A gearbox for mini tillers with convenient gear adjustment

Abstract

This utility model relates to the field of gearbox technology, and in particular to a micro-tiller gearbox with convenient gear adjustment. It includes an input shaft and an output shaft on a housing, connected by a transmission structure. The transmission structure includes a reverse gear shaft and an intermediate shaft arranged on the housing and parallel to the input shaft. A first double gear is axially movable on the input shaft, and a second double gear and a third double gear are respectively provided on the reverse gear shaft and the intermediate shaft, with the small tooth of the second double gear meshing with the large tooth of the third double gear. A first shift fork is provided on the housing. The working end of the first shift fork extends into the housing and can drive the first double gear to move axially to reverse gear, slow gear, and fast gear. This utility model features a simpler and more compact structural design, more convenient and smoother gear shifting operation, and a more reasonable gear ratio design.

Description

Technical Field

[0001] This utility model relates to the field of gearbox technology, and in particular to a gearbox for a micro-tiller that facilitates gear adjustment. Background Technology

[0002] A mini tiller is an agricultural machine powered by a small diesel or gasoline engine, characterized by its light weight, small size, and simple structure. Mini tillers are widely applicable to dry land, paddy fields, and orchards in plains, mountains, and hills. By using different attachments, they can perform various tasks such as tilling, ditching, fertilizing, weeding, and spraying pesticides.

[0003] However, the current mini-tillers on the market still have the following shortcomings due to the unreasonable design of the gearbox: 1. It is inconvenient to adjust the reverse gear, slow gear and fast gear, and the gear adjustment is not convenient and smooth; 2. The gear ratio design is not reasonable, and it is not safe and comfortable to use; 3. The gearbox design is not compact enough and still does not meet the requirements of lightweighting.

[0004] Therefore, how to design a mini-tiller gearbox with a simpler and more compact structure, more convenient and smoother gear shifting operation, more reasonable gear ratio design for each gear, and better meet the requirements of lightweight design has become a technical problem that needs to be solved by those skilled in the art. Utility Model Content

[0005] In view of the above-mentioned defects of the prior art, the technical problem to be solved by this utility model is how to design a micro-tiller gearbox with a simpler and more compact structure, more convenient and smoother gear shifting operation, more reasonable gear ratio design, and better able to meet the requirements of lightweight design.

[0006] To achieve the above objectives, this utility model provides a convenient gearbox for a micro-tiller, comprising an input shaft and an output shaft on a housing, the input shaft and the output shaft being connected by a transmission structure; characterized in that: the transmission structure includes a reverse gear shaft and an intermediate shaft arranged on the housing and parallel to the input shaft; a first double gear is axially movable on the input shaft, and a second double gear and a third double gear are respectively provided on the reverse gear shaft and the intermediate shaft, with the small teeth of the second double gear meshing with the large teeth of the third double gear; a first shift fork is provided on the housing; the working end of the first shift fork extends into the housing and can drive the first double gear to move axially to reverse gear, slow gear, and fast gear; such that the large teeth of the first double gear mesh with the large teeth of the second double gear to form reverse gear; such that the small teeth of the first double gear mesh with the large teeth of the third double gear to form slow gear; such that the large teeth of the first double gear mesh with the small teeth of the third double gear to form fast gear.

[0007] In this way, in the aforementioned mini-tiller gearbox, the first shift fork mounted on the gearbox body can drive the first double gear on the input shaft to move axially to reverse, slow, and fast gears. In reverse gear, the large teeth of the first double gear mesh with the large teeth of the second double gear; in slow gear, the small teeth of the first double gear mesh with the large teeth of the third double gear; and in fast gear, the large teeth of the first double gear mesh with the small teeth of the third double gear. Controlling the movement of the first double gear via the first shift fork to achieve the adjustment of the three gears makes gear shifting more convenient and smoother.

[0008] As an optimization, the first double gear has 20 teeth on its large tooth, a gear module of 1.75, and a tooth tip circle diameter of 39.16 cm; the first double gear has 16 teeth on its small tooth, a gear module of 1.75, and a tooth tip circle diameter of 31.8 cm.

[0009] The second double gear has 21 teeth on its large tooth, a gear module of 1.75, and a tooth tip circle diameter of 39.4 cm; the second double gear has 16 teeth on its small tooth, a gear module of 1.75, and a tooth tip circle diameter of 31.8 cm.

[0010] The third double gear has 36 teeth on its large tooth, a gear module of 1.75, and a tooth tip circle diameter of 66.0 cm; the third double gear has 32 teeth on its small tooth, a gear module of 1.75, and a tooth tip circle diameter of 59.6 cm.

[0011] This results in a reverse gear ratio of 51.5:1 and a reverse gear speed of 70 rpm; a slow gear ratio of 39:1 and a slow gear speed of 92 rpm; and a fast gear ratio of 27.5:1 and a fast gear speed of 130 rpm.

[0012] In this way, the design of the number of teeth, gear module, and tip circle diameter of the large and small teeth of the first, second, and third double gears is more reasonable, resulting in a more compact overall structure. Furthermore, the resulting transmission ratio and speed design are more reasonable and better meet usage requirements.

[0013] As an optimization, a first mounting hole is provided on the housing, and the first shift fork includes a rotating shaft rod that is rotatably installed in the first mounting hole. A connecting block is integrally formed on the inner end of the rotating shaft rod, and a shift fork block is provided on the connecting block. A mating groove is provided on the inner side of the shift fork block, and the corresponding side of the large tooth of the first double gear extends into the mating groove. Furthermore, a first shift fork operating rod is connected and fixed to the outer end of the rotating shaft rod outside the housing.

[0014] In this way, the structural design of the first shift fork is more reasonable. By setting a shift fork block and setting a mating groove on the shift fork block, it can better mesh with the large tooth of the first double gear, thereby improving the reliability of the first shift fork's operation. Secondly, it also makes the design of the first double gear more compact and the axial dimension smaller.

[0015] Furthermore, a protective bushing is provided between the rotating shaft and the first mounting hole, and two sealing grooves are provided on the rotating shaft, each with a sealing ring.

[0016] In this way, by setting up protective bushings and sealing rings, the installation of the rotating shaft can be made more convenient.

[0017] As an optimization, a clutch is installed inside the housing and at one end corresponding to the input shaft; one end of the clutch is connected to the input shaft for transmission, and the other end of the clutch is used to connect to the engine power output shaft for transmission; and a thrust ball bearing is sleeved on the mounting cylinder at the inner end of the clutch housing; a clutch control fork is provided on the housing, and the inner end of the clutch control fork extends into the housing and can abut against and be supported on the thrust ball bearing, so that a thrust can be applied to the clutch housing through the thrust ball bearing, so that the friction plates inside the clutch contact and transmit power.

[0018] This design simplifies the clutch placement and allows for a more compact overall gearbox structure. Furthermore, the included clutch control fork provides better clutch operation.

[0019] As an optimization, the clutch control shift fork includes a rotatable mounting shaft mounted on the housing; a clutch operating lever is connected to one end of the mounting shaft; and a connecting sleeve is fitted on the mounting shaft, the connecting sleeve having an anti-rotation pin inserted into a pin hole on the mounting shaft; and drive rods are integrally formed at both ends of the connecting sleeve, such that the drive rods are respectively supported on both sides of the thrust ball bearing.

[0020] This design makes the clutch control fork more rational, allowing for better application of control force to the clutch via the thrust ball bearing.

[0021] As an optimization, a first bevel gear is provided at the inner end of the third double gear; a vertically arranged drive shaft is also provided in the housing, a second bevel gear is provided at the upper end of the drive shaft, and the second bevel gear meshes with the first bevel gear; a third bevel gear is provided at the lower end of the drive shaft, and a fourth bevel gear is provided on the output shaft, and the third bevel gear meshes with the fourth bevel gear and can drive the output shaft to rotate.

[0022] This simplifies the transmission connection between the third double gear and the output shaft, and makes the overall structural design more compact.

[0023] Furthermore, the two ends of the drive shaft are each mounted on the housing via bearings.

[0024] Furthermore, two bearings are spaced apart at one end of the intermediate shaft and mounted on the housing.

[0025] As an optimization, the housing includes an upper housing and a lower housing that are fixed together by bolts. The input shaft, intermediate shaft and reverse gear shaft are arranged in the upper housing; the transmission shaft is arranged in the lower housing, and the output shaft is also arranged on the lower housing.

[0026] This makes the design of the box simpler and more reasonable, and easier to process and manufacture.

[0027] Furthermore, the upper box includes the upper box body and the box cover.

[0028] This technical solution also discloses a mini-tiller, characterized in that it includes the aforementioned mini-tiller gearbox with convenient gear adjustment.

[0029] In summary, the above structure has the following advantages: 1. It only has three axes, making it lightweight and compact; 2. All gears can be switched with a single shift fork, making operation simple; 3. The walking speed can be adjusted, ensuring safety. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a micro-tiller gearbox with convenient gear adjustment according to a specific embodiment of this utility model.

[0031] Figure 2 yes Figure 1 The left view.

[0032] Figure 3 yes Figure 1 The main view.

[0033] Figure 4 yes Figure 1 A structural diagram with some parts of the box removed.

[0034] Figure 5 yes Figure 4 A magnified view of position A in the diagram.

[0035] Figure 6 yes Figure 4 A schematic diagram after rotating by one angle.

[0036] Figure 7 yes Figure 4 A diagram showing the result after rotating to another angle.

[0037] Figure 8 yes Figure 7 A magnified view of position B in the diagram.

[0038] Figure 9 yes Figure 1 A structural diagram omitting the box section. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that in the description of the present invention, terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing the present invention and for 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 manner. Therefore, they should not be construed as limitations on the present invention. Terms such as "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] like Figures 1 to 9 As shown, a convenient gearbox for a micro-tiller includes an input shaft 1 and an output shaft 2 on a housing, connected by a transmission structure. The transmission structure includes a reverse gear shaft 3 and an intermediate shaft 4 arranged on the housing and parallel to the input shaft. A first double gear 5 is axially movable on the input shaft, and a second double gear 6 and a third double gear 7 are respectively provided on the reverse gear shaft and the intermediate shaft, with the small teeth of the second double gear meshing with the large teeth of the third double gear. A first shift fork 8 is provided on the housing. The working end of the first shift fork extends into the housing and can drive the first double gear to move axially to reverse gear, slow gear, and fast gear. The large teeth of the first double gear mesh with the large teeth of the second double gear to form reverse gear; the small teeth of the first double gear mesh with the large teeth of the third double gear to form slow gear; and the large teeth of the first double gear mesh with the small teeth of the third double gear to form fast gear.

[0041] In this way, in the aforementioned mini-tiller gearbox, the first shift fork mounted on the gearbox body can drive the first double gear on the input shaft to move axially to reverse, slow, and fast gears. In reverse gear, the large teeth of the first double gear mesh with the large teeth of the second double gear; in slow gear, the small teeth of the first double gear mesh with the large teeth of the third double gear; and in fast gear, the large teeth of the first double gear mesh with the small teeth of the third double gear. Controlling the movement of the first double gear via the first shift fork to achieve the adjustment of the three gears makes gear shifting more convenient and smoother.

[0042] In this specific embodiment, the large tooth 9 of the first double gear has 20 teeth, a gear module of 1.75, and a tooth tip circle diameter of 39.16 cm; the small tooth 10 of the first double gear has 16 teeth, a gear module of 1.75, and a tooth tip circle diameter of 31.8 cm.

[0043] The second double gear has 21 teeth on the large tooth 11, a gear module of 1.75, and a tooth tip circle diameter of 39.4 cm; the second double gear has 16 teeth on the small tooth 12, a gear module of 1.75, and a tooth tip circle diameter of 31.8 cm.

[0044] The third double gear has 36 teeth (large tooth 13), a gear module of 1.75, and a tooth tip circle diameter of 66.0 cm; the third double gear has 32 teeth (small tooth 14), a gear module of 1.75, and a tooth tip circle diameter of 59.6 cm.

[0045] This results in a reverse gear ratio of 51.5:1 and a reverse gear speed of 70 rpm; a slow gear ratio of 39:1 and a slow gear speed of 92 rpm; and a fast gear ratio of 27.5:1 and a fast gear speed of 130 rpm.

[0046] In this way, the design of the number of teeth, gear module, and tip circle diameter of the large and small teeth of the first, second, and third double gears is more reasonable, resulting in a more compact overall structure. Furthermore, the resulting transmission ratio and speed design are more reasonable and better meet usage requirements.

[0047] In this specific embodiment, a first mounting hole is provided on the housing, and the first shift fork includes a rotating shaft 15 rotatably mounted in the first mounting hole. A connecting block 16 is integrally formed on the inner end of the rotating shaft, and a shift fork block 17 is provided on the connecting block. A mating groove is provided on the inner side of the shift fork block, and the corresponding side of the large tooth of the first double gear extends into the mating groove. Furthermore, a first shift fork operating rod 18 is connected and fixed to the outer end of the rotating shaft outside the housing.

[0048] In this way, the structural design of the first shift fork is more reasonable. By setting a shift fork block and setting a mating groove on the shift fork block, it can better mesh with the large tooth of the first double gear, thereby improving the reliability of the first shift fork's operation. Secondly, it also makes the design of the first double gear more compact and the axial dimension smaller.

[0049] Furthermore, a protective bushing 19 is provided between the rotating shaft and the first mounting hole, and two sealing grooves are provided on the rotating shaft, each with a sealing ring.

[0050] In this way, by setting up protective bushings and sealing rings, the installation of the rotating shaft can be made more convenient.

[0051] In this specific embodiment, a clutch 20 is installed inside the housing and at one end corresponding to the input shaft; one end of the clutch is connected to the input shaft for transmission, and the other end of the clutch is used to connect to the engine power output shaft for transmission; and a thrust ball bearing 21 is sleeved on the mounting cylinder at the inner end of the clutch housing; a clutch control fork 22 is provided on the housing, and the inner end of the clutch control fork extends into the housing and can abut against and be supported on the thrust ball bearing, so that a thrust can be applied to the clutch housing through the thrust ball bearing, so that the friction plates inside the clutch contact and transmit power.

[0052] This design simplifies the clutch placement and allows for a more compact overall gearbox structure. Furthermore, the included clutch control fork provides better clutch operation.

[0053] In this specific embodiment, the clutch control shift fork includes a rotatable mounting shaft 23 mounted on the housing; a clutch operating lever 24 is connected to one end of the mounting shaft; and a connecting sleeve 25 is sleeved on the mounting shaft, the connecting sleeve is provided with an anti-rotation pin and is inserted into the pin hole of the mounting shaft; each end of the connecting sleeve is integrally formed with a drive support rod 26, and the drive support rods are respectively supported on both sides of the thrust ball bearing.

[0054] This design makes the clutch control fork more rational, allowing for better application of control force to the clutch via the thrust ball bearing.

[0055] In this specific embodiment, a first bevel gear 27 is provided at the inner end of the third double gear; a vertically arranged transmission shaft 28 is also provided in the housing, a second bevel gear 29 is provided at the upper end of the transmission shaft, and the second bevel gear meshes with the first bevel gear; a third bevel gear 30 is provided at the lower end of the transmission shaft, and a fourth bevel gear 31 is provided on the output shaft, and the third bevel gear meshes with the fourth bevel gear and can drive the output shaft to rotate.

[0056] This simplifies the transmission connection between the third double gear and the output shaft, and makes the overall structural design more compact.

[0057] Furthermore, the two ends of the drive shaft are each mounted on the housing via bearings.

[0058] Furthermore, two bearings are spaced apart at one end of the intermediate shaft and mounted on the housing.

[0059] In this specific embodiment, the housing includes an upper housing 32 and a lower housing 33 that are fixed together by bolts. The input shaft, intermediate shaft and reverse gear shaft are arranged in the upper housing; the transmission shaft is arranged in the lower housing, and the output shaft is also arranged on the lower housing.

[0060] This makes the design of the box simpler and more reasonable, and easier to process and manufacture.

[0061] Furthermore, the upper box body includes the upper box body and the box cover 34.

[0062] This technical solution also discloses a mini-tiller, characterized by including the aforementioned mini-tiller gearbox with convenient gear adjustment.

[0063] Furthermore, the first bevel gear, the second bevel gear, the third bevel gear, and the fourth bevel gear have 8, 34, 8, and 30 teeth, respectively; and a module of 3.5.

[0064] In summary, the above structure has the following advantages: 1. It only has three axes, making it lightweight and compact; 2. All gears can be switched with a single shift fork, making operation simple; 3. The walking speed can be adjusted, ensuring safety.

[0065] The preferred embodiments of this utility model have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of this utility model without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of this utility model through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A convenient gearbox for a micro-tiller, comprising an input shaft and an output shaft on a housing, the input shaft and the output shaft being connected via a transmission structure; characterized in that... ； The transmission structure includes a reverse gear shaft and an intermediate shaft arranged on the housing and parallel to the input shaft; a first double gear is axially movable on the input shaft, and a second double gear and a third double gear are respectively arranged on the reverse gear shaft and the intermediate shaft, with the small tooth of the second double gear meshing with the large tooth of the third double gear; a first shift fork is provided on the housing; the working end of the first shift fork extends into the housing and can drive the first double gear to move axially to the reverse gear, slow gear, and fast gear; so that the large tooth of the first double gear meshes with the large tooth of the second double gear to form the reverse gear; so that the small tooth of the first double gear meshes with the large tooth of the third double gear to form the slow gear; so that the large tooth of the first double gear meshes with the small tooth of the third double gear to form the fast gear.

2. The micro-tiller gearbox with convenient gear adjustment as described in claim 1, characterized in that; The first double gear has 20 teeth on its large tooth, a gear module of 1.75, and a tooth tip circle diameter of 39.16 cm; the first double gear has 16 teeth on its small tooth, a gear module of 1.75, and a tooth tip circle diameter of 31.8 cm. The second double gear has 21 teeth on its large tooth, a gear module of 1.75, and a tooth tip circle diameter of 39.4 cm; the second double gear has 16 teeth on its small tooth, a gear module of 1.75, and a tooth tip circle diameter of 31.8 cm. The third double gear has 36 teeth on its large tooth, a gear module of 1.75, and a tooth tip circle diameter of 66.0 cm; the third double gear has 32 teeth on its small tooth, a gear module of 1.75, and a tooth tip circle diameter of 59.6 cm.

3. The micro-tiller gearbox with convenient gear adjustment as described in claim 1, characterized in that; A first mounting hole is provided on the housing. The first shift fork includes a rotating shaft rod that is rotatably installed in the first mounting hole. A connecting block is integrally formed on the inner end of the rotating shaft rod. A shift fork block is provided on the connecting block. A mating groove is provided on the inner side of the shift fork block, such that the large tooth side of the first double gear extends into the mating groove. A first shift fork operating rod is connected and fixed to the outer end of the rotating shaft rod outside the housing.

4. The micro-tiller gearbox with convenient gear adjustment as described in claim 1, characterized in that; A clutch is installed inside the housing and at one end corresponding to the input shaft; one end of the clutch is connected to the input shaft for transmission, and the other end of the clutch is used to connect to the engine power output shaft for transmission; and a thrust ball bearing is sleeved on the mounting cylinder at the inner end of the clutch housing; a clutch control fork is provided on the housing, and the inner end of the clutch control fork extends into the housing and can abut against and be supported on the thrust ball bearing, so that a thrust can be applied to the clutch housing through the thrust ball bearing, so that the friction plates inside the clutch contact and transmit power.

5. A convenient gearbox for a micro-tiller as described in claim 4, characterized in that... ； The clutch control shift fork includes a rotatable mounting shaft mounted on a housing; a clutch operating lever is connected to one end of the mounting shaft; a connecting sleeve is fitted on the mounting shaft, the connecting sleeve is provided with an anti-rotation pin and is inserted into a pin hole on the mounting shaft; each end of the connecting sleeve is integrally formed with a drive support rod, such that the drive support rods are respectively supported on both sides of a thrust ball bearing.

6. A convenient gearbox for a micro-tiller as described in claim 1, characterized in that; A first bevel gear is provided at the inner end of the third double gear; a vertically arranged drive shaft is also provided in the housing, a second bevel gear is provided at the upper end of the drive shaft, and the second bevel gear meshes with the first bevel gear; a third bevel gear is provided at the lower end of the drive shaft, and a fourth bevel gear is provided on the output shaft, and the third bevel gear meshes with the fourth bevel gear and can drive the output shaft to rotate.

7. A convenient gearbox for a micro-tiller as described in claim 6, characterized in that; The housing includes an upper housing and a lower housing that are fixed together by bolts. The input shaft, intermediate shaft and reverse gear shaft are arranged in the upper housing; the transmission shaft is arranged in the lower housing, and the output shaft is also arranged on the lower housing.

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