Three-shaft transmission with intermediate shaft and second shaft meshed normally

Abstract

The three-shaft transmission comprises the intermediate shaft, a first shaft and a second shaft, the first shaft and the second shaft are located on the same axis and rotationally connected, a gear shifting gear is sleeved on the first shaft in an empty mode, and a combination sleeve used for being sleeved with the gear shifting gear is installed on the first shaft. A plurality of fixed gears meshed with the variable gears are correspondingly fixed on the intermediate shaft, and the second shaft is in transmission connection with the intermediate shaft through a frequently meshed gear pair. The three-shaft transmission is lighter, the size can be reduced, the weight can be reduced, and abrasion of the synchronizer can be reduced.

Description

Technical Field

[0001] The utility model relates to a three-shaft transmission with an intermediate shaft and a second shaft in constant meshing engagement. Background Art

[0002] In the automotive field, the three-axis transmission is the most popular and most complete structural form. It has been used in various automotive transmission products for more than 100 years.

[0003] The names of the main components of the three-shaft transmission have been standardized and unified worldwide: the input shaft connected to the clutch is called the first shaft, the output shaft connected to the transmission shaft is called the second shaft; the first shaft and the second shaft are on the same axis; the intermediate shaft is engaged with the first and second shafts and is responsible for power transmission. Figure 1 shown.

[0004] Although the three-shaft transmission has been continuously evolving and improving in terms of structural details, the basic configuration still retains only one structure: the intermediate shaft is constantly meshing with the first shaft, that is, the speed and torque of the intermediate shaft are in a fixed proportional relationship with the speed and torque of the first shaft. This relationship is determined by Figure 1 It is determined by the constant meshing relationship between gear 1 on the first shaft and gear 2 on the intermediate shaft.

[0005] This unique feature of the three-shaft transmission, where the first and intermediate shafts are constantly meshing, has been a hallmark of its superiority and continues to this day. However, with the diversification of market demands, especially the development of new energy commercial vehicles, new requirements have emerged. Utility Model Content

[0006] The purpose of the utility model is to provide a three-shaft transmission in which an intermediate shaft is constantly meshed with a second shaft. The three-shaft transmission is lighter and helps to reduce the wear of synchronizers.

[0007] The technical solution of the utility model is: a three-shaft transmission with an intermediate shaft and a second shaft constantly meshing, comprising an intermediate shaft, a first shaft and a second shaft, wherein the first shaft and the second shaft are located on the same axis and are rotationally connected, a shift gear is loosely sleeved on the first shaft and a coupling sleeve for sleeve-engaging the shift gear is installed, a plurality of fixed gears meshing with the speed gears are correspondingly fixed on the intermediate shaft, and the second shaft and the intermediate shaft are constantly meshing with a gear pair for transmission connection.

[0008] Furthermore, the first shaft is connected to the clutch, and the second shaft is connected to the transmission shaft.

[0009] Furthermore, the number of teeth of the multiple shift gears on the first shaft is different; the number of teeth of the multiple fixed gears on the intermediate shaft is different.

[0010] Further, the number of teeth of the multiple shift gears on the first shaft gradually increases from left to right along the axial direction; the number of teeth of the multiple fixed gears on the intermediate shaft gradually decreases from left to right along the axial direction.

[0011] Further, the constant-mesh gear pair is composed of a driving gear fixed to the right end of the intermediate shaft and a driven gear fixed to the left end of the second shaft.

[0012] Further, one end of the first shaft close to the second shaft is rotatably connected to the bushing on the driven gear.

[0013] Compared with the prior art, the utility model has the following advantages:

[0014] 1. When realizing the same transmission ratio function, the selectable meshing gear pair of the B-type structure of the utility model is located at the front end of the constant-mesh gear pair, and the selectable gear pair amplifies the torque of the first shaft. While the selectable meshing gear pair of the A-type structure is located at the rear end of the constant-mesh gear pair, and the selectable gear pair amplifies the torque of the intermediate shaft; since the intermediate shaft of the A-type structure has already amplified the torque of the first shaft, the torque borne by all the gear pairs of the A-type structure is larger than that of the B-type structure. In other words: the gear parts of the B-type structure can be made lighter and more compact due to the smaller load, and the volume and weight can be reduced.

[0015] 2. For each shifting process of the three-shaft transmission, the synchronizer of the coupling sleeve needs a friction and synchronization process. This process forcibly makes the speeds of the rotating parts at both ends of the coupling sleeve the same by friction. Since the rear end of the coupling sleeve is connected to the huge inertia of the whole vehicle, the friction synchronization process basically "grinds" down (or "grinds" up) the speed of the rotating part at its front end by means of the synchronizer. Therefore, the moment of inertia of the rotating part at the front end of the coupling sleeve synchronizer will have a significant impact on the friction synchronization process time and the wear of the synchronizer: the larger the moment of inertia of the rotating part at the front end of the synchronizer, the longer the synchronization time (i.e., the shifting time), and the greater the wear of the synchronizer. It can be seen from the composition of the structure that the front rotating part of the synchronizer of the A-type structure includes the entire intermediate shaft and all the gears fixed thereon, the first shaft and the clutch driven disk; while the front rotating part of the synchronizer of the B-type structure only includes the first shaft and the clutch driven disk, and its moment of inertia is much smaller than that of the front rotating part of the synchronizer of the A-type structure. Therefore, the shifting synchronization time of the B-type structure is significantly reduced, and the wear of the synchronizer will also be significantly reduced.

[0016] 3. For new energy commercial vehicles, when it is necessary to increase the motor power, it is introduced from the intermediate shaft. By adopting the B-type structure of the present utility model, the motor is constantly meshed with the second shaft (output shaft) and is not controlled by the shifting mechanism, so that the power can be uninterrupted during the shifting process. This is an important technical way to improve the shifting quality. (In the A-type structure, whether the motor is introduced from the first shaft or the intermediate shaft of the transmission, it is controlled by the shifting mechanism and cannot output power to the second shaft (output shaft) during the shifting process, so the power cannot be uninterrupted during the shifting process). BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of an existing three-axis transmission;

[0018] Figure 2 is a three-axis transmission with the intermediate shaft and the first shaft constantly meshed conventionally;

[0019] Figure 3 is a schematic structural diagram of a three-axis transmission with the intermediate shaft and the second shaft constantly meshed according to the present utility model;

[0020] In the figure: 1 - intermediate shaft; 2 - first shaft; 3 - second shaft; 4 - shifting gear; 5 - coupling sleeve; 6 - fixed gear; 7 - driving gear; 8 - driven gear. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to make the above features and advantages of the present utility model more understandable, the following specific embodiments are given and described in detail in conjunction with the accompanying drawings. However, the present utility model is not limited thereto.

[0022] Reference Figure 3

[0023] A three-axis transmission with the intermediate shaft and the second shaft constantly meshed includes an intermediate shaft 1 that undertakes the power transmission function, as well as a first shaft 2 and a second shaft 3. The first shaft and the second shaft are on the same axis and are rotationally connected. A shifting gear 4 is sleeved on the first shaft and a coupling sleeve 5 for sleeving the shifting gear is slidably installed through a spline. A plurality of fixed gears 6 meshing with the transmission gears are correspondingly fixed on the intermediate shaft. The second shaft and the intermediate shaft are connected by a constantly meshing gear pair for transmission.

[0024] In this embodiment, the first shaft is connected to a clutch for power input; the second shaft is connected to a drive shaft for power output.

[0025] In this embodiment, the number of teeth of the plurality of shifting gears on the first shaft is different; the number of teeth of the plurality of fixed gears on the intermediate shaft is different. Specifically, for example, the number of teeth of the plurality of shifting gears on the first shaft gradually increases from left to right along the axis; the number of teeth of the plurality of fixed gears on the intermediate shaft gradually decreases from left to right along the axis.

[0026] In this embodiment, the constantly meshing gear pair consists of a driving gear 7 fixed to the right end of the countershaft and a driven gear 8 fixed to the left end of the second shaft.

[0027] In this embodiment, one end of the first shaft close to the second shaft is rotatably connected to a bushing on the driven gear.

[0028] For the convenience of description, the conventional three-shaft transmission with the countershaft constantly meshing with the first shaft is simply referred to as the A-type structure, and the three-shaft transmission with the countershaft constantly meshing with the second shaft involved in the present invention is simply referred to as the B-type structure.

[0029] I. The A-type structure and the B-type structure have the following common points:

[0030] 1. Both the A-type structure and the B-type structure have a countershaft, and multiple gears on the countershaft are fixedly connected to the countershaft.

[0031] 2. Both the A-type structure and the B-type structure rely on a certain synchronizer sleeve to exclusively select and engage a certain gear position (mesh a certain pair of gears) to transmit power with the countershaft.

[0032] 3. Except for the direct gear, the power transmission of each gear position in the A-type structure and the B-type structure passes through two-stage gear meshing transmission. One stage has a constant meshing fixed transmission ratio i fixed, and the other stage has the transmission ratio i gear of the pair of gears selected by the synchronizer sleeve of that gear position. The total transmission ratio from input to output in both configurations is equal to the product of the constant meshing fixed transmission ratio and the selectable gear position transmission ratio: i total = i fixed × i gear.

[0033] II. The A-type structure and the B-type structure also have the following differences:

[0034] 1. The countershaft of the A-type structure is constantly meshed with the first shaft, and its fixed transmission ratio is i fixed A.

[0035] The countershaft of the B-type structure is constantly meshed with the second shaft, and its fixed transmission ratio is i fixed B.

[0036] 2. The shift gears of each gear position in the A-type structure are all freely sleeved on the second shaft, and the synchronizer sleeve corresponding to the gear position on the second shaft is used to select and engage a certain shift gear. Power is received from the countershaft through the fixed gear on the corresponding countershaft and output to the second shaft. At this time, the total transmission ratio i total = i fixed A × i gear (where i fixed A is the constant meshing transmission ratio between the countershaft and the first shaft).

[0037] For the B-type structure, the shift gears of each gear position are freely sleeved on the first shaft. The coupling sleeve corresponding to the gear position on the first shaft is used to select and engage a certain shift gear. The power is transmitted to the intermediate shaft through the fixed gear corresponding to the intermediate shaft and then output through meshing to the second shaft. At this time, the total transmission ratio i_total = i_gear × i_fixed_B (i_fixed_B is the constant mesh transmission ratio between the intermediate shaft and the second shaft).

[0038] If terms such as "first" and "second" are used in the present invention to limit components, those skilled in the art should understand that the use of "first" and "second" is only for the convenience of differentiating components in description. Unless otherwise stated, these terms have no special meaning.

[0039] If the present invention discloses or involves components or structural parts that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (such as using bolts or screws), or it can also be understood as: a non-detachable fixed connection (such as riveting, welding). Of course, the mutual fixed connection can also be replaced by an integral structure (such as manufactured by integral casting process) (except when it is obviously impossible to use the integral forming process).

[0040] In addition, unless otherwise stated, the terms used to represent positional relationships or shapes in any of the technical solutions disclosed in the present invention include states or shapes that are approximate, similar, or close to them.

[0041] Any component provided by the present invention can either be assembled from multiple separate components or be a single component manufactured by an integral forming process.

[0042] The above are only the preferred embodiments of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope covered by the present invention.

Claims

1. A three-shaft transmission with a constant mesh between the countershaft and the second shaft, comprising a countershaft, a first shaft and a second shaft, characterized in that, The first shaft and the second shaft are on the same axis and are rotatably connected. A shift gear is sleeved on the first shaft, and a clutch sleeve for engaging the shift gear is installed. A plurality of fixed gears meshing with the transmission gears are correspondingly fixed on the intermediate shaft, and the second shaft and the intermediate shaft are connected by a constant-mesh gear pair.

2. A three-shaft transmission with a middle shaft and a second shaft in constant meshing engagement according to claim 1, characterized in that: The first shaft is connected to the clutch, and the second shaft is connected to the transmission shaft.

3. A three-shaft transmission with constant mesh between the countershaft and the second shaft according to claim 1 or 2, characterized in that, The number of teeth of the plurality of shift gears on the first shaft is different; the number of teeth of the plurality of fixed gears on the intermediate shaft is different.

4. A three-shaft transmission with a constant mesh between the countershaft and the second shaft, characterized in that, The number of teeth of the plurality of shift gears on the first shaft gradually increases from left to right along the axis; the number of teeth of the plurality of fixed gears on the intermediate shaft gradually decreases from left to right along the axis.

5. A three-shaft transmission with a middle shaft and a second shaft in constant meshing engagement according to claim 1, characterized in that: The constant-mesh gear pair is composed of a driving gear fixed at the right end of the intermediate shaft and a driven gear fixed at the left end of the second shaft.

6. A three-shaft transmission with constant mesh between the countershaft and the second shaft, characterized in that, One end of the first shaft close to the second shaft is rotatably connected to the shaft sleeve on the driven gear.

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