reducer

Abstract

This invention discloses a speed reducer, comprising: a base housing for connecting a motor housing, the base housing having a mounting hole for inserting the output shaft of the motor; an eccentric shaft rotatably connected to the inner circumferential surface of the mounting hole, the eccentric shaft being coaxially connected to the output shaft along a first direction, the eccentric shaft having a first eccentric circumferential surface; a first cycloidal gear disposed within the base housing, the first cycloidal gear having a first inner circumferential surface and a first outer tooth circumferential surface, the first inner circumferential surface being drive-connected to the first eccentric circumferential surface; a first linkage member disposed between the base housing and the first cycloidal gear, the first linkage member being movable relative to the first cycloidal gear along a second direction, and being movable relative to the base housing along a third direction; wherein the first direction, the second direction, and the third direction are perpendicular to each other; an output housing rotatably connected to the base housing, the output housing having a transmission inner circumferential surface, the transmission inner circumferential surface being disposed opposite to the first outer tooth circumferential surface; and N first needle rollers disposed between the transmission inner circumferential surface and the first outer tooth circumferential surface.

Description

Technical Field

[0001] This invention relates to the field of speed reducers, and particularly to speed reducers. Background Technology

[0002] Reducers are core components of industrial robots, typically used in drive joints or rotating parts. The performance of the reducer largely determines the robot's precision, rigidity, and lifespan. Currently, most reducers used in these applications are harmonic reducers or RV reducers. Harmonic reducers generally have lower rigidity and cannot handle large loads; RV reducers are generally larger and heavier, and their input ends typically use keyed shaft or gear shaft structures. These two input structures inherently have certain clearances, thus sacrificing some transmission accuracy. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a speed reducer that can improve transmission accuracy and service life.

[0004] A speed reducer according to an embodiment of the present invention includes:

[0005] A base housing for connecting a motor housing, the base housing having mounting holes for inserting the output shaft of the motor;

[0006] An eccentric shaft is rotatably connected to the inner circumferential surface of the mounting hole. The eccentric shaft can be coaxially connected to the output shaft along a first direction. The eccentric shaft has a first eccentric circumferential surface.

[0007] A first cycloidal gear is disposed within the base shell. The first cycloidal gear has a first inner circumferential surface and a first outer tooth circumferential surface. The first inner circumferential surface is connected to the first eccentric circumferential surface.

[0008] A first linkage is disposed between the base shell and the first cycloidal gear. The first linkage is capable of moving relative to the first cycloidal gear in a second direction and relative to the base shell in a third direction.

[0009] Wherein, the first direction, the second direction, and the third direction are perpendicular to each other;

[0010] An output housing is rotatably connected to the base housing. The output housing has a transmission inner circumferential surface, which is disposed opposite to the first external tooth circumferential surface.

[0011] N first needle rollers are driven between the inner circumferential surface of the transmission and the circumferential surface of the first outer tooth;

[0012] The output housing is configured such that when the eccentric shaft rotates one revolution, the first cycloidal gear performs a non-rotating cycloidal motion and drives the output housing to rotate by an angle corresponding to the pitch of the first needle roller through the first needle roller.

[0013] The speed reducer according to embodiments of the present invention has at least the following beneficial effects:

[0014] 1. The base shell is directly fixed to the motor housing, which allows the eccentric shaft to be directly connected to the motor output shaft, thereby shortening the transmission distance, improving transmission accuracy, and making the overall size of the reducer and motor smaller after assembly, occupying less space and improving space utilization.

[0015] 2. When the motor output shaft drives the eccentric shaft to rotate around the first direction, the first eccentric circumferential surface of the eccentric shaft rotates eccentrically and drives the first cycloidal gear to move. The first cycloidal gear is guided by the first linkage and makes a non-rotating cycloidal motion along the second and third directions. The first cycloidal gear drives the first needle roller to rotate through the cycloidal motion, which in turn drives the output housing to rotate. When the eccentric shaft rotates one revolution, the output housing rotates by the angle corresponding to the pitch of a single first needle roller, thereby achieving deceleration. The first cycloidal gear does not need to rotate to achieve the rotation of the output housing, which simplifies the overall assembly and effectively reduces the size and weight of the reducer.

[0016] 3. The first cycloidal gear can move relative to the first linkage member in the second direction. The first cycloidal gear can also move together with the first linkage member relative to the base shell in the third direction. The first cycloidal gear achieves cycloidal movement in the second and third directions through the guidance of the first linkage member, making the movement of the cycloidal gear more precise and the transmission accuracy higher.

[0017] 4. There is no direct contact between the first cycloidal gear and the base shell, thus avoiding friction between the first cycloidal gear and the base shell. Furthermore, there is a relative movement stroke between the first cycloidal gear and the first linkage, which reduces the friction between them. This eliminates the frictional heat between the first cycloidal gear and the base shell and reduces the frictional heat between the first cycloidal gear and the first linkage, thereby reducing the wear of the reducer and increasing its service life.

[0018] According to some embodiments of the present invention, the eccentric shaft has a second eccentric circumferential surface, and the second eccentric circumferential surface and the first eccentric circumferential surface are distributed sequentially along the first direction;

[0019] The reducer also includes:

[0020] A second cycloidal gear is disposed within the base shell. The second cycloidal gear has a second inner circumferential surface and a second outer tooth circumferential surface. The second inner circumferential surface is driven to the second eccentric circumferential surface. The second outer tooth circumferential surface can eccentrically oscillate. The second outer tooth circumferential surface is driven to the output housing through N second needle rollers.

[0021] The second linkage is disposed between the base shell and the second cycloidal gear. The second linkage is capable of moving relative to the base shell in a second direction and relative to the second cycloidal gear in a third direction.

[0022] According to some embodiments of the present invention, the base shell comprises:

[0023] Wheel seat, having a first connecting part;

[0024] A pressure cap having a second connecting portion, the second connecting portion being aligned along the first direction and connected to the first connecting portion;

[0025] The wheel seat, the first linkage component, the first cycloidal gear, the second cycloidal gear, the second linkage component, and the pressure cap are distributed sequentially along the first direction;

[0026] The first cycloidal gear passes through the first connecting portion and is movable relative to the first connecting portion along the second direction and the third direction; the second cycloidal gear passes through the second connecting portion and is movable relative to the second connecting portion along the second direction and the third direction.

[0027] According to some embodiments of the present invention, the difference between the circumferential positions of the first eccentric circumferential surface and the second eccentric circumferential surface along the circumferential direction of the eccentric axis is X, and the reducer satisfies: X = 180°.

[0028] According to some embodiments of the present invention, the first external tooth circumferential surface includes N+1 tooth circumferential surfaces.

[0029] According to some embodiments of the present invention, the first linkage includes a first surface relative to the first cycloidal gear and a first guide portion disposed on the first surface and along the second direction. The first cycloidal gear includes a first end face relative to the first surface and a second guide portion disposed on the first end face and along the second direction. The first guide portion and the second guide portion are guided and engaged along the second direction.

[0030] According to some embodiments of the present invention, the first guide portion includes a plurality of first grooves disposed on the first surface, and the plurality of first grooves are arranged side by side along the second direction;

[0031] The second guide portion includes a plurality of first sliders protruding from the first end face, the plurality of first sliders being arranged side by side along the second direction, and the first sliders being slidably disposed in a first groove along the second direction.

[0032] According to some embodiments of the present invention, the first linkage member includes a second surface relative to the base shell and a third guide portion disposed on the second surface and along the third direction. The base shell includes a first inner end surface relative to the second surface and a fourth guide portion disposed on the first inner end surface and along the third direction. The third guide portion and the fourth guide portion guide and cooperate with each other along the third direction.

[0033] According to some embodiments of the present invention, the first eccentric circumferential surface is provided with a first rotating groove along the circumferential direction of the eccentric shaft, and the first inner circumferential surface is provided with a second rotating groove along the circumferential direction of the first cycloidal gear. The first rotating groove and the second rotating groove are slidably connected by a plurality of rolling elements, and the first eccentric circumferential surface is capable of rotating relative to the first inner circumferential surface.

[0034] According to some embodiments of the present invention, the eccentric shaft has a connecting hole for connecting to the outer peripheral surface of the output shaft;

[0035] The reducer also includes a shrink sleeve, which is disposed on the inner circumferential surface of the connecting hole and is used to interference fit the inner circumferential surface of the connecting hole and the outer circumferential surface of the output shaft.

[0036] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0038] Figure 1 This is a cross-sectional schematic diagram of a speed reducer mounted on a motor according to an embodiment of the present invention;

[0039] Figure 2 This is a cross-sectional schematic diagram of a speed reducer according to an embodiment of the present invention;

[0040] Figure 3 This is a top cross-sectional view of a speed reducer according to an embodiment of the present invention;

[0041] Figure 4 This is an exploded view of a speed reducer according to an embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of the eccentric shaft in a speed reducer according to an embodiment of the present invention;

[0043] Figure 6 This is an exploded structural diagram of the wheel seat, the first linkage component, and the first cycloidal gear in a reducer according to an embodiment of the present invention;

[0044] Figure 7 This is a schematic diagram of the assembly structure of the wheel seat and the first linkage component in a reducer according to an embodiment of the present invention;

[0045] Figure 8 This is a schematic diagram of the assembly structure of the intermediate wheel seat, the first linkage component and the first cycloidal gear in a reducer according to an embodiment of the present invention.

[0046] Icon labels:

[0047] Motor 10; Output shaft 11;

[0048] Base shell 100; wheel seat 110; first connecting part 111; pressure cap 120; second connecting part 121; locking hole 130; bolt 140; fourth guide part 150;

[0049] Eccentric shaft 200; First eccentric circumferential surface 210; First rotating groove 211; Rolling element 212; Second eccentric circumferential surface 220; Connecting hole 230; Half bearing 240;

[0050] First cycloidal gear 300; first inner circumferential surface 310; second rotating groove 311; first outer tooth circumferential surface 320; second guide portion 330;

[0051] First linkage component 400; First guide part 410; Third guide part 420;

[0052] Output housing 500; Rotary bearing 510; Sealing ring 520;

[0053] First needle roller 600;

[0054] Second cycloidal gear 700;

[0055] Second linkage component 800;

[0056] 900mm expansion sleeve. Detailed Implementation

[0057] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown 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 are only used to explain the present invention, and should not be construed as limiting the present invention.

[0058] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0059] In the description of this invention, "several" refers to one or more, and "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0060] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0061] It should be noted that harmonic reducers typically have relatively low rigidity and cannot handle large loads; RV reducers are generally larger and heavier. Traditional harmonic reducers and RV reducers generally cannot be directly connected to the motor, but must be connected through an adapter plate. For example, the input end of an RV reducer generally uses a key shaft structure or a gear shaft input structure. These two input structures inherently have a certain clearance, which will result in a loss of some transmission accuracy.

[0062] Reference Figures 1 to 8 As shown in the figure, an embodiment of the present invention proposes a speed reducer, including: a base housing 100, an eccentric shaft 200, a first cycloidal gear 300, a first linkage 400, an output housing 500, and N first needle rollers 600.

[0063] The base housing 100 is used to connect the housing of the motor 10, and the base housing 100 has a mounting hole for inserting the output shaft 11 of the motor 10.

[0064] In this embodiment, refer to Figure 1 and Figure 2 As shown, the base shell 100 includes a wheel seat 110 and a cover 120. The wheel seat 110 and the cover 120 are spaced apart, and the space between them forms an installation space for other parts. The wheel seat 110 and the cover 120 are basically disc-shaped, and the ends of the wheel seat 110 and the ends of the cover 120 are aligned along a first direction. The middle part of the wheel seat 110 and the cover 120 are provided with through holes, and the wheel seat 110 and the cover 120 are aligned to form an installation hole.

[0065] The wheel seat 110 and the pressure cover 120 are fixed together to the housing of the motor 10 by bolts 140, and the output shaft 11 of the motor 10 is located inside the mounting hole.

[0066] It is worth noting that there is no need for any other structure to connect the reducer and the output shaft 11 of the motor 10. Furthermore, the base shell 100 is directly fixed to the outer shell of the motor 10, which allows the eccentric shaft 200 to be directly connected to the output shaft 11 of the motor 10. This shortens the transmission distance and improves the transmission accuracy. At the same time, the overall size of the reducer and the motor 10 after assembly is smaller and occupies less space, thus improving space utilization.

[0067] Reference Figure 2 and Figure 3 As shown, the eccentric shaft 200 is rotatably connected to the inner circumferential surface of the mounting hole. The eccentric shaft 200 can be coaxially connected to the output shaft 11 along the first direction. The eccentric shaft 200 has a first eccentric circumferential surface 210.

[0068] The eccentric shaft 200 is installed in the mounting hole and connected to the output shaft 11. When the output shaft 11 rotates, the eccentric shaft 200 rotates relative to the base shell 100 and the mounting hole to realize the transmission of power. The first eccentric circumferential surface 210 of the eccentric shaft 200 will also undergo eccentric motion.

[0069] The first eccentric circumferential surface 210 refers to a circular outer circumferential surface, but the center line of the circular surface does not coincide with the axis of rotation. During the rotation, the first eccentric circumferential surface 210 will make an eccentric oscillation similar to the motion of a cam.

[0070] Specifically, refer to Figure 2 , Figure 3 and Figure 5 As shown, the outer peripheral surfaces of both ends of the eccentric shaft 200 are connected to the inner peripheral surfaces of the mounting holes via half-bearings 240. One end of the eccentric shaft 200 abuts against the wheel seat 110 or the pressure cap 120, or the eccentric shaft 200 is suspended within the mounting area by a bearing structure. Each of the outer peripheral surfaces of the eccentric shaft 200 has a sliding step surface. A first sliding groove is provided at the junction of the sliding step surface and the outer peripheral surface of the eccentric shaft 200. The first sliding groove replaces the inner ring of the bearing and contacts the balls of the half-bearing 240, forming a structure similar to a sliding bearing between the wheel seat 110 and the eccentric shaft 200, thus reducing friction. Simultaneously, a second sliding groove also forms a structure similar to a sliding bearing between the pressure cap 120 and the eccentric shaft 200, further reducing friction. Furthermore, compared to directly setting a single bearing between the eccentric shaft 200 and the wheel seat 110, the first sliding groove of the eccentric shaft 200 replaces the inner ring of the single bearing, making the size between the eccentric shaft 200 and the wheel seat 110 smaller, which is more conducive to reducing the overall size of the reducer.

[0071] A first cycloidal gear 300 is disposed within the base shell 100. The first cycloidal gear 300 has a first inner circumferential surface 310 and a first outer tooth circumferential surface 320. The first inner circumferential surface 310 is drively connected to a first eccentric circumferential surface 210. A first linkage member 400 is disposed between the base shell 100 and the first cycloidal gear 300. The first linkage member 400 is movable relative to the first cycloidal gear 300 in a second direction and is movable relative to the base shell 100 in a third direction; wherein the first direction, the second direction, and the third direction are perpendicular to each other.

[0072] In this embodiment, refer to Figure 6 , Figure 7 and Figure 8 As shown, the first cycloidal gear 300 is guided and restricted by the first linkage 400, causing the first cycloidal gear 300 to move along the second direction and the third direction. The first cycloidal gear 300 can also perform a composite motion along the second direction and the third direction. When the first cycloidal gear 300 is powered by the eccentric shaft 200, the first cycloidal gear 300 performs a non-rotational cycloidal motion. The non-rotational cycloidal motion means that the first cycloidal gear 300 does not rotate. The second direction and the third direction have an upper end, a left end, a lower end, and a right end, respectively. The first cycloidal gear 300 will extend and retract sequentially at the four ends in a clockwise or counterclockwise direction to achieve cycloidal motion.

[0073] Reference Figure 2 and Figure 3 As shown, the output housing 500 is rotatably connected to the base housing 100. The output housing 500 has a transmission inner circumferential surface, which is disposed opposite to the first external tooth circumferential surface 320. N first needle rollers 600 are driven between the transmission inner circumferential surface and the first external tooth circumferential surface 320.

[0074] In this embodiment, the two ends of the output housing 500 along the first direction are connected to the wheel seat 110 and the pressure cap 120 respectively via two rotating bearings 510. A sealing ring 520 is also provided between the wheel seat 110, the output housing 500, and the rotating bearings 510 between them to seal the lubricating grease inside the output housing 500 and prevent leakage; sealing rings 520 can also be provided between the pressure cap 120, the wheel seat 110, the output housing 500, and the rotating bearings 510 between them.

[0075] In this system, the first cycloidal gear 300 performs a cycloidal motion, driving the first needle roller 600 to move. The first needle roller 600 then rotates the output housing 500. The output housing 500 is configured such that when the eccentric shaft 200 rotates one revolution, the first cycloidal gear 300 performs a non-rotating cycloidal motion, driving the output housing 500 to rotate by an angle corresponding to the pitch of the first needle roller 600. Therefore, the transmission ratio of the reducer is 1:N, meaning that for every N revolutions the eccentric shaft 200 rotates, the output housing 500 rotates one full revolution, achieving speed reduction.

[0076] It is understandable that when the output shaft 11 of the motor 10 drives the eccentric shaft 200 to rotate around the first direction, the first eccentric circumferential surface 210 of the eccentric shaft 200 rotates eccentrically and drives the first cycloidal gear 300 to move. The first cycloidal gear 300 is guided by the first linkage 400 and makes a non-rotating cycloidal motion along the second and third directions. The first cycloidal gear 300 drives the first needle roller 600 to rotate through the cycloidal motion, which in turn drives the output housing 500 to rotate. When the eccentric shaft 200 rotates one revolution, the output housing 500 rotates by the angle corresponding to the pitch of a single first needle roller 600, thereby achieving deceleration. The first cycloidal gear 300 does not need to rotate to achieve the rotation of the output housing 500, which simplifies the overall assembly and effectively reduces the size and weight of the reducer.

[0077] The first cycloidal gear 300 can move relative to the first linkage 400 in a second direction, and can also move together with the first linkage 400 relative to the base shell 100 in a third direction. The first cycloidal gear 300 achieves cycloidal movement in the second and third directions through the guidance of the first linkage 400, making the movement of the cycloidal gear more precise and the transmission accuracy higher. There is no direct contact between the first cycloidal gear 300 and the base shell 100, thus avoiding friction between the first cycloidal gear 300 and the base shell 100. Furthermore, the relative movement stroke between the first cycloidal gear 300 and the first linkage 400 reduces the friction between them. This eliminates frictional heat between the first cycloidal gear 300 and the base shell 100 and reduces frictional heat between the first cycloidal gear 300 and the first linkage 400, thereby reducing wear on the reducer and increasing its service life.

[0078] Reference Figure 2 , Figure 4 and Figure 5 As shown, in some specific embodiments of the present invention, the eccentric shaft 200 has a second eccentric circumferential surface 220, and the second eccentric circumferential surface 220 and the first eccentric circumferential surface 210 are distributed sequentially along a first direction;

[0079] The reducer also includes: a second cycloidal gear 700 and a second linkage member 800. The second cycloidal gear 700 is disposed within the base housing 100. The second cycloidal gear 700 has a second inner circumferential surface and a second outer tooth circumferential surface. The second inner circumferential surface is drivenly connected to the second eccentric circumferential surface 220. The second outer tooth circumferential surface can eccentrically oscillate. The second outer tooth circumferential surface is drivenly connected to the output housing 500 through N second needle rollers. The second linkage member 800 is disposed between the base housing 100 and the second cycloidal gear 700. The second linkage member 800 can move relative to the base housing 100 in a second direction and can move relative to the second cycloidal gear 700 in a third direction.

[0080] Furthermore, the difference in circumferential position between the first eccentric circumferential surface 210 and the second eccentric circumferential surface 220 along the circumferential direction of the eccentric axis 200 is X, and the reducer satisfies: X=180°.

[0081] In this embodiment, the specific movement of the second cycloidal gear 700 and the second linkage 800 is the same as that of the first cycloidal gear 300 and the first linkage 400, and will not be described again here. The difference between the two is that the circumferential position difference between the first eccentric circumferential surface 210 and the second eccentric circumferential surface 220 along the circumferential direction of the eccentric shaft 200 is 180°, so the circumferential position difference between the first cycloidal gear 300 and the second cycloidal gear 700 along the circumferential direction of the eccentric shaft 200 is also 180°. Therefore, the eccentric force generated by the first cycloidal gear 300 and the eccentric force generated by the second cycloidal gear 700 are exactly opposite and basically the same in magnitude, so that the output shaft 11 of the motor 10 can be in a state of force balance, thereby reducing the off-center load of the output shaft 11, improving the service life of the output shaft 11 of the motor 10, and making the reducer less prone to damage.

[0082] Reference Figure 2 , Figure 3 and Figure 4 As shown, in some specific embodiments of the present invention, the base shell 100 includes: a wheel seat 110 and a pressure cap 120.

[0083] Wheel seat 110 has a first connecting part 111;

[0084] The pressure cap 120 has a second connecting portion 121, which is aligned along a first direction and connected to the first connecting portion 111;

[0085] Among them, the wheel seat 110, the first linkage 400, the first cycloidal gear 300, the second cycloidal gear 700, the second linkage 800, and the pressure cover 120 are distributed sequentially along the first direction;

[0086] The first cycloidal gear 300 passes through the first connecting part 111 and is able to move relative to the first connecting part 111 in the second direction and the third direction; the second cycloidal gear 700 passes through the second connecting part 121 and is able to move relative to the second connecting part 121 in the second direction and the third direction.

[0087] In this embodiment, the wheel seat 110 and the pressure cap 120 are connected via a first connecting part 111 and a second connecting part 121. The first connecting part 111 has a through hole along the axial direction of the mounting hole, and the second connecting part 121 also has a through hole along the axial direction of the mounting hole. After the wheel seat 110 and the pressure cap 120 are assembled, the through holes of the first connecting part 111 and the second connecting part 121 are aligned to form a locking hole 130. Bolts 140 and other connecting parts can pass through the locking hole 130 and be locked onto the housing of the motor 10, thereby fixing the reducer to the housing of the motor 10 and making the connection between the reducer and the motor 10 more reliable. The locking holes 130 are multiple and evenly spaced along the axial direction of the mounting hole to ensure a uniform distribution of the locking force between the reducer and the motor 10.

[0088] The first cycloidal gear 300 passes through the first connecting part 111, and there is a large gap between the first cycloidal gear 300 and the first connecting part 111, so that the first cycloidal gear 300 can move to the limit position relative to the first connecting part 111 in the second direction and the third direction. In other words, the first connecting part 111 will not affect the cycloidal motion of the first cycloidal gear 300, so that the first cycloidal gear 300 can smoothly drive the output housing 500 to rotate. Furthermore, the first cycloidal gear 300 will not collide or rub against the first connecting part 111 during the cycloidal motion, thus preventing damage. The structure of the second cycloidal gear 700 passing through the second connecting part 121 is the same as the structure of the first cycloidal gear 300 passing through the first connecting part 111, and will not be described again here. However, it should be noted that the first cycloidal gear 300, the second cycloidal gear 700, the first connecting part 111 and the second connecting part 121 all adopt the same structure. The reducer can be regarded as a central axis symmetrical structure, so that the center of gravity of the reducer is basically coincident with the center line. The reducer has less eccentric force due to its own weight distribution, and the eccentric load on the output shaft 11 is less affected, which can improve the service life of the reducer and the motor 10.

[0089] Reference Figure 3 As shown, in some specific embodiments of the present invention, the first external tooth circumferential surface 320 includes N+1 tooth circumferential surfaces. In this embodiment, the first external tooth circumferential surface 320 drives the first needle roller 600 through the N+1 tooth circumferential surfaces, so that the first needle roller 600 can drive the output housing 500 to rotate under the drive of the first external tooth circumferential surface 320.

[0090] Reference Figure 6 , Figure 7 and Figure 8 As shown, in some embodiments of the present invention, the first linkage 400 includes a first surface relative to the first cycloidal gear 300 and a first guide portion 410 disposed on the first surface and along a second direction. The first cycloidal gear 300 includes a first end face relative to the first surface and a second guide portion 330 disposed on the first end face and along a second direction. The first guide portion 410 and the second guide portion 330 are guided and engaged along the second direction.

[0091] In this embodiment, the first linkage 400 and the first cycloidal gear 300 are guided and engaged in the second direction by the first guide part 410 and the second guide part 330, so that the first cycloidal gear 300 can move in the second direction.

[0092] Furthermore, in some specific embodiments of the present invention, the first guide portion 410 includes a plurality of first slide grooves disposed on the first surface, the plurality of first slide grooves being arranged in parallel along the second direction; the second guide portion 330 includes a plurality of first sliders protruding from the first end surface, the plurality of first sliders being arranged in parallel along the second direction, and the first sliders being slidably disposed in a first slide groove along the second direction.

[0093] In this embodiment, the first linkage 400 and the first cycloidal gear 300 move along the second direction through the guiding cooperation of the first slide groove and the first slider. The reducer is also filled with grease, which lubricates the first slider and the first slide groove, thereby reducing friction and heat generation. The number of first slide grooves and the number of first sliders can be one or more. When there are multiple first slide grooves and multiple first sliders, the relative movement of the first linkage 400 and the first cycloidal gear 300 along the second direction is more precise. The first cycloidal gear 300 can move accurately relative to the first linkage 400 along the second direction, resulting in higher overall transmission accuracy of the reducer.

[0094] Alternatively, the first guide part 410 can be the first slider and the second guide part 330 can be the first slide groove. The specific arrangement can be selected according to actual needs.

[0095] As another implementation, the first guide portion 410 and the second guide portion 330 can also move along the second direction through the structure of a linear guide rail. The first guide portion 410 can be a linear slide rail, and the second guide portion 330 can be a slider that slides along the linear slide rail in the second direction, or the second guide portion 330 can be a linear slide rail, and the first guide portion 410 can be a slider.

[0096] Reference Figure 6 , Figure 7 and Figure 8As shown, in some specific embodiments of the present invention, the first linkage member 400 includes a second surface relative to the base shell 100 and a third guide portion 420 disposed on the second surface and along a third direction. The base shell 100 includes a first inner end surface relative to the second surface and a fourth guide portion 150 disposed on the first inner end surface and along a third direction. The third guide portion 420 and the fourth guide portion 150 are guided and engaged along a third direction.

[0097] In this embodiment, the base shell 100 includes a wheel seat 110 and a pressure cap 120. The side of the wheel seat 110 opposite to the pressure cap 120 is a first inner end face. The first inner end face has a fourth guide portion 150. The first linkage member 400 and the wheel seat 110 are guided and engaged in a third direction by the third guide portion 420 and the fourth guide portion 150, so that the first linkage member 400 can move relative to the base shell 100 in a third direction. In other words, the first cycloidal gear 300 can move relative to the base shell 100 in a third direction together with the first linkage member 400, thereby realizing the movement of the first cycloidal gear 300 in a third direction.

[0098] The guiding and mating structure of the third guide section 420 and the fourth guide section 150 is the same as that of the first guide section 410 and the second guide section 330, and will not be described again here.

[0099] Reference Figure 4 As shown, in some embodiments of the present invention, the second linkage 800 includes a third surface relative to the second cycloidal gear 700 and a fifth guide portion disposed on the third surface and along the second direction. The second cycloidal gear 700 includes a second end surface relative to the third surface and a sixth guide portion disposed on the second end surface and along the second direction. The fifth guide portion and the sixth guide portion are guided and engaged along the second direction.

[0100] In this embodiment, the second linkage 800 and the second cycloidal gear 700 are guided and engaged in the second direction by the fifth guide part and the sixth guide part, so that the second cycloidal gear 700 can move in the second direction.

[0101] Furthermore, in some specific embodiments of the present invention, the fifth guide portion includes a plurality of second slide grooves disposed on the first surface, the plurality of second slide grooves being arranged in parallel along the second direction; the sixth guide portion includes a plurality of second sliders protruding from the second end surface, the plurality of second sliders being arranged in parallel along the second direction, and the second sliders being slidably disposed in a second slide groove along the second direction.

[0102] In this embodiment, the second linkage 800 and the second cycloidal gear 700 move along the second direction through the guiding engagement of the second slide groove and the second slider. The reducer is also filled with grease, which lubricates the second slider and the second slide groove, thereby reducing friction and heat. The number of second slide grooves and second sliders can be one or more. When there are multiple second slide grooves and multiple second sliders, the relative movement of the second linkage 800 and the second cycloidal gear 700 along the second direction is more precise. The second cycloidal gear 700 can move accurately relative to the second linkage 800 along the second direction, resulting in higher overall transmission accuracy of the reducer.

[0103] Alternatively, the fifth guide section can be the second slider, and the sixth guide section can be the second slide groove. The specific arrangement can be selected according to actual needs.

[0104] As another implementation, the fifth guide part and the sixth guide part can also move along the second direction through the structure of a linear guide rail. The fifth guide part can be a linear slide rail, and the sixth guide part can be a slider that slides along the linear slide rail in the second direction, or the sixth guide part can be a linear slide rail and the fifth guide part can be a slider.

[0105] Reference Figure 4 As shown, in some specific embodiments of the present invention, the second linkage member 800 includes a fourth surface relative to the base shell 100 and a seventh guide portion disposed on the fourth surface and along a third direction. The base shell 100 includes a second inner end surface relative to the fourth surface and an eighth guide portion disposed on the second inner end surface and along a third direction. The seventh guide portion and the eighth guide portion guide and cooperate along a third direction.

[0106] In this embodiment, the base shell 100 includes a wheel seat 110 and a cover 120. The side of the wheel seat 110 opposite to the cover 120 is a second inner end face. The second inner end face has an eighth guide portion. The second linkage member 800 and the wheel seat 110 are guided and engaged in a third direction by the seventh guide portion and the eighth guide portion, so that the second linkage member 800 can move relative to the base shell 100 in a third direction. In other words, the second cycloidal gear 700 can move relative to the base shell 100 in a third direction together with the second linkage member 800, thereby realizing the movement of the second cycloidal gear 700 in a third direction.

[0107] Reference Figure 5As shown, in some specific embodiments of the present invention, the first eccentric circumferential surface 210 is provided with a first rotating groove 211 along the circumferential direction of the eccentric shaft 200, and the first inner circumferential surface 310 is provided with a second rotating groove 311 along the circumferential direction of the first cycloidal gear 300. The first rotating groove 211 and the second rotating groove 311 are slidably connected by a plurality of rolling elements 212, and the first eccentric circumferential surface 210 can rotate relative to the first inner circumferential surface 310.

[0108] It is understandable that the first eccentric peripheral surface 210 of the eccentric shaft 200 and the first inner peripheral surface 310 of the first cycloidal gear 300 are slidably connected by a rolling element 212. When the first cycloidal gear 300 is subjected to the eccentric rotational thrust applied by the eccentric shaft 200, the rolling element 212 reduces the friction between the eccentric shaft 200 and the first cycloidal gear 300, thus reducing wear and frictional heat. Simultaneously, the rolling element 212 absorbs the rotational kinetic energy of the eccentric shaft 200, allowing the eccentric shaft 200 and the rolling element 212 to rotate together relative to the first cycloidal gear 300. Since the first cycloidal gear 300 is mainly subjected to linear thrust along the second and third directions, the absorption of rotational kinetic energy by the rolling element 212 makes the first cycloidal gear 300 less prone to damage, thereby increasing its service life.

[0109] It should be noted that the first eccentric circumferential surface 210 has a first rotating groove 211, and the first cycloidal gear 300 has a second rotating groove 311. A rolling element 212 is provided between the first rotating groove 211 and the second rotating groove 311, and the rotation of the eccentric shaft 200 relative to the first cycloidal gear 300 is realized through the rolling element 212, making the overall local area of ​​the eccentric shaft 200 and the first cycloidal gear 300 more compact. Furthermore, the eccentric rotation of the eccentric shaft 200 is transmitted through the rolling element 212 as a composite motion of the first cycloidal gear 300 along a second direction and a third direction, realizing the non-rotational cycloidal motion of the first cycloidal gear 300. In this embodiment, the rolling element 212 is a ball, the first rotating groove 211 is an arc groove, and the second rotating groove 311 is also an arc groove.

[0110] Reference Figure 1 and Figure 5 As shown, in some specific embodiments of the present invention, the eccentric shaft 200 has a connecting hole 230 for connecting the outer peripheral surface of the output shaft 11; the reducer also includes a shrink sleeve 900 disposed on the inner peripheral surface of the connecting hole 230 and used for interference connection between the inner peripheral surface of the connecting hole 230 and the outer peripheral surface of the output shaft 11.

[0111] In this embodiment, the output shaft 11 is inserted into the connecting hole 230 of the eccentric shaft 200, and the gap between the output shaft 11 and the eccentric shaft 200 is eliminated by the expansion sleeve 900, so that the connection between the outer peripheral surface of the output shaft 11 and the inner peripheral surface of the connecting hole 230 of the eccentric shaft 200 is tighter, thereby improving the stability of the power transmission of the output shaft 11 and making the power transmission more stable.

[0112] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A speed reducer, characterized in that, include: A base housing for connecting a motor housing, the base housing having mounting holes for inserting the output shaft of the motor; An eccentric shaft is rotatably connected to the inner circumferential surface of the mounting hole. The eccentric shaft can be coaxially connected to the output shaft along a first direction. The eccentric shaft has a first eccentric circumferential surface. A first cycloidal gear is disposed within the base shell. The first cycloidal gear has a first inner circumferential surface and a first outer tooth circumferential surface. The first inner circumferential surface is connected to the first eccentric circumferential surface. A first linkage is disposed between the base shell and the first cycloidal gear. The first linkage is capable of moving relative to the first cycloidal gear in a second direction and relative to the base shell in a third direction. Wherein, the first direction, the second direction, and the third direction are perpendicular to each other; An output housing is rotatably connected to the base housing. The output housing has a transmission inner circumferential surface, which is disposed opposite to the first external tooth circumferential surface. N first needle rollers are driven between the inner circumferential surface of the transmission and the circumferential surface of the first outer tooth; The output housing is configured such that when the eccentric shaft rotates one revolution, the first cycloidal gear performs a non-rotating cycloidal motion and drives the output housing to rotate by an angle corresponding to the pitch of the first needle roller through the first needle roller. The eccentric shaft has a second eccentric circumferential surface, and the second eccentric circumferential surface and the first eccentric circumferential surface are distributed sequentially along the first direction; The reducer also includes: A second cycloidal gear is disposed within the base shell. The second cycloidal gear has a second inner circumferential surface and a second outer tooth circumferential surface. The second inner circumferential surface is driven to the second eccentric circumferential surface. The second outer tooth circumferential surface can eccentrically oscillate. The second outer tooth circumferential surface is driven to the output housing through N second needle rollers. The second linkage is disposed between the base shell and the second cycloidal gear. The second linkage can move relative to the base shell in a second direction and can move relative to the second cycloidal gear in a third direction. The first linkage includes a first surface relative to the first cycloidal gear and a first guide portion disposed on the first surface and along the second direction. The first cycloidal gear includes a first end face relative to the first surface and a second guide portion disposed on the first end face and along the second direction. The first guide portion and the second guide portion are guided and engaged along the second direction.

2. The reducer according to claim 1, characterized in that, The base shell includes: Wheel seat, having a first connecting part; A pressure cap having a second connecting portion, the second connecting portion being aligned along the first direction and connected to the first connecting portion; The wheel seat, the first linkage component, the first cycloidal gear, the second cycloidal gear, the second linkage component, and the pressure cap are distributed sequentially along the first direction; The first cycloidal gear passes through the first connecting portion and is movable relative to the first connecting portion along the second direction and the third direction; the second cycloidal gear passes through the second connecting portion and is movable relative to the second connecting portion along the second direction and the third direction.

3. The reducer according to claim 1, characterized in that: The difference in circumferential position between the first eccentric circumferential surface and the second eccentric circumferential surface along the circumferential direction of the eccentric axis is X, and the reducer satisfies: X = 180°.

4. The reducer according to claim 1, characterized in that: The first external tooth circumferential surface includes N+1 tooth circumferential surfaces.

5. The reducer according to claim 1, characterized in that: The first guide portion includes a plurality of first grooves disposed on the first surface, and the plurality of first grooves are arranged side by side along the second direction; The second guide portion includes a plurality of first sliders protruding from the first end face, the plurality of first sliders being arranged side by side along the second direction, and the first sliders being slidably disposed in a first groove along the second direction.

6. The reducer according to claim 1, characterized in that: The first linkage includes a second surface relative to the base shell and a third guide portion disposed on the second surface and along the third direction. The base shell includes a first inner end surface relative to the second surface and a fourth guide portion disposed on the first inner end surface and along the third direction. The third guide portion and the fourth guide portion guide and cooperate with each other along the third direction.

7. The reducer according to claim 1, characterized in that: The first eccentric circumferential surface is provided with a first rotating groove along the circumferential direction of the eccentric shaft, and the first inner circumferential surface is provided with a second rotating groove along the circumferential direction of the first cycloidal gear. The first rotating groove and the second rotating groove are slidably connected by a plurality of rolling elements, and the first eccentric circumferential surface can rotate relative to the first inner circumferential surface.

8. The reducer according to claim 1, characterized in that: The eccentric shaft has a connecting hole for connecting to the outer peripheral surface of the output shaft; The reducer also includes a shrink sleeve, which is disposed on the inner circumferential surface of the connecting hole and is used to interference fit the inner circumferential surface of the connecting hole and the outer circumferential surface of the output shaft.

Images