitch circle transverse module, standard pitch circle normal module, engagement side standard pitch circle transverse pressure angle, non-engagement side standard pitch circle transverse pressure angle, engagement side standard pitch circle normal pressure angle, non-engagement side standard pitch circle normal pressure angle are respectively: z, β, m _t, m _n, α _Td, α _Tc, α _Nd, α _Nc

The value of z meets that velocity ratio requires and satisfies not undercut principle;

β＝8～20°；

m _nValue size according to " gear handbook (China Machine Press, 2004-2 the 2nd edition, No. the 09768th, Chinese depository library CIP digital core word (2000)) is selected or make by oneself as required;

m _t=m _n/ cos β millimeter;

α _Td=atan (tan α _Nd/ cos β) degree;

α _Tc=atan (tan α _Nc/ cos β) degree;

α _nc＝20°；

α _NdUnder the prerequisite of satisfied not undercut and gear teeth shock resistance, satisfy: 45 °＞α _Nd＞α _Nc＞14 °.

The radius of described second base cylinder

Millimeter, wherein: d is the standard pitch diameter of involute helical gear,

Millimeter.

Described β _Bd=atan (tan β cos α _Td) degree, and 0＜β _Bd＜90 °.

The radius of described first base cylinder

Millimeter.

Described β _Bc=atan (tan β cos α _Tc), and 0＜β _Bc＜90 °.

The normal plane tip clearance coefficient of the normal plane addendum coefficient of described engagement side flank profil, the normal plane addendum coefficient of non-engagement side flank profil, engagement side flank profil, the normal plane tip clearance coefficient of non-engagement side flank profil are respectively

Wherein:

$h_{\mathrm{anc}}^{*}=1;$

$c_{\mathrm{nc}}^{*}=0.25;$

$h_{\mathrm{and}}^{*}=1+0.25-(1-\sin {\mathrm{\α}}_{\mathrm{nd}})\frac{\frac{\mathrm{\π}{m}_n}{2}-(\tan {\mathrm{\α}}_{\mathrm{nc}}+\tan {\mathrm{\α}}_{\mathrm{nd}})(m_n+0.25m_n+x_n{m}_n)}{\sec {\mathrm{\α}}_{\mathrm{nc}}+\sec {\mathrm{\α}}_{\mathrm{nd}}-\tan {\mathrm{\α}}_{\mathrm{nc}}-\tan {\mathrm{\α}}_{\mathrm{nd}}};$

$c_{\mathrm{nd}}^{*}=(1-\sin {\mathrm{\α}}_{\mathrm{nd}})\frac{\frac{\mathrm{\π}{m}_n}{2}-(\tan {\mathrm{\α}}_{\mathrm{nc}}+\tan {\mathrm{\α}}_{\mathrm{nd}})(m_n+0.25m_n+x_n{m}_n)}{\sec {\mathrm{\α}}_{\mathrm{nc}}+\sec {\mathrm{\α}}_{\mathrm{nd}}-\tan {\mathrm{\α}}_{\mathrm{nc}}-\tan {\mathrm{\α}}_{\mathrm{nd}}}.$

The standard pitch circle normal plane transverse tooth thickness of involute helical gear, transverse tooth thickness are respectively s _n, s _t

Then: $s_n=\frac{\mathrm{\π}{m}_n}{2}+x_n{m}_n(\tan {\mathrm{\α}}_{\mathrm{nd}}+\tan {\mathrm{\α}}_{\mathrm{nc}})$ Millimeter, $s_t=\frac{\mathrm{\π}{m}_t}{2}+x_t{m}_t(\tan {\mathrm{\α}}_{\mathrm{td}}+\tan {\mathrm{\α}}_{\mathrm{tc}})$ Millimeter.

x _nBe the normal plane modification coefficient of involute helical gear, x _tBe the end face modification coefficient of involute helical gear, then x _t=x _nCos β, and To prevent that helical gear from producing undercut.

The tip diameter of involute helical gear is d _a,

The root diameter of involute helical gear is d _f,

Compare with existing involute helical gear, involute helical gear of the present utility model can significantly improve bearing capacity and (studies show that: adopt large pressure angle as Surface of action, the little pressure angle helical gear as non-Surface of action, can improve its bearing capacity.), reduced volume, weight reduction (adopt gear that Surface of action and non-Surface of action pressure angle do not wait with respect to Surface of action equate with non-Surface of action pressure angle gear for, its flank of tooth narrows down, volume and weight diminishes naturally), increase the service life (intensity improve then life-span prolong), reduce vibration and noise (because vibration displacement the during gear transmission that Surface of action and non-Surface of action pressure angle do not wait and dynamic load are all than having the little of gear now, thereby gear transmission time vibration and noise have also just reduced), market prospects are wide, have huge social and economic benefit.

Obviously, the foregoing description of the present utility model only is for the utility model example clearly is described, and is not to be qualification to mode of execution of the present utility model.For those of ordinary skill in the field, can also make other changes in different forms on the basis of the above description.Here need not also can't give exhaustive to all mode of executions.And these belong to conspicuous variation or the change that spirit of the present utility model extended out and still are among the protection domain of the present utility model.

Claims (10)

1. involute helical gear, it is characterized in that: the flank profil pressure angle of the gear teeth both sides of this involute helical gear is unequal, and the bigger flank of tooth of pressure angle is Surface of action, and the less flank of tooth of pressure angle is non-Surface of action.

2. involute helical gear according to claim 1 is characterized in that: the helix angle on the number of teeth of this involute helical gear, the calibration cylinder, standard pitch circle transverse module, standard pitch circle normal module, engagement side standard pitch circle transverse pressure angle, non-engagement side standard pitch circle transverse pressure angle, engagement side standard pitch circle normal pressure angle, non-engagement side standard pitch circle normal pressure angle are respectively: z, β, m _t, m _n, α _Td, α _Tc, α _Nd, α _Nc

The value of z meets that velocity ratio requires and satisfies not undercut principle;

β＝8～20°；

m _nValue size according to " the gear handbook is selected or make by oneself as required;

m _t=m _n/ cos β millimeter;

α _Td=atan (tan α _Nd/ cos β) degree;

α _Tc=atan (tan α _Nc/ cos β) degree;

α _Nc, α _NdSatisfy: 45 °＞α _Nd＞α _Nc＞14 °.

3. involute helical gear according to claim 2 is characterized in that: the radius of described second base cylinder

Millimeter, wherein: d is the standard pitch diameter of involute helical gear, Millimeter.

4. involute helical gear according to claim 3 is characterized in that: described β _Bd=atan (tan β cos α _Td) degree, and 0＜β _Bd＜90 °.

5. involute helical gear according to claim 4 is characterized in that: the radius of described first base cylinder Millimeter.

6. involute helical gear according to claim 5 is characterized in that: described β _Bc=atan (tan β cos α _Tc) degree, and 0＜β _Bc＜90 °.

7. involute helical gear according to claim 6 is characterized in that: described engagement side flank profil normal plane addendum coefficient, non-engagement side flank profil normal plane addendum coefficient, the normal plane tip clearance coefficient of engagement side flank profil, the normal plane tip clearance coefficient of non-engagement side flank profil are respectively

Wherein:

$h_{\mathrm{anc}}^{*}=1,c_{\mathrm{nc}}^{*}=0.25,$

$h_{\mathrm{and}}^{*}=1+0.25-(1-{\sin \mathrm{\α}}_{\mathrm{nd}})\frac{\frac{{\mathrm{\πm}}_n}{2}-({\tan \mathrm{\α}}_{\mathrm{nc}}+{\tan \mathrm{\α}}_{\mathrm{nd}})(m_n+0.25m_n+x_n{m}_n)}{{\sec \mathrm{\α}}_{\mathrm{nc}}+{\sec \mathrm{\α}}_{\mathrm{nd}}-{\tan \mathrm{\α}}_{\mathrm{nc}}-{\tan \mathrm{\α}}_{\mathrm{nd}}},$

$c_{\mathrm{nd}}^{*}=(1-{\sin \mathrm{\α}}_{\mathrm{nd}})\frac{\frac{{\mathrm{\πm}}_n}{2}-({\tan \mathrm{\α}}_{\mathrm{nc}}+{\tan \mathrm{\α}}_{\mathrm{nd}})(m_n+0.25m_n+x_n{m}_n)}{{\sec \mathrm{\α}}_{\mathrm{nc}}+{\sec \mathrm{\α}}_{\mathrm{nd}}-{\tan \mathrm{\α}}_{\mathrm{nc}}-{\tan \mathrm{\α}}_{\mathrm{nd}}}.$

8. involute helical gear according to claim 7 is characterized in that: the standard pitch circle normal plane transverse tooth thickness of involute helical gear, transverse tooth thickness are respectively s _n, s _t

Then:

Millimeter,

Millimeter.

9. involute helical gear according to claim 8 is characterized in that: x _nBe the normal plane modification coefficient of involute helical gear, x _tBe helical gear end face modification coefficient, then x _t=x _nCos β, and

$x_n\≥h_{\mathrm{and}}^{*}-\frac{z{\left(\sin {\mathrm{\α}}_{\mathrm{td}}\right)}^2}{2\cos \mathrm{\β}}.$

10. involute helical gear according to claim 9 is characterized in that: helical gear tip diameter is d _a,

Helical gear root diameter is d _f,

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