Planetary cycloid pin wheel coupling cascade speed reducer

Abstract

The application discloses a planetary cycloid pin wheel coupling cascade speed reducer. The speed reducer comprises a planetary gear reducer, a sun gear for accepting external high-speed rotating power input, a planet carrier for power output and an outer gear ring located at the periphery of the central sun gear; a cycloid pin wheel reducer, the input end of which is connected with the planet carrier in transmission, and the output end of which is fixed with the outer ring sun gear, so that the outer gear ring finally generates low-speed rotating power output 。 The speed reducer adopts two-stage speed reduction coupling, reduces the space occupation of the speed reduction structure in the axial direction of the speed reducer, and thus has a small thickness. The output cage structure penetrates through the machine body, and the output structure has great rigidity and strong overload capacity.

Description

Technical Field

[0001] This application relates to the technical field of speed reducers, and more particularly to a planetary cycloidal pinwheel coupled cascade speed reducer. Background Technology

[0002] For robotic arm joints, which are characterized by high torque and low speed, high torque joints often require reducers with large reduction ratios to meet the load-bearing requirements. Currently, the main reducers used in the robotics industry are harmonic reducers and cycloidal pinwheel reducers. Harmonic reducers can achieve large reduction ratios in a single stage, but their overload resistance is weak, making them only suitable for low-load applications. Cycloidal pinwheel reducers feature high rigidity and high overload capacity, but their reduction ratio is directly related to the reducer diameter, making it difficult to achieve large reduction ratios with small dimensions. Therefore, cycloidal pinwheel reducers often employ multi-stage reduction.

[0003] Currently, Chinese invention patent CN113565932A discloses a cycloidal planetary gear reducer mechanism, which employs a symmetrical cycloidal ball reducer (single-stage harmonic reducer) and a single-stage planetary gear reducer. Through cascading, it achieves an effect similar to an RV reducer while ensuring smooth operation. However, on the high-speed side, there is significant sliding friction between the steel balls and their mating parts, which greatly limits the rated input speed of the reducer. Furthermore, the point contact engagement of the steel balls also significantly limits the input torque of the reducer. Summary of the Invention

[0004] In view of this, this application provides a planetary cycloidal pinwheel coupled cascade reducer, which can improve the reduction ratio, and the increase in the reduction ratio also increases the output torque.

[0005] This application provides a planetary cycloidal pinwheel coupled cascade reducer, comprising:

[0006] A planetary gear reducer has a sun gear for receiving high-speed rotating power input from the outside, a planet carrier for power output, and an external gear ring located around the central sun gear;

[0007] A cycloidal pinwheel reducer has its input end connected to the planetary carrier and its output end fixed to the external gear ring, so that the external gear ring ultimately generates low-speed rotational power output.

[0008] Optionally, the external gear ring is fixedly mounted on the second shaft output bearing, which is used to transmit the low-speed rotational power output.

[0009] Optionally, it also includes an output flange for fixing the output end of the cycloidal pinwheel reducer, wherein a first output bearing is fixedly mounted on the output flange.

[0010] Optionally, the output end of the cycloidal pinwheel reducer is an output bearing, and the output bearing is provided with a third shim.

[0011] Optionally, it also includes an upper housing and a lower housing for interlocking, with the second shaft bearing mounted on the lower housing.

[0012] Optionally, the first output bearing is mounted on the upper housing.

[0013] Optionally, a planetary gear bearing is installed on the planetary gear of the planetary gear reducer, and a first shim is installed between the planetary gear bearing and the planet carrier.

[0014] Optionally, a second washer is provided on the pinwheel bearing of the cycloidal pinwheel reducer.

[0015] Compared with the prior art, the beneficial effects of this application are as follows:

[0016] Thin and highly rigid. The coupling of the two-stage reduction gear reduces the space occupied by the reduction structure along the reducer axis, thus allowing for a thinner profile. The output cage structure runs through the entire body, giving the output structure high rigidity and strong load capacity.

[0017] High reduction ratio and large torque. Because the input and output directions of the cycloidal reducer are opposite, the planet carrier of the planetary gear reducer will generate an additional speed in the opposite direction. Compared with uncoupled cascaded transmissions, this additional speed will increase the reduction ratio, and the increase in the reduction ratio will also increase the output torque. Attached Figure Description

[0018] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0019] Figure 1 This is a cross-sectional view of the planetary cycloidal pinwheel coupled cascade reducer of this application.

[0020] Figure 2 This is an assembly structure diagram of the housing of this application.

[0021] Figure 3 This is an exploded view of the casing of this application.

[0022] Figure 4 This is an exploded view of a portion of the planetary gear reducer in this application.

[0023] Figure 5 This is a partial assembly drawing of the planetary gear reducer of this application.

[0024] Figure 6 This is an exploded view of part of the cycloidal pinwheel reduction structure of this application.

[0025] Figure 7 This is a partial assembly drawing of the cycloidal pinwheel reduction structure of this application.

[0026] The components in the diagram are labeled as follows:

[0027] 1-Housing, 2-Planetary gear reducer, 3-Cycloidal pinwheel reducer;

[0028] 4-Lower end cover, 5-Second output bearing, 6-Lower housing, 7-First output bearing, 8-Upper housing, 9-Upper end cover, 10-Output flange, 11-External gear ring;

[0029] 12-Planetary gear, 13-Planetary gear bearing, 14-First washer, 15-Stabilizer, 16-Planet carrier, 17-Planet carrier bearing, 18-Planet carrier end cap, 19-Sun gear;

[0030] 20-Needle roller retainer, 21-Needle roller pin, 22-Input eccentric shaft, 23-Second washer, 24-Needle roller bearing, 25-Cycloidal wheel, 26-Output screw, 27-Third washer, 28-Output load bearing, 29-Needle roller pin. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0032] In the description of this application, it should be understood that 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. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0033] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0034] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0035] Please refer to Figure 1 , Figure 2 The basic parameters of the reducer in this application are: diameter 111mm, thickness 25mm, mass 0.86kg, and basic performance parameters are: reduction ratio 101.86, maximum input speed 4000r / min, and maximum output torque 200Nm.

[0036] This application describes a high reduction ratio and large torque. Because the input and output directions of the cycloidal reducer are opposite, the planet carrier of the planetary gear reducer will generate an additional, opposing speed. Compared to uncoupled cascaded transmissions, this additional speed increases the reduction ratio, which in turn increases the output torque. Specifically:

[0037] Assume the input rotational speed is N m The output speed is N out The planetary gear reducer has a reduction ratio of i1, and the cycloidal reducer has a reduction ratio of i2. Since the input and output directions of the cycloidal gear reducer are opposite, the sun gear and output flange are fixedly connected, and the rotational speed of the input gear relative to the sun gear is N. in +N out The input speed of the planetary carrier and cycloidal gear reducer is...

[0038]

[0039] Establish speed relationship based on cycloidal reducer

[0040]

[0041] The overall reduction ratio can be expressed as

[0042]

[0043] Due to the characteristics of planetary gear reducers, i1 > 1, therefore i > i1i2. That is, by coupling the reduction stages, the reduction ratio is increased compared to simple cascaded transmission, and the increase in reduction ratio also increases the output torque.

[0044] refer to Figure 1It includes a housing 1, a planetary gear reducer 2, and a cycloidal pinwheel reducer 3.

[0045] refer to Figure 2 , Figure 3 The housing 1 constitutes the main body of the reducer of this application. The housing 1 includes an upper housing 8, a lower housing 6, an upper end cover 9, a lower end cover 4, a first output bearing 7, a second output bearing 5, and an output flange 10. The upper housing 8 and the lower housing 6 are fastened together by screws arranged in a ring on the upper housing 8, which has ring-shaped threaded holes for fixing the rear motor and installing the reducer. The first output bearing 7 and the second output bearing 5 are installed in the inner holes of the upper housing 8 and the lower housing 6, respectively. The output flange 10 is fixedly installed on the inner ring of the first output bearing 7, and the outer gear ring 11 is fixedly installed on the inner ring of the second output bearing 5. The first output bearing 7 and the second output bearing 5 are the main load-bearing bearings of the output section.

[0046] The upper housing 8 and lower housing 6 also have annularly distributed pin holes for mounting the pin wheel pins 29 of the cycloidal reducer. The upper end cover 9 and lower end cover 4 are respectively mounted on the planetary carrier 16 and the external gear ring 11 with screws, which serve as a dustproof and oil-proof sealing function.

[0047] refer to Figure 4 , Figure 5 The planetary gear reducer 2 includes a sun gear 19, planetary gears 12, planetary gear bearings 13, a first shim 14, a planet carrier 16, a planet carrier bearing 17, a planet carrier end cover 18, a spacer 15, and an external gear ring 11. The sun gear 19 receives high-speed rotational power input from the outside and is located at the center of the structure. Three planetary gears 12 are evenly distributed between the sun gear 19 and the external gear ring 11, and each planetary gear 12 meshes with both the external gear ring 19 and the sun gear 12. Planetary gear bearings 13 are installed in the inner holes of the planetary gears 12 and are connected and fixed to the planet carrier 16 by screws. The first shim 14 is installed between the planetary gear bearings 13 and the planet carrier 16 to adjust the installation distance. The sun gear 19, planetary gears 12, and planet carrier 16 constitute the basic planetary gear reducer. The planet carrier 16 has a symmetrical eccentric structure (not shown in the figure) and also serves as the input shaft of the cycloidal pinwheel reducer. The planetary carrier bearing 17 is installed in the inner bore of the planetary carrier 16, and the planetary carrier end cap 18 is installed on the outer surface of the planetary carrier 16. The planetary carrier bearing 17 is connected to the sun gear 19 by screws, thereby achieving the positioning of the planetary carrier. The shim 15 is used to adjust the height of the planetary carrier 16.

[0048] Since the reduction principle of the planetary gear reducer 2 is well known in the field, it will not be described in detail here.

[0049] refer to Figure 6 , Figure 7The cycloidal pinwheel reducer 3 includes an input eccentric shaft 22, needle roller pins 21, a needle roller cage 20, a cycloidal wheel 25, pinwheel pins 29, pinwheel bearings 24, an output screw 26, an output load-bearing bearing 28, a second washer 23, and a third washer 27. The input eccentric shaft 22 is a component of the planetary carrier 16 and has two symmetrically offset circular features. Several needle roller pins 21 are tangentially fitted on each of the two circular features. The other side of each needle roller pin 21 is tangentially fitted to the inner hole of the cycloidal wheel 25. The needle roller cage 20 ensures the uniform distribution of the needle roller pins 21. The needle roller pins 21, input eccentric shaft 22, cycloidal wheel 25, and needle roller cage 20 constitute a needle roller bearing structure. Several pinwheel bearings 24 are tangentially fitted to the outer side of the cycloidal wheel 25. The pinwheel bearings 24 are evenly distributed, and their number is one more than the number of teeth on the cycloidal wheel 25. There are two sets of pinwheel bearings 24, which respectively mate with the upper and lower cycloidal wheels 25. Two sets of pinwheel bearings 24 are coaxial, and their installation height is adjusted by a second shim 23. Pinwheel pins 29 are installed in the inner holes of the pinwheel bearings 24, and these pins are mounted on the upper housing 8 and the lower housing 6. The cycloidal wheel 25 has several annularly distributed through holes, within which output load bearings 28 are installed tangentially. The installation height of the output load bearings 28 is adjusted by a third shim 27. The output load bearings 28 are fixedly connected to the output flange 10 and the external gear ring 11 by output screws 26. The connection between the output load bearings 28 and the output flange 10, and the connection between the output load bearings 28 and the external gear ring 11, respectively form two different output paths for rotational power. The output flange 10 and the external gear ring 11 form a cage-like structure via the output screws 26.

[0050] Since the reduction principle of the planetary gear reducer 2 is well known in the field, it will not be described again.

[0051] The deceleration process of this application will now be described in a common application scenario. It should be noted that this common implementation scheme should not be used as the basis for determining the essential features for understanding the technical problem claimed to be solved by this application; it is merely an example.

[0052] The working principle of the planetary cycloidal pinwheel coupled cascade reducer of this application is as follows:

[0053] The rear-drive motor (i.e., the external high-speed rotational power input) transmits rotational motion to the sun gear 19 via the sun gear 19, causing the planetary carrier 16 to generate corresponding deceleration motion. The decelerated rotational motion of the planetary carrier 16 is converted into eccentric rotational motion through its eccentric structure. This eccentric rotational motion is transmitted to the cycloidal wheel 25 via the needle roller pin 21 (i.e., the input end of the cycloidal pinwheel reducer). The cycloidal wheel 25 oscillates, and this oscillation is converted into pure rotational motion by the tangential engagement between the cycloidal wheel 25 and the output bearing 28, and output by the bearing 28 (i.e., the output end of the cycloidal pinwheel reducer). One output path for this rotational power is through the output flange 10 to the first output bearing 7, forming a cascaded reduction. Another output path is to transmit it to the external gear ring 11 and output it through the second output bearing 5. For the external gear ring 11, the coupling of the rotational power output from the sun gear 11 and the rotational power output from the bearing 28 ultimately increases the reduction ratio of the planetary reducer.

[0054] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A planetary cycloidal pinwheel coupled cascade reducer, characterized in that, include: A planetary gear reducer has a sun gear for receiving high-speed rotating power input from the outside, a planet carrier for power output, and an external gear ring located around the central sun gear; A cycloidal pinwheel reducer has its input end connected to the planetary carrier and its output end fixed to the external gear ring. The output end of the cycloidal pinwheel reducer is an output bearing. The cycloidal pinwheel reducer includes a cycloidal wheel with several annularly distributed through holes. The output bearing is tangentially installed in the through holes. It also includes an output flange for fixing the output end of the cycloidal pinwheel reducer. The output bearing is fixedly connected to the output flange and the external gear ring by output screws. The output flange and the external gear ring form a cage-like structure by the output screws. The connection between the output bearing and the output flange, and the connection between the output bearing and the external gear ring, respectively form two different rotational power output paths, so that the external gear ring ultimately generates low-speed rotational power output.

2. The planetary cycloidal pinwheel coupled cascade reducer according to claim 1, characterized in that, The external gear ring is fixedly mounted on the second shaft output bearing, which is used to transmit the low-speed rotational power output.

3. The planetary cycloidal pinwheel coupled cascade reducer according to claim 2, characterized in that, The first output bearing is fixedly installed on the output flange.

4. The planetary cycloidal pinwheel coupled cascade reducer according to claim 1, characterized in that, The output bearing is equipped with a third shim.

5. The planetary cycloidal pinwheel coupled cascade reducer according to claim 2, characterized in that, It also includes an upper housing and a lower housing for interlocking, with the second shaft bearing mounted on the lower housing.

6. The planetary cycloidal pinwheel coupled cascade reducer according to claim 5, characterized in that, The first output bearing is mounted on the upper housing.

7. The planetary cycloidal pinwheel coupled cascade reducer according to claim 1, characterized in that, The planetary gear reducer has planetary gear bearings mounted on its planetary gears, and a first shim is installed between the planetary gear bearings and the planet carrier.

8. The planetary cycloidal pinwheel coupled cascade reducer according to claim 1, characterized in that, The cycloidal pinwheel reducer has a second washer on the pinwheel bearing.

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