CN210830369U

CN210830369U - Arc gear for harmonic gear transmission

Info

Publication number: CN210830369U
Application number: CN201921646828.9U
Authority: CN
Inventors: 石年平
Original assignee: Guizhou Qunjian Precision Machine Co ltd
Current assignee: Guizhou Qunjian Precision Machine Co ltd
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2020-06-23
Anticipated expiration: 2029-09-27

Abstract

The utility model discloses an arc gear for harmonic gear drive, this arc gear's normal flank profile is one section circular arc, circular arc radius R4 m, tooth width direction centre of a circle offset la equal Rcos α -Sa 2, tooth height direction centre of a circle offset ef equal Rsin α, node pressure angle α equal 18, node tooth thickness Sa equal (1/2) pi m, addendum ha equal 1.2m, working tooth height h equal 2.4m, full tooth height h equal 2.7m, root fillet radius rg 0.38m, addendum fillet radius R equal 0.1m the utility model discloses an arc gear not only can improve the bearing capacity of harmonic gear, but also has the processing cutter simple manufacture, the advantage that flank profile shape and gear machining precision are guaranteed easily.

Description

Arc gear for harmonic gear transmission

Technical Field

The utility model relates to a be used for driven arc gear of harmonic gear belongs to harmonic gear drive technical field.

Background

Harmonic gear transmission is a gear transmission mode for carrying out motion or power transmission by utilizing elastic deformation waves of flexible gears, and is widely applied due to the characteristics of simple structure, few parts, small size, high transmission precision, large transmission ratio and the like. The harmonic gear drive is generally composed of three basic components of a flexible gear, a rigid gear and a wave generator, and the transmission of motion or power forces the flexible gear to generate elastic deformation under the action of the wave generator and interact with the rigid gear to achieve the purpose of transmission.

In harmonic gear drives, the module m of the gear is small, typically less than 0.4mm, and the geometry of the gear basic profile has not been fully standardized as in ordinary gears.

In the prior art, an involute gear or a double-circular-arc gear is generally adopted for harmonic gear transmission. The involute gear tooth profile is simple in shape, a machining tool is easy to manufacture, the machining precision of the gear is easy to guarantee, and the bearing capacity of the involute gear is small; the double-arc gear has complex tooth profile shape and higher bearing capacity, but the double-arc gear with the modulus less than 0.4mm is difficult to machine due to the great difficulty in manufacturing the double-arc gear machining cutter, so that the double-arc gear with the tooth profile shape and the gear precision meeting the requirements is difficult to machine; therefore, the harmonic gear transmission adopting the double-circular-arc gear is difficult to exert the advantage of higher bearing capacity of the double-circular-arc gear. Therefore, the prior art has shortcomings and needs to be further improved.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a circular arc gear for harmonic gear drive when making the gear have higher bearing capacity, still has the advantage that processing cutter simple manufacture, profile shape and gear machining precision guarantee easily to overcome prior art's is not enough.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the utility model discloses a circular arc gear for harmonic gear drive, including the gear that the gear modulus is m, the normal flank profile of gear is one section circular arc, the circular arc radius R of this section circular arc is 4m, tooth width direction centre of a circle offset la is Rcos α -Sa/2, tooth height direction centre of a circle offset ef is Rsin α, node pressure angle α is 18, node tooth thickness Sa is (1/2) pi m, addendum ha is 1.2m, work tooth height h is 2.4m, full tooth height h is 2.7m, tooth root fillet radius rg is 0.38m, addendum fillet radius R is 0.1 m.

Since the technical scheme is used, compared with the prior art, the utility model, the advantage lies in:

1. the utility model discloses the normal direction profile of gear is one section circular arc, is an arc gear, because arc gear's equivalent curvature radius is tens of times greater than the equivalent curvature radius of involute gear, and contact stress will descend by a wide margin during the use, and contact strength will improve greatly, consequently, the utility model discloses bearing capacity is far higher than involute gear.

2. The utility model discloses arc gear node pressure angle α is 18 ═ 18, and general gear node pressure angle is 20, adopts less pressure angle can increase gear engagement's contact ratio, improves its bearing capacity.

3. The tooth top height h of the arc gear of the utility model_a1.2m, working tooth height h' 2.4m, full tooth height h 2.7m, and the tooth crest height coefficient h_a ^*The tooth crest coefficient is 1.2, and the tooth crest coefficient h is 1_a ^*The tooth profile of the long teeth is more than or equal to 1, the contact ratio of the meshing of the gears can be increased again, and the bearing capacity of the gear is further improved.

4. The utility model discloses circular arc gear normal direction profile is one section circular arc, and circular arc radius R is 4m, tooth root fillet radius R_gThe tooth profile shape is simple, a machining tool is easy to manufacture, and the tooth profile shape and the gear machining precision are easy to guarantee, so that the gear tooth profile is used for harmonic gear transmission with the modulus smaller than 0.4mm, and the advantage of high bearing capacity can be fully played.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

The utility model discloses a circular arc gear for harmonic gear drive, as shown in fig. 1, including the gear that the modulus is m, the modulus m and the number of teeth of this gear can be confirmed according to the needs of use according to conventional mode, during the preparation, make the normal flank profile of gear for one section circular arc, and make the circular arc radius R of this section circular arc 4m, tooth width direction centre of a circle offset la equals Rcos α -Sa/2, tooth height direction centre of a circle offset ef equals Rsin α, node pressure angle α equals 18, node tooth thickness Sa equals (1/2) pi m, addendum ha 1.2m, work tooth height h' 2.4m, full tooth height h equals 2.7m, dedendum fillet radius rg equals 0.38m, addendum fillet radius R equals 0.1m, thus can be equal to the utility model discloses a circular arc gear for harmonic gear drive.

Claims

1. The utility model provides a circular arc gear for harmonic gear drive, includes that the gear modulus is the gear of m, its characterized in that: the normal tooth profile of the gear is a section of circular arc, the circular arc radius R of the section of circular arc is 4m, and the circle center offset l in the tooth width direction_a＝Rcosα-S_a/2, center offset e in tooth height direction_fRsin α, pressure angle α at node 18 °, tooth thickness S at node_aPi m (1/2); tooth crest height h_a1.2m, 2.4m working tooth height h' and 2.7m full tooth height h; root fillet radius r_g0.38m, and 0.1m tip fillet radius r.