Variable speed drum transmission structure

Abstract

The utility model discloses transmission structure of variable speed drum, including the engine for all terrain vehicle, be provided with drive part, variable speed part and output part in the engine, the variable speed part includes the gear assembly for speed regulation and the adjusting assembly for adjusting gear, the adjusting assembly includes the fork mechanism, variable speed drum and drive shaft, be provided with driving gear on the drive shaft, the end of variable speed drum is provided with the driven gear that engages with driving gear, and the variable speed drum is integrally formed with driven gear and sets up, the advantage is, has improved the structure overall rigidity and torsional strength of variable speed drum and driven gear, can better bear the impact and vibration in the process of gear shifting, fundamentally avoided the risk of connecting piece loosening, fracture, and transmission reliability significantly enhances.

Description

Technical Field

[0001] This utility model relates to the field of vehicle transmission technology, and in particular to a transmission drum structure. Background Technology

[0002] The gear shift drum (also known as the gear change drum) is a commonly used gear shifting mechanism in the gearboxes of small vehicles such as motorcycles and all-terrain vehicles. It is usually a cylindrical drum with precision curved grooves machined on its surface. When shifting gears, by rotating the gear shift drum, its curved grooves guide the shift fork to move axially, thereby driving the synchronizer or gear engagement sleeve to achieve the switching of different gears.

[0003] In a traditional gear-shifting drum transmission structure, there is usually a gear-shifting drum body and an independent driven gear. The driven gear is assembled onto the gear-shifting drum by means of key connection, spline connection or tight fit, and is driven by an external drive gear (such as a motor or manual shifting mechanism) to rotate, thereby transmitting the rotational motion to the gear-shifting drum.

[0004] However, this split structure has some drawbacks. Since the gears and the transmission drum are two separate parts, they need to be processed separately before being assembled. This inevitably leads to the accumulation of processing and assembly errors, which in turn affects the meshing accuracy of the gears and the concentricity of the transmission drum. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a variable speed drum transmission structure with high transmission accuracy, reliable connection and lower manufacturing cost.

[0006] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: a transmission structure with a gear shift drum, including an engine for an all-terrain vehicle, wherein the engine is provided with a drive unit, a transmission unit and an output unit, the transmission unit includes a gear assembly for speed adjustment and an adjustment assembly for adjusting gear position, the adjustment assembly includes a shift fork mechanism, a transmission drum and a drive shaft, a drive gear is provided on the drive shaft, and a driven gear that meshes with the drive gear is provided at the end of the transmission drum, wherein the transmission drum and the driven gear are integrally formed.

[0007] A further preferred embodiment of this utility model is that the driven gear is a spur gear, helical gear, or worm gear.

[0008] A further preferred embodiment of this utility model is that a shift groove for connecting with a shift fork mechanism is provided on the surface of the shift drum.

[0009] A further preferred embodiment of this utility model is that the inside of the speed-changing drum is provided with lubricating oil channels.

[0010] A further preferred embodiment of this utility model is that the speed-changing drum and the driven gear are machined from cast or forged blanks, or integrally formed by powder metallurgy.

[0011] A further preferred embodiment of this utility model is as follows: a positioning rod is provided on the engine, a positioning bead is provided at the bottom of the positioning rod, and multiple positioning bead engaging grooves are provided circumferentially on the surface of the transmission drum.

[0012] Compared with the prior art, the advantages of this utility model are that the driven gear and the transmission drum body are integrated into one design, eliminating the connection interface of the traditional split structure, making the entire transmission component a continuous rigid body. This greatly improves the overall rigidity and torsional strength of the structure, and can better withstand the impact and vibration during the shifting process. It fundamentally avoids the risk of loosening and breaking of the connecting parts, and significantly enhances the reliability of the transmission. Attached Figure Description

[0013] The present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. However, those skilled in the art will understand that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be construed as limiting the scope of the present invention. Furthermore, unless specifically indicated, the drawings are only schematic representations of the composition or structure of the described objects and may contain exaggerated depictions, and the drawings are not necessarily drawn to scale.

[0014] Figure 1 This is a three-dimensional structural diagram of the engine in this utility model; Figure 2 This is a schematic diagram of the internal structure of the engine in this utility model; Figure 3 This is a three-dimensional structural diagram of the connection between the speed-changing drum and the shift fork mechanism in this utility model. Figure 4 This is a three-dimensional structural diagram of the speed-changing drum in this utility model; Figure 5 This is a three-dimensional structural diagram of the positioning rod in this utility model.

[0015] In the diagram: 1. Engine; 2. Drive unit; 3. Transmission unit; 31. Gear assembly; 4. Output unit; 5. Transmission drum; 51. Groove; 52. Shift groove; 53. Lubrication oil passage; 54. Driven gear; 6. Positioning rod; 61. Positioning ball; 7. Drive shaft; 71. Drive gear; 8. Shift fork mechanism; 81. Guide pin. Detailed Implementation

[0016] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are merely descriptive and exemplary and should not be construed as limiting the scope of protection of the present invention.

[0017] It should be noted that similar labels in the following figures indicate similar items; therefore, once an item is defined in one figure, it may not be further defined and explained in subsequent figures.

[0018] This embodiment mainly describes the structure of the variable speed drum transmission structure, as follows: like Figures 1-5 As shown, the transmission structure includes an engine 1 for an all-terrain vehicle, with a drive unit 2, a transmission unit 3, and an output unit 4. The transmission unit 3 includes a gear assembly 31 for speed adjustment and an adjustment assembly for gear selection. The adjustment assembly includes a shift fork mechanism 8, a transmission drum 5, and a drive shaft 7. A drive gear 71 is mounted on the drive shaft 7, and a driven gear 54 meshing with the drive gear 71 is mounted at the end of the transmission drum 5. The transmission drum 5 and the driven gear 54 are integrally formed, thus designing the driven gear 54 and the transmission drum 5 as a single unit, fundamentally eliminating the need for separate components. The assembly tolerances between the driven gear 54 and the transmission drum 5 ensure that the concentricity of their axes coincides, resulting in smoother gear meshing and more precise shifting. The integrated molding structure eliminates any mechanical connection between the driven gear 54 and the transmission drum 5 body, preventing relative movement or loosening. This allows it to withstand greater torque and impact loads, thus extending the service life of both the transmission drum 5 and the driven gear 54. Furthermore, the integrated molding of the transmission drum 5 and the driven gear 54 eliminates the need for separate gear parts, connectors, and corresponding assembly processes, reducing the number of parts and inventory management costs.

[0019] Furthermore, the driven gear 54 is a spur gear, helical gear, or worm gear, and its module, number of teeth, and pressure angle are precisely designed according to the parameters of the driving gear 71 that drives it in the gearbox to ensure proper meshing and transmission.

[0020] Furthermore, a shift groove 52 for connecting with the shift fork mechanism 8 is provided on the surface of the shift drum 5. The shift groove 52 is used to accommodate the guide pin 81 of the shift fork. When the shift drum 5 rotates, the contour of the shift groove 52 will push the shift fork to move axially along the shift drum 5, thereby actuating the synchronizer or shift gear to achieve gear shifting.

[0021] Furthermore, the transmission drum 5 has a lubricating oil passage 53 inside, which can be used to guide lubricating oil into the shift groove 52, so as to lubricate and cool the guide pin 81 of the shift fork.

[0022] Furthermore, the gear shift drum 5 and the driven gear 54 are machined after casting or forging blanks, or integrally formed by powder metallurgy. In this way, when making the gear shift drum 5 and the driven gear 54, the mature integral forming process such as casting or forging combined with machining or powder metallurgy can be selected according to the production batch and performance requirements, which makes it easy to achieve large-scale and consistent production.

[0023] Furthermore, to ensure the reliability of the gear shift drum 5 during use, a positioning rod 6 is provided on the engine 1, and a positioning bead 61 is retractably provided at the bottom of the positioning rod 6. At the same time, multiple grooves 51 for engaging the positioning beads 61 are circumferentially formed on the surface of the gear shift drum 5. In this way, when the gear shift drum 5 completes gear adjustment, the positioning rod 6 can be inserted into the corresponding groove 51. This avoids the problem of the gear shift drum 5 rotating automatically after the gear adjustment is completed, thus avoiding the problem of skipping gears. When the gear shift drum 5 rotates, the positioning bead 61 can be retracted into the positioning rod 6 by squeezing it until the bottom of the positioning rod 6 is once again above the groove 51 on the gear shift drum 5. At this time, the positioning bead 61 extends out of the positioning rod 6 and engages with the groove 51 on the gear shift drum 5.

[0024] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0025] The variable speed drum transmission structure provided by this utility model has been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand this utility model and its core ideas. It should be noted that those skilled in the art can make several improvements and modifications to this utility model without departing from its principle, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A transmission structure with a variable speed drum, comprising an engine for an all-terrain vehicle, the engine having a drive unit, a transmission unit, and an output unit, the transmission unit comprising a gear assembly for speed regulation and an adjustment assembly for gear adjustment, characterized in that: The adjustment assembly includes a shift fork mechanism, a speed-changing drum, and a drive shaft. A drive gear is provided on the drive shaft, and a driven gear that meshes with the drive gear is provided at the end of the speed-changing drum. The speed-changing drum and the driven gear are integrally formed.

2. The variable speed drum transmission structure according to claim 1, characterized in that: The driven gear is a spur gear, helical gear, or worm gear.

3. The variable speed drum transmission structure according to claim 1, characterized in that: The surface of the gear shift drum is provided with a shift groove for connecting with the shift fork mechanism.

4. The variable speed drum transmission structure according to claim 1, characterized in that: The transmission drum has lubricating oil channels inside.

5. The variable speed drum transmission structure according to claim 1, characterized in that: The speed-changing drum and driven gear are machined from cast or forged blanks, or integrally formed by powder metallurgy.

6. The variable speed drum transmission structure according to claim 1, characterized in that: The engine is equipped with a positioning rod, and a positioning bead is retractably provided at the bottom of the positioning rod. The surface of the transmission drum is provided with multiple grooves for the positioning bead to engage.

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