Planetary gear speed reducer and speed reduction method

Abstract

The invention relates to the technical field of speed reducer equipment, in particular to a planetary gear speed reducer and a speed reduction method. The planetary gear reducer comprises a box body, a first-stage planetary gear reducing mechanism and a second-stage planetary gear reducing mechanism. A differential gear shaft is arranged in the box body, the differential gear shaft is installed in the box body through a bearing, and a first meshing part and a second meshing part are arranged on the differential gear shaft. And a differential gear sleeve is arranged between the first-stage planetary gear speed reducing mechanism and the second-stage planetary gear speed reducing mechanism. An output end used for being connected with an output shaft is arranged on a planetary gear support of the second-stage planetary gear speed reducing mechanism. The differential gear sleeve is provided with a first inner gear ring and a second inner gear ring. And the first inner gear ring is meshed with a first planetary gear of the first-stage planetary gear speed reducing mechanism. And the second inner gear ring is meshed with a second planetary gear in the second-stage planetary gear reducing mechanism. According to the planetary gear speed reducer, the structure of an existing speed reducer is optimized, the cost is reduced, the reduction ratio application range of the speed reducer is greatly widened, and the design difficulty is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of reducer equipment, and in particular to a planetary gear reducer and a reduction method. Background Art

[0002] A reduction gear is a mechanical transmission device that converts the high-speed rotation of the input shaft into the low-speed rotation of the output shaft, while increasing the torque of the output shaft. Common types of reduction gears include gear reducers, planetary reducers, worm gear reducers, and harmonic reducers. The appropriate type of reduction gear can be selected according to the operating conditions.

[0003] Among them, in the process of robot joint control, the main function of the robot joint reducer is to improve the control accuracy and load-bearing capacity of the robot joint by reducing speed and increasing torque. For example, the robot joint reducer adopts a harmonic reducer, which uses the harmonic motion between the flexible gear and the rigid gear to achieve deceleration; or the robot joint reducer adopts a planetary reducer, which achieves deceleration through the interaction of multiple planetary gears; or the robot joint reducer adopts an RV reducer, which has high rigidity, high precision and high load-bearing capacity through the combination of planetary transmission and harmonic transmission.

[0004] However, the use of the above reducers in robot joints will increase costs, especially the use of harmonic reducers and RV reducers, which have high costs due to complex manufacturing processes and high material requirements. In addition, under high load and high-speed operation, the internal friction of the reducer will generate heat, and the temperature increase may affect the performance and life of the reducer, and even cause failure. The design and optimization of the cooling system therefore becomes very important, but it will also increase the complexity and cost of the system.

[0005] In addition, different types of reducers have their own transmission ratio range limitations in design. For example, harmonic reducers are usually suitable for high transmission ratio applications, while planetary reducers are suitable for medium and low transmission ratio applications. As a result, designers need to combine multiple types of reducers in system design, which increases the design complexity.

[0006] After searching, a reduction gearbox is disclosed in Chinese patent document CN114688219A. The reduction gearbox is provided with a fork switch on the housing for adjusting the circumferential motion state of the speed regulating gear ring, so that the speed regulating gear ring can be in a fixed state or a rotatable state. When the speed regulating gear ring is in a rotatable state, the speed regulating gear ring is meshed with the synchronous gear, and the speed regulating gear ring and the planetary reduction mechanism are in a relatively static state; when the speed regulating gear ring is in a fixed state, it cannot rotate circumferentially, the speed regulating gear ring is disengaged from the meshing with the synchronous gear, and the coupling directly drives the output shaft to rotate through the planetary reduction mechanism to achieve deceleration.

[0007] Although the above-mentioned reduction gearbox realizes deceleration through a multi-stage planetary gear structure, and realizes the functional adjustment of only transmitting power and deceleration by switching the state of the adjustment ring gear, in order to ensure normal operation under various working conditions, the reduction gearbox needs to monitor and control the speed regulating ring gear, synchronous gear, planetary reduction mechanism, etc. in real time, which increases the complexity of the control system and may require additional sensors and control algorithm support. If the reduction gearbox needs to frequently switch the state of the speed regulating ring gear, the complexity of the operation may increase the difficulty of use and put higher requirements on the operator or control system. In addition, the range of reduction ratios that can be achieved by the reduction gearbox through the multi-stage planetary gear structure is limited, and it is difficult to meet the use requirements of various working conditions. Especially under the use conditions of robot joints, if the adjustment range of the reduction ratio is increased by simply increasing the number of stages of the planetary gear structure, the volume and weight of the reduction gearbox will continue to increase, thereby affecting the flexibility of the robot joints. Summary of the invention

[0008] The purpose of the present invention is to provide a reduction device for the power transmission of a power motor, so as to optimize the structure of the existing reducer, reduce costs, greatly increase the reduction ratio application range of the reduction device, and reduce design difficulty.

[0009] To achieve the above object, the present invention proposes, on one hand, a planetary gear reducer, comprising a housing, a primary planetary gear reduction mechanism and a secondary planetary gear reduction mechanism;

[0010] A differential gear shaft is arranged in the housing, the differential gear shaft is installed in the housing through a bearing, and a first meshing portion and a second meshing portion are arranged on the differential gear shaft;

[0011] A differential gear sleeve is provided between the primary planetary gear reduction mechanism and the secondary planetary gear reduction mechanism, an output end for connecting the output shaft is provided on the planetary gear support of the secondary planetary gear reduction mechanism, a first inner gear ring and a second inner gear ring are provided on the differential gear sleeve, the first inner gear ring is meshed with the first planetary gear of the primary planetary gear reduction mechanism, and the second inner gear ring is meshed with the second planetary gear in the secondary planetary gear reduction mechanism;

[0012] The number of teeth of the first inner gear ring of the differential gear sleeve is defined as Z1, the number of teeth of the second inner gear ring is defined as Z1', the number of teeth of the differential gear shaft in the first meshing part is defined as Z3, the number of teeth of the second meshing part is defined as Z5, and the actual reduction ratio that the planetary gear reducer can achieve is i 实际 ;

[0013]

[0014] Preferably, the reduction ratio range of the planetary gear reducer is 3000:1-5000:1.

[0015] Preferably, the first-stage planetary gear reduction mechanism includes a first planetary gear and a first planetary gear bracket, the first planetary gear bracket is installed on the first end of the differential gear shaft through a bearing, the first planetary gear bracket is provided with a first rotating shaft for supporting the first planetary gear, the first planetary gear is installed on the first rotating shaft, and the first planetary gear is meshed with the first meshing portion of the differential gear shaft.

[0016] Preferably, the two-stage planetary gear reduction mechanism includes a second planetary gear and a second planetary gear bracket, the second planetary gear bracket is installed on the second end of the differential gear shaft through a bearing, the second planetary gear bracket is provided with a second rotating shaft for supporting the second planetary gear, the second planetary gear is installed on the second rotating shaft, and the second planetary gear is meshed with the second meshing portion of the differential gear shaft.

[0017] Preferably, the first rotating shaft and the second rotating shaft are both pins, the first planetary gear is mounted on the first planetary gear bracket via the pin, the second planetary gear is mounted on the second planetary gear bracket via the pin, and a shaft retaining ring is provided at the end of the pin.

[0018] Preferably, a connecting flange for mounting the power motor is provided at the end of the differential gear shaft.

[0019] Another aspect of the present invention provides a deceleration method using the planetary gear reducer, comprising the following steps:

[0020] The main shaft of the power motor transmits power to the box body through the differential gear shaft, and the first meshing portion and the second meshing portion on the differential gear shaft respectively drive the first-stage planetary gear reduction mechanism and the second-stage planetary gear reduction mechanism to rotate synchronously;

[0021] The first planetary gear rotates under the drive of the differential gear shaft, driving the differential gear sleeve to rotate around the axis of the differential gear shaft. The second planetary gear rotates under the drive of the differential gear shaft and revolves along the axis of the differential gear shaft. During this process, the second planetary gear meshes with the differential gear sleeve, and there is a speed difference between the two, forming a relative motion. The speed difference is used to greatly reduce the speed of the planetary gear bracket of the secondary planetary gear reduction mechanism.

[0022] The planetary gear support of the two-stage planetary gear reduction mechanism transmits the decelerated rotational motion to the output end, which is connected to the output shaft, thereby completing the deceleration of the power motor.

[0023] Preferably, the power motor and the end actuator are located on the same side of the planetary gear reducer.

[0024] Compared with the prior art, the planetary gear reducer and the reduction method provided by the present invention have the following outstanding substantial features and significant progress: the planetary gear reducer realizes the reduction of the power motor by arranging a first-stage planetary gear reduction mechanism and a second-stage planetary gear reduction mechanism in the housing, which is different from the reduction principle of the multi-stage planetary gears in the traditional planetary gear reducer. Through the structural design of the differential gear shaft and the differential gear sleeve, the structure of the entire reduction device is more compact, which saves space and is conducive to realizing efficient reduction function in a limited installation space, reducing costs and design difficulty. Through the design of the differential gear sleeve, the reducer can achieve a more accurate reduction ratio, and the formula It reflects its high precision in tooth number matching, so that the reducer can provide reliable and accurate deceleration effect in a variety of application scenarios. Through the design of the two-stage planetary gear reduction mechanism, the reduction device can provide a high reduction ratio while still maintaining a high load-bearing capacity. The differential gear shaft is installed in the box through bearings to ensure its smooth operation. The uniform load distribution and precision manufacturing process of the planetary gears improve the durability of the equipment and reduce maintenance requirements and use costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of a planetary gear reducer in an embodiment of the present invention.

[0026] Figure 2 It is a schematic diagram of the assembly structure of a planetary gear reducer in an embodiment of the present invention.

[0027] Figure numerals: 1. housing; 2. first-stage planetary gear reduction mechanism; 3. second-stage planetary gear reduction mechanism; 4. differential gear shaft; 5. differential gear sleeve; 6. output shaft; 7. shaft retaining ring; 21. first planetary gear; 22. first planetary gear bracket; 23. first rotating shaft; 31. second planetary gear; 32. second planetary gear bracket; 33. second rotating shaft; 41. first meshing portion; 42. second meshing portion; 51. first inner ring gear; 52. second inner ring gear. DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0029] like Figure 1-Figure 2 As shown, a planetary gear reducer is proposed in an embodiment of the present invention, aiming to optimize the structure of the existing reducer, reduce costs, greatly increase the reduction ratio application range of the reduction device, and reduce design difficulty.

[0030] Existing harmonic reducers and RV reducers have high costs due to complex manufacturing processes and high material requirements. In addition, under high load and high-speed operation, the internal friction of the reducer will generate heat. The temperature increase may affect the performance and life of the reducer, and even cause failure. The design and optimization of the cooling system therefore becomes very important, but it will also increase the complexity and cost of the system. Different types of reducers have their own transmission ratio range limitations in design. For example, harmonic reducers are generally suitable for high transmission ratio applications, while planetary reducers are suitable for medium and low transmission ratios. As a result, designers are required to combine multiple types of reducers in system design, which increases the design complexity.

[0031] A planetary gear reducer proposed in an embodiment of the present invention realizes the deceleration of the power motor by arranging a first-stage planetary gear reduction mechanism 2 and a second-stage planetary gear reduction mechanism 3 in a housing 1. The structure design of the differential gear shaft 4 and the differential gear sleeve 5 makes the structure of the entire reduction device more compact, saves space, and is conducive to realizing efficient deceleration function in a limited installation space, reducing costs and reducing design difficulty. The reduction device is a series combination of two-stage planetary gear reduction mechanisms. The second planetary gear 31 is meshed with the differential gear sleeve 5. There is a speed difference between the two, forming a relative motion. The speed difference is used to greatly reduce the speed of the planetary gear bracket of the second-stage planetary gear reduction mechanism 3, which can not only meet different deceleration requirements, but also significantly reduce the speed of the output shaft 6 while maintaining the high-speed rotation of the input shaft, and adapt to more application scenarios.

[0032] like Figure 1 As shown, a planetary gear reducer includes a housing 1, a primary planetary gear reduction mechanism 2 and a secondary planetary gear reduction mechanism 3. Figure 1 Combination Figure 2 As shown, a differential gear shaft 4 is disposed in the housing 1 . The differential gear shaft 4 is installed in the housing 1 through a bearing. A first meshing portion 41 and a second meshing portion 42 are disposed on the differential gear shaft 4 .

[0033] like Figure 2 As shown, a differential gear sleeve 5 is provided between the primary planetary gear reduction mechanism 2 and the secondary planetary gear reduction mechanism 3. The planetary gear support of the secondary planetary gear reduction mechanism 3 is provided with an output end for connecting the output shaft 6. The differential gear sleeve 5 is provided with a first inner gear ring 51 and a second inner gear ring 52. The first inner gear ring 51 is meshed with the first planetary gear 21 of the primary planetary gear reduction mechanism 2. The second inner gear ring 52 is meshed with the second planetary gear 31 in the secondary planetary gear reduction mechanism 3.

[0034] The number of teeth of the first inner gear ring 51 of the differential gear sleeve 5 is defined as Z1, the number of teeth of the second inner gear ring 52 is defined as Z1', the number of teeth of the differential gear shaft 4 at the first meshing portion 41 is defined as Z3, the number of teeth of the second meshing portion 42 is defined as Z5, and the actual reduction ratio that the planetary gear reducer can achieve is i 实际 ;

[0035]

[0036] The design of the differential gear shaft and differential gear sleeve effectively reduces the loss in the transmission process. Compared with the traditional multi-stage planetary gear transmission, it reduces energy loss and improves the overall transmission efficiency. Through the design of the two-stage planetary gear reduction mechanism, the reduction device can provide a high reduction ratio while still maintaining a high load-bearing capacity.

[0037] The reduction ratio that a traditional planetary gear reducer can provide is usually 100:1. For example, the reduction ratio of a single-stage planetary gear reducer is usually between 3:1 and 10:1; the reduction ratio of a two-stage planetary gear reducer can usually reach about 30:1; the reduction ratio of a three-stage or more planetary gear reducer can usually reach 100:1 or even higher.

[0038] Compared with the traditional planetary gear reducer, the planetary gear reducer proposed in the embodiment of the present invention is a series combination of two-stage planetary gear reduction mechanisms. The second planetary gear is meshed with the differential gear sleeve. There is a speed difference between the two, forming a relative motion. The speed difference is used to greatly reduce the speed of the planetary gear bracket of the two-stage planetary gear reduction mechanism, and then a large reduction ratio is obtained by reasonably designing the number of teeth on the differential gear shaft and the differential gear sleeve. For example, the reduction ratio range of the reduction device is 3000:1-5000:1. It can not only meet different deceleration requirements, but also significantly reduce the speed of the output shaft while maintaining the high-speed rotation of the input shaft, and adapt to more application scenarios.

[0039] The planetary gear reducer proposed in the embodiment of the present invention has a different reduction principle from the traditional planetary gear reducer, so the reduction ratio calculation method of the reduction device is also different from that of the traditional planetary gear reducer. As shown below, the reduction ratio calculation of the reduction device and the number of teeth design of the differential gear shaft and the differential gear sleeve are relatedly deduced.

[0040] by Figure 2 Taking the reduction gear shown in the figure as an example, the number of teeth of the first inner gear ring of the differential sleeve is defined as Z1, the number of teeth of the second inner gear ring is defined as Z1', the number of teeth of the differential shaft at the first meshing part is defined as Z3, and the number of teeth of the second meshing part is defined as Z5.

[0041] Combined with the deceleration principle of the reduction device, the first planetary gear rotates under the drive of the differential gear shaft, driving the differential gear sleeve to rotate around the axis of the differential gear shaft. The second planetary gear forms self-rotation under the drive of the differential gear shaft and revolves along the axis of the differential gear shaft. In this process, the second planetary gear meshes with the differential gear sleeve, and there is a speed difference between the two, forming relative motion. By utilizing this speed difference, the speed of the planetary gear bracket of the two-stage planetary gear reduction mechanism is greatly reduced.

[0042] From the deceleration principle of the above-mentioned deceleration device, we can know that:

[0043]

[0044] Among them, i is the reduction ratio of the reduction device, n 输入 is the input speed of the power motor, N 输出 is the output speed of the reduction gear.

[0045] Since the second planetary gear is meshed with the differential gear sleeve, there is a speed difference between the two, forming a relative motion. Therefore, the output speed is the speed difference between the revolution speed of the second planetary gear and the speed of the differential gear sleeve, that is:

[0046]

[0047] Among them, i1 is the reduction ratio of the first-stage planetary gear reduction mechanism, and i2 is the reduction ratio of the second-stage planetary gear reduction mechanism.

[0048] From the above, we can know that:

[0049]

[0050] The reduction ratio i of the reduction device derived above is the reduction ratio in theoretical calculation. In actual design, the actual reduction ratio of the reduction device will be smaller than the result of theoretical calculation. Therefore, in the design, the reduction ratio i will be compensated, that is:

[0051] i 实际 =ia

[0052] Among them, i 实际 is the reduction ratio that the reduction device can actually achieve, i is the reduction ratio of the reduction device in the above derivation process, and a is the fitting compensation value of the reduction ratio based on the actual test data.

[0053]

[0054] Therefore, the actual reduction ratio that the reduction device can achieve is:

[0055]

[0056] The reduction ratio i1 of the first-stage planetary gear reduction mechanism and the reduction ratio i2 of the second-stage planetary gear reduction mechanism in the above formula are further replaced.

[0057] Among them, i1 and i2 can be expressed approximately as follows:

[0058]

[0059] Substituting the above expressions for i1 and i2 into

[0060]

[0061] therefore,

[0062]

[0063] As shown in the following table:

[0064] <![CDATA[Z1]]> <![CDATA[Z3]]> <![CDATA[Z1’]]> <![CDATA[Z5]]> <![CDATA[i 实际 ]]> 300 12 299 12 7775 32 8 32 9 41 200 5 199 5 8160 300 17 299 17 5576.471

[0065] like Figure 2 As shown, the first-stage planetary gear reduction mechanism 2 includes a first planetary gear 21 and a first planetary gear support 22. The first planetary gear support 22 is mounted on the first end of the differential gear shaft 4 through a bearing. The first planetary gear support 22 is provided with a first rotating shaft 23 for supporting the first planetary gear 21. The first planetary gear 21 is mounted on the first rotating shaft 23. The first planetary gear 21 is meshed with the first meshing portion 41 of the differential gear shaft 4.

[0066] In this way, by directly mounting the first planetary gear 21 on the first rotating shaft 23 and meshing with the first meshing portion 41 of the differential gear shaft 4, the intermediate transmission links are reduced, the energy loss is minimized, and the transmission efficiency is improved. The first planetary gear bracket 22 is mounted on the first end of the differential gear shaft 4 through a bearing, providing stable support, ensuring the stability and accuracy of each component during high-speed operation, reducing vibration and noise, and improving the overall stability of the device. The first planetary gear bracket 22 is mounted on the differential gear shaft 4 through a bearing, which can evenly distribute the load, reduce the pressure on a single gear and bearing, and improve the load-bearing capacity and service life.

[0067] The first planetary gear 21 is precisely meshed with the first meshing portion 41 of the differential gear shaft 4, ensuring the accuracy and consistency of the transmission ratio, thereby achieving a more precise deceleration effect. In addition, due to the use of bearings and reasonable bracket design, wear and mechanical fatigue are reduced, the operating reliability and life of the device are improved, the downtime caused by mechanical failure is reduced, and production efficiency is improved. Through the compact design, the space occupied by the first-stage planetary gear reduction mechanism 2 is smaller, which is conducive to application in space-constrained environments and improves the adaptability and flexibility of the device.

[0068] Compared with the first-stage planetary gear reduction mechanism 2, the second-stage planetary gear reduction mechanism 3 has a similar structure. Figure 2 As shown, the two-stage planetary gear reduction mechanism 3 includes a second planetary gear 31 and a second planetary gear bracket 32. The second planetary gear bracket 32 ​​is installed at the second end of the differential gear shaft 4 through a bearing. The second planetary gear bracket 32 ​​is provided with a second rotating shaft 33 for supporting the second planetary gear 31. The second planetary gear 31 is installed on the second rotating shaft 33, and the second planetary gear 31 is meshed with the second meshing portion 42 of the differential gear shaft 4.

[0069] Similarly, the structural layout of the two-stage planetary gear reduction mechanism 3 is similar to that of the one-stage planetary gear reduction mechanism 2, which brings corresponding beneficial effects. The modular design makes the two-stage planetary gear system more convenient to operate during replacement and maintenance, simplifies the maintenance process, reduces the maintenance cycle and cost, and improves the maintainability of the equipment. The compact two-stage planetary gear design allows the entire reduction device to provide a more efficient reduction function while occupying a smaller space. It is suitable for industrial applications with limited space and improves the adaptability and flexibility of the device. By improving transmission efficiency, increasing load-bearing capacity and reducing maintenance requirements, the overall operating cost of the equipment is reduced, making the two-stage planetary gear reduction mechanism more cost-effective in long-term use.

[0070] For example, the first rotating shaft 23 and the second rotating shaft 33 are both pins. The first planetary gear 21 is mounted on the first planetary gear bracket 22 via a pin. The second planetary gear 31 is mounted on the second planetary gear bracket 32 ​​via a pin, and a shaft retaining ring 7 is provided at the end of the pin. In this way, the use of a pin as a rotating shaft simplifies the installation and disassembly process of the planetary gear, reduces the complexity of assembly and the difficulty of maintenance, and saves time and labor costs. The design of the pin can provide a firm axial fixation, reduce the displacement and swing of the gear during operation, and ensure the stability of the structure and the smoothness of operation. In addition, through the matching design of the pin and the shaft retaining ring 7, the friction between the gear and the bracket is reduced, the wear is reduced, and the durability and service life of the entire device are improved.

[0071] In addition, the precise matching of the pin and the shaft retaining ring 7 ensures the accurate positioning and stable rotation of the gear, improves the accuracy and consistency of the transmission system, and is suitable for applications with high precision requirements. The pin structure can distribute the load more evenly, reduce local stress concentration, enhance the load-bearing capacity of the entire planetary gear reduction mechanism, and adapt to higher load working conditions.

[0072] In order to further reduce the difficulty of assembling the reduction gear, the output shaft 6 is connected to the output end of the second planetary gear support 32 through a fastener. In this way, not only the installation and maintenance process is simplified, but also the reliability and strength of the connection are enhanced, the transmission accuracy is improved, the vibration and noise are reduced, and the safety and cost-effectiveness of the overall equipment are improved.

[0073] According to some preferred embodiments of the present invention, a connecting flange for mounting a power motor is provided at the end of the differential gear shaft 4. The connecting flange provides a standardized interface, which makes the installation process of the power motor simpler and faster, and reduces the installation time and labor. In addition, the connecting flange provides a strong mechanical fixation to ensure that the connection between the differential gear shaft 4 and the power motor is stable and reliable, and can withstand large torques and loads. The design of the flange can evenly distribute mechanical stress, reduce stress concentration at the connection between the differential gear shaft 4 and the motor, and extend the service life of the component. Through the precise docking of the flange, the transmission efficiency between the differential gear shaft 4 and the power motor is improved, the transmission loss is reduced, and the working performance of the entire system is improved.

[0074] The planetary gear reducer proposed in the embodiment of the present invention has a wide range of applications and can be widely used in various industries including but not limited to food processing equipment, crane equipment, robot joints, etc.

[0075] When used, a planetary gear reducer proposed in an embodiment of the present invention includes the following steps:

[0076] The main shaft of the power motor transmits power to the housing 1 through the differential gear shaft 4, and the first meshing portion 41 and the second meshing portion 42 on the differential gear shaft 4 respectively drive the primary planetary gear reduction mechanism 2 and the secondary planetary gear reduction mechanism 3 to rotate synchronously.

[0077] The first planetary gear 21 rotates under the drive of the differential gear shaft 4, driving the differential gear sleeve 5 to rotate around the axis of the differential gear shaft 4. The second planetary gear 31 rotates under the drive of the differential gear shaft 4 and revolves along the axis of the differential gear shaft 4. During this process, the second planetary gear 31 meshes with the differential gear sleeve 5, and there is a speed difference between the two, forming a relative motion. The speed difference is used to greatly reduce the speed of the planetary gear bracket of the secondary planetary gear reduction mechanism 3.

[0078] The planetary gear support of the two-stage planetary gear reduction mechanism 3 transmits the decelerated rotational motion to the output end, which is connected to the output shaft 6, thereby completing the deceleration of the power motor.

[0079] The power motor and the end actuator are located on the same side of the planetary gear reducer, so that the planetary gear reducer can be applied to the joints of the robot.

[0080] The present invention is not limited to the specific technical solutions described in the above embodiments. In addition to the above embodiments, the present invention may also have other implementation modes. For those skilled in the art, any technical solutions formed by any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A planetary gear reducer, comprising a housing, a primary planetary gear reduction mechanism and a secondary planetary gear reduction mechanism, characterized in that: A differential gear shaft is arranged in the housing, the differential gear shaft is installed in the housing through a bearing, and a first meshing portion and a second meshing portion are arranged on the differential gear shaft; A differential gear sleeve is provided between the primary planetary gear reduction mechanism and the secondary planetary gear reduction mechanism, an output end for connecting the output shaft is provided on the planetary gear support of the secondary planetary gear reduction mechanism, a first inner gear ring and a second inner gear ring are provided on the differential gear sleeve, the first inner gear ring is meshed with the first planetary gear of the primary planetary gear reduction mechanism, and the second inner gear ring is meshed with the second planetary gear in the secondary planetary gear reduction mechanism; The number of teeth of the first inner gear ring of the differential gear sleeve is defined as Z1, the number of teeth of the second inner gear ring is defined as Z1', the number of teeth of the differential gear shaft at the first meshing part is defined as Z3, the number of teeth of the second meshing part is defined as Z5, and the actual reduction ratio that the planetary gear reducer can achieve is iactual; 2. The planetary gear reducer according to claim 1, characterized in that: The reduction ratio range of the planetary gear reducer is 3000:1-5000:

1.

3. The planetary gear reducer according to claim 1, characterized in that: The first-stage planetary gear reduction mechanism includes a first planetary gear and a first planetary gear bracket. The first planetary gear bracket is installed at the first end of the differential gear shaft through a bearing. The first planetary gear bracket is provided with a first rotating shaft for supporting the first planetary gear. The first planetary gear is installed on the first rotating shaft, and the first planetary gear is meshed with the first meshing portion of the differential gear shaft.

4. The planetary gear reducer according to claim 3, characterized in that: The two-stage planetary gear reduction mechanism includes a second planetary gear and a second planetary gear bracket, the second planetary gear bracket is installed on the second end of the differential gear shaft through a bearing, the second planetary gear bracket is provided with a second rotating shaft for supporting the second planetary gear, the second planetary gear is installed on the second rotating shaft, and the second planetary gear is meshed with the second meshing portion of the differential gear shaft.

5. The planetary gear reducer according to claim 4, characterized in that: The first rotating shaft and the second rotating shaft are both pins, the first planetary gear is installed on the first planetary gear bracket through the pin, the second planetary gear is installed on the second planetary gear bracket through the pin, and a shaft retaining ring is provided at the end of the pin.

6. The planetary gear reducer according to claim 1, characterized in that: The end of the differential gear shaft is provided with a connecting flange for mounting the power motor.

7. The deceleration method of a planetary gear reducer according to any one of claims 1 to 6, characterized in that: The main shaft of the power motor transmits power to the box body through the differential gear shaft, and the first meshing portion and the second meshing portion on the differential gear shaft respectively drive the first-stage planetary gear reduction mechanism and the second-stage planetary gear reduction mechanism to rotate synchronously; The first planetary gear rotates under the drive of the differential gear shaft, driving the differential gear sleeve to rotate around the axis of the differential gear shaft. The second planetary gear rotates under the drive of the differential gear shaft and revolves along the axis of the differential gear shaft. During this process, the second planetary gear meshes with the differential gear sleeve, and there is a speed difference between the two, forming a relative motion. The speed difference is used to greatly reduce the speed of the planetary gear bracket of the secondary planetary gear reduction mechanism. The planetary gear support of the two-stage planetary gear reduction mechanism transmits the decelerated rotational motion to the output end, which is connected to the output shaft, thereby completing the deceleration of the power motor.

8. The speed reduction method of a planetary gear reducer according to claim 7, characterized in that: The power motor and the end actuator are located on the same side of the planetary gear reducer.

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