Speed reducer with multiple stages of gear rings
By using different modulus ring gears and planetary wheels in the reducer, the load overflow problem caused by excessive modulus of planetary wheels and ring gears in the prior art is solved, and the load capacity and rated load are matched, reducing cost and weight.
Patent Information
- Application Number
- CN202422390108.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-09-29
AI Technical Summary
In the prior art, the planetary wheel and ring gear are both at the same high module, resulting in the torque received by the reducer exceeds the rated load under multi-stage transmission, causing waste, while reducing the load capacity cannot meet the rated demand.
Design a reducer with multi-stage ring gear. By using different modulus ring gears and planetary wheels in the same reducer, ensure that the load capacity of the reducer can reach or approach the rated load while avoiding excessive load.
The load capacity of the reducer is matched with the rated load, reducing the waste of load capacity spillage, while reducing the generation cost and transmission weight.
Smart Images
Figure CN222992046U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of speed reducers, and more specifically, to a speed reducer with multiple ring gears. Background Art
[0002] The planetary gear speed reducer needs to meet the rated load during use and production. The existing method of adjusting the load torque is to change the module of the planetary gear and the corresponding ring gear, and increase the module to improve the load capacity. However, for a multi-stage planetary gear speed reducer, if the planetary gear and the ring gear both have the same relatively high module, it will cause unnecessary waste. For example, if the rated load is 300 N·m, the speed reducer uses a ring gear with a module of M = 1.5, the number of teeth is 46, the reduction stage is 4, and the speed ratio is between 700 - 900, and the reduction ratio of the last output stage is between 4 - 5. Then the torque borne by the third-stage reduction mechanism of the speed reducer is between 60 - 75 N·m. The torque borne by the gear with M = 1.5 has far exceeded 60 - 75 N·m. But if the ring gear and the planetary gear are both changed to M = 1 module, it will lead to not meeting the rated load requirements. Summary of the Utility Model
[0003] The purpose of the utility model is to overcome the deficiency that the planetary gear and the ring gear both have the same relatively high module in the prior art, which will exceed the rated load too much, and provide a speed reducer with multiple ring gears. Different modules of ring gears and planetary gears are adopted in the same speed reducer, which can just meet the rated load or will not exceed the rated load too much.
[0004] To solve the above technical problems, the technical solution adopted by the utility model is:
[0005] Provide a speed reducer with multiple ring gears, including a housing and a transmission mechanism installed in the housing. The housing includes an input end connecting cover, a ring gear housing, and an end cover connected in sequence. The transmission mechanism includes a rotor shaft located at the input end connecting cover, a multi-stage planetary gear assembly located inside the ring gear, and an output shaft. One end of the multi-stage planetary gear assembly meshes with the rotor shaft, and the other end meshes with the output shaft. The ring gear housing includes at least two ring gears with different modules fixedly connected in sequence. A plurality of clamping parts and corresponding engaging parts are respectively arranged between adjacent two ring gears, and the clamping parts and the engaging parts are in interference fit.
[0006] For the speed reducer with multi-stage gear rings of the present utility model, the power source can be that the output shaft of the motor is connected to the rotor shaft through a connecting member such as a coupling. Then, through the combined transmission of the multi-stage planetary gear assembly and the gear ring housing, the power is transmitted to the output shaft. The gear ring housing can be split into multiple gear rings fixedly connected at one time. Each gear ring can select a different module. Generally, the rule is that the gear ring closer to the input end has a lower module. Based on the different modules of the gear rings, different modules of planetary gears can be selected according to the rated load for matching, so that the matched multi-stage planetary gear assembly can make the load capacity of the speed reducer reach the standard of the rated load and be equal to or not exceed the rated load too much, reducing the waste caused by the overflow of the load capacity. Since the gear ring housing is formed by sequentially connecting gear rings, if only one fixed connection method is used, it is easy for the gear ring housing to become loose under external vibration and the acting force from the planetary gears. Therefore, the adjacent gear rings are in interference fit through the clamping part and the engaging part, improving the connection tightness between the gear rings, making it not easy for the gear rings of the gear ring housing to become loose and more durable.
[0007] Further, the engaging part is a first mounting hole provided on the end face of one end of the gear ring, and the clamping part is a cylinder provided on the end face of one end of the gear ring. The cylinder is in interference fit with the first mounting hole. When assembling two adjacent gear rings, insert the cylinder of one gear ring into the first mounting hole of the other gear ring to achieve rapid interference fit.
[0008] Further, a second mounting hole is provided on the end face of the gear ring where the cylinder is provided. At least part of the cylinder is mounted in the second mounting hole and is in interference fit with the second mounting hole.
[0009] Further, the clamping part is a first circular ring provided on the end of one end of the gear ring, and the engaging part is a second circular ring provided on the end of one end of the gear ring. The outer surface of the first circular ring abuts against the inner wall surface of the second circular ring, and the first circular ring is in interference fit with the second circular ring. When assembling two adjacent gear rings, insert the first circular ring of one gear ring into the second circular ring of the other gear ring to achieve rapid interference fit.
[0010] Further, the gear ring housing includes at least two gear rings with different modules, namely an output end gear ring and an input end gear ring. One end of the output end gear ring is connected to the input end gear ring, and the other end is connected to the end cover. The other end of the input end gear ring is connected to the input end connection cover; the clamping part is provided on the end face of one end of the input end gear ring, and the engaging part is provided on the end face of one end of the output end gear ring. Both the clamping part and the engaging part are located on the end face. After the output end gear ring and the input end gear ring are installed, the clamping part and the engaging part cannot be seen on the appearance, which can not only avoid affecting the installation of the transmission but also be more beautiful.
[0011] Further, a threaded hole is provided on the end face of the engaging portion provided on the output end gear ring, and a through hole for a fastener to pass through is provided on the input end gear ring. The fastener passes through the through hole and is threadedly connected to the threaded hole to realize the fixed connection between the input end gear ring and the output end gear ring.
[0012] Further, a first annular groove is provided on the outer surface edge of one end of the output end gear ring where the engaging portion is provided, and a second annular groove is provided on the outer surface edge of one end of the input end gear ring where the engaging portion is provided. After the output end gear ring and the input end gear ring are connected, the first annular groove and the second annular groove are spliced into a welding groove, and the output end gear ring and the input end gear ring are welded along the splicing seam of the welding groove. The output end gear ring and the input end gear ring are fixedly connected by welding. Due to the function of the welding groove, welding slag can be accommodated in the welding groove, preventing the welding slag from protruding from the surface of the gear ring housing and affecting the installation and aesthetics of the transmission.
[0013] Further, the multi-stage planetary gear assembly includes an input end planetary gear mechanism provided in the input end gear ring and an output end planetary gear mechanism provided in the output end gear ring, and the module of the output end planetary gear mechanism is greater than that of the input end planetary gear mechanism.
[0014] Further, the input end planetary gear mechanism includes a first-stage planetary gear set meshing with the rotor shaft, a first-stage planetary carrier connected to the first-stage planetary gear set, a first transmission gear installed at the center of the first planetary carrier, a second-stage planetary gear set fitting with the first transmission gear, a second-stage planetary carrier connected to the second-stage planetary gear set, a second transmission gear installed at the center of the second planetary carrier, a third-stage planetary gear set fitting with the second transmission gear, a third-stage planetary carrier connected to the third-stage planetary gear set, and a third transmission gear installed at the center of the third planetary carrier. The first-stage planetary gear set, the second-stage planetary gear set, and the third-stage planetary gear set are all meshed with the input end gear ring; the output end planetary gear mechanism includes a fourth-stage planetary gear set meshing with the third transmission gear and a fourth-stage planetary carrier connected to the fourth-stage planetary gear set. The fourth-stage planetary gear set is meshed with the output end gear ring, and the fourth-stage planetary carrier is fixedly connected to the output shaft.
[0015] Further, the fourth-stage planetary carrier is integrally formed with the output shaft.
[0016] Compared with the prior art, the beneficial effects of the present utility model are:
[0017] 1. The speed reducer with multi-stage gear rings of the present utility model has a gear ring housing with at least two gear rings of different module numbers. According to the needs of the rated load, the planet gears and gear rings of different module numbers can be matched, so that the load capacity of the transmission can meet the rated load, and at the same time, there will not be too much overflow to cause waste of load performance. Reducing the module numbers of some gear rings and planet gears is further beneficial to reducing the production cost and the weight of the transmission. In addition to being fixedly connected, the gear rings are also connected by the interference fit of the clamping part and the engaging part to improve the connection strength between the gear rings, making the connection state of the gear ring housing more stable and not easy to loosen.
[0018] 2. The adjacent gear rings are connected by fasteners or welding, and cooperate with the interference fit of the clamping part and the engaging part to improve the connection tightness between the gear rings. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 FIG. 9 is an exploded view of the first embodiment of a speed reducer with multi-stage gear rings;
[0020] Figure 2 FIG. 13 is a schematic structural view of the gear ring housing of the second embodiment of a speed reducer with multi-stage gear rings;
[0021] Figure 3 is Figure 2 a partial enlarged view of position A of
[0022] Figure 4 FIG. 23 is a schematic structural view of the multi-stage planet gear assembly of the third embodiment of a speed reducer with multi-stage gear rings.
[0023] In the drawings: 100, input end connection cover; 200, gear ring housing; 210, output end gear ring; 211, threaded hole; 212, first annular groove; 220, input end gear ring; 221, fastener; 222, second annular groove; 300, end cover; 400, rotor shaft; 500, multi-stage planet gear assembly; 510, input end planet gear mechanism; 511, first-stage planet gear set; 512, first-stage planet carrier; 513, first transmission gear; 514, second-stage planet gear set; 515, second-stage planet carrier; 516, second transmission gear; 517, third-stage planet gear set; 518, third-stage planet carrier; 519, third transmission gear; 520, output end planet gear mechanism; 521, fourth-stage planet gear set; 600, output shaft; 610, fourth-stage planet carrier; 700, clamping part; 800, engaging part. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0024] The present utility model will be further described below in conjunction with specific embodiments. Among them, the attached drawings are only for illustrative purposes, showing only schematic diagrams rather than physical diagrams, and should not be construed as a limitation of this patent; in order to better illustrate the embodiments of the present utility model, some components in the attached drawings will be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the attached drawings may be omitted.
[0025] In the attached drawings of the embodiments of the present utility model, the same or similar reference numerals correspond to the same or similar components; in the description of the present utility model, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the attached drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the attached drawings are only for illustrative purposes and should not be construed as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.
[0026] Embodiment 1
[0027] This embodiment is the first embodiment of a reducer with a multi-stage gear ring. As Figure 1 shown, it includes a housing and a transmission mechanism installed in the housing. The housing includes an input end connection cover 100, a gear ring housing 200, and an end cover 300 connected in sequence. The transmission mechanism includes a rotor shaft 400 located at the input end connection cover 100, a multi-stage planetary gear assembly 500 located inside the gear ring, and an output shaft 600. One end of the multi-stage planetary gear assembly 500 meshes with the rotor shaft 400, and the other end meshes with the output shaft 600; the gear ring housing 200 includes at least two gear rings with different module values that are fixedly connected in sequence. A plurality of clamping parts 700 and engaging parts 800 corresponding to the clamping parts 700 one by one are respectively arranged between adjacent two gear rings. The clamping part 700 and the engaging part 800 are in interference fit. One-to-one correspondence means that one clamping part 700 is in interference fit with one engaging part 800.
[0028] In this embodiment, the gear ring housing 200 includes at least two gear rings with different module values, namely an output end gear ring 210 and an input end gear ring 220. One end of the output end gear ring 210 is connected to the input end gear ring 220, and the other end is connected to the end cover 300. The other end of the input end gear ring 220 is connected to the input end connection cover 100; the clamping part 700 is arranged on the end face of one end of the input end gear ring 220, and the engaging part 800 is arranged on the end face of one end of the output end gear ring 210.
[0029] In this embodiment, the engaging portion 800 is a first mounting hole provided on one end face of the output end gear ring 210, and the engaging portion 700 is a cylinder provided on one end face of the input end gear ring 220. The cylinder is in interference fit with the first mounting hole. When assembling two adjacent gear rings, insert the cylinder of one gear ring into the first mounting hole of the other gear ring to achieve rapid interference fit.
[0030] Specifically, a threaded hole 211 is provided on the end face of the output end gear ring 210 where the engaging portion 800 is provided, and a through hole for the fastener 221 to pass through is provided on the input end gear ring 220. The fastener 221 passes through the through hole and is threadedly connected to the threaded hole 211 to achieve the fixed connection between the input end gear ring 220 and the output end gear ring 210.
[0031] The working principle of the speed reducer with multiple-stage gear rings in this embodiment is as follows:
[0032] The power source, which can be the output shaft 600 of the motor, is connected to the rotor shaft 400 through a connecting member such as a coupling. After that, the drill shaft transmits the power to the output shaft 600 through the combined drive of the multi-stage planetary gear assembly 500 and the gear ring housing 200. The gear ring housing 200 can be split into multiple gear rings fixedly connected in sequence, and each gear ring can choose a different module. Generally, the rule is that the gear ring closer to the input end has a lower module. Based on the different modules of the gear rings, different modules of planetary gears can be selected for matching according to the rated load, so that the matched multi-stage planetary gear assembly 500 can make the load capacity of the speed reducer reach the standard of the rated load and be equal to or not exceed the rated load too much, reducing the waste caused by the overflow of the load capacity. Since the gear ring housing 200 is formed by connecting gear rings in sequence, if only fixed by the fastener 221, it is easy for the gear ring housing 200 to become loose under external vibration and the acting force from the planetary gears. Therefore, the adjacent gear rings are in interference fit through the engaging portion 700 and the engaging portion 800 to improve the connection tightness between the gear rings.
[0033] The beneficial effects of this embodiment: The gear ring housing 200 has two gear rings with different modules. According to the needs of the rated load, different modules of planetary gears and gear rings can be matched, so that the load capacity of the transmission finally meets the rated load and will not overflow too much to cause waste of load performance. Reducing the modules of some gear rings and planetary gears is further beneficial to reducing the production cost and the weight of the transmission. By connecting with the fastener 221 and adding the interference fit of the engaging portion 700 and the engaging portion 800, the connection strength between the gear rings is improved, and the connection state of the gear ring housing 200 is more stable and not easy to become loose.
[0034] In this embodiment, the threaded holes 211 and the first mounting holes are both circumferentially equidistantly distributed along the end face of the output end gear ring 210, and the threaded holes 211 and the first mounting holes are arranged at intervals. At the same time, one end of the cylinder is tapered to facilitate insertion into the first mounting hole.
[0035] Another embodiment of the clamping portion 700 is also provided. A second mounting hole is provided on the end face of the cylinder provided on the input end gear ring 220, and at least a part of the cylinder is mounted in the second mounting hole and is in interference fit with the second mounting hole.
[0036] Embodiment Two
[0037] This embodiment is the second embodiment of a speed reducer with a multi-stage gear ring. This embodiment is similar to Embodiment One, and the difference lies in that, as Figure 2-3 shown, the clamping portion 700 is a first ring provided at one end of the output end gear ring 210, and the engaging portion 800 is a second ring provided at one end of the input end gear ring 220. The outer surface of the first ring abuts against the inner wall surface of the second ring, and the first ring and the second ring are in interference fit. An outer surface edge of the end of the output end gear ring 210 where the engaging portion 800 is provided is provided with a first annular groove 212, and an outer surface edge of the end of the input end gear ring 220 where the clamping portion 700 is provided is provided with a second annular groove 222. After the output end gear ring 210 and the input end gear ring 220 are connected, the first annular groove 212 and the second annular groove 222 are spliced into a welding groove, and the output end gear ring 210 and the input end gear ring 220 are welded along the splicing seam of the welding groove.
[0038] The working principle of this embodiment is as follows: When assembling the input end gear ring 220 and the output end gear ring 210, insert the first ring of one of the gear rings into the second ring of the other gear ring to achieve rapid interference fit. At the same time, after the first ring and the second ring are in interference fit, and after the input end gear ring 220 and the output end gear ring 210 are spliced, the first annular groove 212 and the second annular groove 222 are spliced into a welding groove, and the input end gear ring 220 and the output end gear ring 210 are fixedly connected by laser welding along the splicing seam in the splicing groove. The splicing groove can accommodate welding slag to prevent the welding slag from protruding from the surface of the gear ring housing 200 and affecting the installation and aesthetics of the transmission.
[0039] The beneficial effects of this embodiment compared to Embodiment One: In the state of interference fit between the first ring and the second ring, the contact area is larger and the connection strength is higher. And the welding method also has stronger stability than the connection method of the fastener 221. Therefore, the input end gear ring 220 and the output end gear ring 210 of this embodiment have higher connection strength.
[0040] Embodiment Three
[0041] This embodiment is the third embodiment of a speed reducer with a multi-stage gear ring. This embodiment is similar to Embodiment 1 or Embodiment 2, except that, as Figure 1 and 4 shown, the multi-stage planetary gear assembly 500 includes an input planetary gear mechanism 510 disposed within the input gear ring 220 and an output planetary gear mechanism 520 disposed within the output gear ring 210. The module of the output planetary gear mechanism 520 is greater than that of the input planetary gear mechanism 510.
[0042] In this embodiment, the input planetary gear mechanism 510 includes a first-stage planetary gear set 511 meshing with the rotor shaft 400, a first-stage planetary carrier 512 connected to the first-stage planetary gear set 511, a first transmission gear 513 mounted at the center of the first planetary carrier, a second-stage planetary gear set 514 meshing with the first transmission gear 513, a second-stage planetary carrier 515 connected to the second-stage planetary gear set 514, a second transmission gear 516 mounted at the center of the second planetary carrier, a third-stage planetary gear set 517 meshing with the second transmission gear 516, a third-stage planetary carrier 518 connected to the third-stage planetary gear set 517, and a third transmission gear 519 mounted at the center of the third-stage planetary carrier. The first-stage planetary gear set 511, the second-stage planetary gear set 514, and the third-stage planetary gear set 517 are all meshed with the input gear ring 220; the output planetary gear mechanism 520 includes a fourth-stage planetary gear set 521 meshing with the third transmission gear 519 and a fourth-stage planetary carrier 610 connected to the fourth-stage planetary gear set 521. The fourth-stage planetary gear set 521 is meshed with the output gear ring 210, and the fourth-stage planetary carrier 610 is fixedly connected to the output shaft 600. The fourth-stage planetary carrier 610 is integrally formed with the output shaft 600.
[0043] The working principle of this embodiment is as follows: The rotor shaft 400 is mounted on the input connection cover 100 through bearings. The rotor shaft 400 transmits power to the first-stage planetary gear set 511, causing the first-stage planetary gear set 511 to travel along the input gear ring 220 while driving the first-stage planetary carrier 512 to rotate. The first transmission gear 513 of the first-stage planetary carrier 512 drives the second-stage planetary gear set 514 to rotate in the same manner as the first-stage planetary gear set 511, and is transmitted to the fourth-stage planetary gear set 521 in the same form. The fourth-stage planetary gear set 521 travels along the output gear ring 210 while driving the output shaft 600 to rotate.
[0044] In this embodiment, the first-stage planetary gear set 511, the second-stage planetary gear set 514, and the third-stage planetary gear set 517 each have three planetary gears, and the fourth-stage planetary gear set 521 has five planetary gears.
[0045] In the specific content of the above specific embodiments, each technical feature can be combined arbitrarily without contradiction. For the sake of concise description, not all possible combinations of the above technical features are described. However, as long as the combinations of these technical features do not conflict, they should all be considered to be within the scope described in this specification.
[0046] Obviously, the above embodiments of the present invention are merely examples given to clearly illustrate the present invention, rather than limitations on the embodiments of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the embodiments here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.
Claims
1. A reducer with a multi-stage ring gear, comprising a housing and a transmission mechanism installed in the housing, wherein the housing comprises an input end connection cover (100), a ring gear housing (200) and an end cover (300) connected in sequence, wherein the transmission mechanism comprises a rotor shaft (400) located at the input end connection cover (100), a multi-stage planetary gear assembly (500) located in the ring gear and an output shaft (600), wherein one end of the multi-stage planetary gear assembly (500) is meshed with the rotor shaft (400), and the other end is meshed with the output shaft (600), wherein: The gear ring housing (200) comprises at least two gear rings with different modules that are fixedly connected in sequence, and a plurality of clamping parts (700) and clamping parts (800) corresponding to the clamping parts (700) are respectively arranged between two adjacent gear rings, and the clamping parts (700) and the clamping parts (800) are interference fit.
2. The reducer with a multi-stage gear ring according to claim 1, characterized in that: The engaging portion (800) is a first mounting hole arranged on the end surface of one end of the gear ring, and the engaging portion (700) is a column arranged on the end surface of one end of the gear ring, and the column is interference-fitted with the first mounting hole.
3. The reducer with a multi-stage ring gear according to claim 2, characterized in that: The end surface of the gear ring provided with the column is provided with a second mounting hole, and the column is at least partially mounted in the second mounting hole and is interference fit with the second mounting hole.
4. The reducer with a multi-stage ring gear according to claim 1, characterized in that: The clamping portion (700) is a first circular ring arranged at one end of the gear ring, and the clamping portion (800) is a second circular ring arranged at one end of the gear ring, the outer surface of the first circular ring abuts against the inner wall surface of the second circular ring, and the first circular ring and the second circular ring are interference fit.
5. The reducer with a multi-stage gear ring according to any one of claims 1 to 4, characterized in that: The gear ring housing (200) comprises at least two gear rings with different modules, namely an output end gear ring (210) and an input end gear ring (220); one end of the output end gear ring (210) is connected to the input end gear ring (220), and the other end is connected to the end cover (300); the other end of the input end gear ring (220) is connected to the input end connection cover (100); the clamping portion (700) is arranged on the end surface of one end of the input end gear ring (220), and the clamping portion (800) is arranged on the end surface of one end of the output end gear ring (210).
6. The reducer with a multi-stage ring gear according to claim 5, characterized in that: The end surface of the output end gear ring (210) provided with the engaging portion (800) is provided with a threaded hole (211), and the input end gear ring (220) is provided with a through hole for a fastener (221) to pass through, and the fastener (221) passes through the through hole and is threadedly connected to the threaded hole (211) to achieve fixed connection between the input end gear ring (220) and the output end gear ring (210).
7. The reducer with a multi-stage ring gear according to claim 5, characterized in that: The outer surface edge of one end of the output end gear ring (210) provided with the engaging portion (800) is provided with a first annular groove (212), and the outer surface edge of one end of the input end gear ring (220) provided with the engaging portion (700) is provided with a second annular groove (222); after the output end gear ring (210) and the input end gear ring (220) are connected, the first annular groove (212) and the second annular groove (222) are spliced into a welding groove, and the output end gear ring (210) and the input end gear ring (220) are welded along the splicing seam of the welding groove.
8. The reducer with a multi-stage ring gear according to claim 5, characterized in that: The multi-stage planetary gear assembly (500) comprises an input-end planetary gear mechanism (510) arranged in the input-end ring gear (220) and an output-end planetary gear mechanism (520) arranged in the output-end ring gear (210), wherein the module of the output-end planetary gear mechanism (520) is greater than the module of the input-end planetary gear mechanism (510).
9. The reducer with a multi-stage ring gear according to claim 8, characterized in that: The input-end planetary gear mechanism (510) comprises a first-stage planetary gear set (511) meshed with the rotor shaft (400), a first-stage planet carrier (512) connected to the first-stage planetary gear set (511), a first transmission gear (513) mounted on the axis of the first planet carrier, a second-stage planetary gear set (514) fitted with the first transmission gear (513), a second-stage planet carrier (515) connected to the second-stage planetary gear set (514), a second transmission gear (516) mounted on the axis of the second planet carrier, a third-stage planetary gear set (517) fitted with the second transmission gear (516), and a third-stage planetary gear set (517) connected to the third-stage planetary gear set (517). A planet carrier (518), a third transmission gear (519) mounted on the axis of the third-stage planet carrier (518), the first-stage planetary gear set (511), the second-stage planetary gear set (514) and the third-stage planetary gear set (517) are all meshed with the input-end ring gear (220); the output-end planetary gear mechanism (520) comprises a fourth-stage planetary gear set (521) meshed with the third transmission gear (519) and a fourth-stage planet carrier (610) connected to the fourth-stage planetary gear set (521), the fourth-stage planetary gear set (521) is meshed with the output-end ring gear (210), and the fourth-stage planet carrier (610) is fixedly connected to the output shaft (600).
10. The reducer with a multi-stage ring gear according to claim 9, characterized in that: The fourth-stage planet carrier (610) and the output shaft (600) are integrally formed.