CN115411878A - Rotor shaft, motor and rotor shaft assembling method - Google Patents

Abstract

The invention relates to a rotor shaft, a motor and a rotor shaft assembling method. The rotor shaft comprises a shaft main body and a shaft extension, wherein a first assembling part is arranged at the first end of the shaft main body, a second assembling part is arranged at the second end of the shaft extension, a first assembling hole is formed in the first assembling part, a second assembling hole is formed in the second assembling part, and the first end is opposite to the second end; one of them assembly portion can form tenon fourth of twelve earthly branches structure together with second assembly portion interference fit, under the nested interference fit state of first assembly portion and second assembly portion, first pilot hole is corresponding with the second pilot hole, has embedded the fastener in first pilot hole and second pilot hole, wherein fastener and first pilot hole and second pilot hole interference fit. The invention can combine the shaft main part and different shaft extensions to form different rotor shafts according to requirements, thereby improving the universality of the motor.

Description

Rotor shaft, motor and rotor shaft assembling method

Technical Field

The invention relates to the technical field of motors, in particular to a rotor shaft, a motor and a rotor shaft assembling method.

Background

As a power device, a servo motor is often required to be assembled with a speed reducer or other mechanical devices, the dimensions of the servo motor such as the shaft extension degree and the shaft extension diameter are important dimensions for assembling the servo motor with other equipment, and in order to meet actual assembly requirements, a rotor shaft is often required to be redesigned so as to meet actual installation requirements.

Because the application occasions of the servo motor are wide, the required shaft extension sizes of the same type of servo motor are different in different application places, the servo motor is often required to be developed in a customized mode to meet the actual installation requirements, and because the shaft extension sizes are different, the motor is developed in a customized mode, the cost of purchasing the servo motor by a client is increased, and the production and management cost of a manufacturer is increased due to the fact that a machine type is newly developed.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a rotor shaft, a motor and a rotor shaft assembling method.

The invention provides a rotor shaft, which comprises a shaft main body and a shaft extension, wherein a first assembling part is arranged at the first end of the shaft main body, a second assembling part is arranged at the second end of the shaft extension, a first assembling hole is formed in the first assembling part, a second assembling hole is formed in the second assembling part, and the first end is opposite to the second end; wherein first assembly portion can with second assembly portion interference fit forms tenon fourth of twelve earthly branches structure together first assembly portion with under the nested interference fit state of second assembly portion, first pilot hole with the second pilot hole is corresponding first pilot hole with the second pilot hole is embedded to have the fastener, wherein the fastener with first pilot hole with second pilot hole interference fit.

In some embodiments, the interference fit amount of the first assembling portion and the second assembling portion ranges from 0.04mm to 0.016 mm; and/or the interference fit amount of the fastener and the first assembling hole and the second assembling hole is in the range of 0.04 mm-0.016 mm.

In some embodiments, the first fitting part is a fourth-part formed at the first end of the shaft body, the fourth-part being formed by the first end face of the shaft body being inwardly concave toward the shaft; the second assembly portion is formed at a tenon portion of a second end of the shaft extension, and the tenon portion is formed by the second end face of the shaft extension protruding outward in the axial direction.

In some embodiments, the first assembly aperture forms a counterbore through the mortise portion sidewall and the shaft body peripheral wall; the second assembling hole penetrates through the tenon part to form a through hole.

In some embodiments, the first fitting portion is a tenon portion formed at the first end of the shaft main body, the tenon portion being convexly formed axially outward from the first end face of the shaft main body; the second assembling portion is a rivet portion formed at the second end of the shaft extension, and the rivet portion is formed by inward recessing of the second end surface of the shaft extension towards the axial inner side.

In some embodiments, the first assembly hole forms a through hole through the tenon portion; the second assembly hole penetrates through the mortise part side wall and the shaft main body peripheral wall to form a counter bore.

In some embodiments, the first and second fitting holes each extend radially of the rotor shaft.

In some embodiments, the first fitting portion is adapted to the cross-sectional shape of the second fitting portion, and the shapes of the first fitting hole, the second fitting hole and the fastener are adapted; the cross sections of the first assembling part and the second assembling part are in any one of rectangular, circular, trapezoidal and dovetail shapes; the first assembly hole, the second assembly hole and the fastener are in any one of a rectangular shape, a circular shape and a trapezoidal shape.

In some embodiments, the shaft extension includes a mating section adjacent to the second mounting portion of the shaft extension for mounting a bearing and an extension section for connecting a load.

The present invention also provides a motor comprising: a stator, a rotor and a rotor shaft, the rotor shaft being the rotor shaft according to any of the above-mentioned embodiments, the rotor being fixed to the shaft body of the rotor shaft.

The present invention also provides a rotor shaft assembly method for assembling a rotor shaft as in any of the above-mentioned embodiments, the method comprising: preheating the mortise part of the mortise and tenon structure to enable the mortise part to be in a preheating state; embedding the tenon part of the tenon-and-mortise structure into the mortise part in a preheating state, so that the shaft main body and the shaft extension are assembled together, and the first assembling hole corresponds to the second assembling hole; cooling the assembled shaft main body and shaft extension to room temperature to enable the tenon part and the mortise part to form interference fit; preheating the assembled shaft main body and shaft extension again to enable the first assembling hole and the second assembling hole to be in a preheating state; and embedding the fastener into the first assembling hole and the second assembling hole in a preheated state, and cooling to room temperature to enable the fastener to be in interference fit with the first assembling hole and the second assembling hole.

After adopting the technical scheme, compared with the prior art, the invention has the following beneficial effects:

the rotor shaft structure is divided into two parts, namely a shaft extension part and a shaft main body, wherein the shaft extension part and the shaft main body are in interference fit through the first assembly part and the second assembly part to form a tenon-and-mortise structure, and the first assembly hole and the second assembly hole are embedded into the fastener and are in interference fit to limit axial displacement of the shaft extension part and the shaft main body, so that a complete rotor shaft is formed. The main body part of the shaft can be combined with shaft extensions with different lengths and/or different diameters to form different rotor shafts according to needs, so that the shaft extension size can be changed according to the assembly requirements of different occasions under the condition that the performance of the motor is not influenced, the production cost of the motor is greatly reduced, and the universality of the motor is improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention, are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without limiting the invention to the right. It is obvious that the drawings in the following description are only some embodiments and that for a person skilled in the art, other drawings can also be derived from them without inventive effort. In the drawings:

FIG. 1 is a schematic diagram of a motor structure according to an exemplary embodiment of the present invention;

FIG. 2 is a schematic view of a shaft extension shown in various angles in accordance with an exemplary embodiment of the present invention;

FIG. 3 is a schematic view of a shaft body structure shown from a different angle in accordance with an exemplary embodiment of the present invention;

FIG. 4 is a schematic view of a fastener structure shown from a different angle according to an exemplary embodiment of the invention;

it should be noted that the drawings and the description are not intended to limit the scope of the inventive concept in any way, but to illustrate it by a person skilled in the art with reference to specific embodiments.

Detailed Description

In the description of the present invention, it should be noted that the terms "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," "contacting," and "communicating" are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.

The embodiment of the invention provides a rotor shaft, which has variable shaft extension, can change the shaft extension size according to the assembly requirements of different occasions under the condition of not influencing the performance of a motor, greatly reduces the production cost of the motor and improves the universality of the motor.

As shown in fig. 1 to 4, the rotor shaft according to the embodiment of the present invention includes a shaft main body 11 and a shaft extension 12. The first end 101 of the shaft body 11 is provided with a first fitting portion 13, the second end 102 of the shaft extension 12 is provided with a second fitting portion 14, the first fitting portion 13 is provided with a first fitting hole 131, the second fitting portion 14 is provided with a second fitting hole 141, and the first end 101 is opposite to the second end 102. Wherein first assembly portion 13 can form the mortise-tenon joint structure together with the interference fit of second assembly portion 14, under the nested assembly fit state of first assembly portion 13 with second assembly portion 14, first pilot hole 131 corresponds with second pilot hole 141, has embedded fastener 15 at first pilot hole 131 and second pilot hole 141, and wherein fastener 15 and first pilot hole 131 and second pilot hole 141 interference fit to form a whole with axle main body 11 and shaft extension 12.

The material of the shaft body 11, shaft extension 12 and fastener 15 may be 45 steel or other materials meeting the structural strength and processing requirements. The specific assembly process is as follows:

firstly, preheating the mortise part of the mortise and tenon structure to enable the mortise part to be in a preheating state. The opening of the mortise part in the preheating state is slightly larger than that of the mortise part at normal temperature so as to facilitate the insertion of the mortise part of the mortise and tenon structure.

And secondly, embedding the tenon part of the tenon-and-mortise structure into the mortise part in a preheating state, assembling the shaft main body 11 and the shaft extension 12 together, and enabling the first assembling hole to correspond to the second assembling hole. The mortise part in the preheating state enables the mortise part of the mortise and tenon structure to be smoothly embedded into the mortise part, and interference fit is achieved.

Then, the assembled shaft body 11 and shaft extension 12 are cooled to room temperature, so that the tenon part and the mortise part form interference fit. The interference fit is formed by the mortise and tenon joint structure cooled to the room temperature, so that the shaft main body 11 and the shaft extension 12 are formed into a whole.

Then, the shaft main body and the shaft extension which are assembled together are preheated again, so that the first assembling hole and the second assembling hole are in a preheated state. The shaft main body and the shaft extension which are assembled together are subjected to preset treatment under the condition that the tenon-and-mortise structure forms an interference fit state, so that the space of the first assembling hole and the space of the second assembling hole are slightly larger, and a fastener is conveniently inserted.

Finally, the fastening member 15 is inserted into the first fitting hole and the second fitting hole in a preheated state and cooled to room temperature, so that the fastening member is interference-fitted with the first fitting hole and the second fitting hole to restrict the axial displacement of the shaft extension 12 and the shaft main body 11.

The rotor shaft structure is divided into two parts, namely a shaft extension 12 and a shaft main body 11, wherein the shaft extension 12 and the shaft main body 11 are in interference fit with each other through a first assembling part 13 and a second assembling part 14 to form a tenon-and-mortise structure, and then are embedded into a first assembling hole 131 and a second assembling hole 141 in a fastener 15 and are in interference fit with each other to limit axial displacement of the shaft extension 12 and the shaft main body 11, so that a complete rotor shaft is formed. The shaft main body 11 can be combined with the shaft extensions 12 with different lengths and/or different diameters to form different rotor shafts according to needs, so that the shaft extension size can be changed according to the assembly requirements of different occasions under the condition of not influencing the performance of the motor, the production cost of the motor is greatly reduced, and the universality of the motor is improved.

In some embodiments, the interference fit amount of the first fitting part 13 and the second fitting part 14 is not less than 0.04mm, and preferably, the interference fit amount is in the range of 0.04mm to 0.016 mm; and/or the interference fit amount of the fastener 15 with the first assembling hole 131 and the second assembling hole 141 is not less than 0.04mm, and preferably, the interference fit amount is in the range of 0.04 mm-0.016 mm. The interference fit amount can change the shaft extension size according to the assembly requirements of different occasions on the premise of not influencing the performance of the rotor shaft, thereby greatly reducing the production cost of the motor and improving the universality of the motor.

In some examples, as shown in fig. 2 and 3, the first fitting part 13 is a mortise 13 formed at the first end 101 of the shaft main body 11, the mortise 13 being formed by recessing the first end surface of the shaft main body 11 inward in the axial direction. The first assembling hole 131 penetrates through the side wall of the mortise part 13 and the outer peripheral wall of the shaft main body 11 to form a counter bore, namely, the first assembling hole 131 is communicated with the mortise part 13. The second fitting portion 14 is a tenon portion 14 formed at the second end of the shaft extension 12, the tenon portion being formed by the second end face of the shaft extension 12 projecting axially outward. The second fitting hole 141 forms a through hole through the tenon portion 14. For example, the first fitting hole 131 extends in the radial direction of the shaft main body 11. The second fitting hole 141 extends in the radial direction of the shaft extension 12. The shape and size of the mortise part 13 and the tenon part 14 can be matched so as to meet the interference fit.

In other examples, the first fitting portion 13 is a tenon portion formed at the first end of the shaft main body 11, the tenon portion being formed to be convex outward in the axial direction from the first end face of the shaft main body 11, and the first fitting hole 131 is formed as a through hole through the tenon portion; the second assembling portion 14 is a female portion formed at the second end of the shaft extension 12, the female portion is formed by recessing the second end face of the shaft extension 12 inward in the axial direction, and the second assembling hole 141 penetrates through the side wall of the female portion and the outer peripheral wall of the shaft main body to form a counter bore.

In other words, the mortise and tenon parts of the mortise and tenon structure formed by the rotor shaft can be exchanged at the positions of the shaft main body 11 and the shaft extension.

In some embodiments, the first mounting portion 13 is adapted to the cross-sectional shape of the second mounting portion 14, and the first mounting hole 131, the second mounting hole 141 and the fastener 15 are adapted to the cross-sectional shape.

As some examples, the cross-sectional shapes of the first and second fitting parts 13 and 14 are any one of rectangular, circular, trapezoidal, and dovetail shapes, but are not limited thereto, and may be other shapes that can be combined together by fitting. The first and second attachment holes 131 and 141 and the fastener 15 may have any one of a rectangular shape, a circular shape and a trapezoidal shape. But is not limited thereto and may be in other shapes that can be fit and combined together.

In some embodiments, as shown in fig. 1, the shaft extension 12 includes a mating segment 121 and an extension segment 122, the bearing mating segment 121 being adjacent to the second mounting portion 14 of the shaft extension 12 for mounting the bearing 32, and the extension segment 122 for connecting a load. The fitting section 121 and the extension section 122 of the shaft extension 12 form a stepped shaft, the outer diameter of the fitting section 121 is larger than that of the extension section 122, and a protruding tenon portion can be formed on the front end face of the fitting section 121 in an extending manner. The fitting section 121 for fitting the bearing 32 is adjacent to the second fitting portion 14 of the shaft extension 12, and can suppress the wobbling of the rotor shaft due to the fitting tolerance to the maximum extent. When the shaft extension 12 is stressed radially, the bearing is used as a fulcrum, the second assembling portion 14 can be stressed by radial force opposite to the direction of the shaft extension 12, the motor shaft can shake in the motor operation process, but the tenon-and-mortise structural design and the interference fit of the bearing matching section 112, the motor matching section 111 and the fastener 15 can enable the bearing matching section 112, the motor matching section 111 and the fastener 15 to be stressed and restricted mutually, and therefore the shaking of the rotor shaft caused by assembly tolerance is reduced.

The shaft body 11 includes a detection section 113, a bearing fitting section 112, and a motor fitting section 111. The motor rotor 22 is fixed to at least a portion of the motor fitting section 111, the motor rotor 22 is adjacent to the first mounting portion 13, the bearing 21 is mounted on the bearing fitting section 112, and the encoder 50 is mounted on the detecting section 113.

The embodiment of the present invention further provides an electric machine, which includes a stator 21, a rotor 22, and a rotor shaft, where the rotor shaft is the rotor shaft according to any of the above-mentioned embodiments, and the rotor is fixed on the shaft main body 11 of the rotor shaft. The front bearing 31 is supported on the mating section 112 (which may be referred to as a first mating section 112) of the shaft body 11, and the rear bearing 32 is supported on the mating section 121 (which may be referred to as a second mating section 121) of the shaft extension 12. The shaft body 11 further comprises a front end cover 41 supporting the front bearing 31, a rear end cover 42 supporting the rear bearing 32, an encoder 50 mounted on the detection section 113 of the shaft body 11, and an encoder cover 60 connected to the front end cover 41 and covering the encoder 50.

The motor can ensure that the shaft main body 11 can be combined with the shaft extensions 12 with different lengths and/or different diameters to form different rotor shafts according to requirements, so that the shaft extension size can be changed according to the assembly requirements of different occasions under the condition of not influencing the performance of the motor, the production cost of the motor is greatly reduced, and the universality of the motor is improved.

Embodiments of the present invention further provide a rotor shaft assembling method, for assembling a rotor shaft according to any one of the above embodiments, the method including:

step 1, preheating the mortise part of the mortise and tenon structure to enable the mortise part to be in a preheating state. The opening of the mortise part in the preheating state is slightly larger than that of the mortise part at normal temperature so as to facilitate the insertion of the mortise part of the mortise and tenon structure.

And 2, embedding the tenon part of the tenon-and-mortise structure into the mortise part in a preheating state, assembling the shaft main body 11 and the shaft extension 12 together, and enabling the first assembling hole to correspond to the second assembling hole. The mortise part under the preheating state enables the mortise part of the mortise and tenon structure to be smoothly embedded into the mortise part, and interference fit is achieved.

And 3, cooling the assembled shaft main body 11 and shaft extension 12 to room temperature to enable the tenon part and the mortise part to form interference fit. The mortise and tenon structure cooled to room temperature forms interference fit, so that the shaft main body 11 and the shaft extension 12 form a whole.

And 4, preheating the assembled shaft main body and shaft extension again to enable the first assembling hole and the second assembling hole to be in a preheating state. The shaft main body and the shaft extension which are assembled together are subjected to preset treatment under the condition that the tenon-and-mortise structure forms an interference fit state, so that the space of the first assembling hole and the space of the second assembling hole are slightly larger, and a fastener is conveniently inserted.

And 5, embedding the fastening piece 15 into the first assembling hole and the second assembling hole in a preheated state, cooling to room temperature, and enabling the fastening piece to be in interference fit with the first assembling hole and the second assembling hole so as to limit the axial displacement of the shaft extension 12 and the shaft main body 11.

It is further understood that the use of "a plurality" in this disclosure means two or more, and other terms are analogous. "and/or" describes the association relationship of the associated object, indicating that there may be three relationships, for example, a and/or B, which may indicate: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. The singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It will be further understood that the terms "first," "second," and the like are used to describe various information and that such information should not be limited by these terms. These terms are only used to distinguish one type of information from another and do not denote a particular order or importance. Indeed, the terms "first," "second," and the like are fully interchangeable. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present disclosure.

It is further to be understood that while operations are depicted in the drawings in a particular order, this is not to be understood as requiring that such operations be performed in the particular order shown or in serial order, or that all illustrated operations be performed, to achieve desirable results. In certain environments, multitasking and parallel processing may be advantageous.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It will be understood that the present disclosure is not limited to the precise arrangements that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is to be limited only by the scope of the appended claims.

Claims (11)

1. A rotor shaft, characterized in that,

comprises a shaft main body and a shaft extension,

a first assembling portion is arranged at a first end of the shaft main body, a second assembling portion is arranged at a second end of the shaft extension, a first assembling hole is formed in the first assembling portion, a second assembling hole is formed in the second assembling portion, and the first end is opposite to the second end;

wherein first assembly portion can with second assembly portion interference fit forms tenon fourth of twelve earthly branches structure together first assembly portion with under the interference fit state of second assembly portion, first pilot hole with the second pilot hole is corresponding first pilot hole with the second pilot hole is embedded to have the fastener, wherein the fastener with first pilot hole with second pilot hole interference fit.

2. The rotor shaft of claim 1,

the first assembling portion is a mortise portion formed at the first end of the shaft main body, the mortise portion being formed by the first end surface of the shaft main body being inwardly recessed toward the shaft;

the second assembly portion is formed at a tenon portion of a second end of the shaft extension, and the tenon portion is formed by the second end face of the shaft extension protruding outward in the axial direction.

3. The rotor shaft of claim 2,

the first assembling hole penetrates through the inner side wall of the mortise part and the outer peripheral wall of the shaft main body to form a counter bore;

the second assembling hole penetrates through the tenon part to form a through hole.

4. The rotor shaft of claim 2,

the first assembling portion is a tenon portion formed at the first end of the shaft main body, and the tenon portion is formed by the first end surface of the shaft main body protruding outwards in the axial direction;

the second assembling portion is a mortise portion formed at the second end of the shaft extension, and the mortise portion is formed by inward recessing of the second end surface of the shaft extension toward the axial inner side.

5. The rotor shaft of claim 4,

the first assembling hole penetrates through the tenon part to form a through hole;

the second assembly hole penetrates through the inner side wall of the mortise part and the outer peripheral wall of the shaft main body to form a counter bore.

6. The rotor shaft of claim 1,

the first fitting hole and the second fitting hole each extend in a radial direction of the rotor shaft.

7. The rotor shaft of claim 1,

the first assembling part is matched with the cross section shape of the second assembling part,

the shapes of the first assembling hole, the second assembling hole and the fastener are matched;

the cross sections of the first assembling part and the second assembling part are in any one of rectangular, circular, trapezoidal and dovetail shapes;

the first assembly hole, the second assembly hole and the fastener are in any one of a rectangular shape, a circular shape and a trapezoidal shape.

8. The rotor shaft of claim 1,

the interference fit amount of the first assembling part and the second assembling part is in the range of 0.04 mm-0.016 mm; and/or

The interference fit amount of the fastener and the first assembling hole and the second assembling hole is in the range of 0.04 mm-0.016 mm.

9. The rotor shaft according to any one of claims 1-8,

the shaft extension comprises a matching section and an extension section, the matching section is close to the second assembling portion of the shaft extension and used for assembling a bearing, and the extension section is used for connecting a load.

10. An electric machine, comprising:

a stator, a rotor and a rotor shaft, the rotor shaft being a rotor shaft according to any one of claims 1-9,

the rotor is fixed to the shaft main body of the rotor shaft.

11. A rotor shaft assembly method for assembling a rotor shaft according to any one of claims 1-9, the method comprising:

preheating the mortise part of the mortise and tenon structure to enable the mortise part to be in a preheating state;

embedding the tenon part of the tenon-and-mortise structure into the mortise part in a preheating state, so that the shaft main body and the shaft extension are assembled together, and the first assembling hole corresponds to the second assembling hole;

cooling the assembled shaft main body and shaft extension to room temperature to enable the tenon part and the mortise part to form interference fit;

preheating the assembled shaft main body and shaft extension again to enable the first assembling hole and the second assembling hole to be in a preheating state;

and embedding the fastener into the first assembling hole and the second assembling hole in a preheated state, and cooling to room temperature to enable the fastener to be in interference fit with the first assembling hole and the second assembling hole.

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