BG67072B1 - 3d printed joint between shaft and a unit - Google Patents

Abstract

The invention relates to a machine element - a shaft or axle connection with a unit, as at least one of the two core elements is obtained after printing with a 3D printer. Because of the complex shape of the surface, the hole cannot be produced with the conventional technology. Attachments such as washers, sprockets, levers, etc. may be attached to the shaft. It can find application in modelling, prototyping and production of 3D printer mechanisms. The 3D printed joint between a shaft and a unit comprises a shaft (1) and a unit (2) joined together by a closed surface (3) formed between a circle (4) and a closed planar shape (5) and the transition from the circle (4) to the figure (5) is smooth. The planar figure (5) may be a regular polygon with rounded tops and can lie in a plane parallel to the circle (4), and the centre of the right polygon (5) coincides with the centre of the circle (4).

Description

(54) 3D PRINTED CONNECTION BETWEEN SHAFT AND LINK

Field of technology

The invention relates to a machine element - connection of a shaft or an axis with a unit, as at least one of the two main elements is obtained after printing is a 3D printer. Due to the complex shape of the surface, the hole cannot be made by conventional technologies. The joint can be detachable or non-detachable, transmitting or not torque. Elements such as washers, gears, levers, etc. can be attached to the shaft. It is used in modeling, prototyping and production of mechanisms and is a 3D printer.

BACKGROUND OF THE INVENTION

An axial connecting front structure is known, comprising a drive shaft, a drive shaft and a clutch, which are interconnected by profile surfaces, holes in the drive and drive shafts and convex surfaces in the clutch. For example, the holes can be square and hexagonal profile and prismatic shape. The cross section of the joint is constant and can be triangular, hexagonal or elliptical in shape. Restrictive face surfaces are used to prevent axial displacement. The structure serves to transmit torque from the drives to the drive shaft / 1 /.

A problem of the axially connecting front structure / 1 / is that there is a sharp transition in the drive and drive shafts and the clutch from a circuit to a prismatic or other shape, which leads to a concentration of stresses during torque transmission.

Also at / 1 /, it is difficult to achieve good alignment between the drive and the drive element, because a very precise location of the profile section relative to the center of rotation of the shaft is required.

A problem of the axially connecting frontal structure / 1 / is that even with a small inaccuracy in the construction of the three main elements there are gaps, which affect the transmitted motion and reduce the reliability of the structure.

Technical essence of the invention

The object of the invention is to create a connection between a shaft and a unit of a mechanism with the following properties: absence of voltage sources; good self-centering; lack of deadlock and silent transmission. The driven unit must be positioned unambiguously towards the shaft and / or have the possibility to step change its orientation towards the shaft. The connection that can be made is a 3D printer and can be used in the modeling and prototyping of robot mechanisms.

This problem is solved by 3D printing a joint between a shaft and a unit, consisting of a shaft and a unit connected to each other by means of a closed connecting surface, which is formed between a circle and a closed planar figure other than a circle, the transition from the circle to the closed plane figure is smooth.

A closed planar figure can be a regular polygon with rounded vertices and be located in a plane parallel to the plane of the circle, and the center of the regular polygon is coaxial with the center of the circle. The connection is secured and clamped axially by means of a screw.

The advantage of 3D printing the connection between the shaft and the unit is that the connecting surfaces of the shaft and the unit are smooth and smooth transitions, which leads to very low concentrations of stress in the elements when transmitting torque.

The advantage of 3D printing a joint between a shaft and a link is that a good centering between the two elements is obtained, which is due to the inclined sections of the smooth transitions, which are axially symmetrical.

The advantage of 3D printing connection between shaft and link is that the connection between the elements is tight without gaps and there is no deadlock.

As an advantage of 3D printing connection between shaft and link, compared to conventional joints can be considered that the technology for the production of its elements is simplified.

Descriptions of issued patents for inventions № 06.1 / 15.06.2020

It is produced directly from a 3D CAD model, without the need for 2D documentation.

Explanation of the attached figures

Figure 1 - General view of the 3D printing connection between shaft and unit - a) and basic dimensions - b);

Figure 2 - various variants of the compound;

Figure 3 - application of the compound in a 3D printed model of a walking robot. The connection connects shaft 1 to link 2 - robot leg.

An embodiment of the invention

3D printing a connection between a shaft and a unit consisting of a shaft 1 and a unit 2 connected to each other by means of a closed connecting surface 3 such that it is formed between a circle 4 and a closed planar figure 5 other than a circle, such as the transition from the circle 4 to figure 5 is smooth. The planar figure 5 can be a regular polygon with rounded vertices and is located in a plane parallel to the circle 4, and the center of the regular polygon 5 is coaxial with the center of the circle 4. The connection is secured and pressed axially by means of a screw 6 (Fig. 1 and Fig. 3).

Unit 2 is made with 3D printing technology. Due to the complex shape of the surface of the hole can not be made with conventional technologies. Shaft 1 can be obtained from a machine with digital program control or again with 3D printing.

The action of 3D printing the connection between the shaft and the unit consists in the fixed connection of the unit 2 to the shaft 1 by means of the surface 3. It is possible to transmit torque from the shaft 1 to the unit 2 and vice versa.

Depending on the proportions of dimensions D, d and L of the torque-transmitting surface 3 (Fig. 1), the joint can be obtained detachable or non-detachable. D is the diameter of the shaft circle 4; d is the diameter of the circumscribed circle around the regular polygon 5; L - length of the joint, they. the distance between the plane of the circle 4 and the plane of the polygon 5. When it is detachable, it is necessary to provide axial fixation, for example by means of a screw 6.

In FIG. 2 a-d show various embodiments of the contact surface 3. FIG. 2a) the planar figure 5 is composed of arcs, fig. 2b) - transition from a circle to an ellipse, fig. 2c) - the planar figure 5 is composed of an arc and a segment.

FIG. 2 e-g shows various embodiments of the compound. Respectively equilateral triangle, square and pentagon with rounded. In these variants, it is possible to rotate the unit 2 stepwise relative to the shaft 1.

Variants a-g are suitable for shaft ends, but can still be used in internal steps.

A variant in which the diameter d of the circumscribed circle around the polygon is larger than the diameter D of the shaft is given in FIG. 2h.

Claims (2)

Patent claims 3D printing connection between a shaft and a unit consisting of a shaft (1) and a unit (2) connected to each other by means of a closed connection surface (3), characterized in that the connection surface (3) is formed between a circle 4) and a closed planar figure (5) other than a circle, the transition from the circle (4) to the figure (5) being smooth. 3D printing joint between a shaft and a unit according to claim 1, characterized in that the planar figure (5) is a regular polygon with rounded vertices is located in a plane parallel to the circle (4) and the center of the regular polygon (5) is coaxial with the center of the circle (4).