CN211231485U - A double arc flexible wheel structure - Google Patents

Abstract

A double-arc flexible wheel structure, comprising a cup body, the outer circumference of the cup body is provided with a gear ring, and the outer contour shape of the cup includes a bottom flange, a conical surface section connected with the bottom flange, and a conical surface connected with the bottom flange. a first transition curve segment connected to the first transition curve segment, a straight line segment connected to the first transition curve segment, a second transition curved surface segment connected to the straight line segment and the ring gear, and a transition segment connected to the second transition curved surface segment Inclined surface section, the second transition curved surface section is arranged at the connection between the root of the ring gear and the side wall of the cup body, which can reduce the phenomenon of stress concentration at the root of the ring gear, and the bottom of the cup body is provided with a conical surface section to improve the bottom of the cup body. The problem of stress concentration reduces the overall stress of the flex wheel, improves the stress concentration phenomenon at the root of the ring gear and the bottom of the flex wheel cup during the working process of the flex wheel, reduces the stress at the root of the ring gear and the bottom of the flex wheel cup, and reduces the stress concentration effect. It is beneficial to improve the bearing capacity, work efficiency and service life of the harmonic reducer.

Description

A double arc flexible wheel structure

technical field

The utility model relates to the technical field of mechanical transmission, in particular to a double-arc flexible wheel structure.

Background technique

The basis of harmonic drive is realized by the continuous elastic deformation of the flex wheel. Whether the structure design of the flex wheel is reasonable will directly affect the bearing capacity, transmission performance, life and manufacturability of the entire harmonic drive mechanism.

In the existing double-arc flex wheel cup-type structure, the schematic diagram of the flex wheel structure is shown in Figure 1. During the operation of the flex wheel, the periodic deformation occurs with the rotation of the wave generator, and it is easy to fail due to fatigue; There is stress concentration at the root of the flexure ring gear and the bottom of the flexure barrel, and the failure causes of harmonic gears are mainly concentrated in the excessive stress of the flexure teeth and the stress and strain caused by the structural parameters of the flexure. In order to improve the stress distribution of the flex wheel, reduce the alternating stress borne by the flex wheel in the working process, improve the service life of the flex wheel, and ensure the transmission performance of the harmonic reducer, it is necessary to improve the structure of the flex wheel.

Compared with the involute tooth shape, the flex wheel of the double-arc middle cup-shaped structure in the prior art has a much larger envelope interval and a larger meshing range of the gear teeth, so it can withstand The larger the external load, the more stable the transmission process; the stress distribution of the flex wheel in actual work is improved, the length of the flex wheel cylinder is increased or the structural parameters such as the wall thickness of the flex wheel are changed to reduce the stress of the flex wheel, but its structure It is more inclined to the flex wheel with smaller axial size, that is, the short-tube flex wheel. In industrial robots, some joints bear a larger moment. When the reduction ratio and the outer diameter of the rigid wheel are the same, they are more inclined to be shorter. The axial size of the short barrel type harmonic reducer cannot meet the needs of use. Therefore, it is necessary to improve the flexible wheel structure.

Utility model content

Aiming at the problems existing in the prior art, the utility model provides a double-arc flexible wheel structure which improves the stress concentration phenomenon, makes the stress distribution uniform, and improves the overall bearing capacity and service life of the harmonic reducer.

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

A double-arc flexible wheel structure, comprising a cup body, the outer circumference of the cup body is provided with a gear ring, and the outer contour shape of the cup includes a bottom flange, a conical surface section connected with the bottom flange, and a conical surface connected with the bottom flange. a first transition curve segment connected to the first transition curve segment, a straight line segment connected to the first transition curve segment, a second transition curved surface segment connected to the straight line segment and the ring gear, and a transition segment connected to the second transition curved surface segment Inclined surface segment, the second transition curved surface segment is arranged at the connection between the root of the ring gear and the side wall of the cup body.

Further, the length of the ring gear is 10-13mm.

Further, the wall thickness of the cup body at the ring gear is 1-1.8 mm.

Further, the wall thickness of the cup body at the straight line segment is 0.8-1.6 mm.

Further, the arc chamfering radius of the second transition curved surface segment is 1-2 mm.

Further, the thickness of the ring gear is 0-0.4mm.

Further, the inclination angle of the outer side surface of the tapered surface segment relative to the inner side surface is 2°-5°.

Further, the inclination angle of the transition slope section is 10°-25°.

Further, the boss of the bottom flange and the end of the conical surface segment are connected by a third transition curved surface segment.

Further, the third transition curved surface segment and the second transition curved surface segment are connected to both ends of the conical surface segment with rounded corners.

The beneficial effects of the present utility model:

A second transition surface segment is added at the connection between the root of the ring gear and the side wall of the cup body, which can reduce the stress concentration at the root of the ring gear. The conical surface segment is set at the bottom of the cup body to improve the stress concentration problem at the bottom of the cup body and reduce the overall stress of the flexible wheel. , Improve the stress concentration phenomenon at the root of the ring gear and the bottom of the flex wheel cup during the working process of the flex wheel, the stress at the root of the ring gear and the bottom of the flex wheel cup is reduced, and the stress concentration effect is reduced, which is beneficial to improve the bearing capacity of the harmonic reducer. capacity, work efficiency and service life.

Description of drawings

FIG. 1 is a schematic structural diagram of a flexible wheel in the background technology;

Fig. 2 is the structural schematic diagram of the double-arc flexible wheel of the present utility model;

Fig. 3 is the partial enlarged view of A place in Fig. 2;

In the figure, 1-cup body, 2-ring gear, 3-bottom flange, 4-conical surface segment, 5-first transition surface segment, 6-straight line segment, 7-second transition surface segment, 8-transition slope segment, 9—the third transition surface segment.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, not all of them. Example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the difference between the various components under a certain posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly.

As shown in Figure 2 and Figure 3, the stress of the flex wheel in the harmonic drive is mainly concentrated in the flex wheel ring gear part, and there is a stress concentration phenomenon at the root of the flex wheel ring gear and the bottom of the flex wheel cup. In order to make the stress distribution of the flex wheel uniform, The phenomenon of stress concentration is reduced, and the utility model improves the flexible wheel structure on the basis of the existing double-arc flexible wheel structure.

The utility model provides an improved double-arc flexible wheel structure. The double-arc flexible wheel structure comprises a cup body 1, the outer circumference of the cup body 1 is provided with a gear ring 2, and the outer contour shape of the cup body 1 includes a bottom flange 3, and The conical surface section 4 connected with the bottom flange 3, the first transition curve section 5 connected with the conical surface section 4, the straight line section 6 connected with the first transition curve section 5, and the second transition connecting the straight line section 6 with the ring gear 2 The curved surface segment 7 and the transition inclined surface segment 8 connected with the second transition curved surface segment 7 are arranged at the connection between the root of the ring gear 2 and the side wall of the cup body 1 .

Among them, the length B of the ring gear 2 is 10-13mm, the thickness of the ring gear 2 is 0-0.4mm, the wall thickness t of the cup body 1 at the 2 places of the ring gear is 1-1.8mm, and the wall thickness h of the cup body 1 at the 6 places in the straight section is 0.8 -1.6mm. Compared with the prior art, the utility model reduces the length of the ring gear 2, increases the wall thickness of the cup body 1 at the ring gear 2, and sets a second transition curved surface segment at the transition portion between the root of the ring gear 2 and the side wall of the cup body 1. 7, so as to improve the stress concentration phenomenon at 2 of the ring gear. Preferably, the arc chamfering radius R2 of the second transition curved surface segment 7 is 1-2 mm, and the inclination angle θ of the transition inclined surface segment 8 connected to the second transition curved surface segment 7 is 10°-25°.

A cone surface segment 4 is provided at the bottom of the cup body 1 , and the outer side surface of the cone surface segment 4 is inclined at an angle γ of 2°-5° relative to the inner side surface. The boss of the bottom flange 3 and the end of the conical surface segment 4 are connected by a third transition curved surface segment 9 . The third transition curved surface segment 9 and the second transition curved surface segment 7 are connected to both ends of the conical surface segment 4 with rounded corners with radii R3 and R1, respectively. By changing the shape of the cup body 1, the stress concentration phenomenon at the bottom of the cup is improved.

After the above-mentioned changes to the size parameters of the flex wheel geometry, the overall stress of the flex wheel is reduced, the length-diameter ratio of the flex wheel is reduced, and the length of the cup body 1 is reduced, so that the materials required for the manufacture of the flex wheel are reduced, and the cost is saved. At the same time, the thickness of the flexible wheel wall and the chamfering of the flexible wheel cup bottom remain unchanged.

The utility model reduces the overall stress of the flex wheel, improves the deformation of the flex wheel and the concentration of stress distribution during the working process, and makes the stress distribution of the flex wheel uniform; during the working process of the flex wheel, the stress concentration at the root of the ring gear 2 and the bottom of the flex wheel cup is improved. The phenomenon reduces the stress at the root of the ring gear 2 and the bottom part of the flexible wheel cup, and reduces the stress concentration effect, which is beneficial to improve the bearing capacity, work efficiency and service life of the harmonic reducer.

The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced. , without departing from the purpose and scope of the technical solution, it should be covered within the scope of the claims of the present invention.

Claims (10)

1. A double-circular-arc flexible gear structure is characterized by comprising: the cup comprises a cup body, wherein a gear ring is arranged on the periphery of the cup body, the outer contour shape of the cup body comprises a bottom flange, a conical surface section connected with the bottom flange, a first transition curve section connected with the conical surface section, a straight line section connected with the first transition curve section, a second transition curved surface section connected with the gear ring and a transition inclined surface section connected with the second transition curved surface section, and the second transition curved surface section is arranged at the joint of the root part of the gear ring and the side wall of the cup body.

2. The bi-arc flexspline structure of claim 1, wherein: the length of the gear ring is 10-13 mm.

3. The bi-arc flexspline structure of claim 1, wherein: the wall thickness of the cup body at the gear ring is 1-1.8 mm.

4. The bi-arc flexspline structure of claim 1, wherein: the wall thickness of the cup body at the straight line section is 0.8-1.6 mm.

5. The bi-arc flexspline structure of claim 1, wherein: and the radius of the arc chamfer of the second transition curved surface section is 1-2 mm.

6. The bi-arc flexspline structure of claim 1, wherein: the thickness of the gear ring is 0-0.4 mm.

7. The bi-arc flexspline structure of claim 1, wherein: the outer side surface of the conical surface section has an inclination angle of 2-5 degrees relative to the inner side surface.

8. The bi-arc flexspline structure of claim 1, wherein: the bevel angle of the transition bevel section is 10-25 degrees.

9. The bi-arc flexspline structure of claim 1, wherein: and the boss of the bottom flange is connected with the end part of the conical surface section through a third transition curved surface section.

10. The bi-arc flexspline structure of claim 9, wherein: and the third transition curved surface section and the second transition curved surface section are connected with two ends of the conical surface section through fillets.

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