CN202418491U

CN202418491U - Cubic parabola circular tooth gear

Info

Publication number: CN202418491U
Application number: CN2012200559835U
Authority: CN
Inventors: 顾雪明; 朱金祥; 陆宏一
Original assignee: TAICHANG HYDRAULIC COMPONENTS CO Ltd
Current assignee: TAICHANG HYDRAULIC COMPONENTS CO Ltd
Priority date: 2012-02-21
Filing date: 2012-02-21
Publication date: 2012-09-05
Anticipated expiration: 2022-02-21

Abstract

The utility model discloses a cubic parabola circular tooth gear. The tooth profile of the gear on the normal section is the tooth profile of a cubic parabola; the tooth crest and the tooth root of the gear are both in a circular arc shape; and the gear is in concave-convex tooth surface engagement, so that the gear is stable in transmission, low in noise, long in service life and high in transmission efficiency.

Description

A kind of cubic parabola-circular tooth gear

Technical field

The utility model relates to gear, particularly relates to a kind of cubic parabola-circular tooth gear.

Background technique

Involutes Gears Transmission commonly used at present exists some potential weakness: first; Contact Stress of Gear is big; This is that they are bigger at the induced normal curvature of conjugation point of contact because involute gear is the transmission of power between a pair of convex side gear teeth, thereby produces bigger contact stress; The second, the flexural strength of involute gear is lower, and this is because less of its Gear Root thickness causes; The 3rd, when inevitably producing entrap phenomenon during as oil pump gear with involute gear; The 4th, only if roll flute, the Involutes Gears Transmission noise is bigger, and these weakness certainly will require to improve the transmission design and craft, for example, must improve the precision of gear, increases tooth face hardness and degree of finish, carry out shaving or roll flute etc., thus cost of production improved; On the other hand; Novikov gears with double circular arc tooth profiles commonly used at present is widely used in the transmission of heavy machinery and petroleum machinery, and rotating speed is lower; This Novikov gears with double circular arc tooth profiles must be avoided near engagement driving pitch circle in transmission; It does not solve the smooth transition of conjugate condition between the gear teeth tips dome curved tooth face and the tooth root concave circular arc flank of tooth, and this gear does not have a continuous seal line, so can not be used as the oil hydraulic pump gear.

The model utility content

For addressing the above problem, the utility model provides a kind of stable drive, and noise is little, cubic parabola-circular tooth gear that the life-span is long and transmission efficiency is high.

For realizing above-mentioned purpose, the utility model provides following technological scheme: a kind of cubic parabola-circular tooth gear, and said gear is the cubic parabola flank profil in the flank profil of normal section; The tooth top and the tooth root of said gear are circular arc; Said gear meshing is concavo-convex flank engagement.

Said tooth-formation of gear is a screw serrated form.

Adopt the beneficial effect of above technological scheme to be: during said cubic parabola-circular tooth gear engagement driving is the engagement of a pair of concavo-convex flank of tooth; Induced normal curvature at the conjugation point of contact is very little, and on certain direction even can reach zero, promptly two flank of tooth are fitted fully on this direction; This has just improved the contact strength of the flank of tooth greatly; Be difficult for spot corrosion, with the phenomenon of shaving clearly, the root of gear then was one section complete circular arc when spot corrosion was serious; Its transverse tooth thickness is more much bigger than involute gear; Thereby the flexural strength of circular tooth gear is improved a lot, so utilize cubic parabola-circular tooth gear can reduce the material requirement of gear, it is modified for example can to change carburizing fire steel 20CrMnTi into 40Cr; For common gear transmission, its gear through essence roll or finish-milling after can directly assemble use, can significantly reduce production costs; Cubic parabola-circular tooth gear is spent near 90 at the transmission power and the angle between the arm of force at pitch circle place; The scalar product of two vectors is at (at remaining part all about in the of 0.5) about 0.17; Gear transmission is reduced the pressure that bearing causes greatly, can be as small as about 10 degree near the Operating pressure angle the pitch circle; Cubic parabola-circular tooth gear has a long flank of tooth contact zones near pitch circle, it rotates along with gear and moves along axis, so stable drive, and noise is little, can form thicker dynamic pressure oil film, reduces tooth surface abrasion, and good race and performance are arranged; The number of teeth of cubic parabola-circular tooth gear can be done fewerly (like four teeth), and this is that involute gear is difficult to accomplish, under identical power condition of transmitting, few number of teeth can be dwindled small product size and weight effectively; There is not the phenomenon of topping in cubic parabola-circular tooth gear; The mutual slippage of the flank of tooth of cubic parabola-circular tooth gear in transmission is more half as large than involute gear, so tooth surface abrasion is less, and gear life greatly increases than involute gear, and under the same conditions, the energy consumption of cubic parabola-circular tooth gear can descend about 10%; The transmission noise of cubic parabola-circular tooth gear is average littler by about 30% than involute gear; Cubic parabola-circular tooth gear need be designed to the helical tooth shape, can improve the gear meshing coefficient; But the used hobboing cutter of cubic parabola-circular tooth gear is complicated than involute gear hob, and cost is high slightly, for the bigger cubic parabola-circular tooth gear of modulus (M>10), can adopt shaping plate-like milling cutter to process.

Description of drawings

Fig. 1 is the transmission sectional view of the utility model;

Fig. 2 is the flank of tooth schematic representation of the utility model.

Wherein, the 1. flank profil 2. tooth tops 3. tooth roots 4. profiles of tooth 5. recessed flank of tooth 6. convex sides.

Embodiment

Specify the preferred implementation of the utility model below in conjunction with accompanying drawing.

Embodiment 1

Referring to Fig. 1 and Fig. 2, shown in legend wherein, a kind of cubic parabola-circular tooth gear, said gear is the cubic parabola flank profil in the flank profil 1 of normal section; The tooth top 2 and the tooth root 3 of said gear are circular arc; Said gear meshing is the recessed flank of tooth 5 and convex side 6 engagements.

Said tooth-formation of gear 4 is the screw serrated form of 45 degree.

Said gear is six tooth gears.

Embodiment 2

All the other are identical with said embodiment 1, and difference is that said gear is four tooth gears.

Embodiment 3

All the other are identical with said embodiment 1, and difference is that said tooth-formation of gear is the helix angle of 30 degree.

Above-described only is the preferred implementation of the utility model; Should be pointed out that for the person of ordinary skill of the art, under the prerequisite that does not break away from the utility model creation design; Can also make some distortion and improvement, these all belong to the protection domain of the utility model.

Claims

1. a cubic parabola-circular tooth gear is characterized in that, said gear is the cubic parabola flank profil in the flank profil of normal section; The tooth top and the tooth root of said gear are circular arc; Said gear meshing is concavo-convex flank engagement.

2. cubic parabola-circular tooth gear according to claim 1 is characterized in that, said tooth-formation of gear is a screw serrated form.