A planetary speed reducer

Abstract

The present invention discloses a planetary reducer, which comprises a base provided with a cavity, an input shaft and a first turntable both rotatably mounted on the base, a planetary gear rotatably mounted on the first turntable, a gear mounted on the planetary gear, a second turntable relatively fixed to the first turntable, and an output shaft mounted on the second turntable; a circular ring is provided on the inner wall of the cavity, and a rack is annularly provided on the inner circumferential side of the circular ring; the circumferential side of the input shaft is in contact with the circumferential side of the planetary gear, the gear rotates coaxially with the planetary gear, the gear meshes with the rack, the input shaft, the first turntable, the circular ring, the second turntable, and the output shaft are coaxially arranged, and the axis of the input shaft is parallel to the axis of the planetary gear. The present invention can drive the planetary gear to rotate through the frictional force between the input shaft and the planetary gear, so as to drive the gear to rotate self and roll along the rack while rotating, achieving the purpose of deceleration, and belongs to the technical field of reducers.

Description

Technical Field

[0001] The present invention relates to the technical field of speed reducers, and particularly to a planetary speed reducer. Background Art

[0002] A speed reducer plays a role in matching speeds and transmitting torques between a prime mover and a working machine or an actuator, and is widely used in modern machinery. Currently, general speed reducers are achieved by the sequential meshing of two or more gears of different sizes. Compared with other speed reducers, gear speed reducers are much larger, have a smaller space, poor seismic resistance, and the tooth roots are prone to fracture. Summary of the Invention

[0003] Aiming at the technical problems existing in the prior art, the object of the present invention is to provide a planetary speed reducer. The present invention can drive the planetary gear to rotate through the friction force between the input shaft and the planetary gear, thereby driving the gear to rotate and roll along the rack while rotating, achieving the purpose of speed reduction.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A planetary speed reducer includes a base provided with a cavity, an input shaft and a first turntable both rotatably mounted on the base, a planetary gear rotatably mounted on the first turntable, a gear mounted on the planetary gear, a second turntable relatively fixed to the first turntable, and an output shaft mounted on the second turntable; a circular ring is provided on the inner wall of the cavity, and a rack is provided on the inner circumferential side of the circular ring; the circumferential side of the input shaft is in contact with the circumferential side of the planetary gear, the gear rotates coaxially with the planetary gear, the gear meshes with the rack, the input shaft, the first turntable, the circular ring, the second turntable, and the output shaft are coaxially arranged, and the axis of the input shaft is parallel to the axis of the planetary gear.

[0006] As a preferred solution, the planetary speed reducer further includes a coupling shaft; one end of the coupling shaft is fixedly connected to the first turntable, the other end of the coupling shaft is fixedly connected to the second turntable, and the planetary gear and the gear are sequentially fixed on the coupling shaft along the axial direction of the coupling shaft.

[0007] As a preferred solution, there are multiple planetary gears and multiple gears, the multiple planetary gears and the multiple gears correspond one by one, all the gears mesh with the rack, all the planetary gears are circumferentially distributed along the input shaft, and the circumferential sides of all the planetary gears are in contact with the circumferential side of the input shaft.

[0008] As a preferred solution, there are three planetary gears and three gears. The three planetary gears and the three gears correspond one by one. The three gears are all meshed with the rack. The three planetary gears are evenly distributed along the circumferential direction of the input shaft, and the circumferential sides of the three planetary gears are all in contact with the circumferential side of the input shaft.

[0009] As a preferred solution, the planetary gears and the gears are integrally formed with the coupling shaft.

[0010] As a preferred solution, the planetary speed reducer further includes a hoop; the hoop is sleeved on all the planetary gears and is in contact with the circumferential sides of all the planetary gears.

[0011] As a preferred solution, the planetary speed reducer further includes a reinforcing shaft; one end of the reinforcing shaft is fixedly connected to the first turntable, and the other end of the reinforcing shaft is fixedly connected to the second turntable.

[0012] As a preferred solution, the planetary speed reducer further includes a first end cover and a second end cover; an input port and an output port are further provided on the base; the input port and the output port are both communicated with the cavity. The first end cover is fixed at the input port, the input shaft is rotatably installed on the first end cover, the second end cover is fixed at the output port, and the output shaft is fixed on the second end cover.

[0013] As a preferred solution, a first bearing is installed on the first end cover, the input shaft is rotatably installed on the first end cover through the first bearing, a second bearing is installed on the second end cover, and the output shaft is rotatably installed on the second end cover through the second bearing.

[0014] As a preferred solution, gear teeth are provided on the circumferential side of the output shaft.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: In this planetary speed reducer, the input shaft contacts the planetary gears. The input shaft makes the planetary gears rotate through rolling friction. The gears are coaxial and rotate synchronously with the planetary gears. While the gears rotate self, they roll on the rack to achieve speed reduction. This planetary speed reducer has a compact structure and saves space. When this planetary speed reducer rotates at a high speed, it has a stable structure and strong load-bearing capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of the planetary speed reducer.

[0017] Figure 2 is an exploded view of the planetary speed reducer.

[0018] Figure 3 is Figure 2 a schematic diagram from another perspective

[0019] In the figure, 1 is the base, 2 is the first turntable, 3 is the planet gear, 4 is the gear, 5 is the second turntable, 6 is the input shaft, 7 is the output shaft, 8 is the coupling shaft, 9 is the reinforcement shaft, 10 is the ferrule, 11 is the first end cover, 12 is the second end cover, 13 is the ring, 14 is the rack, 15 is the first bearing, 16 is the second bearing, 17 is the rotating shaft, 18 is the bearing groove, 19 is the first snap ring, and 20 is the second snap ring. Detailed implementation mode

[0020] The following combines the accompanying drawings and embodiments to further describe in detail the specific implementation mode of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0021] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", "connection", and "communication" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0022] Such as Figures 1 to 3As shown in the figure, this embodiment provides a planetary reducer, which includes a base 1 provided with a cavity, an input shaft 6 and a first turntable 2 that are both rotatably mounted on the base 1, a planetary gear 3 rotatably mounted on the first turntable 2, a gear 4 mounted on the planetary gear 3, a second turntable 5 relatively fixed to the first turntable 2, and an output shaft 7 mounted on the second turntable 5; the input shaft, the first turntable, the ring, the second turntable, and the output shaft are coaxially arranged, the axis of the input shaft is parallel to the axis of the planetary gear, a ring 13 is provided on the inner wall of the cavity, and a rack 14 is annularly arranged on the inner circumferential side of the ring 13; the circumferential side of the input shaft 6 is in contact with the circumferential side of the planetary gear 3, the gear 4 rotates coaxially with the planetary gear 3, and the gear 4 meshes with the rack 14. The planetary gear 3 and the gear 4 rotate coaxially and synchronously, and the first turntable 2 and the second turntable 5 rotate coaxially and synchronously. The base 1 is fixedly installed, a circular hole in the base 1 is provided with the cavity, and the ring 13 is provided on the inner wall of the cavity and integrally formed with the inner wall of the cavity. The right end of the input shaft 6 extends into the cavity and is connected to the circumferential side of the planetary gear 3. When the input shaft 6 rotates, it drives the planetary gear 3 to rotate by friction, consumes a certain amount of the kinetic energy of the input shaft 6 by the friction between the input shaft 6 and the planetary gear 3, and at the same time, the diameter of the input shaft 6 is smaller than that of the planetary gear 3, jointly achieving speed reduction. The planetary gear 3 drives the gear 4 to rotate. When the gear 4 rotates, it rolls along the rack 14, causing the gear 4 to make a circular motion around the inner wall of the cavity. When the gear 4 makes a circular motion, it drives the first turntable 2 and the second turntable 5 to rotate. The output shaft 7 is fixed at the center of the second turntable 5. Finally, the second turntable 5 drives the output shaft 7 to rotate. The input shaft 6, the first turntable 2, and the second turntable 5 all rotate coaxially.

[0023] Specifically, in one embodiment, the planetary reducer further includes a coupling shaft 8; one end of the coupling shaft 8 is fixedly connected to the first turntable 2, the other end of the coupling shaft 8 is fixedly connected to the second turntable 5, and the planetary gear 3 and the gear 4 are sequentially fixedly arranged on the coupling shaft 8 along the axial direction of the coupling shaft 8. First through holes are provided on both the first turntable 2 and the second turntable 5. The two ends of the coupling shaft 8 respectively pass through the first through hole of the first turntable 2 and the first through hole of the second turntable 5, and the first turntable 2 drives the second turntable 5 to rotate through the coupling shaft 8.

[0024] Specifically, in one embodiment, the diameter of the planetary gear 3 is smaller than that of the gear 4, so that the force on the planetary gear 3 and the gear 4 is more uniform. The width of the planetary gear 3 is equal to the width of the gear 4. When the gear 4 meshes with the rack 14, the circumferential side of the planetary gear 3 will not interfere with the rack 14 on the inner wall of the cavity.

[0025] Specifically, in one embodiment, a rotating shaft 17 is fixedly provided on the end face of the first turntable 2. A first shaft hole is provided on the rotating shaft 17, and a second shaft hole communicating with the first shaft hole is provided on the end face of the first turntable 2. The diameter of the first shaft hole is greater than or equal to the diameter of the input shaft 6. The input shaft 6 passes through the first shaft hole and the second shaft hole in sequence and then contacts the circumferential side surface of the planetary gear 3. When the input shaft 6 rotates, the rotation direction of the input shaft 6 is opposite to the rotation direction of the gear 4, and the rotation direction of the input shaft 6 is the same as the rotation direction of the first turntable 2.

[0026] Specifically, in one embodiment, there are multiple planetary gears 3 and gears 4. The multiple planetary gears 3 and the multiple gears 4 correspond one by one. All the gears 4 are engaged with the rack 14. All the planetary gears 3 are evenly distributed along the circumferential side surface of the input shaft 6, and the circumferential side surfaces of all the planetary gears 3 contact the circumferential side surface of the input shaft 6. There are also multiple coupling shafts 8, and the multiple coupling shafts 8 correspond one by one to the multiple planetary gears 3 and the multiple gears 4. When the input shaft 6 rotates, it drives all the planetary gears 3 to rotate, thereby driving all the gears 4 to rotate while rolling along the rack 14.

[0027] Specifically, in one embodiment, there are three planetary gears 3 and three gears 4. The three planetary gears 3 and the three gears 4 correspond one by one. The three gears 4 are all engaged with the rack 14. The three planetary gears 3 are evenly distributed along the circumferential side surface of the input shaft 6, and the circumferential side surfaces of the three planetary gears 3 contact the circumferential side surface of the input shaft 6.

[0028] Specifically, in one embodiment, the planetary gears 3 and the gears 4 are integrally formed with the coupling shaft 8, ensuring the strength of rotation.

[0029] Specifically, in one embodiment, the planetary speed reducer further includes a ferrule 10; the ferrule 10 is sleeved on all the planetary gears 3 and contacts the circumferential side surfaces of all the planetary gears 3. The ferrule 10 is in the shape of a ring 13, the inner wall of the ferrule 10 is in close contact with the circumferential side surfaces of all the planetary gears 3, and the ferrule 10 presses all the planetary gears 3 towards the axis direction of the input shaft 6, increasing the rolling friction between the input shaft 6 and the planetary gears 3.

[0030] Specifically, in one embodiment, the planetary speed reducer further includes a reinforcing shaft 9; one end of the reinforcing shaft 9 is fixedly connected to the first turntable 2, and the other end of the reinforcing shaft 9 is fixedly connected to the second turntable 5. Second through holes are provided on both the first turntable 2 and the second turntable 5. The two ends of the reinforcing shaft 9 respectively pass through the second through hole of the first turntable 2 and the second through hole of the second turntable 5. The reinforcing shaft 9 makes the connection strength between the first turntable 2 and the second turntable 5 better, and makes the rotation of the first turntable 2 and the second turntable 5 more synchronous.

[0031] Specifically, in one embodiment, there are multiple reinforcing shafts 9, and one reinforcing shaft 9 is provided between adjacent two coupling shafts 8.

[0032] Specifically, in one embodiment, the diameter of the reinforcement shaft 9 is 2-3 times the diameter of the coupling shaft 8, which ensures the strength of the reinforcement shaft 9. At the same time, the reinforcement shaft 9 shares the shear stress received by the coupling shaft 8, making the service life of the coupling shaft 8 longer. The reinforcement shaft 9 can rotate. When the first turntable 2 drives the second turntable 5 to rotate, a part of the shear stress can be eliminated through the rotation of the reinforcement shaft 9.

[0033] Specifically, in one embodiment, the planetary reducer further includes a first end cover 11 and a second end cover 12; an input port and an output port are further provided on the base 1; both the input port and the output port are communicated with the cavity. The first end cover 11 is fixed at the input port, the input shaft 6 is rotatably installed on the first end cover 11, the second end cover 12 is fixed at the output port, and the output shaft 7 is fixed on the second end cover 12. The input port and the output port are respectively located at both ends in the axial direction of the circular hole-shaped cavity. The planetary gears 3, the first turntable 2, the second turntable 5, and the gear 4 are all located between the first end cover 11 and the second end cover 12.

[0034] Specifically, in one embodiment, a first bearing 15 is installed on the first end cover 11, and the input shaft 6 is rotatably installed on the first end cover 11 through the first bearing 15. A second bearing 16 is installed on the second end cover 12, and the output shaft 7 is rotatably installed on the second end cover 12 through the second bearing 16.

[0035] Specifically, in one embodiment, the diameter of the output shaft 7 is equal to the inner diameter of the second bearing 16. The output shaft 7 is directly installed on the second bearing 16.

[0036] Specifically, in one embodiment, the rotating shaft 17 of the first turntable 2 is rotatably installed on the first bearing 15. The first bearing 15 provides a rotational support for the rotation of the rotating shaft 17, which can make the rotation of the first turntable 2 more stable.

[0037] Specifically, in one embodiment, the length of the rotating shaft 17 in the axial direction is 1.5-2 times the length of the first turntable 2 in the axial direction, that is, the width of the rotating shaft 17 is 1.5-2 times the width of the first turntable 2. Since the rotating shaft 17 is installed in the first bearing 15, the gravity of the first turntable 2, the rotating shaft 17, and the components (planetary gears 3, gear 4) on the turntable are all applied to the first bearing 15 through the rotating shaft 17. The larger width of the rotating shaft 17 than the width of the first turntable 2 can better disperse the force received by the rotating shaft 17 and ensure the strength of the rotating shaft 17.

[0038] Specifically, in one embodiment, both the first end cover 11 and the second end cover 12 are disc-shaped. Bearing grooves 18 are provided on one end face of the first end cover 11 and one end face of the second end cover 12. The bearing grooves 18 are located at the center of the first end cover 11 or the second end cover 12. The first bearing 15 is installed in the bearing groove 18 of the first end cover 11, and the first bearing 15 is installed in the bearing groove 18 of the second end cover 12.

[0039] Specifically, in one embodiment, the bearing grooves 18 of the first end cover 11 and the second end cover 12 are both in communication with the cavity, so that the first end cover 11 and the second end cover 12 seal the cavity. The first bearing 15 and the second shaft are sealed in the closed area jointly formed by the first end cover 11, the second end cover 12 and the cavity, preventing the first bearing 15 and the second bearing 16 from being contaminated by dust and the like, which may affect the accuracy and service life.

[0040] Specifically, in one embodiment, a first snap ring 19 is further provided on the end face of the first end cover 11, and a second snap ring 20 is further provided on the end face of the second end cover 12. The bearing groove 18 of the first end cover 11 is located within the first snap ring 19, and the bearing groove 18 of the second end cover 12 is located within the second snap ring 20. The diameters of the first end cover 11 and the second end cover 12 are larger than the diameter of the cavity, the diameter of the ferrule 10 is equal to the diameter of the cavity, the outer diameters of the first snap ring 19 and the second snap ring 20 are the same as the inner diameter of the cavity. The first snap ring 19 is stuck at the input port and contacts one end face of the ferrule 10, the other end face of the ferrule 10 contacts one end face of the ring 13, the second snap ring 20 is stuck at the output port and contacts the other end face of the ring 13, which realizes the positioning of the ferrule 10 in the radial and axial directions and prevents the ferrule 10 from detaching from the planetary gear 3.

[0041] Specifically, in one embodiment, the distance from the first snap ring 19 to the inner wall of the bearing groove 18 is 1 - 1.5 times the distance from the first snap ring 19 to the circumferential side face of the first end cover 11. The first snap ring 19 is closer to the circumferential side face of the first end cover 11, which ensures the flatness of the first end cover 11. The distance from the second snap ring 20 to the inner wall of the bearing groove 18 is 1 - 1.5 times the distance from the second snap ring 20 to the circumferential side face of the second end cover 12. The second snap ring 20 is closer to the circumferential side face of the second end cover 12, which ensures the flatness of the first end cover 11. The first snap ring 19 can prevent the first end cover 11 from moving radially, and the second snap ring 20 can prevent the second end cover 12 from moving radially.

[0042] Specifically, in one embodiment, gear teeth are provided on the circumferential side face of the output shaft 7. The output shaft 7 is connected to an external device through the gear teeth, so that the kinetic energy after deceleration of the input shaft 6 is transmitted out through the output shaft 7.

[0043] The working principle of the present invention is as follows: When the input shaft rotates, the base remains stationary. The input shaft drives the planet gear to rotate through rolling friction. The planet gear drives the gear to rotate. While the gear rotates around the coupling shaft, it also makes a circular roll along the rack, so that the gear drives the first turntable and the second turntable to rotate. Finally, the second turntable drives the output shaft to rotate.

[0044] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A planetary speed reducer, characterized in that: It includes a base provided with a cavity, an input shaft and a first turntable both rotatably mounted on the base, a planetary gear rotatably mounted on the first turntable, a gear mounted on the planetary gear, a second turntable fixed to the first turntable, an output shaft mounted on the second turntable, a ferrule, and a reinforcing shaft; a circular ring is provided on the inner wall of the cavity, and a rack is provided on the inner circumferential side of the circular ring; the circumferential side of the input shaft is in contact with the circumferential side of the planetary gear, the gear rotates coaxially with the planetary gear, the gear meshes with the rack, the input shaft, the first turntable, the circular ring, the second turntable, and the output shaft are coaxially arranged, and the axis of the input shaft is parallel to the axis of the planetary gear; There are multiple planetary gears and multiple gears, the multiple planetary gears and the multiple gears correspond one by one, all the gears mesh with the rack, all the planetary gears are circumferentially distributed along the input shaft, the circumferential sides of all the planetary gears are in contact with the circumferential side of the input shaft, and the diameter of the input shaft is smaller than the diameter of the planetary gear; The ferrule is sleeved on all the planetary gears and is in contact with the circumferential sides of all the planetary gears, and the ferrule presses the planetary gears towards the axis direction of the input shaft to increase the rolling friction between the input shaft and the planetary gears; One end of the reinforcing shaft is connected to the first turntable, and the other end of the reinforcing shaft is connected to the second turntable.

2. A planetary speed reducer according to claim 1, characterized in that: It further includes a coupling shaft; one end of the coupling shaft is connected to the first turntable, the other end of the coupling shaft is connected to the second turntable, and the planetary gears and the gears are sequentially fixed on the coupling shaft along the axis direction of the coupling shaft.

3. A planetary speed reducer according to claim 2, characterized in that: There are three planetary gears and three gears, the three planetary gears and the three gears correspond one by one, the three gears all mesh with the rack, the three planetary gears are evenly circumferentially distributed along the input shaft, and the circumferential sides of the three planetary gears are all in contact with the circumferential side of the input shaft.

4. A planetary speed reducer according to claim 2, characterized in that: The planetary gears and the gears are integrally formed with the coupling shaft.

5. A planetary speed reducer according to claim 1, characterized in that: It further includes a first end cover and a second end cover; an input port and an output port are further provided on the base; the input port and the output port are both communicated with the cavity, the first end cover is fixed at the input port, the input shaft is rotatably mounted on the first end cover, the second end cover is fixed at the output port, and the output shaft is fixed on the second end cover.

6. A planetary speed reducer according to claim 5, characterized in that: A first bearing is mounted on the first end cover, the input shaft is rotatably mounted on the first end cover through the first bearing, a second bearing is mounted on the second end cover, and the output shaft is rotatably mounted on the second end cover through the second bearing.

7. A planetary speed reducer according to claim 1, characterized in that: Teeth are provided on the circumferential side of the output shaft.

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