Low-noise high-power middle motor reducing mechanism

Abstract

The utility model relates to a mid-motor, in particular to a low-noise high-power mid-motor reducing mechanism, which comprises a shell, and an input shaft with a first gear, a driven shaft with a second gear, an intermediate shaft with a third gear and an output shaft with a fourth gear are arranged in the shell in parallel; the third gear of the intermediate shaft is respectively meshed and connected with the second gear of the driven shaft and the first gear of the output shaft; the high-power middle motor reducing mechanism further comprises a transmission belt, and the transmission belt is arranged on the first gear of the input shaft and the second gear of the driven shaft in a sleeving mode so that the first gear of the input shaft and the second gear of the driven shaft can be in transmission connection. By means of the structure, the first gear of the input shaft can be in transmission connection with the second gear of the driven shaft through the transmission belt, the second gear of the driven shaft is connected with the third gear of the middle shaft, and therefore the purpose of low-noise operation is achieved.

Description

Technical Field

[0001] The utility model relates to a mid-mounted motor, in particular to a high-power mid-mounted motor reduction mechanism with low noise. Background Art

[0002] The description in this part only provides background information related to the disclosure of the utility model, and does not constitute prior art.

[0003] A mid-mounted motor refers to a drive motor installed in the middle position of an assisted bicycle. It transmits power to the rear wheel through a belt or a chain, and a pedal assembly is installed on both sides of the motor, allowing the rider to achieve human power drive by pedaling. The mid-mounted motor matches the input signal of the torque sensor or speed sensor with the pedaling frequency of human power, so as to provide greater torque.

[0004] According to the different power and speed of the motor, the mid-mounted motor adopts a multi-stage gear reduction transmission structure. Sometimes, the mid-mounted motor also uses planetary gears, etc. to achieve a greater reduction ratio. For a high-power three-stage gear reduction mechanism, due to space limitations, the module and number of teeth of the gear driven by the input shaft are small, resulting in large noise, fast gear wear, and short service life. In addition, due to space limitations, the input shaft cannot be provided with a conventional support structure on the main housing, resulting in the output shaft gear being in a single support state, which is easy to wear and affects the running stability.

[0005] At present, there is no high-power mid-mounted motor reduction mechanism with low noise that can solve the above problems. Summary of the Utility Model

[0006] The purpose of the utility model is to provide a high-power mid-mounted motor reduction mechanism with low noise, which can drive-connect the first gear of the input shaft and the second gear of the driven shaft through a transmission belt, and connect the second gear of the driven shaft and the third gear of the intermediate shaft to achieve the purpose of low-noise operation.

[0007] To achieve the above purpose, the utility model discloses a high-power mid-mounted motor reduction mechanism with low noise; the high-power mid-mounted motor reduction mechanism with low noise includes:

[0008] A housing, in which an input shaft with a first gear, a driven shaft with a second gear, an intermediate shaft with a third gear, and an output shaft with a fourth gear are arranged in parallel;

[0009] Wherein, the third gear of the intermediate shaft is meshed and connected with the second gear of the driven shaft and the first gear of the output shaft respectively;

[0010] The high-power mid-motor reduction mechanism further includes a drive belt, which is sleeved on the first gear of the input shaft and the second gear of the driven shaft, so as to drive-connect the first gear of the input shaft and the second gear of the driven shaft.

[0011] Further, the input shaft is arranged to avoid the third gear of the intermediate shaft, so that one end of the input shaft is connected to the ball bearing on the inner wall of the housing.

[0012] Further, the number of the intermediate shafts is one, so that the driven shaft and the output shaft are drive-connected through the same intermediate shaft.

[0013] Further, the number of the intermediate shafts is multiple, and the third gears of the multiple intermediate shafts are alternately meshed in the middle. The third gear of one of the intermediate shafts is also meshed with the second gear of the driven shaft, and the third gear of one of the intermediate shafts is also meshed with the fourth gear of the output shaft.

[0014] Further, the drive belt is set as a toothed belt with a pitch of 2 mm or 3 mm.

[0015] Further, the drive belt is composed of ethylene propylene diene monomer rubber or hydrogenated nitrile rubber, and the hardness of the drive belt is greater than 85 ShA.

[0016] Further, the first gear of the input shaft is made of steel, and the second gear of the driven shaft is made of steel or special engineering plastics.

[0017] Further, the second gear of the driven shaft is made of special engineering plastics, specifically POM or PEEK.

[0018] Further, the input shaft and the corresponding motor rotor are integrally designed.

[0019] By means of the above technical solutions, the beneficial effects of the present utility model are as follows:

[0020] The low-noise high-power mid-motor reduction mechanism of the present utility model can drive-connect the first gear of the input shaft and the second gear of the driven shaft through a drive belt, and connect the second gear of the driven shaft with the third gear of the intermediate shaft. By means of the drive belt, it avoids the disadvantages in the prior art that the first gear of the input shaft is directly meshed with the third gear of the intermediate shaft, resulting in large noise, fast gear wear and short service life due to the small modulus and number of teeth of the first gear of the input shaft, and significantly improves the riding experience.

[0021] 2. In the transmission belt of the low-noise high-power mid-mounted motor reduction mechanism of the present utility model, more than 6 teeth of the first gear of the input shaft or the second gear of the driven shaft can be engaged simultaneously, which is more stable and reliable and has less noise.

[0022] 3. Due to the intervention of the transmission belt in the low-noise high-power mid-mounted motor reduction mechanism of the present utility model, the layout of the existing input shaft is changed, so that one end of the input shaft can be connected to the ball bearing on the inner wall of the housing, avoiding the single support state, with less wear and more stable operation.

[0023] To further understand the features and technical content of the present utility model, please refer to the following detailed description and drawings of the present utility model. However, the provided drawings are only for reference and illustration, and are not used to limit the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in this specification. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 It is a schematic diagram of a low-noise high-power mid-mounted motor reduction mechanism with a housing provided by an embodiment of this specification;

[0026] Figure 2 It is a schematic diagram of the internal connection relationship of a low-noise high-power mid-mounted motor reduction mechanism without a housing provided by an embodiment of this specification;

[0027] In the figure: 1. Housing; 2. Input shaft; 21. First gear; 3. Driven shaft; 31. Second gear; 4. Intermediate shaft; 41. Third gear; 5. Output shaft; 51. Fourth gear; 6. Transmission belt. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In order to enable those skilled in the art to better understand the technical solutions in this specification, the following will clearly and completely describe the technical solutions in the embodiments of this specification with reference to the drawings in the embodiments of this specification. Obviously, the described embodiments are only some embodiments of this specification, rather than all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this specification.

[0029] The following is to illustrate the implementation mode of the present utility model through specific embodiments. Those skilled in the art can understand the advantages and effects of the present utility model from the content disclosed in this specification. The present utility model can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present utility model. In addition, the drawings of the present utility model are only for simple schematic illustration and are not drawn according to actual dimensions. The following implementation modes will further detail the related technical content of the present utility model, but the disclosed content is not used to limit the protection scope of the present utility model.

[0030] It should be understood that although terms such as "first", "second", "third", etc. may be used in this article to describe various components or signals, these components or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another component, or one signal from another signal. In addition, the term "or" used in this article should, depending on the actual situation, possibly include any one or a combination of more of the associated listed items.

[0031] Please refer to Figure 1-2 , which is a high-power mid-mounted motor reduction mechanism with low noise in this embodiment; wherein the high-power mid-mounted motor reduction mechanism with low noise includes:

[0032] A housing 1, inside which an input shaft 2 with a first gear 21, a driven shaft 3 with a second gear 31, an intermediate shaft 4 with a third gear 41, and an output shaft 5 with a fourth gear 51 are arranged in parallel;

[0033] Wherein, the third gear 41 of the intermediate shaft 4 is respectively meshed and connected with the second gear 31 of the driven shaft 3 and the fourth gear 51 of the output shaft 5;

[0034] The high-power mid-mounted motor reduction mechanism further includes a transmission belt 6, and the transmission belt 6 is sleeved on the first gear 21 of the input shaft 2 and the second gear 31 of the driven shaft 3, so as to enable a transmission connection between the first gear 21 of the input shaft 2 and the second gear 31 of the driven shaft 3.

[0035] For the above structure, during installation, firstly, the input shaft 2, the driven shaft 3, the intermediate shaft 4 and the output shaft 5 of preset length are prepared respectively, and are passed through one side of the housing 1 and the corresponding gears are installed on the other side of the housing 1. When installing the gears, it is necessary to keep a certain distance between the first gear 21 of the input shaft 2 and the second gear 31 of the driven shaft 3, rather than directly meshing, and the transmission belt 6 is sleeved on the first gear 21 of the input shaft 2 and the second gear 31 of the driven shaft 3, so that the first gear 21 of the input shaft 2 and the second gear 31 of the driven shaft 3 can be connected by the transmission belt 6. At the same time, the second gear 31 of the driven shaft 3 is meshed with the third gear 41 of the intermediate shaft 4, and the third gear 41 of the intermediate shaft 4 is meshed with the fourth gear 51 of the output shaft 5, and the housing 1 is closed after the subsequent adjustment work is completed, so that the installation of the low-noise high-power mid-mounted motor reduction mechanism in this embodiment is completed. Among them, it is worth noting that when the input shaft 2 is installed, the input shaft 2 is set to avoid the third gear 41 of the intermediate shaft 4, so that one end of the input shaft 2 is connected to the ball bearing on the inner wall of the shell 1. It is necessary to take advantage of the intervention of the transmission belt 6 in the design stage to adjust the distance between the input shaft 2 and the driven shaft 3, so that one end of the input shaft 2 and the driven shaft 3 can avoid the third gear 41 on the intermediate shaft 4, etc., so that in this structure, one end of the input shaft 2 and the driven shaft 3 can be connected to the ball bearing on the inner wall of the shell 1, avoiding the existence of a single-supported shaft.

[0036] With the above structure, during use, the operator drives the electric motor to apply a torsional force for the rotation of the input shaft 2. The first gear 21 of the input shaft 2 then drives the transmission belt 6 engaged therewith to move, causing the transmission belt 6 to drive the second gear 31 of the driven shaft 3 on the side away from the input shaft 2 to rotate, and driving the driven shaft 3 to be connected to an external clutch. Synchronously, since the second gear 31 of the driven shaft 3 and the third gear 41 of the intermediate shaft 4 are engaged, the second gear 31 of the driven shaft 3 can drive the third gear 41 of the intermediate shaft 4 to rotate. Similarly, since the fourth gear 51 of the output shaft 5 and the third gear 41 of the intermediate shaft 4 are engaged, the third gear 41 of the intermediate shaft 4 can drive the fourth gear 51 of the output shaft 5 to rotate, and finally the force is transmitted to the pedal at the preset position through the rotation of the fourth gear 51 of the output shaft 5 to achieve the effect of assisting the rider. Among them, from the input shaft 2, the driven shaft 3, the intermediate shaft 4 to the output shaft 5, the number of teeth of the corresponding gears increases. Therefore, under the above gear ratio relationship, after the force is input from the input shaft 2 and output from the output shaft 5, the rotational speed of the output shaft 5 is reduced compared to that of the input shaft 2, completing the deceleration effect on the external motor in this embodiment and outputting a smooth force to the pedal. At the same time, in this embodiment, the input shaft 2 and the corresponding motor rotor are integrally designed, and based on the motor model, the layout of the transmission belt 6 and other driven structures can be preferentially considered in terms of the position of the input shaft 2, and its structure is more compact.

[0037] During the above use process, due to the intervention of the transmission belt 6, the input shaft 2 indirectly transmits force to the intermediate shaft 4 through the driven shaft 3. And due to its physical properties, the number of teeth meshing between the transmission belt 6 and the first gear 21 of the input shaft 2 is more than 6, while the number of teeth meshing between only two gears is significantly less than 6. At the same time, the transmission belt 6 itself has a certain flexibility compared to generally metal gears, that is to say, the noise in this embodiment is significantly reduced and the wear is smaller. It should be noted that the rotational speed of the motor connected to the input shaft 2 also needs to be kept consistent with the human pedaling frequency to ensure a stable assisting effect.

[0038] At the same time, due to the intervention of the transmission belt 6, the positions of the input shaft 2 and the intermediate shaft 4 can have a certain degree of flexibility in the design stage, enabling one end of the input shaft 2 to effectively avoid other gear surfaces, mainly the third gear 41 of the intermediate shaft 4 with a relatively large area, and enabling one end of the input shaft 2 to be directly connected to the ball bearing on the inner wall of the housing 1 (not shown in the figure). Compared with the prior art where the structure of the input shaft 2 is limited and generally needs to be set as a single-supported shaft body, the input shaft 2 in this embodiment has support, its operating effect is more stable, and it is not easy to wear the first gear 21 of the input shaft 2, effectively extending the service life of the high-power mid-mounted motor deceleration mechanism.

[0039] Furthermore, the number of the intermediate shafts 4 is one, so that the driven shaft 3 and the output shaft 5 are connected by the same intermediate shaft for transmission. That is to say, this embodiment is a three-stage gear reducer, and the size of the whole reducer is relatively small, which is suitable for occasions with limited space and has a relatively low cost.

[0040] Certainly, in another embodiment, there are also the following differences. The number of the intermediate shafts 4 is multiple, and the third gears 41 of the multiple intermediate shafts 4 are meshed alternately. The third gear 41 of one of the intermediate shafts 4 is also meshed with the second gear 31 of the driven shaft 3, and the third gear 41 of one of the intermediate shafts 4 is also meshed with the fourth gear 51 of the output shaft 5. For example, in this embodiment, there are two mutually meshed intermediate shafts 4 in the middle position. That is to say, this embodiment is a four-stage gear reducer, which has a larger reduction ratio compared with the previous three-stage gear reducer, can better disperse the load, and is suitable for application scenarios that require high torque output.

[0041] Furthermore, in this embodiment, the drive belt 6 is set as a toothed belt with a pitch of 2 mm or 3 mm, and the drive belt 6 is composed of ethylene propylene diene monomer rubber or hydrogenated nitrile butadiene rubber. The hardness of the drive belt 6 is greater than 85 ShA. The purpose is to ensure that there are enough teeth of the drive belt 6 participating in the meshing, and at the same time, the sufficient structural strength can be ensured through material selection, meeting the requirements of the torque output by the motor, and being able to withstand the high temperature generated during the operation of the motor.

[0042] Furthermore, the first gear 21 of the input shaft 2 is made of steel, and the second gear 31 of the driven shaft 3 is made of steel or special engineering plastics. Preferably, the second gear 31 of the driven shaft 3 is special engineering plastics, specifically POM (polyoxymethylene) or PEEK (polyether ether ketone). As a common gear structure, steel has a relatively low cost and is easy to prepare, but it has a large weight and high noise. Therefore, in this embodiment, POM or PEEK with a smaller mass and lower noise is selected. Among them, the weight of POM is significantly lighter than that of metal or PEEK, but its strength is slightly inferior to that of PEEK, and it can be selected according to actual needs.

[0043] The content disclosed above is only the preferred and feasible embodiment of the present utility model, and does not limit the scope of the patent application of the present utility model. Therefore, all equivalent technical changes made by using the content of the specification and drawings of the present utility model are included in the scope of the patent application of the present utility model.

[0044] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments.

[0045] Although the present application is depicted by way of examples, those of ordinary skill in the art know that the present application has many variations and changes without departing from the spirit of the present application. It is hoped that the appended embodiments include these variations and changes without departing from the present application.

Claims

1. A high-power mid-mounted motor reduction mechanism with low noise; characterized in that, The low-noise high-power mid-mounted motor reduction mechanism comprises: A housing, wherein an input shaft having a first gear, a driven shaft having a second gear, an intermediate shaft having a third gear, and an output shaft having a fourth gear are arranged in parallel in the housing; Wherein, the third gear of the intermediate shaft is meshed and connected with the second gear of the driven shaft and the first gear of the output shaft respectively; The high-power mid-mounted motor reduction mechanism also includes a transmission belt, which is sleeved on the first gear of the input shaft and the second gear of the driven shaft to achieve a transmission connection between the first gear of the input shaft and the second gear of the driven shaft.

2. The low-noise high-power mid-motor speed reduction mechanism according to claim 1, wherein: The input shaft is arranged to avoid the third gear of the intermediate shaft, so that one end of the input shaft is connected to the ball bearing on the inner wall of the housing.

3. The low-noise high-power mid-mounted motor reduction mechanism according to claim 1, wherein: The number of the intermediate shaft is one, so that the driven shaft and the output shaft are transmission-connected via the same intermediate shaft.

4. The low-noise high-power mid-motor reduction mechanism according to claim 1, characterized in that: There are multiple intermediate shafts, and the third gears of the multiple intermediate shafts are alternately meshed. The third gear of one of the intermediate shafts is also meshed with the second gear of the driven shaft, and the third gear of one of the intermediate shafts is also meshed with the fourth gear of the output shaft.

5. The low-noise high-power mid-mounted motor reduction mechanism according to claim 1, characterized in that: The transmission belt is configured as a toothed belt with a pitch of 2 mm or 3 mm.

6. The low-noise high-power mid-motor speed reduction mechanism according to claim 1, wherein: The transmission belt is made of EPDM rubber or hydrogenated nitrile rubber, and the hardness of the transmission belt is greater than 85ShA.

7. The low-noise high-power mid-motor speed reduction mechanism according to claim 1, characterized in that: The first gear of the input shaft is configured to be made of steel, and the second gear of the driven shaft is configured to be made of steel or special engineering plastics.

8. The low-noise high-power mid-mounted motor reduction mechanism according to claim 7, wherein: The second gear of the driven shaft is configured to be a special engineering plastic, specifically POM or PEEK.

9. The low-noise high-power mid-motor speed reduction mechanism according to claim 1, wherein: The input shaft and the corresponding motor rotor are designed in one piece.

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