Disclosure of Invention
The invention provides a cycloidal-pin-wheel deceleration type electric steering engine, which aims to solve the technical problem that the electric steering engine cannot bear larger torque and bending moment in a narrow space.
In order to solve the technical problems, the invention adopts the following technical scheme:
the utility model provides a cycloid pinwheel deceleration formula electric steering engine which characterized in that includes: the device comprises a servo motor, a servo motor bevel gear, a shell, an eccentric shaft, a rear end cover, a first cross roller bearing assembly, a second cross roller bearing assembly, a first cycloidal gear bracket, a second cycloidal gear bracket, a first cycloidal gear bracket roller assembly, a second cycloidal gear bracket roller assembly, a needle roller assembly, a cycloidal gear, a flange and an axial locking component, wherein the eccentric shaft, the rear end cover, the first cross roller bearing assembly, the second cross roller bearing assembly, the first cycloidal gear bracket roller assembly;
the servo motor is connected with the shell, a servo motor bevel gear is arranged at the output end of the servo motor, and the servo motor bevel gear is connected with the eccentric shaft;
the middle of the rear end cover is provided with a first through hole matched with the eccentric shaft, one side of the rear end cover is provided with an annular ring structure for bearing the rolling of the first crossed roller bearing assembly, and one side of the rear end cover provided with the annular ring is provided with a plurality of first protruding parts;
the first cycloidal gear bracket and the second cycloidal gear bracket are both of a cross structure, a second through hole matched with the eccentric shaft is arranged in the middle of the first cycloidal gear bracket and is used for bearing the rolling of the roller component of the first cycloidal gear bracket, and the second cycloidal gear bracket is used for bearing the rolling of the roller component of the second cycloidal gear bracket;
the inner surface of one end of the shell is provided with a first sunken part for placing the first crossed roller bearing assembly, and the inner surface of the other end of the shell is provided with a second sunken part for placing the second crossed roller bearing assembly;
the needle roller assembly is arranged on a cycloid profile on the surface of an outer ring of the cycloid wheel, the cycloid profile is matched with the needle roller assembly, a third through hole matched with the eccentric shaft is formed in the middle of the cycloid wheel, a plurality of fourth through holes for allowing axial locking components to penetrate through are formed around the third through hole, a plurality of second protruding portions matched with the first cycloid wheel support are arranged at one end of the cycloid wheel, the second protruding portions are matched with the first protruding portions to bear the rolling of the first cycloid wheel support roller assembly, and a plurality of third protruding portions matched with the second cycloid wheel support are arranged at the other end of the cycloid wheel;
a fifth through hole matched with the eccentric shaft is formed in the middle of the flange, an annular ring structure is arranged on one side of the flange and used for bearing the rolling of the second crossed roller bearing assembly, a plurality of fourth protruding portions are arranged on one side, provided with an annular ring, of the flange, and the fourth protruding portions are matched with the third protruding portions to bear the rolling of the second cycloidal gear support roller assembly;
the axial locking component sequentially penetrates through the fifth through hole and the fourth through hole to be connected with the rear end cover so as to clamp the first crossed roller bearing assembly and the second crossed roller bearing assembly.
Preferably, the flange is provided with an angle feedback rod, a sixth through hole matched with the angle feedback rod is formed in the middle of the eccentric shaft, the angle feedback rod penetrates through the sixth through hole and is connected with the corner sensor, and the corner sensor is used for monitoring corner information of the flange in real time.
Preferably, one side of the corner sensor is provided with a corner sensor cover plate, the other side of the corner sensor is provided with a corner sensor mounting bracket, and the corner sensor is fixed on the shell through the corner sensor cover plate and the corner sensor mounting bracket.
Preferably, the eccentric shaft includes an eccentric shaft bevel gear, a first central cylinder, an eccentric cylinder, a second central cylinder, a first boss, and a second boss, the eccentric shaft bevel gear is disposed at an end of the first central cylinder and engaged with the servo motor bevel gear, the first boss is disposed at a joint of the first central cylinder and the eccentric cylinder, and the second boss is disposed at a joint of the eccentric cylinder and the second central cylinder, wherein the first central cylinder is coaxial with the second central cylinder, and the eccentric cylinder is not coaxial with both the first central cylinder and the second central cylinder.
Preferably, the eccentric shaft further comprises a first central shaft roller bearing assembly disposed on the first central cylinder, a second central shaft roller bearing assembly disposed on the second central cylinder, and an eccentric shaft roller bearing assembly disposed on the eccentric cylinder.
Preferably, the first and second cross roller bearing assemblies each comprise a plurality of cylindrical rollers arranged orthogonally to one another at 90 degrees.
Preferably, the length of the cylindrical roller is greater than the diameter of the cylindrical roller, and the size of each cylindrical roller is the same.
Preferably, the axial locking component is a screw, each first protruding portion is provided with a blind hole connected with the screw, and the screw is in threaded connection with the blind hole.
The technical scheme of the invention has the following beneficial effects:
(1) the transmission precision is high, the existing harmonic reducer type steering engine can be replaced under the same volume and weight, the reduction ratio is large, and large torque and bending moment which cannot be borne by the harmonic reducer type steering engine are realized;
(2) the internal transmission parts are in line contact, so that the shock resistance is high, the transmission rigidity is high, and high dynamic characteristics can be realized;
(3) the structure is compact, the device is suitable for installation in narrow empty space, and the device has the advantages of incomparable miniaturization and light weight compared with a ball screw and connecting rod mechanism type electric steering engine. The device is suitable for a medium-low power electric steering engine in a narrow empty space;
(4) simple structure, easy manufacturing and assembly and higher working reliability.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
Fig. 1 is an exploded schematic view of a cycloidal-pin-wheel deceleration type electric steering engine according to an embodiment of the present invention.
Fig. 2 is a schematic cross-sectional view illustrating a cycloidal-pin-wheel-reduced electric steering engine according to an embodiment of the present invention.
Fig. 3 shows an overall structural schematic diagram of a cycloidal-pin-wheel deceleration type electric steering engine according to an embodiment of the present invention.
Fig. 4 shows a schematic structural diagram of an eccentric shaft provided by an embodiment of the present invention.
Fig. 5 shows a schematic structural diagram of a housing provided by an embodiment of the invention.
Fig. 6 shows a schematic structural diagram of the cycloid wheel provided by the embodiment of the invention.
Fig. 7 shows a schematic structural diagram of the needle roller assembly provided by the embodiment of the invention.
Fig. 8 shows a schematic structural diagram of a flange provided in an embodiment of the present invention.
Fig. 9 shows a schematic structural diagram of a rear end cap provided by an embodiment of the present invention.
FIG. 10 illustrates a schematic structural view of a crossed roller bearing assembly provided by an embodiment of the present invention.
Fig. 11 shows a schematic structural diagram of a cycloid wheel support provided by an embodiment of the invention.
Description of the reference numerals
1. A servo motor; 2. a housing; 3. a flange; 4. a corner sensor cover plate;
5. a rotation angle sensor; 6. a corner sensor mounting bracket; 7. an eccentric shaft;
8. a first central shaft roller bearing assembly; 9. a rear end cap;
10. a first cross roller bearing assembly; 11. a first cycloid gear support;
12. a first cycloidal gear carrier roller assembly; 13. a servo motor bevel gear;
14. a needle roller assembly; 15. a cycloid wheel; 16. an eccentric shaft roller bearing assembly;
17. an axial locking member; 18. a first central cylinder; 19. a second central cylinder;
20. an eccentric cylinder; 21. an eccentric shaft bevel gear; 22. a first boss;
23. a second boss; 24. a second central shaft roller bearing assembly;
25. a second cross roller bearing assembly; 26. a second cycloid gear support;
27. a second cycloidal gear carrier roller assembly; 28. a sixth through hole; 29. a semi-circular arc groove;
30. a cycloid profile; 31. a fourth via hole; 32. a second boss portion; 33. a third through hole;
34. rolling needles; 35. a fourth boss; 36. an annular ring of flanges; 37. an angle feedback lever;
38. a first boss portion; 39. blind holes; 40. an annular ring of the rear end cap.
Detailed Description
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.
As shown in fig. 1 to 3, schematic structural diagrams of a cycloidal-pin-wheel deceleration type electric steering engine according to an embodiment of the present invention are shown. Referring to fig. 1-3, one embodiment of the present invention provides a cycloidal-pin-wheel-reduced electric steering engine, comprising: the device comprises a servo motor 1, a servo motor bevel gear 13, a shell 2, an eccentric shaft 7, a rear end cover 9, a first cross roller bearing assembly 10, a second cross roller bearing assembly 25, a first cycloidal gear bracket 11, a second cycloidal gear bracket 26, a first cycloidal gear bracket roller assembly 12, a second cycloidal gear bracket roller assembly 27, a needle roller assembly 14, a cycloidal gear 15, a flange 3 and an axial locking component 17, wherein the eccentric shaft 7, the rear end cover 9, the first cross roller bearing assembly 10, the second cross roller bearing assembly 25, the first cycloidal gear bracket;
the servo motor 1 is connected with the shell 2, a servo motor bevel gear 13 is arranged at the output end of the servo motor 1, and the servo motor bevel gear 13 is connected with the eccentric shaft 7;
a first through hole matched with the eccentric shaft 7 is formed in the middle of the rear end cover 9, an annular ring 40 structure is arranged on one side of the rear end cover 9 and used for bearing the rolling of the first crossed roller bearing assembly 10, and a plurality of first protruding parts 38 are arranged on one side, provided with the annular ring 40, of the rear end cover 9;
the first cycloid gear bracket 11 and the second cycloid gear bracket 26 are both of a cross structure, a second through hole matched with the eccentric shaft 7 is formed in the middle of the first cycloid gear bracket 11, the first cycloid gear bracket 11 is used for bearing the rolling of the first cycloid gear bracket roller assembly 12, and the second cycloid gear bracket 26 is used for bearing the rolling of the second cycloid gear bracket roller assembly 27;
a plurality of semi-arc grooves 29 are arranged on the inner surface of the shell 2 and are used for bearing the rolling of the needle roller assembly 14, a first concave part for placing the first crossed roller bearing assembly 10 is arranged on the inner surface of one end of the shell 2, and a second concave part for placing the second crossed roller bearing assembly 25 is arranged on the inner surface of the other end of the shell 2;
the needle roller assembly 14 is arranged on a cycloid profile 30 on the outer ring surface of the cycloid wheel 15, the cycloid profile 30 is matched with the needle roller assembly 14, a third through hole 33 matched with the eccentric shaft 7 is arranged in the middle of the cycloid wheel 15, a plurality of fourth through holes 31 for allowing the axial locking component 17 to pass through are arranged around the third through hole 33, a plurality of second protrusions 32 matched with the first cycloid wheel bracket 11 are arranged at one end of the cycloid wheel 15, the second protrusions 32 are matched with the first protrusions 38 to bear the rolling of the first cycloid wheel bracket roller assembly 12, and a plurality of third protrusions matched with the second cycloid wheel bracket 26 are arranged at the other end of the cycloid wheel 15;
a fifth through hole matched with the eccentric shaft 7 is formed in the middle of the flange 3, an annular ring 36 structure is arranged on one side of the flange 3 and used for bearing the rolling of the second crossed roller bearing assembly 25, a plurality of fourth protruding portions 35 are arranged on one side, provided with the annular ring 36, of the flange 3, and the fourth protruding portions 35 are matched with the third protruding portions to bear the rolling of the second cycloidal gear bracket roller assembly 27;
the axial locking member 17 is connected to the rear end cover 9 through the fifth through hole and the fourth through hole 31 in sequence to clamp the first cross roller bearing assembly 10 and the second cross roller bearing assembly 25.
According to the technical scheme, the first cycloid wheel support 11 is matched with the cycloid wheel 15 and the rear end cover 9, and the second cycloid wheel support 26 is matched with the cycloid wheel 15 and the flange 3, so that the torque and bending moment bearing capacity of a steering engine hinge is remarkably improved, and the steering engine has the advantages of high rigidity, high precision and simple and compact structure.
Fig. 4 shows a schematic structural diagram of an eccentric shaft provided by an embodiment of the present invention. Referring to fig. 4, the eccentric shaft 7 according to an embodiment of the present invention includes an eccentric shaft bevel gear 21, a first central cylinder 18, an eccentric cylinder 20, a second central cylinder 19, a first boss 22, and a second boss 23, the eccentric shaft bevel gear 21 being disposed at an end of the first central cylinder 18 and engaged with the servo motor bevel gear 13, the first boss 22 being disposed at a junction of the first central cylinder 18 and the eccentric cylinder 20, and the second boss 23 being disposed at a junction of the eccentric cylinder 20 and the second central cylinder 19, wherein the first central cylinder 18 is coaxial with the second central cylinder 19, and the eccentric cylinder 20 is not coaxial with both the first central cylinder 18 and the second central cylinder 19.
Wherein the eccentric shaft bevel gear 21 receives the rotation speed and torque transmitted from the servo motor bevel gear 13 to thereby generate the "eccentric motion" of the eccentric cylinder 20, and the first and second central cylinders 18 and 19 support the eccentric cylinder 20 to rotate. The eccentric shaft 7 is compact and may, for example, be of an integrated design.
The eccentric shaft of the cycloid pin gear reduction type electric steering engine according to the embodiment of the invention further comprises a first central shaft roller bearing assembly 8, a second central shaft roller bearing assembly 24 and an eccentric shaft roller bearing assembly 16, wherein the first central shaft roller bearing assembly 8 is arranged on the first central cylinder 18, the second central shaft roller bearing assembly 24 is arranged on the second central cylinder 19, and the eccentric shaft roller bearing assembly 16 is arranged on the eccentric cylinder 20.
Wherein the eccentric shaft roller bearing assembly 16 rolls between the eccentric cylinder 20 and the third through hole 33 of the cycloid wheel 15; the first central shaft roller bearing assembly 8 rolls between the first central cylinder 18 and the third through hole of the rear end cap 9; the second central shaft roller bearing assembly 24 rolls between the second central cylinder 19 and the fifth through hole of the flange 3.
Fig. 5 shows a schematic structural diagram of the housing 2 according to the embodiment of the present invention. Referring to fig. 5, a plurality of semi-circular grooves 29 are formed on the inner surface of the housing 2 according to an embodiment of the present invention to support the rolling of the needle roller assemblies 14. The eccentric shaft 7, the rear end cover 9, the first cross roller bearing assembly 10, the second cross roller bearing assembly 25, the first cycloid gear bracket 11, the second cycloid gear bracket 26, the first cycloid gear bracket roller assembly 12, the second cycloid gear bracket roller assembly 27, the needle roller assembly 14, the cycloid gear 15, the flange 3 and the axial locking component 17 are all arranged inside the housing 2. And, the inner surface of one end of the housing 2 is provided with a first recess for placing the first crossed roller bearing assembly 10, the inner surface of the other end of the housing 2 is provided with a second recess for placing the second crossed roller bearing assembly 25, and both the first recess and the second recess play a supporting role. One side that casing 2 and servo motor are connected is equipped with the screw hole for installation servo motor 1.
Fig. 6 shows a schematic structural diagram of the cycloid wheel provided by the embodiment of the invention. Referring to fig. 6, the outer ring surface of the cycloid wheel 15 according to an embodiment of the present invention is provided with a cycloid profile 30 for realizing "cycloid pin gear reduction", one end of the cycloid wheel 15 is provided with a plurality of second protrusions 32 adapted to the first cycloid wheel support 11, and the other end is provided with a plurality of third protrusions adapted to the second cycloid wheel support 26, for transmitting the "cycloid pin gear reduction" to the large torque and the low rotation speed of the cycloid wheel 15, and transmitting to the first cycloid wheel support 11 through the first cycloid wheel support roller assembly 12, and transmitting to the second cycloid wheel support 26 through the second cycloid wheel support roller assembly 27.
Fig. 7 shows a schematic structural diagram of the needle roller assembly provided by the embodiment of the invention. Referring to fig. 7, the needle roller assembly 14 according to an embodiment of the present invention includes a plurality of individual needle rollers 34, and the individual needle rollers 34 roll between the plurality of semi-circular grooves 29 formed in the inner surface of the housing 2 and the cycloid discs 30 formed in the outer circumferential surface of the cycloid disc 15.
Fig. 8 shows a schematic structural diagram of a flange provided in an embodiment of the present invention. Referring to fig. 8, an angle feedback rod 37 is disposed on the flange 3 according to an embodiment of the present invention, a sixth through hole 28 adapted to the angle feedback rod 37 is disposed in the middle of the eccentric shaft 7, the angle feedback rod 37 passes through the sixth through hole 28 and is connected to a rotation angle sensor 5, and the rotation angle sensor 5 is configured to monitor rotation angle information of the flange 3 in real time. And a corner sensor cover plate 4 is arranged on one side of the corner sensor 5, a corner sensor mounting bracket 6 is arranged on the other side of the corner sensor 5, and the corner sensor 5 is fixed on the shell 2 through the corner sensor cover plate 4 and the corner sensor mounting bracket 6.
Fig. 9 shows a schematic structural diagram of a rear end cap provided by an embodiment of the present invention. Referring to fig. 9, the axial locking member 17 according to an embodiment of the present invention is a screw, and each first boss 38 of the rear end cover 9 is provided with a blind hole 39 for coupling the screw, and the coupling of the locking member 17 and the rear end cover 9 is performed by screwing the screw into and out of the blind hole 39 to clamp the first cross roller bearing assembly 10 and the second cross roller bearing assembly 25, and the pre-tightening damping adjustment is performed by screwing the screw in and out.
FIG. 10 illustrates a schematic structural view of a crossed roller bearing assembly provided by an embodiment of the present invention. Referring to fig. 10, each of the first and second cross roller bearing assemblies 10 and 25 according to an embodiment of the present invention includes a plurality of cylindrical rollers arranged to cross each other perpendicularly at 90 degrees. The length of the cylindrical roller is larger than the diameter of the cylindrical roller, and the size of each cylindrical roller is the same.
Wherein the first cross roller bearing assembly 10 rolls on the first recess in the inner surface of one end of the housing 2 and the annular ring 40 structure on the rear end cap 9 side, and the second cross roller bearing assembly 25 rolls on the second recess in the inner surface of the other end of the housing 2 and the annular ring 36 structure on the flange 3 side. The rear end cover 9 and the flange 3 are supported on the housing 2 by the first and second cross roller bearing assemblies 10 and 25, respectively, and the first and second cross roller bearing assemblies 10 and 25 can bear axial and radial loads, occupy a small axial space and a small radial space, and have high rotational accuracy and support rigidity.
Fig. 11 shows a schematic structural diagram of a cycloid wheel support provided by an embodiment of the invention. Referring to fig. 11, the first and second cycloid wheel supports 11 and 26 according to an embodiment of the present invention are each of a cross-shaped structure. The cross-shaped structure of the first cycloid gear bracket 11 is matched with the second protruding portion 32 of the cycloid gear 15 and the first protruding portion 38 of the rear end cover 9, so that the first cycloid gear bracket roller assembly 12 arranged in the vertical direction of the cross-shaped structure rolls between the first protruding portion 38 of the rear end cover 9 and the vertical direction structure of the first cycloid gear bracket 11; the first cycloid gear carrier roller assembly 12 disposed in the horizontal direction of the cross-shaped structure rolls between the second projecting portion 32 of the cycloid gear 15 and the horizontal direction structure of the first cycloid gear carrier 11.
The cross-shaped structure of the second cycloid gear carrier 26 is adapted to the third projection of the cycloid gear 15 and the fourth projection 35 of the flange 3, so that the second cycloid gear carrier roller assembly 27 arranged in the vertical direction of the cross-shaped structure rolls between the fourth projection 35 of the flange 3 and the vertical structure of the second cycloid gear carrier 26; the second cycloid gear carrier roller assembly 27 disposed in the horizontal direction of the cross-shaped structure rolls between the fourth convex portion 35 of the cycloid gear 15 and the horizontal direction structure of the second cycloid gear carrier 26.
The electric steering engine comprises two-stage speed reduction. The first stage is bevel gear reduction, which is accomplished by the engagement of the eccentric shaft bevel gear 21 with the servo motor bevel gear 13. The first stage is cycloidal pin gear speed reduction, and the two-stage speed reduction is completed through the cooperation of the shell 2, the eccentric shaft 7, the rear end cover 9, the first crossed roller bearing assembly 10, the second crossed roller bearing assembly 25, the first cycloidal gear bracket 11, the second cycloidal gear bracket 26, the first cycloidal gear bracket roller assembly 12, the second cycloidal gear bracket roller assembly 27, the needle roller assembly 14, the cycloidal gear 15, the flange 3 and the axial locking component 17.
The working process of the electric steering engine comprises the following steps:
the servo motor 1 outputs high rotating speed and small moment, and the high rotating speed and the small moment are transmitted to the eccentric shaft 7 through a bevel gear reduction formed by the bevel gear 13 of the servo motor and an eccentric shaft bevel gear 21 arranged on the eccentric shaft 7; the eccentric shaft 7 rotates under the support of two central shaft roller bearing assemblies, drives an eccentric cylinder 20 on the eccentric shaft 7 to perform eccentric motion, transmits the eccentric motion to the cycloidal gear 15 through an eccentric shaft roller bearing assembly 16, and a cycloidal profile 30 on the outer ring surface of the cycloidal gear 15 completes cycloidal pinwheel type speed reduction under the limit of a needle roller assembly 14 arranged in the shell 2 to output low rotating speed and large torque; the low rotating speed and the large torque output by the cycloid wheel 15 are transmitted to a first cycloid wheel support 11 through a roller arranged in the horizontal direction of a cross structure in a first cycloid wheel roller component 12, the first cycloid wheel support 11 is transmitted to a rear end cover 9 through a roller arranged in the vertical direction of the cross structure in the first cycloid wheel roller component 12, meanwhile, a roller arranged in the horizontal direction of the cross structure in a second cycloid wheel roller component 25 is transmitted to a second cycloid wheel support 26, the second cycloid wheel support 26 is transmitted to a flange 3 through a roller arranged in the vertical direction of the cross structure in the second cycloid wheel roller component 25, wherein the rear end cover 9 and the flange 3 are connected through screws, and finally, the large torque and the low rotating speed are output to an external load through an output end mounting groove and an output end mounting threaded hole in the flange 3.
Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.