Gear shifting mechanism

Abstract

The utility model provides a gear shifting mechanism, and belongs to the technical field of agricultural machinery. The gear shifter solves the problem that an existing gear shifter is not provided with a structure for positioning a shifting fork after gear shifting. The shifting fork shaft is sleeved with the movable sleeve in a sliding mode, the shifting fork head is arranged on the movable sleeve, the gear shifting rod is used for driving the movable sleeve to move in the axial direction of the shifting fork shaft, the shifting fork shaft is provided with a plurality of limiting grooves formed in the annular direction, and the movable sleeve is provided with a positioning structure capable of being clamped into the limiting grooves. When the positioning structure is clamped into the limiting groove, axial positioning of the movable sleeve can be achieved. Due to the fact that the multiple limiting grooves are formed in the shifting fork shaft in the annular direction, each limiting groove corresponds to the position of one gear, positioning of the movable sleeve is achieved through the positioning ball of the spring, and the stability of the shifting fork head is guaranteed; a strip-shaped groove is formed in the shifting block, the shifting shaft is arranged in the strip-shaped groove in a penetrating mode, the two ends of the strip-shaped groove are blocked, and the shifting shaft can be prevented from being disengaged from the strip-shaped groove in the movement process; the sealing ring is arranged between the shaft sleeve and the rotating shaft, so that the sealing performance is enhanced.

Description

Technical Field

[0001] The utility model belongs to the technical field of agricultural machinery and relates to a shifting mechanism. Background Art

[0002] The micro-tiller is powered by a small diesel engine or gasoline engine and has the characteristics of light weight, small volume, simple structure, etc. The micro-tiller uses a shifter to shift gears. The existing shifter (such as the structure disclosed in the Chinese patent with the authorization announcement number CN215763083U) includes a shift lever, a shaft arm and a fork. One end of the shift lever is arranged outside the transmission housing, and the other end is arranged inside the transmission housing. One end of the shift lever inside the transmission housing is fixedly connected to one end of the shaft arm, and the connection part is rotatably connected to the housing. The other end of the shaft arm is connected to the fork, and the fork drives the first driven wheel and the second driven wheel to move axially along the output shaft. Since there is no structure to position the fork after shifting, the fork is unstable on the fork shaft and is prone to sliding. Content of the Utility Model

[0003] The purpose of the utility model is to address the above problems existing in the prior art and propose a shifting mechanism with good stability.

[0004] The purpose of the utility model can be achieved by the following technical solutions:

[0005] A shifting mechanism includes a fork shaft, a moving sleeve slidably sleeved on the fork shaft, a fork head arranged on the moving sleeve, and a shift lever for driving the moving sleeve to move axially along the fork shaft. A plurality of circumferentially arranged limiting grooves are formed on the fork shaft, and a positioning structure capable of being inserted into the limiting grooves is arranged on the moving sleeve. When the positioning structure is inserted into the limiting grooves, axial positioning of the moving sleeve can be realized.

[0006] In the above shifting mechanism, the positioning structure includes a positioning hole arranged on the inner surface of the moving sleeve, a spring and a positioning ball arranged in the positioning hole. The positioning hole extends radially along the fork shaft, and the positioning ball can be inserted into the limiting groove under the action of the spring force.

[0007] When the shift lever is rotated, it can drive the moving sleeve to move axially along the fork shaft, thereby driving the fork head to move. The fork head drives the shift gear to move to achieve gear shifting. After the gear position is switched in place, the positioning ball is inserted into the limiting groove under the action of the spring to realize axial positioning of the moving sleeve and ensure the stability of the current gear position. The depth of the limiting groove is less than the radius of the positioning ball. When gear shifting is required, the positioning ball can be disengaged from the limiting groove by the extrusion of the moving sleeve.

[0008] In the above-mentioned shifting mechanism, the movable sleeve is provided with a fork column extending radially along the movable sleeve, and the fork head is fixed on the fork column; the positioning hole is axially penetrated through the fork column, and the end of the positioning hole away from the movable sleeve is threadedly connected with a plug, one end of the spring rests on the plug, and the other end of the spring acts on the positioning ball.

[0009] During installation, place the positioning ball and spring into the positioning hole in sequence, then thread the plug into the positioning hole, and cooperate with the fork shaft to encapsulate the spring and positioning ball.

[0010] The above-mentioned shift mechanism also includes a rotating shaft perpendicular to the fork shaft, the shift lever is vertically fixed to the outer end of the rotating shaft, and a driving structure is provided between the rotating shaft and the movable sleeve for driving the movable sleeve to move axially along the fork shaft when the shift lever rotates.

[0011] In the above-mentioned shifting mechanism, the driving structure includes a swing arm vertically fixed to the inner end of the rotating shaft, a shift shaft arranged on the swing arm and parallel to the rotating shaft, and a shift block arranged on the movable sleeve, the shift block is provided with a strip groove extending radially along the movable sleeve, the shift shaft extends into the strip groove and the shift shaft and the strip groove are slidably matched.

[0012] When shifting is required, the shift lever is toggled to rotate around the center line of the shaft, and the swing arm is driven to rotate together through the shaft, so that the shift shaft pushes the moving sleeve to move axially. Both ends of the strip groove are closed to prevent the shift shaft from escaping from the strip groove. The outer diameter of the shift shaft is equal to the width of the strip groove, and there is no empty position when shifting.

[0013] In the above-mentioned shifting mechanism, a sleeve is provided on the rotating shaft, and a sealing ring is provided between the sleeve and the rotating shaft. At least two sealing rings are provided and are respectively provided near the two ends of the sleeve. The sleeve is fixed on the gearbox, and the rotating shaft is rotatably provided in the sleeve. The purpose of providing the sealing ring is to prevent foreign matter, rainwater, etc. from entering the gearbox.

[0014] In the above-mentioned shifting mechanism, an annular groove is provided on the rotating shaft, and the sealing ring is arranged in the annular groove. The annular groove limits the sealing ring to prevent the sealing ring from axial movement.

[0015] Compared with the prior art, the shift mechanism has the following advantages:

[0016] Since a plurality of circumferentially arranged limit grooves are provided on the shift fork shaft, each limit groove corresponds to a gear position, and the positioning of the movable sleeve is achieved by the positioning ball of the spring, thereby ensuring the stability of the shift fork head; a strip groove is provided on the shift block, and the shift shaft is passed through the strip groove, and both ends of the strip groove are blocked to prevent the shift shaft from escaping from the strip groove during movement; a sealing ring is provided between the shaft sleeve and the rotating shaft to enhance the sealing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of this shifting mechanism.

[0018] Figure 2 It is another structural schematic diagram of the shifting mechanism.

[0019] Figure 3 It is a cross-sectional view of the shift mechanism through the shift fork shaft and the shift fork column.

[0020] Figure 4 It is a cross-sectional view of the shift mechanism passing through the rotating shaft.

[0021] Figure 5 It is a schematic diagram of the coordination between the shift mechanism and the shift gear.

[0022] In the figure, 1, shift fork shaft; 2, moving sleeve; 3, shift fork head; 4, shift lever; 5, limit groove; 6, positioning hole; 7, spring; 8, positioning ball; 9, shift fork column; 10, plug; 11, rotating shaft; 12, swing arm; 13, shift shaft; 14, shift block; 15, strip groove; 16, bushing; 17, sealing ring; 18, shift gear. DETAILED DESCRIPTION

[0023] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0024] like Figure 1 and Figure 2 The shift mechanism shown includes a shift fork shaft 1 arranged in the gearbox, a moving sleeve 2 slidingly arranged on the shift fork shaft 1, a shift fork head 3 arranged on the moving sleeve 2 and a shift rod 4 for driving the moving sleeve 2 to move axially along the shift fork shaft 1. It also includes a rotating shaft 11 perpendicular to the shift fork shaft 1, the rotating shaft 11 is rotatably arranged in the gearbox, the shift rod 4 is vertically fixed to the outer end of the rotating shaft 11 extending out of the gearbox, and a driving structure is provided between the rotating shaft 11 and the moving sleeve 2 for driving the moving sleeve 2 to move axially along the shift fork shaft 1 when the shift rod 4 rotates.

[0025] like Figure 1 , 2 As shown in , 4, the driving structure includes a swing arm 12 vertically fixed to the rotating shaft 11 and extending into the inner end of the gearbox, a toggle shaft 13 arranged on the swing arm 12 and parallel to the rotating shaft 11, and a toggle block 14 arranged on the moving sleeve 2, the toggle block 14 is provided with a strip groove 15 extending radially along the moving sleeve 2, the toggle shaft 13 extends into the strip groove 15 and the toggle shaft 13 and the strip groove 15 are slidably matched.

[0026] When shifting gears, the shift lever 4 is toggled to rotate around the midline of the rotating shaft 11, driving the swing arm 12 to rotate together through the rotating shaft 11, so that the shifting shaft 13 pushes the moving sleeve 2 to move axially. Both ends of the strip-shaped groove 15 are closed to prevent the shifting shaft 13 from slipping out of the strip-shaped groove 15. The outer diameter of the shifting shaft 13 is equal to the width of the strip-shaped groove 15, and there is no virtual position during gear shifting.

[0027] To improve the sealing performance, a shaft sleeve 16 is sleeved on the rotating shaft 11. The shaft sleeve 16 is fixed on the transmission, and a sealing ring 17 is provided between the shaft sleeve 16 and the rotating shaft 11. At least two sealing rings 17 are provided and are respectively arranged near both ends of the shaft sleeve 16. The rotating shaft 11 is rotatably arranged in the shaft sleeve 16. The purpose of setting the sealing ring 17 is to prevent external impurities, rainwater, etc. from entering the transmission.

[0028] To limit the sealing ring 17, as Figure 4 shown, an annular groove is provided on the rotating shaft 11, and the sealing ring 17 is arranged in the annular groove.

[0029] As Figure 3 shown, a plurality of circumferentially arranged limiting grooves 5 are formed on the shift fork shaft 1, and a positioning structure capable of being inserted into the limiting grooves 5 is provided on the moving sleeve 2. When the positioning structure is inserted into the limiting grooves 5, axial positioning of the moving sleeve 2 can be realized.

[0030] As Figure 3 shown, the positioning structure includes a positioning hole 6 provided on the inner surface of the moving sleeve 2, a spring 7 provided in the positioning hole 6, and a positioning ball 8. The positioning hole 6 extends radially along the shift fork shaft 1, and the positioning ball 8 can be inserted into the limiting groove 5 under the action of the elastic force of the spring 7.

[0031] When the shift lever 4 is rotated, the moving sleeve 2 can be driven to move axially along the shift fork shaft 1, thereby driving the shift fork head 3 to move. The shift fork head 3 drives the shift gear 18 to move to realize gear shifting. After the gear position is switched in place, the positioning ball 8 is inserted into the limiting groove 5 under the action of the spring 7 to realize axial positioning of the moving sleeve 2 and ensure the stability of the current gear position. The depth of the limiting groove 5 is less than the radius of the positioning ball 8. When gear shifting is required, the positioning ball 8 can be disengaged from the limiting groove 5 by the extrusion of the moving sleeve 2.

[0032] As Figures 1-3 shown, a shift fork column 9 extending radially along the moving sleeve 2 is provided on the moving sleeve 2, and the shift fork head 3 is fixed on the shift fork column 9; the positioning hole 6 axially penetrates through the shift fork column 9, and a plug 10 is threadedly connected to one end of the positioning hole 6 away from the moving sleeve 2. One end of the spring 7 abuts against the plug 10, and the other end of the spring 7 acts on the positioning ball 8. During installation, the positioning ball 8 and the spring 7 are sequentially placed into the positioning hole 6, and then the plug 10 is threadedly connected into the positioning hole 6 to cooperate with the shift fork shaft 1 to package the spring 7 and the positioning ball 8.

[0033] When shifting gears, rotate the shift lever 4 to drive the rotating shaft 11 to rotate within the bushing 16, thereby driving the swing arm 12 to swing, so as to realize the rotation of the shifting shaft 13 around the midline of the rotating shaft 11. Since the shifting shaft 13 extends into the strip-shaped groove 15 and is slidably engaged with the strip-shaped groove 15, the moving sleeve 2 and the fork head 3 are driven to move axially along the shift fork shaft 1 as shown in Figure 5 As shown, the shift fork shaft 1 is fork-mounted on the shift gear 18, thereby realizing the axial movement of the shift gear 18 to achieve gear shifting.

[0034] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A gear shifting mechanism, characterized in that: The invention comprises a shift fork shaft (1), a moving sleeve (2) which is slidably sleeved on the shift fork shaft (1), a shift fork head (3) which is arranged on the moving sleeve (2), and a shift rod (4) which is used for driving the moving sleeve (2) to move axially along the shift fork shaft (1); the shift fork shaft (1) is provided with a plurality of circumferentially arranged limiting grooves (5); the moving sleeve (2) is provided with a positioning structure which can be inserted into the limiting grooves (5); when the positioning structure is inserted into the limiting grooves (5), the axial positioning of the moving sleeve (2) can be achieved.

2. The shift mechanism according to claim 1, characterized in that: The positioning structure comprises a positioning hole (6) arranged on the inner surface of the movable sleeve (2), a spring (7) and a positioning ball (8) arranged in the positioning hole (6); the positioning hole (6) extends radially along the shift fork shaft (1); and the positioning ball (8) can be inserted into the limiting groove (5) under the action of the elastic force of the spring (7).

3. The shift mechanism according to claim 2, characterized in that: The movable sleeve (2) is provided with a fork column (9) extending radially along the movable sleeve (2), and the fork head (3) is fixed on the fork column (9); the positioning hole (6) is axially penetrated through the fork column (9), and a plug (10) is threadedly connected to one end of the positioning hole (6) away from the movable sleeve (2), one end of the spring (7) abuts against the plug (10), and the other end of the spring (7) acts on the positioning ball (8).

4. The shift mechanism according to claim 1, characterized in that: It also comprises a rotating shaft (11) perpendicular to the shift fork shaft (1), the shift lever (4) being vertically fixed to the outer end of the rotating shaft (11), and a driving structure being provided between the rotating shaft (11) and the moving sleeve (2) for driving the moving sleeve (2) to move axially along the shift fork shaft (1) when the shift lever (4) rotates.

5. The shift mechanism according to claim 4, characterized in that: The driving structure comprises a swing arm (12) vertically fixed to the inner end of the rotating shaft (11), a toggle shaft (13) arranged on the swing arm (12) and parallel to the rotating shaft (11), and a toggle block (14) arranged on the moving sleeve (2), wherein the toggle block (14) is provided with a strip groove (15) extending radially along the moving sleeve (2), the toggle shaft (13) extends into the strip groove (15), and the toggle shaft (13) and the strip groove (15) are slidably matched.

6. The shift mechanism according to claim 4, characterized in that: A shaft sleeve (16) is sleeved on the rotating shaft (11), and a sealing ring (17) is provided between the shaft sleeve (16) and the rotating shaft (11).

7. The shift mechanism according to claim 6, characterized in that: The rotating shaft (11) is provided with an annular groove, and the sealing ring (17) is arranged in the annular groove.

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