Gear motor structure and assembling method

Abstract

The invention belongs to the technical field of speed reducers, and particularly relates to a speed reduction motor structure and an assembling method thereof. The speed reduction motor structure comprises a bottom shell, a stator, a rotor, an upper cover, an inner gear ring, a coupler, a sun gear, a planet carrier and a planet gear; the bottom shell comprises a barrel shell and a bottom plate, a first bearing is arranged on the bottom plate, a mounting part is arranged on the inner side of the rotor, and a connecting part is arranged on the bottom side of the mounting part; a first shaft of the sun gear is connected with the mounting part, and the coupler is rotationally connected to a second shaft; a plurality of planet shafts are arranged on the bottom side of the coupler at equal angles, the lower ends of the planet shafts are connected with a planet carrier, each planet shaft is rotationally sleeved with a planet gear, and the planet gears and the sun gear are herringbone gears meshed with each other; the upper cover is provided with a supporting ring extending downwards to the inner ring of the rotor, the inner gear ring comprises a first gear ring and a second gear ring, first inner teeth are arranged in the first gear ring, second inner teeth are arranged in the second gear ring, and the first inner teeth and the second inner teeth are combined into herringbone teeth and meshed with the planetary gear; the outer diameter of the planet carrier is smaller than the inner diameter of the inner gear ring.

Description

Technical Field

[0001] This invention belongs to the field of speed reducer technology, and particularly relates to a method for installing a speed reducer motor structure. Background Technology

[0002] The robot reducer is the most critical component used in the rotary joint of a robotic arm. The reducer provides rotational motion to the robotic arm joint and ensures the operational accuracy of the robotic arm's end effector under a certain load.

[0003] Currently, most industrial robots on the market use RV reducers, which consist of two stages: the first stage is an involute spur planetary reducer, and the second stage is a cycloidal pinwheel reducer. The cycloidal pinwheel drive in the RV reducer offers advantages such as high transmission ratio, high precision, and high torsional stiffness, but it also has drawbacks. The needle roller bearing at the crankshaft is the weakest link in the entire RV reducer transmission chain. Under high stress, the needle roller bearing is prone to fatigue failure and wear, and even needle breakage. Moreover, it is currently difficult to solve this problem by improving material strength or machining precision. The cycloidal gear modification technology in the RV reducer is complex, and there is no mature software for it, resulting in a long development cycle. The heat treatment and machining processes for key components such as the cycloidal gear and pinwheel housing are also immature, requiring significant time and money to improve. A small number of industrial robot reducers on the market also use multi-stage involute spur planetary reducers. While providing the same transmission ratio as the RV reducer, the involute spur planetary reducer often requires a larger volume, while having lower torsional stiffness, leading to greater deformation under load.

[0004] To overcome the aforementioned technical deficiencies, Chinese utility model patent document CN210661232U discloses a precision reducer for robots, including a planetary gear mechanism. The planetary gear mechanism includes a sun gear, a planet carrier, a first planetary gear driven by the sun gear, and a gear ring meshing with the first planetary gear. The contour contact line of the first planetary gear forms an angle with its axis. A housing is also included, with the gear ring fixedly mounted on the housing. A first shaft is rotatably mounted on the housing and driven by the sun gear. The precision reducer for robots further includes a first gear fixed to the first shaft, a second gear meshing with the first gear, and a second shaft fixedly connected to and inserted with the second gear. The second shaft is rotatably mounted on the housing and fixedly connected to the sun gear. Both the second gear and the first gear are helical gears. The precision reducer for robots also includes a worm gear mechanism, with the worm rotatably mounted on the housing, the worm wheel fixedly connected to the first shaft, and the first shaft fixedly connected to the sun gear. The planetary gear mechanism also includes a second planetary gear, which is coaxially fixed with the first planetary gear and meshes with the sun gear. The first planetary gear is a herringbone gear, and the gear ring includes a detachably connected first gear ring and a second gear ring. The teeth of both the first and second gear rings are helical teeth and mesh with the first planetary gear. By setting the contour contact line of the first planetary gear at an angle to its axis, the meshing area and overlap between the first planetary gear and the gear ring are increased, thereby improving the load-bearing capacity of both. Simultaneously, the relative rotation of the first planetary gear and the gear ring generates an axial component force, which diverts the load between their teeth, further enhancing their load-bearing capacity. This, in turn, improves the overall load-bearing capacity and rigidity of the precision reducer for robots, making the various structures within the precision reducer less prone to deformation.

[0005] In the aforementioned patent literature, the sun gear, planetary gears, and ring gear employ a herringbone gear structure for meshing and transmission. Because the herringbone gears cannot be installed axially, the ring gear uses a split-type structure. However, due to the structural limitations of the planet carrier, it cannot be used as the base structure for assembly. Therefore, during assembly, the sun gear, planetary gears, and ring gear must first be assembled using positioning fixtures, and then the planet carrier is assembled with the ring gear, planetary gears, and sun gear. This requires ensuring the accuracy of the assembly positions of all three components, making assembly difficult and potentially leading to assembly failure due to assembly errors. Summary of the Invention

[0006] The purpose of this invention is to provide a method for assembling a geared motor structure, which aims to solve the problem that existing herringbone gears are difficult to assemble and may even fail to assemble properly.

[0007] To achieve the above objectives, an embodiment of the present invention provides a geared motor structure, including a base shell, a stator, a rotor, a top cover, an internal gear ring, a coupling, a sun gear, a planetary carrier, and planetary gears; The bottom shell includes a cylindrical shell and a base plate disposed at the bottom of the cylindrical shell, and a first bearing is provided on the base plate; the stator is fixed inside the cylindrical shell, and the rotor is rotatably disposed inside the cylindrical shell, with a mounting part on the inner side of the rotor, and a connecting part connected to the first bearing on the bottom side of the mounting part; a first shaft extends from the bottom end of the sun gear, and a second shaft extends from the top end, the first shaft being connected to the mounting part, and the coupling being rotatably connected to the second shaft; multiple planetary shafts are arranged at equal angles on the bottom side of the coupling, the lower end of the planetary shafts being connected to the planet carrier, and each planetary shaft being rotatably fitted with a planetary gear, the planetary gears and the sun gear being herringbone gears that mesh with each other; The upper cover is located at the upper end of the cylindrical shell. The upper cover has a support ring extending downward to the inner ring of the rotor. The lower end of the inner ring of the support ring has a support step. The internal gear ring is located inside the support ring. The internal gear ring includes a first gear ring and a second gear ring. The first gear ring has a first internal tooth, and the second gear ring has a second internal tooth. The first internal tooth and the second internal tooth are combined to form a herringbone pattern and mesh with the planetary gear. The outer diameter of the planet carrier is smaller than the inner diameter of the internal gear ring.

[0008] Furthermore, the mounting part is provided with a spline hole, the first shaft is a spline shaft, and the spline shaft meshes with the spline hole.

[0009] Furthermore, the upper end of the support ring is provided with a limiting ring, and a second bearing is provided inside the limiting ring. The bottom of the coupling is provided with a boss, and the boss is connected to the inner ring of the second bearing.

[0010] Furthermore, a pressure ring is provided on the top side of the upper cover, and the pressure ring limits the top side of the second bearing.

[0011] Furthermore, the inner wall of the support ring is provided with multiple positioning grooves, and the outer side of the internal gear ring is provided with positioning ribs.

[0012] Furthermore, the bottom of the base shell has an upwardly recessed cavity for mounting the control circuit.

[0013] Furthermore, copper sleeves are fitted at both ends of the planetary shaft, and both the coupling and the planetary carrier are provided with mounting holes, with the copper sleeves disposed in the corresponding mounting holes.

[0014] Furthermore, an oil hole is provided on one side of the top cover, and the other end of the oil hole extends to the inner side of the internal gear ring.

[0015] Furthermore, the lower end of the inner ring of the first gear ring is provided with a first annular groove, and the upper end of the inner ring of the second gear ring is provided with a second annular groove. The first annular groove and the second annular groove form an annular oil groove, and the oil hole communicates with the annular oil groove.

[0016] The above-mentioned technical solutions in the geared motor structure provided by the embodiments of the present invention have at least the following technical effects: During assembly, the stator and rotor of this geared motor can be installed inside the cylindrical housing, and the connecting part at the bottom of the rotor is connected to the first bearing, allowing the rotor to rotate freely and be supported within the housing. Centered on the sun gear, multiple planetary gears mesh at equal angles with the sun gear. Planetary shafts pass through the corresponding planetary gears and connect to the planet carrier. Through the meshing action of the planetary gears and the sun gear, the sun gear, planetary gears, and planet carrier form a unified structure. Therefore, the first gear ring can be fitted onto the outer side of the unified structure formed by the planetary gears from the top, and the second gear ring can be fitted onto the outer side of the unified structure formed by the planetary gears from the bottom, with the first and second gear rings locked together by screws. The upper ends of each planetary shaft, as well as the second shaft of the sun gear, are combined with the coupling to form a unified structure. Finally, the gear rings are installed into the support ring of the top cover, and the top cover is installed on the top of the cylindrical housing. The first shaft is then connected to the mounting part, thus completing the assembly. Since the planet carrier is used as the basis for assembling the first and second gear rings, only the positioning accuracy of the meshing between the first and second internal teeth and the planetary gears needs to be considered during assembly, making assembly easier. Furthermore, the overall structure is more compact and simpler. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A structural diagram of a geared motor is provided for an embodiment of the present invention.

[0019] Figure 2 An exploded view of a geared motor provided in an embodiment of the present invention.

[0020] Figure 3 An internal structural diagram of the geared motor is provided for embodiments of the present invention.

[0021] Figure 4 This is a cross-sectional view of a geared motor provided in an embodiment of the present invention. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the embodiments of the present invention, and should not be construed as limiting the present invention.

[0023] In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] In the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0026] In one embodiment of the geared motor of the present invention, please refer to... Figures 1 to 4 The geared motor of this embodiment includes a base housing 100, a stator 200, a rotor 300, a top cover 400, an internal gear ring 500, a coupling 600, a sun gear 700, a planetary carrier 800, and a planetary gear 900.

[0027] The bottom shell 100 includes a cylindrical shell 110 and a bottom plate 120 disposed at the bottom of the cylindrical shell 110. A first bearing 130 is provided on the bottom plate 120. Specifically, a positioning sleeve 121 is provided on the bottom plate 120, and the first bearing 130 is disposed within the positioning sleeve 121. The stator 200 is fixedly disposed within the cylindrical shell 110, and the rotor 300 is rotatably disposed within the cylindrical shell 110. A mounting portion 310 is provided on the inner side of the rotor 300. Specifically, the stator 200 is an electromagnetic coil disposed within the cylindrical shell 110, and the rotor 300 includes a rotating cylinder 301 and a magnet 302 attached to the outer side of the rotating cylinder 301. The mounting portion 310 is a structure formed by multiple ribs disposed on the inner side of the rotating cylinder 301.

[0028] The mounting portion 310 has a connecting portion 311 on its bottom side that connects to the first bearing 130. The sun gear 700 has a first shaft 710 extending from its bottom end and a second shaft 720 extending from its top end. The first shaft 710 is connected to the mounting portion 310. Specifically, the mounting portion 310 has a splined hole, and the first shaft 710 is a splined shaft. When the first shaft 710 is connected to the mounting portion 310, the splined shaft is inserted into the splined hole.

[0029] The coupling 600 is rotatably connected to the second shaft 720. Multiple planetary shafts 610 are arranged at equal angles on the bottom side of the coupling 600. The lower end of the planetary shaft 610 is connected to the planet carrier 800. Each planetary shaft 610 is rotatably fitted with a planetary gear 900. The planetary gear 900 and the sun gear 700 are herringbone gears that mesh with each other.

[0030] The upper cover 400 is located at the upper end of the cylindrical shell 110. The upper cover 400 is provided with a support ring 410 extending downward to the inner ring of the rotor 300. The lower end of the inner ring of the support ring 410 is provided with a support step 411. The internal gear ring 500 is located inside the support ring 410. The internal gear ring 500 includes a first gear ring 510 and a second gear ring 520. The first gear ring 510 is provided with a first internal tooth 511, and the second gear ring 520 is provided with a second internal tooth 521. The first internal tooth 511 and the second internal tooth 521 are both helical teeth and are combined into herringbone teeth and mesh with the planetary gear 900. The outer diameter of the planet carrier 800 is smaller than the inner diameter of the internal gear ring 500.

[0031] The assembly method of the geared motor in this embodiment is as follows: the stator 200 and rotor 300 are installed inside the cylindrical shell 110, and the connecting part 311 at the bottom of the rotor 300 is connected to the first bearing 130, so that the rotor 300 can be freely rotated and supported inside the cylindrical shell 110. With the sun gear 700 as the center, multiple planetary gears 900 mesh with the sun gear 700 at equal angles. In this embodiment, there are three planetary gears 900. The planetary shaft 610 then passes through the corresponding planetary gear 900 and connects to the planet carrier 800. Under the meshing action of the planetary gears 900 and the sun gear 700, the sun gear 700, planetary gears 900, and planet carrier 800 form a whole. Therefore, the first gear ring 510 can be fitted from the top to the outside of the whole formed by each planetary gear 900, and the second gear ring 520 can be fitted from the bottom to the outside of the whole formed by each planetary gear 900, with the first gear ring 510 and the second gear ring 520 locked together by screws. The upper ends of each planetary shaft 610, the second shaft 720 of the sun gear 700, and the coupling 600 are combined to form an integral structure. Finally, the gear ring 500 is inserted into the support ring 410 of the upper cover 400, and the upper cover 400 is installed on top of the cylindrical shell 110; the first shaft 710 is then connected to the mounting part 310, thus completing the overall assembly. Since the planetary carrier 800 is used as the basis for assembling the first gear ring 510 and the second gear ring 520, only the positioning accuracy of the meshing between the first internal gear 511, the second internal gear 521, and the planetary gear 900 needs to be considered during assembly, making assembly easier. Furthermore, the overall structure is more compact and simpler.

[0032] Furthermore, refer to Figure 2 The planetary carrier 800 is provided with multiple support platforms 810, which support the connecting shaft 600. The support platform 810 is provided with a through hole, through which the locking screw passes and locks the connecting shaft 600, so that the planetary carrier 800 and the coupling 600 form a whole.

[0033] Furthermore, refer to Figures 2 to 4 The upper end of the support ring 410 is also provided with a limiting ring 412, and a second bearing 413 is provided inside the limiting ring 412. The bottom of the coupling 600 is provided with a boss 620, which is connected to the inner ring of the second bearing 413. In addition, the second bearing 413 limits the gear ring 500.

[0034] Furthermore, refer to Figures 1 to 4 The top side of the cover 400 is also provided with a pressure ring 420, which limits the top side of the second bearing 413 and keeps the second bearing 413 within the limiting ring 412.

[0035] Furthermore, refer to Figure 2The inner wall of the support ring 410 is also provided with multiple positioning grooves 414, and the outer side of the internal gear ring 500 is provided with positioning ribs 501. In this embodiment, when the internal gear ring 500 is installed into the support ring 410, the positioning ribs 501 and the positioning grooves 414 are positioned and engaged, so that the internal gear ring 500 is fixed in the support ring 410.

[0036] Furthermore, refer to Figure 4 The bottom of the base 100 has an upwardly recessed cavity 101 for mounting control circuitry. Additionally, the top wall of the cavity 101 forms a base plate 120.

[0037] Furthermore, refer to Figures 2 to 3 The planetary shaft 610 has copper sleeves 611 fitted at both ends. Both the coupling 600 and the planetary carrier 800 have mounting holes, and the copper sleeves 611 are positioned within the corresponding mounting holes. In this embodiment, the copper sleeves 611 can be pressed into the corresponding mounting holes. When the planetary shaft 610 is installed into the corresponding mounting hole, it engages with the copper sleeves 611, allowing for an interference fit between the planetary shaft 610 and the mounting hole, and facilitating the insertion of the planetary shaft 610 into the copper sleeves 611.

[0038] Furthermore, refer to Figure 2 and Figure 4 The top cover 400 also has an oil hole 401 on one side, with the other end of the oil hole 401 extending to the inside of the internal gear ring 500. Lubricating oil can be injected into the internal gear ring 500 through the oil hole 401. Furthermore, the top cover 400 has two oil holes 401 on its side, which facilitates the replacement of lubricating oil.

[0039] Furthermore, refer to Figure 4 The lower end of the inner ring of the first gear ring 510 is provided with a first annular groove, and the upper end of the inner ring of the second gear ring 520 is provided with a second annular groove. The first annular groove and the second annular groove form an annular oil groove 502, and the oil hole 401 is connected to the annular oil groove 502.

[0040] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A geared motor structure, characterized in that, It includes the bottom housing, stator, rotor, top cover, internal gear ring, coupling, sun gear, planet carrier, and planet gears; The bottom shell includes a cylindrical shell and a base plate disposed at the bottom of the cylindrical shell, and a first bearing is provided on the base plate; the stator is fixed inside the cylindrical shell, and the rotor is rotatably disposed inside the cylindrical shell, with a mounting part on the inner side of the rotor, and a connecting part connected to the first bearing on the bottom side of the mounting part; a first shaft extends from the bottom end of the sun gear, and a second shaft extends from the top end, the first shaft being connected to the mounting part, and the coupling being rotatably connected to the second shaft; multiple planetary shafts are arranged at equal angles on the bottom side of the coupling, the lower end of the planetary shafts being connected to the planet carrier, and each planetary shaft being rotatably fitted with a planetary gear, the planetary gears and the sun gear being herringbone gears that mesh with each other; The upper cover is located at the upper end of the cylindrical shell. The upper cover has a support ring extending downward to the inner ring of the rotor. The lower end of the inner ring of the support ring has a support step. The internal gear ring is located inside the support ring. The internal gear ring includes a first gear ring and a second gear ring. The first gear ring has a first internal tooth, and the second gear ring has a second internal tooth. The first internal tooth and the second internal tooth are combined to form a herringbone pattern and mesh with the planetary gear. The outer diameter of the planet carrier is smaller than the inner diameter of the internal gear ring.

2. The geared motor structure according to claim 1, characterized in that: The mounting part is provided with a spline hole, and the first shaft is a spline shaft that meshes with the spline hole.

3. The geared motor structure according to claim 1, characterized in that: The upper end of the support ring is also provided with a limiting ring, and a second bearing is provided inside the limiting ring. The bottom of the coupling is provided with a boss, and the boss is connected to the inner ring of the second bearing.

4. The geared motor structure according to claim 3, characterized in that: The top side of the upper cover is also provided with a pressure ring, which limits the top side of the second bearing.

5. The geared motor structure according to any one of claims 1 to 4, characterized in that: The inner wall of the support ring is also provided with multiple positioning grooves, and the outer side of the internal gear ring is provided with positioning ribs.

6. The geared motor structure according to claim 1, characterized in that: The bottom of the base shell has an upwardly recessed cavity for mounting control circuitry.

7. The geared motor structure according to claim 1, characterized in that: The planetary shaft is fitted with copper sleeves at both ends, and both the coupling and the planetary carrier are provided with mounting holes, with the copper sleeves placed in the corresponding mounting holes.

8. The geared motor structure according to claim 1, characterized in that: An oil hole is provided on one side of the top cover, and the other end of the oil hole extends to the inside of the internal gear ring.

9. The geared motor structure according to claim 8, characterized in that: The lower end of the inner ring of the first gear ring is provided with a first annular groove, and the upper end of the inner ring of the second gear ring is provided with a second annular groove. The first annular groove and the second annular groove form an annular oil groove, and the oil hole communicates with the annular oil groove.

10. The assembly method of the geared motor structure according to any one of claims 1 to 9, characterized in that: Includes the following steps: Step 1: The stator and the rotor are installed inside the cylindrical shell; Step 2: With the sun gear as the center, multiple planetary gears mesh with the sun gear at equal angles, and the planetary shaft passes through the corresponding planetary gear and connects to the planet carrier, so that the sun gear, planetary gears and planet carrier form a whole; Step 3: The first gear ring is fitted onto the outer side of the integral formed by each of the planetary gears from the top end, and the second gear ring is fitted onto the outer side of the integral formed by each of the planetary gears from the bottom end, and the first gear ring and the second gear ring are locked together by screws. Step 4: The upper ends of each planetary shaft and the second shaft of the sun gear are combined with the coupling to form an integral structure; Step 5: Insert the toothed ring from the overall structure in Step 4 into the support ring of the upper cover, and install the upper cover on the top of the cylindrical shell; and connect the first shaft to the mounting part.

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