Speed reducer structure

Abstract

The application provides a speed reducer structure, defining an axis, an input shaft extending along the axis, a first external gear eccentric to the axis and rotatably connected to the input shaft, when the input shaft rotates, the first external gear rotates around the axis, a first internal gear arranged outside the first external gear, a second internal gear arranged outside the first external gear, the first and second internal gears are arranged in sequence along the axis, wherein the number of teeth of the first internal gear is different from the number of teeth of the second internal gear, the first external gear is engaged with the first and second internal gears at the same time, an output shaft is connected to the second internal gear, covering and supporting the related groups, the first internal gear is fixed in the housing, thereby providing a speed reducer with smaller volume and easy to manufacture.

Description

Technical Field

[0001] This invention relates to a speed reducer. Background Technology

[0002] A speed reducer is a device used in machinery to reduce rotational speed and thus increase torque. Based on differences in their operating principles, speed reducers can be classified into planetary speed reducers, cycloidal pinwheel speed reducers, worm gear speed reducers, harmonic speed reducers, etc.

[0003] However, most of the aforementioned speed reducers are relatively bulky and cannot be used under conditions requiring lightweight machinery, or they require the manufacture of special components such as flexible gears or eccentric gears, which are costly and difficult to manufacture. In addition, flexible gear structures have low strength and are difficult to withstand large loads.

[0004] Therefore, how to reduce the overall size and cost of the speed reducer while also ensuring its service life is a pressing issue that the industry needs to address. Summary of the Invention

[0005] The purpose of this invention is to provide a speed reducer that is small in size, has a high reduction ratio, and is easy to process and manufacture. Another purpose is to improve the structural strength of the speed reducer components so as to increase their service life.

[0006] To achieve the above objectives, the present invention provides a speed reducer structure, characterized in that it comprises:

[0007] An input shaft extends along this axis, with a large end supporting a single external gear and a counterweight retainer.

[0008] A first external gear extends parallel to the axis of the input shaft and is eccentric relative to the input shaft. When the input shaft rotates, it drives the first external gear to rotate around the axis of the input shaft.

[0009] First internal gear;

[0010] A second internal gear, wherein the number of teeth of the first internal gear is different from the number of teeth of the second internal gear, and the first external gear meshes with both the first internal gear and the second internal gear simultaneously;

[0011] An output shaft is connected to the second internal gear and extends parallel to the axis;

[0012] An outer casing is provided outside the first external gear, the first internal gear and the second internal gear, and the first internal gear is fixed inside the outer casing.

[0013] The aforementioned reducer structure includes a counterweight when a single external gear is used. The counterweight is located on the opposite side of the first external gear and is also eccentrically positioned relative to the input shaft axis. One end of the counterweight is connected to the retainer. When the input shaft rotates, the counterweight is driven to rotate around the axis via the retainer.

[0014] The speed reducer structure wherein: the distance from one axis of the first external gear to the axis of the speed reducer structure is equal to the distance from one axis of the counterweight to the axis of the speed reducer structure, and the line connecting the axis of the first external gear and the axis of the counterweight passes through the axis of the speed reducer structure.

[0015] The reducer structure wherein: the counterweight is replaced with a second external gear, the second external gear having the same number of teeth as the first external gear and simultaneously meshing with the first internal gear and the second internal gear, the second external gear being located on the opposite side of the first external gear, and when the input shaft rotates, the retainer drives the second external gear to rotate around the axis.

[0016] In the aforementioned reducer structure, when the difference in tooth thickness between the two internal gears is N teeth, the number of external gears installed on the input shaft retainer is N or 2N.

[0017] The reducer structure provided by this invention uses general gear production equipment for both internal and external gears, eliminating the need to manufacture special curves or flexible gears. The overall volume is much smaller than that of conventional reducers under the requirement of high reduction ratio. More importantly, it is easy to manufacture and assemble. The overall structure is symmetrical and stable, and it is stable and not prone to vibration during rotation, resulting in a long service life. Attached Figure Description

[0018] Figure 1 This is a perspective view of the present invention.

[0019] Figure 2 This is a side view of the present invention.

[0020] Figure 3 for Figure 2 AA cross-section view.

[0021] Figure 4 This is an exploded perspective view of the present invention.

[0022] Figure 5 This is a partial perspective view of the present invention.

[0023] Figures 6a to 6u This is a schematic diagram illustrating the continuous operation of the present invention.

[0024] Figure 7 This is a cross-sectional view of the second embodiment of the present invention.

[0025] Explanation of reference numerals in the attached drawings: Input shaft 10; First external gear 20; First through-hole 21; First internal gear 30; Second internal gear 40; Output shaft 50; Housing 60; Retainer 70; First through-hole 71; Counterweight 80; Second through-hole 81; Second external gear 90; Third through-hole 91. Detailed Implementation

[0026] To provide a better understanding of the present invention, a preferred embodiment is described in detail below with reference to the accompanying drawings:

[0027] This invention provides a speed reducer structure; please refer to the exploded view. Figure 4 The reducer structure includes an input shaft 10, a first external gear 20, a first internal gear 30, a second internal gear 40, an output shaft 50, and a housing 60.

[0028] The input shaft 10 extends along this axis; the external gear 20, parallel to the axis of the first external gear 20, is supported in the hole of the large end retainer 71 of the input shaft 10 during assembly. When the input shaft 10 rotates, it drives the first external gear 20 to rotate around the axis of the input shaft 10. The first internal gear 30 has a parallel axis, and the second internal gear 40 has a concentric axis. The number of teeth of the first internal gear 30 is different from the number of teeth of the second internal gear 40, and the difference in the number of teeth can be 1, 2, or 3. During operation, the first external gear 20 meshes with the first internal gear 30 and the second internal gear 40 simultaneously. The output shaft 50 and the second internal gear 40 are an integral structure. The housing 60 supports the output shaft 50 via bearings, and the first internal gear 30 is fixed inside the housing 60. Please refer to the combined structure. Figure 5 .

[0029] To prevent vibration caused by the shift of the center of gravity during high-speed rotation of the input shaft of the reducer, a counterweight 80 is designed to be located on the symmetrical side of the first external gear 20 and connected to the 71 side holes at the large end of the input shaft 10.

[0030] In detail, in the main embodiment of the present invention, the first internal gear 30 is fixed to the outer casing 60 and cannot rotate. When the input shaft 10 rotates, it drives the first external gear 20 to rotate around the axis of the input shaft 10. The first external gear 20 revolves around the first internal gear 30 like a planet, and rotates on its own axis due to meshing with the first internal gear 30. The first external gear 20 also meshes with the second internal gear. Because the first internal gear and the second internal gear have different numbers of teeth, there is a situation of misalignment between them. While the first external gear revolves and rotates, the reaction force of the first internal gear drives the second internal gear, thereby pushing the second internal gear to rotate and achieving the output of force. Specifically, the first external gear has 17 teeth, the first internal gear has 40 teeth, and the second internal gear has 41 teeth. The difference in the number of teeth between the first internal gear and the second internal gear is 1. When the first external gear revolves once, it can push the second internal gear to rotate 1 tooth distance, that is, 1 / 40 of a revolution. Therefore, a reduction ratio of 1:40 can be achieved. For its operation process, please refer to Figures 6a to 6u It can be seen that the first internal gear and the second internal gear mesh simultaneously. The first external gear moves with the revolution of the first external gear, moving counterclockwise one revolution from the 12 o'clock position, which causes the second internal gear to rotate relative to the first internal gear, producing a deceleration effect due to the tooth difference.

[0031] Please refer to the following: Figure 7 This is the second embodiment of the present invention. In this embodiment, a second external gear 90 is further included. The second external gear 90 has the same number of teeth as the first external gear 20 and also meshes with the first internal gear 30 and the second internal gear 40 respectively. That is, the counterweight is replaced by a pair of identical external gears on the left and right.

[0032] In this embodiment, the first external gear 20 and the second external gear 90 have the same number of teeth, 17 teeth. In order for the first external gear 20 and the second external gear 90 to mesh with the first internal gear 30 and the second internal gear 40 at the same time, the difference in the number of teeth between the first internal gear 30 and the second internal gear 40 is an integer multiple of 2. For example, the first internal gear 30 has 40 teeth and the second internal gear 40 has 42 teeth. When the first external gear 20 and the second external gear 90 revolve one revolution, the second internal gear will rotate a distance of 2 teeth, that is, 2 / 40 revolutions. Therefore, a reduction ratio of 1:20 can be achieved. This lower reduction ratio design, because it uses the same first external gear 20 and the second external gear 90, not only achieves the best effect in balancing the weight, but also allows two teeth to bear the load at the same time, which multiplies the load of the overall structure and makes the force transmission more uniform. In practice, it is also a good embodiment.

[0033] In addition, the rotating elements of this invention are equipped with conventional combinations such as bearings at the front and rear to ensure smooth operation, which will not be described in detail here.

[0034] In summary, the speed reducer structure provided by this invention has a relatively smaller volume when achieving a high reduction ratio compared to conventional speed reducers, and does not require the manufacture of specially shaped components such as special curved parts, eccentric parts, or flexible wheels. In principle, it only requires the use of a general-shaped circular gear, which is easier to manufacture, process, assemble, and maintain than conventional technology. It can provide a stable reduction effect and avoid vibration and wear, which is exactly what the industry has been looking forward to.

[0035] This invention has been actually manufactured and applied to the precision indexing and positioning of a vertical lathe worktable and similar indexing mechanisms, with good results.

Claims

1. A speed reducer structure, characterized in that, Include: An input shaft extends along this axis, with a large end supporting a single external gear and a counterweight retainer. A first external gear extends parallel to the axis of the input shaft and is eccentric relative to the input shaft. When the input shaft rotates, it drives the first external gear to rotate around the axis of the input shaft. First internal gear; A second internal gear, wherein the number of teeth of the first internal gear is different from the number of teeth of the second internal gear, and the first external gear meshes with both the first internal gear and the second internal gear simultaneously; An output shaft is connected to the second internal gear and extends parallel to the axis; An outer casing is provided outside the first external gear, the first internal gear and the second internal gear, and the first internal gear is fixed inside the outer casing.

2. The reducer structure as described in claim 1, characterized in that: When a single external gear is used, a counterweight is included. The counterweight is located on the opposite side of the first external gear and is also eccentrically positioned relative to the input shaft axis. One end of the counterweight is connected to the retainer. When the input shaft rotates, the counterweight is driven to rotate around the axis via the retainer.

3. The reducer structure as described in claim 2, characterized in that: The distance from one axis of the first external gear to the axis of the reducer structure is equal to the distance from one axis of the counterweight to the axis of the reducer structure, and the line connecting the axis of the first external gear and the axis of the counterweight passes through the axis of the reducer structure.

4. The reducer structure as described in claim 1, characterized in that: The counterweight is replaced with a second external gear, which has the same number of teeth as the first external gear and also meshes with the first internal gear and the second internal gear. The second external gear is located on the opposite side of the first external gear. When the input shaft rotates, the second external gear is driven to rotate around the axis via the retainer.

5. The reducer structure as described in claim 1, characterized in that: When the difference in tooth thickness between the two internal gears is N teeth, the number of external gears set on the input shaft retainer is N or 2N.

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