A transmission device for small agricultural machinery

Abstract

This utility model discloses a transmission device for a small agricultural machine, including a housing. Inside the housing are a clutch and an input shaft. The clutch includes a driving disc, a driven disc, a driving friction plate connected to the driving disc, a driven friction plate connected to the driven disc, and a pressure plate. The driven disc is splinedly connected to the input shaft. The pressure plate is located on the side of the driven disc opposite to the driving disc. A clutch sleeve and a retaining ring are located on the side of the pressure plate opposite to the driven disc. The clutch sleeve is rotatably mounted on the input shaft. The clutch sleeve is slidably fitted with an operating mechanism for driving the pressure plate. The operating mechanism is hinged to the housing, and its rotation axis is perpendicular to the input shaft. The operating mechanism is connected to the clutch sleeve profile. A release spring is provided between the pressure plate and the driven disc to abut against the clutch sleeve. This solution solves the problem of long power disconnection delay time in existing transmission devices.

Description

Technical Field

[0001] This utility model relates to a transmission device for small agricultural machinery. Background Technology

[0002] Small agricultural work machines are agricultural machines with engine power below 15 horsepower. Due to their compact structure, light weight, ease of operation, and wide applicability, they are increasingly favored by consumers. The transmission device used in small agricultural work machines transmits the power output from the engine to the working mechanism (cutting tools) and the traveling mechanism. The transmission device generally includes a housing, inside which are installed a clutch, a power input shaft, a power output shaft, and a gear mechanism between the power input shaft and the power output shaft. The clutch is a friction clutch, with the clutch's driving disc and driven disc connected by a friction plate assembly. The driven disc of the clutch is splined to the power input shaft. The clutch also includes a pressure plate that cooperates with the driven disc to keep the friction plate assembly engaged. A clutch sleeve is loosely fitted on the power input shaft to push the pressure plate and maintain the friction plate assembly engaged. In actual use, it has been found that agricultural work machines are prone to high operating loads, high starting loads, and alternating loads, causing the clutch to wear out quickly and have poor durability.

[0003] Chinese patent document CN217814915U discloses a micro-tiller and its transmission mechanism, including a main drive shaft, a secondary shaft, and a reverse gear shaft. One end of the main drive shaft is connected to an engine, and the other end is connected to a starter motor. One or more gear pairs are provided between the main drive shaft and the secondary shaft, and at least one gear pair is provided between the main drive shaft and the reverse gear shaft. At least one gear pair is also provided between the reverse gear shaft and the secondary shaft. The main drive shaft is arranged longitudinally, with the engine located at the front end and the starter motor located at the rear end. The starter motor is connected to the transmission main shaft via a pair of reduction gears, and the engine is connected to the transmission main shaft via a clutch. The clutch includes a housing connected to the output shaft of the engine, a friction plate assembly connected to one end of the transmission main shaft and located within the housing, and a pressure plate that acts axially on the friction plate assembly. It also includes a starter drive mechanism that drives the pressure plate. The starter drive mechanism includes a starter fork shaft and a starter fork mounted on the starter fork shaft. The starter fork acts on the end face of the pressure plate, and one end of the starter fork shaft is connected to a starter handle.

[0004] In practical use, it has been found that the friction plate assembly of the clutch is prone to incomplete disengagement, resulting in a relatively long delay in the power disconnection of the transmission device, which affects the safety of small agricultural machinery. Utility Model Content

[0005] The purpose of this invention is to provide a transmission device for small agricultural machinery to solve the problem of long power disconnection delay time in the prior art.

[0006] To achieve the above objectives, the basic solution of this utility model provides a transmission device for a small agricultural machine, including a housing. Inside the housing are a clutch and an input shaft. The clutch includes a driving disc, a driven disc, a driving friction plate connected to the driving disc, a driven friction plate connected to the driven disc, and a pressure plate that slides with the driven disc to maintain the driving and driven friction plates in a engaged state. The driven disc is splined to the input shaft. The pressure plate is located on the side of the driven disc opposite to the driving disc. A clutch sleeve and a retaining ring are provided on the side of the pressure plate opposite to the driven disc. The retaining ring is located on the side of the clutch sleeve opposite to the pressure plate. The clutch sleeve is rotatably mounted on the input shaft. The clutch sleeve is slidably fitted with an operating mechanism for driving the pressure plate. The operating mechanism is hinged to the housing, and its rotation axis is perpendicular to the input shaft. The retaining ring is snapped onto the outside of the input shaft. The operating mechanism is connected to the clutch sleeve profile. A release spring is provided between the pressure plate and the driven disc to abut against the clutch sleeve.

[0007] The beneficial effects of this basic scheme are as follows: By controlling the operating mechanism to move away from the pressure plate, the pressure plate loses the squeezing effect of the operating mechanism and moves away from the driven plate under the elastic force of the separation spring. This causes the active and driven friction plates to gradually separate from the pressure plate and driven plate. At this time, the pressure plate abuts against the clutch sleeve under the elastic force of the separation spring, increasing the friction between the pressure plate and the clutch sleeve. The clutch sleeve cannot rotate due to the restriction effect of its connection with the operating mechanism. This friction between the pressure plate and the clutch sleeve forms a resistance that hinders the pressure plate from continuing to rotate. The pressure plate transmits this resistance to the driven plate, increasing the rotational resistance of the driven plate. This increases the tendency for relative sliding between the active and driven friction plates, allowing them to quickly and completely separate and achieve complete power disconnection. This significantly shortens the power disconnection delay time of the transmission device, which is beneficial to improving the safety of agricultural machinery.

[0008] Preferably, the outer side of the clutch sleeve is provided with a sliding plane that slides with the operating mechanism, and the sliding plane is arranged parallel to the input shaft. This arrangement allows the operating mechanism to move along the sliding plane when it slides relative to the clutch sleeve, thus facilitating manufacturing and assembly operations.

[0009] Preferably, the release spring is a helical spring. This design, compared to a disc spring, offers advantages in terms of mature structure and lower cost, thus helping to reduce overall costs.

[0010] Preferably, the operating mechanism includes a clutch fork and a fork shaft. The fork shaft is perpendicular to the input shaft and is rotatably connected to the housing. The clutch fork is statically connected to the fork shaft. This configuration simplifies the structure of the operating mechanism and improves its reliability.

[0011] Preferably, a planar bearing is provided between the pressure plate and the operating mechanism, and the planar bearing is connected to the pressure plate. This arrangement allows the operating mechanism to move the pressure plate through contact with the planar bearing, thereby avoiding wear caused by relative rotation between the pressure plate and the operating mechanism, and thus improving the service life of both the pressure plate and the operating mechanism.

[0012] Preferably, an intermediate bearing is coaxially connected inside the drive disc, with the outer ring of the intermediate bearing connected to the drive disc and the inner ring of the intermediate bearing coaxially connected to the input shaft. This arrangement allows the drive disc to be supported on the input shaft by the intermediate bearing, thereby improving the stability of the drive disc during rotation, ensuring the coaxiality between the drive disc and the input shaft, and reducing clutch vibration.

[0013] Preferably, the drive disc is coaxially provided with an input keypad, which rotatably engages with the drive disc. A buffer spring is provided between the input keypad and the drive disc, and the buffer spring is distributed in a ring around the rotation axis of the input keypad. This arrangement utilizes the input keypad and buffer spring to cushion the impact forces on the clutch, thus improving the clutch's service life.

[0014] Preferably, a support bearing is coaxially connected to the outer side of the input keyboard. This arrangement allows the support bearing to support the input keyboard during use, thereby improving its stability. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an embodiment of a transmission device for a small agricultural machine according to the present invention; Figure 2 for Figure 1 A schematic diagram of the engagement between the clutch and the input shaft. Detailed Implementation

[0016] The following detailed description illustrates the specific implementation methods: The reference numerals in the accompanying drawings include: support bearing 1, input keypad 2, buffer spring 3, intermediate bearing 4, driving disc 5, driving friction plate 6, driven friction plate 7, driven disc 8, pressure plate 9, release spring 10, plane bearing 11, shift fork shaft 12, clutch shift fork 13, clutch sleeve 14, retaining ring 15, housing 16, and input shaft 17.

[0017] The basic implementation examples are as follows: Figure 1 and Figure 2 The diagram shows a transmission device for a small agricultural machine, comprising a housing 16. Inside the housing 16 are a clutch, an input shaft 17, an output shaft, and a gear mechanism. The input shaft 17 and the output shaft are rotatably connected to the housing 16. The gear mechanism is positioned between the input shaft 17 and the output shaft to transmit power. The clutch is located at the end of the input shaft 17. The clutch includes a driving disc 5, a driven disc 8, a driving friction plate 6 connected to the driving disc 5, a driven friction plate 7 connected to the driven disc 8, and a pressure plate 9 that slides with the driven disc 8 to maintain the driving friction plate 6 and the driven friction plate 7 in a engaged state. The driven disc 8 is splinedly connected to the input shaft 17, and the pressure plate 9 is located on the side of the driven disc 8 opposite to the driving disc 5.

[0018] In this embodiment, a clutch sleeve 14 and a retaining ring 15 are provided on the side of the pressure plate 9 opposite to the driven plate 8 to limit the movement range of the pressure plate 9. The retaining ring 15 is located on the side of the clutch sleeve 14 opposite to the pressure plate 9. The clutch sleeve 14 is rotatably fitted onto the input shaft 17, allowing the clutch sleeve 14 and the input shaft 17 to rotate relative to each other. The retaining ring 15 is engaged with the outside of the input shaft 17, thereby allowing the retaining ring 15 to axially limit the clutch sleeve 14 and prevent the clutch sleeve 14 from moving away from the pressure plate 9. The clutch sleeve 14 is slidably fitted with an operating mechanism for driving the movement of the pressure plate 9. The operating mechanism is connected to the profile of the clutch sleeve 14, preventing the clutch sleeve 14 from rotating with the input shaft 17 under the limiting effect of the operating mechanism. In this embodiment, the operating mechanism includes a clutch fork 13 and a fork shaft 12. The fork shaft 12 is perpendicular to the input shaft 17 and is rotatably connected to the housing 16. The clutch fork 13 is fixedly connected to the fork shaft 12, so that the rotation of the fork shaft 12 causes the clutch fork 13 to slide relative to the clutch sleeve 14, thereby allowing the clutch fork 13 to push the pressure plate 9 to move. In this embodiment, the outer side of the clutch sleeve 14 is provided with a sliding plane that slides with the clutch fork 13 of the operating mechanism. The sliding plane is parallel to the input shaft 17. In this embodiment, the outer contour of the cross-section of the clutch sleeve 14 is a quadrilateral with a set of parallel opposite sides.

[0019] A plane bearing 11 is provided between the pressure plate 9 and the operating mechanism. The plane bearing 11 is connected to the pressure plate 9, so that the operating mechanism pushes the pressure plate 9 to move by contacting the plane bearing 11. This prevents the operating mechanism from directly contacting the pressure plate 9 and avoids wear caused by the relative rotation between the pressure plate 9 and the operating mechanism.

[0020] In this embodiment, a release spring 10 is provided between the pressure plate 9 and the driven plate 8 to abut against the clutch sleeve 14. The release spring 10 is preferably a helical spring, with one end abutting against the driven plate 8 and the other end abutting against the pressure plate 9. When the pressure plate 9 and the driven plate 8 move away from each other under the action of the release spring 10, the driving friction plate 6 and the driven friction plate 7 separate due to the gradual decrease in pressure.

[0021] In this embodiment, an intermediate bearing 4 is coaxially connected inside the drive disc 5. The outer ring of the intermediate bearing 4 is connected to the drive disc 5, and the inner ring of the intermediate bearing 4 is coaxially connected to the input shaft 17. This allows the drive disc 5 to be supported and connected to the input shaft 17 via the intermediate bearing 4, improving the coaxiality between the drive disc 5 and the input shaft 17, and also enhancing the stability of the drive disc 5. An input keypad 2 is coaxially mounted on the drive disc 5, rotating in conjunction with it. A buffer spring 3 is positioned between the input keypad 2 and the drive disc 5, arranged in a ring around the rotation axis of the input keypad 2. When the input keypad 2 rotates, it compresses the buffer spring 3, causing the buffer spring 3 to push the drive disc 5 to rotate, thus using the buffer spring 3 to cushion the impact between the input keypad 2 and the drive disc 5. A support bearing 1 is coaxially connected to the outer side of the input keypad 2. During use, the support bearing 1 connects the input keypad 2 to the engine, further enhancing its stability.

[0022] The specific implementation process is as follows: When the power of the transmission device is disconnected, the operating mechanism is controlled to move away from the pressure plate 9, that is, the clutch fork 13 is controlled to move away from the pressure plate 9. This causes the pressure plate 9 to lose the squeezing action of the clutch fork 13 and move away from the driven plate 8 under the elastic force of the release spring 10. As a result, the driving friction plate 6 and the driven friction plate 7 lose the clamping and pressing action of the pressure plate 9 and the driven plate 8 and gradually separate. At this time, the pressure plate 9 abuts against the clutch sleeve 14 under the elastic force of the release spring 10, which increases the friction between the pressure plate 9 and the clutch sleeve 14. The clutch sleeve 14 then reacts with the operating mechanism... The mechanism is restricted from rotating due to the surface connection, which causes the friction between the pressure plate 9 and the clutch sleeve 14 to form a resistance that prevents the pressure plate 9 from rotating further. The pressure plate 9 transmits the resistance to the driven plate 8, which increases the rotational resistance of the driven plate 8. This increases the tendency for relative sliding between the driving friction plate 6 and the driven friction plate 7, allowing the driving friction plate 6 and the driven friction plate 7 to quickly and completely separate, thus achieving a complete disconnection of power. This significantly shortens the delay time of power disconnection in the transmission device, which is beneficial to improving the safety of agricultural machinery.

[0023] The above description is merely an embodiment of this utility model, and common knowledge such as specific structures and characteristics of the solution is not described in detail here. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of this utility model, and these should also be considered within the protection scope of this utility model. These modifications and improvements will not affect the effectiveness of the implementation of this utility model or the practicality of the patent.

Claims

1. A transmission device for a small agricultural machine, comprising a housing, wherein a clutch and an input shaft are disposed inside the housing; the clutch comprises a driving disc, a driven disc, a driving friction plate connected to the driving disc, a driven friction plate connected to the driven disc, and a pressure plate that slides with the driven disc to maintain the driving friction plate and the driven friction plate in an engaged state; the driven disc is splinedly connected to the input shaft; the pressure plate is located on the side of the driven disc opposite to the driving disc; a clutch sleeve and a retaining ring are disposed on the side of the pressure plate opposite to the driven disc; the retaining ring is located on the side of the clutch sleeve opposite to the pressure plate; the clutch sleeve is rotatably fitted onto the input shaft; the clutch sleeve is slidably fitted with an operating mechanism for driving the pressure plate to move; the operating mechanism is hinged to the housing; the rotation axis of the operating mechanism is perpendicular to the input shaft; the retaining ring is snapped onto the outside of the input shaft; characterized in that: The operating mechanism is connected to the clutch sleeve profile, and a separation spring is provided between the pressure plate and the driven plate to make the pressure plate abut against the clutch sleeve.

2. The transmission device for a small agricultural machine according to claim 1, characterized in that: The outer side of the clutch sleeve is provided with a sliding plane that slides with the operating mechanism, and the sliding plane is arranged parallel to the input shaft.

3. The transmission device for a small agricultural machine according to claim 2, characterized in that: The release spring is a helical spring.

4. The transmission device for a small agricultural machine according to claim 3, characterized in that: The operating mechanism includes a clutch fork and a fork shaft. The fork shaft is perpendicular to the input shaft and is rotatably connected to the housing. The clutch fork is statically connected to the fork shaft.

5. A transmission device for a small agricultural machine according to claim 4, characterized in that: A planar bearing is provided between the pressure plate and the operating mechanism, and the planar bearing is connected to the pressure plate.

6. A transmission device for a small agricultural machine according to claim 5, characterized in that: An intermediate bearing is coaxially connected inside the drive disc. The outer ring of the intermediate bearing is connected to the drive disc, and the inner ring of the intermediate bearing is coaxially connected to the input shaft.

7. A transmission device for a small agricultural machine according to claim 6, characterized in that: The active disk is coaxially provided with an input keypad, which is rotatably engaged with the active disk. A buffer spring is provided between the input keypad and the active disk, and the buffer spring is distributed in a ring around the rotation axis of the input keypad.

8. A transmission device for a small agricultural machine according to claim 7, characterized in that: The input keyboard is coaxially connected to a support bearing on its outer side.

Images