Double-stage planetary deceleration structure and decelerator

Abstract

The utility model relates to mechanical drive technical field, especially a kind of two-stage planetary reduction structure and including the speed reducer of this two-stage planetary reduction structure. Wherein, primary sun gear and secondary sun gear are coaxially fixedly connected with input shaft, primary ring gear is fixedly arranged at the outer circumferential side of primary sun gear, primary planetary gear is engaged with primary sun gear and primary ring gear simultaneously;Secondary ring gear is rotatably connected at the outer circumferential side of secondary sun gear, secondary planetary gear is engaged with secondary sun gear and secondary ring gear simultaneously, secondary ring gear is fixedly connected with output shaft;Primary planetary gear and secondary planetary gear are connected with planet carrier;The sum of the number of teeth of primary sun gear and primary ring gear is equal to the sum of the number of teeth of secondary sun gear and secondary ring gear, and the number of teeth of primary sun gear is not equal to the number of teeth of secondary sun gear. Thus, a larger speed reduction ratio can be achieved, meeting the needs of different application scenarios for low-speed, high-torque power output.

Description

Technical Field

[0001] This utility model relates to the field of mechanical transmission technology, and in particular to a two-stage planetary reduction structure and a reducer including the two-stage planetary reduction structure. Background Technology

[0002] In robotic systems, servo motors serve as the power source, providing the driving force for the robot's movement. The reducer paired with the servo motor plays a crucial role. Common RV reducers, due to their advantages such as high reduction ratios and high control precision, are widely used in the robotics field, providing strong support for the stable operation and high-precision manipulation of robots. However, the manufacturing process for RV reducers requires extremely stringent machining precision, resulting in relatively high manufacturing costs. Utility Model Content

[0003] The purpose of this invention is to provide a two-stage planetary deceleration structure that is simple in structure and can achieve a high reduction ratio.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] This utility model provides a two-stage planetary deceleration structure, including:

[0006] The input shaft, primary sun gear, primary planetary gear, and primary gear ring are coaxially and fixedly connected to the input shaft. The primary gear ring is fixedly set on the outer periphery of the primary sun gear. The primary planetary gear meshes with both the primary sun gear and the primary gear ring.

[0007] The secondary sun gear, secondary planetary gear, secondary ring gear, and output shaft are coaxially and fixedly connected to the input shaft. The secondary ring gear is rotatably connected to the outer circumference of the secondary sun gear. The secondary planetary gear meshes with both the secondary sun gear and the secondary ring gear. The secondary ring gear is fixedly connected to the output shaft.

[0008] The planetary carrier is rotatably mounted around the central axis of the input shaft, and both the primary planetary gear and the secondary planetary gear are connected to the planetary carrier.

[0009] The sum of the number of teeth of the primary sun gear and the primary ring gear is equal to the sum of the number of teeth of the secondary sun gear and the secondary ring gear, but the number of teeth of the primary sun gear is not equal to the number of teeth of the secondary sun gear.

[0010] Preferably, the number of teeth on the primary sun gear is greater than the number of teeth on the secondary sun gear.

[0011] Preferably, the number of teeth on the primary sun gear is less than the number of teeth on the secondary sun gear.

[0012] Preferably, the secondary gear ring is coaxially and fixedly connected to the output shaft.

[0013] Preferably, the number of primary planetary gears is at least three.

[0014] Preferably, the number of secondary planetary gears is at least three.

[0015] Preferably, the input shaft is fixedly connected to the primary sun gear and the secondary sun gear by a key connection or by integral molding.

[0016] Preferably, the secondary gear ring and the output shaft are fixedly connected by a key or by integral molding.

[0017] Preferably, both the primary sun gear and the secondary sun gear are helical gears, and the helical directions of the primary sun gear and the secondary sun gear are opposite.

[0018] This utility model also provides a speed reducer, including the two-stage planetary speed reduction structure described above.

[0019] Compared with the prior art, this utility model has significant progress:

[0020] This invention's two-stage planetary reduction structure drives the primary and secondary sun gears to rotate via the input shaft. The primary planetary gears, through the meshing of the primary sun gear and the primary ring gear, achieve both revolution and rotation, transmitting power to the planet carrier. Similarly, the secondary planetary gears, through the meshing of the secondary sun gear and the secondary ring gear, also achieve both revolution and rotation, with the revolution speed of the secondary planetary gear matching the rotation speed of the planet carrier. Ultimately, the secondary planetary gears drive the secondary ring gear, which transmits power to the output shaft, achieving power output. This two-stage planetary reduction structure achieves a large reduction ratio, effectively reducing the high speed of the input shaft and meeting the needs of various application scenarios for low-speed, high-torque power output. Attached Figure Description

[0021] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0022] Figure 1 This is a schematic diagram of the overall structure of the two-stage planetary deceleration structure according to an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the meshing transmission structure of the primary sun gear, primary planet gear, and primary ring gear in the two-stage planetary reduction structure of this utility model embodiment;

[0024] Figure 3This is a schematic diagram of the meshing transmission structure of the secondary sun gear, secondary planet gear, and secondary ring gear in the two-stage planetary reduction structure of this utility model embodiment.

[0025] Explanation of reference numerals in the attached diagram: 1-Input shaft; 2-Primary sun gear; 3-Primary planetary gear; 4-Primary ring gear; 5-Secondary sun gear; 6-Secondary planetary gear; 7-Secondary ring gear; 8-Output shaft; 9-Planet carrier. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this utility model clearer, the various embodiments of this utility model will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this utility model to facilitate a better understanding of this application. However, the technical solutions claimed in the claims of this application can be implemented even without these technical details and with various variations and modifications based on the following embodiments.

[0027] like Figures 1 to 3 The image shows one embodiment of the two-stage planetary deceleration structure provided by this utility model.

[0028] See Figures 1 to 3 The two-stage planetary reduction structure in this embodiment includes an input shaft 1, a primary sun gear 2, a primary planetary gear 3, a primary ring gear 4, a secondary sun gear 5, a secondary planetary gear 6, a secondary ring gear 7, an output shaft 8, and a planet carrier 9.

[0029] Among them, the input shaft 1 serves as the power input end of the two-stage planetary deceleration structure in this embodiment. The main function of the input shaft 1 is to introduce the power provided by the external power source into the deceleration structure, providing initial power for subsequent power transmission and deceleration process.

[0030] Both the primary sun gear 2 and the secondary sun gear 5 adopt a cylindrical gear design. The teeth of the primary sun gear 2 and the secondary sun gear 5 are evenly distributed on their tooth surfaces. In order to meet specific transmission requirements and coordinate with the overall size of the reduction structure, the key parameters such as the tooth profile and module of the primary sun gear 2 and the secondary sun gear 5 have been precisely calculated and optimized.

[0031] Both the primary gear ring 4 and the secondary gear ring 7 are annular gear components, with teeth machined on their inner sides to mesh with the primary planetary gear 3 and the secondary planetary gear 6. The annular structure of the primary gear ring 4 and the secondary gear ring 7 allows the planetary gears to freely revolve and rotate within them, thereby achieving a planetary deceleration motion mode.

[0032] In this embodiment, to ensure the uniformity of power transmission, the balance and stability of the system, the number of primary planetary gears 3 and secondary planetary gears 6 is at least three. Multiple planetary gears can be evenly distributed between the sun gear and the ring gear, thereby distributing the load during power transmission and preventing damage or instability caused by excessive pressure on a single planetary gear.

[0033] The planet carrier 9 supports and mounts the primary planetary gear 3 and the secondary planetary gear 6, ensuring that the primary planetary gear 3 and the secondary planetary gear 6 correctly mesh with their corresponding sun gear and ring gear, respectively. By configuring the planet carrier 9, the planetary gears can stably revolve and rotate, thereby achieving efficient power transmission and speed reduction. Furthermore, the revolution speed of the primary planetary gear 3 and the secondary planetary gear 6 is the same as the rotation speed of the planet carrier 9.

[0034] Output shaft 8 is the power output end of the two-stage planetary reduction structure in this embodiment. The main function of output shaft 8 is to output the reduced power from the reduction structure for use by subsequent mechanical systems or other equipment.

[0035] In this embodiment, the primary sun gear 2 is coaxially and fixedly connected to the input shaft 1. The primary ring gear 4 is fixedly disposed on the outer periphery of the primary sun gear 2. The primary planetary gear 3 meshes with both the primary sun gear 2 and the primary ring gear 4. The secondary sun gear 5 is also coaxially and fixedly connected to the input shaft 1. The secondary ring gear 7 is rotatably connected to the outer periphery of the secondary sun gear 5. The secondary planetary gear 6 meshes with both the secondary sun gear 5 and the secondary ring gear 7. The secondary ring gear 7 is coaxially and fixedly connected to the output shaft 8. The planet carrier 9 is rotatably disposed around the central axis of the input shaft 1. Both the primary planetary gear 2 and the secondary planetary gear 6 are connected to the planet carrier 9. The sum of the number of teeth of the primary sun gear 2 and the primary ring gear 4 is equal to the sum of the number of teeth of the secondary sun gear 5 and the secondary ring gear 7. The number of teeth of the primary sun gear 2 is not equal to the number of teeth of the secondary sun gear 5.

[0036] Therefore, in this embodiment, the two-stage planetary reduction structure drives the primary sun gear 2 and the secondary sun gear 5 to rotate via the input shaft 1. The primary planetary gear 3 revolves and rotates on its own axis under the meshing of the primary sun gear 2 and the primary ring gear 4, transmitting power to the planet carrier 9. Similarly, the secondary planetary gear 6 revolves and rotates on its own axis under the meshing of the secondary sun gear 5 and the secondary ring gear 7, with the revolution speed of the secondary planetary gear 6 being the same as the rotation speed of the planet carrier 9. Finally, the secondary planetary gear 6 drives the secondary ring gear 7 to rotate, and the secondary ring gear 7 transmits power to the output shaft 8, realizing power output. Through the two-stage planetary reduction structure, a large reduction ratio can be achieved, effectively reducing the high speed of the input shaft 1 and meeting the needs of different application scenarios for low-speed, high-torque power output.

[0037] In this embodiment, preferably, the input shaft 1 is fixedly connected to the primary sun gear 2 and the secondary sun gear 5 via a key connection or integral molding, and the secondary gear ring 7 is fixedly connected to the output shaft 8 via a key connection or integral molding. Using key connections or integral molding to fix the input shaft 1 to the primary sun gear 2 and the secondary sun gear 5, and to fix the secondary gear ring 7 to the output shaft 8, not only improves the stability of the connection and the efficiency of power transmission, but also enhances the reliability and operational smoothness of the entire reduction structure, meeting diverse application requirements.

[0038] In this embodiment, preferably, both the primary sun gear 2 and the secondary sun gear 5 are helical gears, and the helix directions of the primary sun gear 2 and the secondary sun gear 5 are opposite. The helix angle of the helical gears causes the gears to generate axial force when meshing. The axial force generated by the left-hand helical gear is opposite to its rotation direction, while the axial force generated by the right-hand helical gear is in the same direction as its rotation direction. Since the primary sun gear 2 and the secondary sun gear 5 are both coaxially fixedly connected to the input shaft 1 and the helix directions of the primary sun gear 2 and the secondary sun gear 5 are opposite, the axial forces generated by the primary sun gear 2 and the secondary sun gear 5 are opposite in direction when the input shaft 1 rotates. This cancels each other out in the two-stage planetary reduction structure, reducing vibration and instability caused by excessive axial force, avoiding the use of additional fasteners, and improving the operational stability of the entire two-stage planetary reduction structure.

[0039] The working process of the two-stage planetary deceleration structure in this embodiment is as follows:

[0040] Power input: Power provided by an external power source is input into the two-stage planetary reduction gear structure through input shaft 1.

[0041] Primary reduction: Input shaft 1 drives primary sun gear 2 to rotate, and primary planet gear 3 revolves and rotates under the meshing action of primary sun gear 2 and primary ring gear 4, transmitting power to planet carrier 9.

[0042] Secondary reduction: Input shaft 1 simultaneously drives secondary sun gear 5 to rotate. Secondary planetary gear 6 revolves and rotates under the meshing action of secondary sun gear 5 and secondary ring gear 7, and the revolution speed of secondary planetary gear 6 is the same as the rotation speed of planet carrier 9.

[0043] Power output: The secondary planetary gear 6 drives the secondary ring gear 7 to rotate, and the secondary ring gear 7 transmits power to the output shaft 8, thus realizing the power output.

[0044] The principle behind the high reduction ratio achieved by the two-stage planetary reduction structure in this embodiment is as follows:

[0045] The rotational speeds of the primary sun gear 2, the primary ring gear 4, and the planet carrier 9 satisfy the following kinematic equations:

[0046] Zs1×ωs1+Zr1×ωr1=(Zs1+Zr1)×ωc (1)

[0047] In equation (1), Zs1 and Zr1 are the number of teeth of the primary sun gear 2 and the primary ring gear 4, respectively, and ωs1, ωr1 and ωc are the rotational speeds of the primary sun gear 2, the primary ring gear 4 and the planet carrier 9, respectively.

[0048] In this embodiment, since the primary gear ring 4 is fixedly mounted on the outer periphery of the primary sun gear 2, ωr1 equals 0, so the rotational speed of the planet carrier 9 is:

[0049]

[0050] Since both the secondary sun gear 5 and the primary sun gear 2 are coaxially and fixedly connected to the input shaft 1, they rotate at the same speed. Furthermore, both the primary planetary gear 2 and the secondary planetary gear 6 are connected to the planet carrier 9. Ultimately, the rotational speeds of the secondary sun gear 5, the secondary ring gear 7, and the planet carrier 9 satisfy the following kinematic equations:

[0051] Zs2×ωs1+Zr2×ωr2=(Zs2+Zr2)×ωc (3)

[0052] In equation (3), Zs2 and Zr2 are the number of teeth of the secondary sun gear 5 and the secondary gear ring 7, respectively, and ωr2 is the rotational speed of the secondary gear ring 7.

[0053] Substituting equation (2) into equation (3):

[0054]

[0055] Since the sum of the number of teeth of the primary sun gear 2 and the primary ring gear 4 is equal to the sum of the number of teeth of the secondary sun gear 5 and the secondary ring gear 7, that is, Zs1 + Zr1 equals Zs2 + Zr2, the final rotational speed of the secondary ring gear 7 is:

[0056]

[0057] In one embodiment of this example, the number of teeth on the primary sun gear 2 is greater than the number of teeth on the secondary sun gear 5. The primary sun gear 2 has 60 teeth, the primary gear ring 4 has 180 teeth, the secondary sun gear 5 has 57 teeth, and the secondary gear ring 7 has 183 teeth. Substituting the corresponding number of teeth into the above formula (5), we obtain:

[0058]

[0059] That is, the rotational speed of the secondary gear ring 7 is 1 / 61 of the rotational speed of the input shaft 1. Since the output shaft 8 is coaxially and fixedly connected to the secondary gear ring 7, the rotational speed of the output shaft 8 is also 1 / 61 of the rotational speed of the input shaft 1, and the rotational directions of the input shaft 1 and the output shaft 8 are the same.

[0060] In another embodiment of this example, the number of teeth of the primary sun gear 2 is less than the number of teeth of the secondary sun gear 5. The primary sun gear 2 has 60 teeth, the primary gear ring 4 has 180 teeth, the secondary sun gear 5 has 61 teeth, and the secondary gear ring 7 has 179 teeth. Substituting the corresponding number of teeth into the above formula (5), we get:

[0061]

[0062] That is, the rotational speed of the secondary gear ring 7 is 1 / 179 of the rotational speed of the input shaft 1. Since the output shaft 8 is coaxially and fixedly connected to the secondary gear ring 7, the rotational speed of the output shaft 8 is also 1 / 179 of the rotational speed of the input shaft 1, and the rotational directions of the input shaft 1 and the output shaft 8 are opposite.

[0063] Based on the two-stage planetary reduction structure of this utility model, this utility model embodiment also provides a reducer, which includes the two-stage planetary reduction structure described above.

[0064] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A two-stage planetary deceleration structure, characterized in that, include: The input shaft (1), primary sun gear (2), primary planetary gear (3) and primary gear ring (4) are provided. The primary sun gear (2) is coaxially and fixedly connected to the input shaft (1). The primary gear ring (4) is fixedly disposed on the outer periphery of the primary sun gear (2). The primary planetary gear (3) meshes with both the primary sun gear (2) and the primary gear ring (4). The system comprises a secondary sun gear (5), a secondary planetary gear (6), a secondary ring gear (7), and an output shaft (8). The secondary sun gear (5) is also coaxially and fixedly connected to the input shaft (1). The secondary ring gear (7) is rotatably connected to the outer periphery of the secondary sun gear (5). The secondary planetary gear (6) meshes with both the secondary sun gear (5) and the secondary ring gear (7). The secondary ring gear (7) is fixedly connected to the output shaft (8). Planetary carrier (9), which is rotatably arranged around the central axis of the input shaft (1), and the primary planetary gear (3) and the secondary planetary gear (6) are both connected to the planetary carrier (9); The sum of the number of teeth of the primary sun gear (2) and the primary gear ring (4) is equal to the sum of the number of teeth of the secondary sun gear (5) and the secondary gear ring (7), but the number of teeth of the primary sun gear (2) is not equal to the number of teeth of the secondary sun gear (5).

2. The two-stage planetary deceleration structure according to claim 1, characterized in that, The primary sun gear (2) has a greater number of teeth than the secondary sun gear (5).

3. The two-stage planetary deceleration structure according to claim 1, characterized in that, The number of teeth of the primary sun gear (2) is less than the number of teeth of the secondary sun gear (5).

4. The two-stage planetary deceleration structure according to claim 1, characterized in that, The secondary gear ring (7) is coaxially and fixedly connected to the output shaft (8).

5. The two-stage planetary deceleration structure according to claim 1, characterized in that, The number of primary planetary gears (3) is at least three.

6. The two-stage planetary deceleration structure according to claim 1, characterized in that, The number of the secondary planetary gears (6) is at least three.

7. The two-stage planetary deceleration structure according to claim 1, characterized in that, The input shaft (1) is fixedly connected to the primary sun gear (2) and the secondary sun gear (5) by key connection or integral molding.

8. The two-stage planetary deceleration structure according to claim 1, characterized in that, The secondary gear ring (7) and the output shaft (8) are fixedly connected by a key or by integral molding.

9. The two-stage planetary deceleration structure according to claim 1, characterized in that, Both the primary sun gear (2) and the secondary sun gear (5) are helical gears, and the helical directions of the primary sun gear (2) and the secondary sun gear (5) are opposite.

10. A speed reducer, characterized in that, Includes the two-stage planetary deceleration structure as described in any one of claims 1 to 9.

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