Reducer and new energy vehicles

Abstract

The present invention belongs to the technical field of new energy vehicles, solves the technical problems of high noise, complex structure and high cost in the conventional transmission in the prior art, and provides a reducer and a new energy vehicle having the reducer, wherein the reducer comprises a first-stage transmission mechanism and a second-stage transmission mechanism connected in transmission, the first-stage transmission mechanism is set as friction transmission, and the second-stage transmission mechanism is set as gear transmission and receives power transmitted by friction transmission. The reducer and new energy vehicle provided by the present invention have the advantages of low noise, simplified structure and low cost.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicles, and in particular to a reducer and a new energy vehicle. Background Art

[0002] At present, with the rapid development of new energy vehicles, the application of reducers is becoming more and more extensive, and thus it has been paid more and more attention by OEMs and power system suppliers. The current reducers mainly include two categories: one: parallel shaft gear reducer, which is composed of two-stage gears. The input shaft of the reducer is parallel to the output shaft, but not on the same horizontal line. Compared with the traditional reducer, this reducer reduces the parts such as gear pairs and shifting mechanisms, and reduces the complexity of the structure. At present, this type of reducer is the most widely used in the market. However, the two-stage transmission of this type of reducer adopts gear transmission, which will produce a lot of gear meshing noise; second: planetary gear reducer, which mainly relies on planetary gear rows to realize the deceleration function. The input shaft and output shaft of the reducer are on the same axis. However, this type of reducer has a complex structure and high requirements for gear processing accuracy, resulting in high cost. It is only used when the installation space is limited. Therefore, it is urgent to provide a reducer and new energy vehicle with low noise, simplified structure and low cost. Summary of the invention

[0003] In view of the deficiencies of the above-mentioned prior art and to achieve one purpose of the present invention, a reducer is provided, which includes a first-stage transmission mechanism and a second-stage transmission mechanism connected in transmission, the first-stage transmission mechanism is configured as a friction transmission, and the second-stage transmission mechanism is configured as a gear transmission and receives power transmitted by the friction transmission.

[0004] Furthermore, the first-stage transmission mechanism includes a power input shaft, a planetary shaft, a first-stage driven gear and a retaining frame, the first-stage driven gear is assembled on the planetary shaft, and the power input shaft is frictionally connected to the planetary shaft; the second-stage transmission mechanism includes a second-stage driving gear fixedly connected to the first-stage driven gear and a main reduction gear meshing with the second-stage driving gear.

[0005] Furthermore, the first-stage driven gear is sleeved on the planetary shaft which is located in a fixed position retaining frame and sleeved on the power input shaft in a heated state.

[0006] Furthermore, two circles of grooves are formed on the side of the first-stage driven gear facing the planetary shaft, and the retaining frame is provided with a pair of protruding plates inserted in the two circles of grooves.

[0007] Furthermore, the first-stage passive gear and the second-stage driving gear are connected to each other via splines.

[0008] Furthermore, the reducer also includes a third-stage transmission mechanism, and the third-stage transmission mechanism includes a differential connected to the main reduction gear via a screw member.

[0009] Furthermore, the reducer also includes a needle roller bearing, which is assembled on an end of the power input shaft away from the planetary shaft.

[0010] Furthermore, the center line of the power input shaft, the center lines of the first-stage passive gear and the second-stage driving gear coincide with each other.

[0011] Furthermore, there is one Y-shaped retainer, three planetary shafts, and the planetary shafts are arranged in parallel and distributed at equal angles with the central axis of the retainer as the center. The central axis of the retainer coincides with the center line of the power input shaft.

[0012] Furthermore, each planetary shaft is in frictional contact with the power input shaft and the first-stage driven gear respectively.

[0013] To achieve another object of the present invention, the present invention also provides a new energy vehicle, which includes any of the above reducers.

[0014] The beneficial effects of the present invention are as follows: the reducer of the present invention and the new energy vehicle having the reducer can greatly reduce the impact and vibration in the power transmission process by adopting friction transmission instead of gear pair transmission in the first stage transmission, thereby greatly reducing noise. Moreover, since the first stage transmission torque is small, slipping of the friction pair during torque transmission can be prevented, thereby also improving the transmission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings required for use in the embodiment of the present invention will be briefly introduced below. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work, and these are all within the protection scope of the present invention.

[0016] Figure 1 It is a stepped cross-sectional view of the reducer structure of the present invention;

[0017] Figure 2 for Figure 1 A bottom-up schematic diagram of the middle structure;

[0018] Description of reference numerals:

[0019] 1. Power input shaft; 2. Planetary shaft; 3. First-stage passive gear; 31. Groove; 4. Cage; 41. Protruding plate; 5. Second-stage driving gear; 6. Main reduction gear; 7. Differential; 8. Needle roller bearing. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described in conjunction with the drawings in the embodiment of the present invention. It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such a process, method, article or device. In the absence of further restrictions, the elements defined by the phrase "comprising..." do not exclude the presence of other identical elements in the process, method, article or device comprising the elements. If there is no conflict, the various features in the embodiments and examples of the present invention can be combined with each other, all within the scope of protection of the present invention.

[0021] refer to Figure 1 and 2 As an object of the present invention, a reducer is provided, which includes a first-stage transmission mechanism and a second-stage transmission mechanism in transmission connection, wherein the first-stage transmission mechanism is configured as a friction transmission, and the second-stage transmission mechanism is configured as a gear transmission and receives power transmitted by the friction transmission. Therefore, since the reducer of the present invention combines the first-stage friction transmission with the second-stage gear transmission, it not only reduces the noise of power transmission, but also, since the friction transmission is set in the first-stage transmission, the torque it is subjected to is smaller, thereby avoiding the risk of slipping of the friction transmission under the action of large torque and improving the power transmission efficiency.

[0022] In one embodiment, the first-stage transmission mechanism includes a power input shaft 1, a planetary shaft 2, a first-stage passive gear 3 and a retaining frame 4. The first-stage passive gear 3 is assembled on the planetary shaft 2. The power input shaft 1 is fixedly connected to the drive motor by a spline so as to reliably receive the power provided by the motor. More specifically, the first-stage passive gear 3 is assembled on the planetary shaft 2 by being tightly sleeved on the outer periphery of the planetary shaft 2. The power input shaft 1 is frictionally connected with the planetary shaft 2, so that when the power input shaft 1 rotates, the planetary shaft 2 is rotated by the friction force between the power input shaft 1 and the planetary shaft 2, and then the first-stage passive gear 3 is rotated by the friction force between the planetary shaft 2 and the first-stage passive gear 3 when the planetary shaft 2 rotates. Therefore, the power of the power input shaft 1 is transmitted to the first passive gear via the planetary shaft 2. The second-stage transmission mechanism includes a second-stage driving gear 5 that is fixedly connected to the first-stage driven gear 3 and a main reduction gear 6 that meshes with the second-stage driving gear 5. Therefore, the first-stage driven gear 3 transmits the power of the power input shaft 1 to the main reduction gear 6 via the second-stage driving gear 5, that is, the secondary driving gear receives the power from the motor transmitted by the friction transmission between the power input shaft 1 and the planetary shaft 2. Since the first-stage transmission of the reducer of the present invention adopts friction transmission, gearless torque transmission can be achieved, the vibration and noise of the transmission system can be greatly reduced, and the NVH performance level of the reducer can be improved.

[0023] In one embodiment, the first-stage passive gear 3 is sleeved in a heated state on the planetary shaft 2 which is located in a fixed position retaining frame 4 and has been sleeved on the power input shaft 1. That is to say, when the first-stage passive gear 3 is assembled on the planetary shaft 2, the position of the retaining frame 4 is first fixed, and then the planetary shaft 2 is assembled in the retaining frame 4. Finally, the first-stage passive gear 3 is heated and installed on the planetary shaft 2. According to the principle of thermal expansion and contraction, the first-stage passive gear 3 will shrink after cooling, thereby generating a huge tightening pressure on the planetary shaft 2, thereby pressing the planetary shaft 2 and the power input shaft 1 together. The heating temperature can be determined based on the material, installation dimensions and material thermal expansion and contraction coefficient table of the first-stage passive gear 3. For example, since gears are often made of steel such as quenched and tempered steel, hardened steel, carburized and hardened steel or nitrided steel, the thermal expansion coefficient α can be roughly set to 13 (10 -6 / K, 20°C). As can be seen from the above, by heating the first-stage passive gear 3 and then installing it on the planetary shaft 2, the first-stage passive gear 3 and the planetary shaft 2, as well as the planetary shaft 2 and the power input shaft 1 are tightly pressed together, thereby ensuring that the input shaft power transmits the power of the motor to the first-stage passive gear 3 with high transmission efficiency through the corresponding friction force.

[0024] In one embodiment, the first-stage passive gear 3 is fixedly connected to the second-stage driving gear 5 via a spline, so that the first-stage passive gear 3 can synchronously drive the second-stage driving gear 5 to rotate, thereby improving transmission efficiency.

[0025] In one embodiment, two circles of grooves 31 are formed on the side of the first-stage passive gear 3 facing the planetary shaft 2, and the retaining frame 4 is provided with a pair of protruding plates 41 inserted into the two circles of grooves. In this way, the pair of protruding plates 41 are inserted into the two circles of grooves 31 to ensure a firm connection between the retaining frame 4 and the first-stage passive gear 3, thereby ensuring that the planetary shaft 2 and the first-stage passive gear 3 maintain accurate positioning and close friction contact.

[0026] In one embodiment, the reducer also includes a third-stage transmission mechanism, which includes a differential 7 connected to the main reduction gear 6 through a screw member. Therefore, the differential 7 and the main reduction gear 6 are firmly connected together, thereby transmitting power to the two half-axles of the vehicle and driving the vehicle forward or backward. In addition, the output shaft of the differential 7 is connected to the wheel by a spline to achieve the function of reducing speed and increasing torque.

[0027] In one embodiment, the reducer also includes a needle bearing 8, which is assembled at the end of the power input shaft 1 away from the planetary shaft 2. The needle bearing 8 supports and positions the power input shaft 1, which helps to stabilize the friction transmission between the power input shaft 1 and the planetary shaft 2.

[0028] In one embodiment, the center line of the power input shaft 1, the center lines of the first-stage passive gear 3 and the second-stage driving gear 5 coincide with each other. Compared with the existing planetary gear reducer, the reducer of the present invention adopts friction transmission between the planetary shaft 2 and the power input shaft 1, and there is no need to set planetary gears with high precision requirements, thereby simplifying the structure.

[0029] In one embodiment, there is one retaining frame 4 which is Y-shaped or trident-shaped, and three planetary shafts 2 which are arranged in parallel and distributed at equal angles with the central axis of the retaining frame 4 as the center. The central axis of the retaining frame 4 coincides with the center line of the power input shaft 1. By such an arrangement, each planetary shaft 2 evenly receives the friction force of the power input shaft 1, and each planetary shaft 2 also applies a uniform friction force to the first-stage passive gear 3. Therefore, the friction transmission has good stability and high transmission efficiency.

[0030] In one embodiment, each planetary shaft 2 is in frictional contact with the power input shaft 1 and the first-stage passive gear 3, respectively. That is, when the power input shaft 1 rotates under the drive of the motor, it generates friction with the three planetary shafts 2 to drive the rotation of each planetary shaft 2, and then the first-stage passive gear 3 is subjected to friction through the rotation of each planetary shaft 2 to make it rotate, thereby realizing that the power of the motor is smoothly and efficiently transmitted to the first-stage passive gear 3. The friction surfaces of each planetary shaft 2, the power input shaft 1 and the first-stage passive gear 3 in frictional contact are provided with external thread protrusions (not shown) extending around their respective friction surfaces and matching with each other. Each external thread protrusion is used to increase the friction coefficient of the mutually matching friction surfaces and the synchronization of the rotation transmission. The nominal diameter of each external thread protrusion can be set according to actual needs. Preferably, the number of lines of the external thread protrusion of the power input shaft 1 is smaller than the number of lines of the external thread protrusion of the first-stage passive gear 3, that is, the number of external thread protrusions of each planetary shaft 2 that cooperate with the external thread protrusion of the power input shaft 1 is smaller than the number of external thread protrusions thereof with the first-stage passive gear 3. In this case, since the outer diameter of the outer friction surface of the power input shaft 1, the outer diameter of the outer friction surface of the planetary shaft 2 and the inner diameter of the inner friction surface of the passive gear 3 increase step by step, the different settings of the above-mentioned number of lines are conducive to ensuring that the friction force transmitted between the two friction surfaces is roughly the same, thereby ensuring the stability and synchronization of the power transmission.

[0031] As another object of the present invention, a new energy vehicle is provided, which is especially a pure electric vehicle. Any of the above reducers is provided in the new energy vehicle. Therefore, the new energy vehicle can obtain any beneficial effect of the reducer described above, which will not be repeated here.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A reducer, comprising a first-stage transmission mechanism and a second-stage transmission mechanism in transmission connection, characterized in that: The first-stage transmission mechanism is set as friction transmission; The second stage transmission mechanism is configured as a gear transmission and receives power transmitted by the friction transmission; The first-stage transmission mechanism comprises a power input shaft, a planetary shaft, a first-stage passive gear and a retainer, the first-stage passive gear is assembled on the planetary shaft, and the power input shaft is frictionally connected with the planetary shaft; The second-stage transmission mechanism comprises a second-stage driving gear fixedly connected to the first-stage passive gear and a main reduction gear meshing with the second-stage driving gear; The retainer is provided in one Y shape, the planetary shafts are provided in three, the planetary shafts are arranged in parallel and are distributed at equal angles with the central axis of the retainer as the center, and the central axis of the retainer coincides with the center line of the power input shaft; Each of the planetary shafts is in frictional contact with the power input shaft and the first-stage passive gear respectively; The friction surfaces of the planetary shafts, the power input shaft and the first-stage passive gear in friction contact are all provided with external thread protrusions extending around the respective friction surfaces and matching with each other, and each of the external thread protrusions is used to increase the friction coefficient of the friction surfaces matching with each other and the synchronization of the rotation transmission; The number of the external thread protrusions of each planetary shaft that cooperate with the external thread protrusions of the power input shaft is less than the number of the external thread protrusions of each planetary shaft that cooperate with the external thread protrusions of the first-stage passive gear.

2. The reducer according to claim 1, characterized in that: The first-stage driven gear is sleeved in a heated state on the planetary shaft which is located in the fixed position retaining frame and is sleeved on the power input shaft.

3. The reducer according to claim 1, characterized in that: The side of the first-stage passive gear facing the planetary shaft is provided with two circles of grooves, and the retaining frame is provided with a pair of protruding plates inserted in the two circles of grooves.

4. The reducer according to claim 1, characterized in that: The reducer further comprises a third-stage transmission mechanism, and the third-stage transmission mechanism comprises a differential connected to the main reduction gear via a screw member.

5. The reducer according to claim 1, characterized in that: The reducer further comprises a needle bearing, and the needle bearing is assembled at an end of the power input shaft away from the planetary shaft.

6. The reducer according to claim 1, characterized in that: The center line of the power input shaft, the center lines of the first-stage passive gear and the second-stage driving gear coincide with each other.

7. New energy vehicles, characterized in that: Comprising the reducer as claimed in any one of claims 1 to 5.

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