RU193296U1 - Planetary thread reducer - Google Patents

Abstract

The planetary threaded gearbox (hereinafter referred to as the gearbox) belongs to the field of mechanical engineering. The gearbox contains a screw, threaded rollers, and nuts. The threaded rollers are made with multidirectional sections of the screw thread and a cylindrical surface located between them in contact with the corresponding cylindrical surface on the screw. The screw and threaded rollers contain gear rims at their ends that engage with each other and the gear rim of the support nut. The diameter of the hollows of the screw thread of the support nut is smaller than the diameter of the vertices of the screw thread of the rotary nut. O-rings are located between the rotary and bearing nuts and between the toothed ring of the bearing nut and screw. The gearbox can be used in devices where the input rotational movement is to be converted into angular movement (rotation) of the output link by a full revolution around the axis of rotation and tight execution.

Description

The planetary threaded gearbox belongs to the field of mechanical engineering and is designed to convert the input rotational motion into the angular displacement (rotation) of the output link.

Known planetary gears of the 3k type [1], consisting of a sun wheel, two-crown satellite, fixed and movable crown wheels.

The disadvantages of the known 3k planetary gears are:

1. design complexity due to the large number of parts included in the gearbox;

2. the presence of a gap between the gears, which creates a backlash between the input and output link;

3. low smoothness when using simple involute gears.

Known transmission screw-nut with threaded rollers [2], containing a screw, threaded rollers, running and supporting nuts, gear rims at the ends of the rollers, meshed with the gear rims of the screw and bearing nut. On the supporting section of the screw and rollers, mating cylindrical surfaces are made.

Screw-nut gears with threaded rollers convert the rotational movement on the screw into the translational movement of the travel nut. In this case, the support nut is not shifted relative to the screw unit with the rollers due to the equality of the elevation angles of the screw thread on the supporting sections of the screw and rollers and the internal screw thread of the support nut. The toothed ring of the support nut serves to synchronize the rotation of the rollers around the screw.

The closest analogue is the “Reducer-hinge" [2], containing two links, the first of which is made in the form of a fork, covering the second link, the mechanism of their relative rotation is made in the form of a planetary screw mechanism with threaded rollers. The screw connected to the engine is installed coaxially with the axis of rotation of the links, and each threaded roller is made with two pairs of sections of multidirectional screw cutting, interacting with the corresponding screw threads on the screw and nuts. Between the sections of multidirectional screw cutting on the screw and rollers are made in contact with each other cylindrical surfaces.

The hinge reducer provides high smoothness of operation due to the use of point threaded pairing, instead of involute gear meshing, the ability to adjust the gap in screw joints.

The disadvantages of the gearbox-hinge are:

1. a small angle of rotation of the output link (second link) relative to the fixed body (plug), which narrows the scope of its application;

2. execution with open threaded surfaces requires the use of additional protection against contaminants on threaded surfaces.

The objective of this utility model is to develop the design of a planetary threaded gearbox with the ability to rotate the output link a full revolution around the axis of rotation and a sealed design.

This goal is achieved in that the planetary threaded gearbox containing a screw, threaded rollers, nuts, threaded rollers are made with opposite directions of the screw thread and the cylindrical surface located between them in contact with the corresponding cylindrical surface on the screw, the screw and threaded rollers contain gear rings on their the ends engaged with each other and the ring gear of the support nut, the diameter of the depressions of the screw thread of the support nut is less than the diameter of the vertices of the screw thread of the rotary nuts, between the rotary and supporting nuts and between the ring gear of the supporting nut and the screw there are O-rings.

The essence of the utility model is presented in the description and in the drawing, which shows a general sectional view of a planetary threaded gearbox (hereinafter referred to as the gearbox).

The gearbox contains a screw 1, threaded rollers 2, ring gears 3 and 4 on the screw and rollers, a rotary nut 5, consisting of two half nuts with multidirectional screw threads, a support nut 6, a gear ring of a support nut 7, o-rings 8 between the support and rotary nuts, O-ring 9 between the ring gear of the support nut and the screw.

The gearbox operates as follows. Screw 1 is driven by the engine. The rollers 2, receiving rotation from the screw, make a planetary movement, rolling around the screw, nuts 5, 6 and the ring gear of the support nut 7. The ring gears 3, 5 and 7 synchronize the rotation of the rollers around the screw, and also prevent the rollers from rolling. The cylindrical surfaces in contact with each other, made on rollers between the opposite directions of the screw thread and the screw, prevent the roller block from bending radially to the axis of the screw.

The angle of elevation of the screw thread of the support nut 6 and the corresponding mating portions of the screw thread of the rollers 2 are the same, thereby rolling the rollers along the screw 1 and the support nut without axial displacement relative to each other. The angle of elevation of the screw thread at the rotary nut 5 and the corresponding mating sections of the screw thread of the rollers do not match, which leads to the angular movement of the rotary nut around the axis of rotation when rolling the rollers along it. Since two half-nuts of the rotary nut are made with multidirectional screw cuts, when the rollers are rolled around them, the axial displacement of the rotary nut does not occur.

To ensure the assembly of the gearbox and to expand the possibilities for choosing the gear ratios, one of the half nuts of the rotary nut 5 is screwed onto the roller block 2 with the screw 1 from the side of the support nut 6. Thus, the diameter of the troughs of the screw thread of the support nut must be less than the diameter of the vertices of the screw thread of the rotary nut nuts.

Since the support nut 6 and the rotary nut 5 are spaced at different ends of the gearbox, this allows you to freely make a complete revolution of the rotary nut around the axis of rotation.

O-rings 8 and 9 seal the gearbox against contaminants on screw surfaces and ring gears.

Thus, the use of the proposed utility model allows you to create the design of a planetary threaded gearbox with the ability to rotate the output link a full revolution around the axis of rotation and a sealed design.

Bibliographic references

1. Kudryavtsev V.N. Planetary gears. Reference book / V.N. Kudryavtsev, Yu.N. Kirdyashev, E.G. Ginzburg et al. - L.: Mechanical Engineering, 1997. - 536 p.

2. Pat. 2339332 Russian Federation, IPC А16В 17/66, F16H 25/20, 1/34. Orthopedic apparatus of osteosynthesis / Kozyrev V.V .; applicant and patent holder Kozyrev Vyacheslav Vasilievich. - 2006103056; declared 08/20/2007; publ. 11/27/2008, bull. No. 33.

3. Pat.na utility model 2663030 Russian Federation, B25J 17/00, F16H 25/00. Hinge reducer / Kochetov D.O., Mamaev I.M., Morozov V.V., Stepenkin A.V .; Applicant and patent holder of FSBEI HE Vladimir State University named after Alexander Grigoryevich and Nikolay Grigoryevich Stoletov (VlSU). - 2017133391; declared 09/25/2017; publ. 08/01/2018, bull. Number 22.

Claims (1)

A planetary threaded gearbox containing a screw, threaded rollers, nuts, threaded rollers are made with opposite directions of the screw thread and a cylindrical surface located between them in contact with the corresponding cylindrical surface on the screw, characterized in that the screw and threaded rollers contain gear crowns at their ends, engaged with each other and the ring gear of the support nut, the diameter of the hollows of the screw thread of the support nut is less than the diameter of the vertices of the screw thread of the rotary nut, between O-ring and support nuts and O-rings are located between the ring gear of the support nut and screw.

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