Off-gear prevention mechanism of wheat machine roller box

Abstract

The utility model discloses a wheat machine roller box out-of-gear preventing mechanism and belongs to the technical field of harvester transmission devices. The roller box has multi-gear rotating speeds and comprises a box body, a speed change gear shaft, a gear shifting mechanism, an input shaft and an output shaft, the input shaft and the speed change gear shaft are in meshing transmission through gears, the gear shifting mechanism comprises a gear shifting rod, and multi-gear speed change gears on the speed change gear shaft are selectively meshed with multi-gear output gears on the output shaft in a paired mode under driving of the gear shifting rod. The roller box is characterized in that the roller box further comprises an out-of-gear preventing mechanism matched with the gear shifting mechanism, the out-of-gear preventing mechanism comprises an adjusting assembly and an adjusting plate, the adjusting assembly comprises a steel ball, a pressing block, a gear shifting spring located between the steel ball and the pressing block and an adjusting screw connected to the adjusting plate in a threaded mode and abutting against the pressing block, and the steel ball abuts against a gear shifting rod of the gear shifting mechanism in a pressing mode. The pressure of the gear shifting spring is adjusted by screwing in and screwing out the adjusting screw, and then the stress of the gear shifting rod is adjusted. The device has the advantages of conveniently adjusting the compression amount of the spring, keeping the shift lever stable and preventing the roller box from being out of gear.

Description

Technical Field

[0001] The utility model belongs to the technical field of harvester transmission devices, and in particular relates to an anti-disengagement mechanism for a drum box of a wheat harvester. Background Art

[0002] Currently, the drum box of a wheat harvester is prone to gear shifting after being engaged. This occurs when vibration or a significant load increase during operation causes a gear shifting failure, resulting in the drum box being unable to transmit power. The industry generally uses a spring-and-steel ball structure, in which the steel ball cooperates with the shift lever groove to prevent gear shifting. However, the spring pressure is constant, and once set, it is impossible to readjust the gear after a gear shifting occurs, or the readjustment operation is cumbersome.

[0003] In view of the above-mentioned prior art, it is necessary to reasonably improve the electric shift structure of the existing wheat harvester gearbox. For this reason, the applicant has made a useful design, and the technical solution to be introduced below is produced under this background. Utility Model Content

[0004] The task of the utility model is to provide a wheat machine drum box anti-disengagement mechanism, which works in conjunction with the shift mechanism to facilitate adjustment of the compression amount of the spring. If disengagement occurs, the spring pressure can be adjusted after manually re-engaging the gear to keep the shift lever stable and prevent the drum box from disengaging again.

[0005] The task of the present utility model is accomplished in this way. A wheat machine drum box anti-slip mechanism, the drum box has a multi-speed speed, specifically includes a box body, a speed change gear shaft, a shift mechanism, an input shaft, and an output shaft, the input shaft and the speed change gear shaft are transmitted by gear meshing, the shift mechanism includes a shift lever, the multi-speed change gear on the speed change gear shaft is selectively paired and meshed with the multi-speed output gear on the output shaft under the drive of the shift lever, and the power from the input shaft is changed and the changed power is transmitted through the output shaft for operation of external equipment. The characteristic is that: the drum box also includes an anti-slip mechanism cooperating with the shift mechanism, the anti-slip mechanism includes an adjusting assembly and an adjusting plate, the adjusting assembly includes a steel ball, a pressure block, a shift spring located between the steel ball and the pressure block, an adjusting screw threaded on the adjusting plate and resting on the pressure block, the steel ball is pressed against the shift lever of the shift mechanism, and the pressure of the shift spring is adjusted by screwing in and out the adjusting screw to adjust the force on the shift lever.

[0006] In a specific embodiment of the present invention, the adjustment plate is fixed on the box body.

[0007] In another specific embodiment of the present invention, an annular groove for installing a sealing ring is provided on the outer ring of the pressing block.

[0008] In another specific embodiment of the present invention, the shift mechanism includes a I-gear shift mechanism and a II-III-gear shift mechanism. The shift lever on the I-gear shift mechanism is a I-gear shift lever, and the shift lever on the II-III-gear shift mechanism is a II-III-gear shift lever. The adjustment assembly has two groups, which respectively cooperate with the I-gear shift lever and the II-III-gear shift lever to lock the positions of the I-gear shift lever and the II-III-gear shift lever relative to the box body.

[0009] In another specific embodiment of the present invention, the I gear shift lever is provided with two fixed grooves corresponding to the steel balls, namely the first neutral groove and the I gear groove; the II-III gear shift lever is provided with three fixed grooves corresponding to the steel balls, namely the II gear groove, the second neutral groove, and the III gear groove, respectively. When the drum box is in the first neutral gear and the second neutral gear, the steel ball presses on the first neutral groove and the second neutral groove. When the drum box is in I gear, the steel ball cooperating with the I gear shift lever presses on the I gear groove. When the drum box is in II gear, the steel ball cooperating with the II-III gear shift lever rests on the II gear groove. When the drum box is in III gear, the steel ball cooperating with the II-III gear shift lever rests on the III gear groove.

[0010] In another specific embodiment of the present invention, the speed gear shaft is equipped with a Ⅰ speed gear, a Ⅱ speed gear, a Ⅲ speed gear, a Ⅰ speed spline hub, and a Ⅱ-Ⅲ speed spline hub, the Ⅰ speed spline hub and the Ⅱ-Ⅲ speed spline hub are fixedly mounted on the speed gear shaft, the Ⅰ speed gear, the Ⅱ speed gear, and the Ⅲ speed gear are rotatably mounted on the speed gear shaft, the output shaft is fixed with a Ⅰ speed output gear, a Ⅱ speed output gear, and a Ⅲ speed output gear, the Ⅰ speed output gear is meshed with the Ⅰ speed gear, the Ⅱ speed output gear is meshed with the Ⅱ speed gear, and the Ⅲ speed output gear is meshed with the Ⅲ speed gear.

[0011] In a further specific embodiment of the present invention, the I-gear shift mechanism includes a I-gear shift sleeve, the I-gear spline hub and the I-gear speed gear are adjacent, the I-gear speed gear is provided with I-gear mating teeth, the I-gear spline hub and the I-gear mating teeth outer ring are selectively engaged with the I-gear shift sleeve, when the I-gear shift sleeve is only engaged with the outer ring of the I-gear spline hub, it is the first neutral gear; when the I-gear shift sleeve is simultaneously engaged with the I-gear spline hub and the outer ring of the I-gear mating teeth, the I-gear is opened.

[0012] In a further specific embodiment of the utility model, the II-III gear shift mechanism further includes a II-III gear shift yoke and a II-III gear shift handle, one end of the II-III gear shift yoke is inserted into the circumferential surface of the II-III gear shift sleeve, and the other end is fixed to a II-III gear shift rod, the II-III gear shift rod is slidably arranged on the box body of the gearbox and one end of the II-III gear shift rod extends out of the box body, and a II-III gear shift handle is fixed to one end of the II-III gear shift rod extending out of the box body.

[0013] In a further specific embodiment of the utility model, the II-III gear shift mechanism further includes a II-III gear shift yoke and a II-III gear shift handle, one end of the II-III gear shift yoke is inserted into the circumferential surface of the II-III gear shift sleeve, and the other end is fixed to a II-III gear shift rod, the II-III gear shift rod is slidably arranged on the box body of the gearbox and one end of the II-III gear shift rod extends out of the box body, and a II-III gear shift handle is fixed to one end of the II-III gear shift rod extending out of the box body.

[0014] The utility model has the beneficial effects that: first, the anti-clutch mechanism and the gear shift mechanism cooperate to conveniently adjust the compression amount of the spring, if the clutching condition occurs, the adjusting screw is adjusted to the lowest point to directly lock the gear shift rod after the gear position is manually re-engaged, the gear shift rod is kept stable, and the clutching condition is ensured; second, the outer ring of the pressing block of the anti-clutch mechanism is provided with a sealing ring, the spring pressure is conveniently adjusted, the leakage of lubricating oil is effectively prevented, and the defects of oil leakage and environmental pollution are eliminated. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is the front view of the wheat machine drum box of the utility model;

[0016] Figure 2 It is the A-A sectional view of Figure 1 ; It is the B-B sectional view of

[0017] Figure 3 It is the B-B sectional view of Figure 1 ; It is the B-B sectional view of

[0018] Figure 4 It is the B-B sectional view of Figure 3Partial cross-sectional view of CC.

[0019] In the figure: 1. Speed ​​change gear shaft, 11. Output gear, 12. Speed ​​change gear of gear I, 121. Speed ​​change gear sleeve of gear I, 122. Matching teeth of gear I, 13. Speed ​​change gear of gear II, 131. Speed ​​change gear sleeve of gear II, 132. Matching teeth of gear II, 14. Speed ​​change gear of gear III, 141. Speed ​​change gear sleeve of gear III, 142. Matching teeth of gear III, 15. Spline hub of gear I, 16. Spline hub of gear II-III; 2. Shift mechanism, 21. Shift mechanism of gear I, 211. Shift sleeve of gear I, 212. Shift fork of gear I, 213. Shift lever of gear I, 2131. First neutral groove, 2132. Groove of gear I, 214. Shift mechanism of gear I Handle, 22. II-III gear shift mechanism, 221. II-III gear shift sleeve, 222. II-III gear shift fork, 223. II-III gear shift lever, 2231. II gear groove, 2232. Second neutral gear groove, 2233. III gear groove, 224. II-III gear shift handle; 3. Input shaft, 31. Input gear; 4. Output shaft, 41. I gear output gear, 42. II gear output gear, 43. III gear output gear; 5. Anti-slip mechanism, 51. Adjustment assembly, 511. Steel ball, 512. Pressure block, 513. Shift spring, 514. Adjustment screw, 515. Sealing ring, 52. Adjustment plate; 10. Housing. DETAILED DESCRIPTION

[0020] The specific implementation methods of the present invention are described in detail below with reference to the accompanying drawings. However, the description of the embodiments does not limit the technical solution. Any changes in form rather than substance based on the concept of the present invention should be regarded as within the scope of protection of the present invention.

[0021] In the following description, all concepts related to directionality or orientation such as up, down, left, right, front and back are based on the positions shown in the corresponding drawings, and therefore cannot be understood as a special limitation on the technical solution provided by the present invention.

[0022] See also Figure 1 、 Figure 2 The utility model relates to an anti-disengagement mechanism for a drum box of a wheat machine. The wheat machine includes a drum box, which has multiple speed gears. It specifically includes a box body 10, a speed change gear shaft 1, a shift mechanism 2, an input shaft 3, and an output shaft 4. The input shaft 3 and the speed change gear shaft 1 are engaged with each other through gear transmission to input external power. In this embodiment, the input gear 31 fixed on the input shaft 3 and the output gear 11 fixed on the speed change gear shaft 1 are engaged with each other for transmission. Furthermore, the input gear 31 and the output gear 11 are a set of bevel gear components.

[0023] The speed change gear shaft 1 and output shaft 4 are arranged parallel to each other in the drum box body 10. The input shaft 3 extends into the body 10 and cooperates with the speed change gear shaft 1 for transmission. The shift mechanism 2 includes a shift lever. Driven by the shift lever of the shift mechanism 2, the multi-speed change gears on the speed change gear shaft 1 selectively mate and mesh with the multi-speed output gears on the output shaft 4, shifting the power from the input shaft 3 and transmitting the changed power through the output shaft 4 to operate external equipment.

[0024] like Figure 2 As shown, the speed gear shaft 1 is mounted with an output gear 11, a first gear speed gear 12, a second gear speed gear 13, a third gear speed gear 14, a first gear spline hub 15, and a second-third gear spline hub 16. The output gear 11, first gear spline hub 15, and second-third gear spline hub 16 are fixedly mounted on the speed gear shaft 1 via a key connection. The first gear speed gear 12, second gear speed gear 13, and third gear speed gear 14 are rotatably mounted on the speed gear shaft 1 via a first gear speed gear sleeve 121, a second gear speed gear sleeve 131, and a third gear speed gear sleeve 141, respectively. The output shaft 4 is fixed with a first gear output gear 41, a second gear output gear 42, and a third gear output gear 43. The first gear output gear 41 is engaged with the first gear speed change gear 12, the second gear output gear 42 is engaged with the second gear speed change gear 13, and the third gear output gear 43 is engaged with the third gear speed change gear 14.

[0025] like Figures 1 to 3 As shown, the shift mechanism 2 includes a I-gear shift mechanism 21 and a II-III-gear shift mechanism 22. The I-gear shift mechanism 21 includes an I-gear shift sleeve 211, an I-gear shift fork 212, an I-gear shift rod 213 and an I-gear shift handle 214; the II-III-gear shift mechanism 22 includes a II-III-gear shift sleeve 221, a II-III-gear shift fork 222, a II-III-gear shift rod 223 and a II-III-gear shift handle 224.

[0026] like Figure 2 、 Figure 3 As shown, the I-speed spline hub 15 and the I-speed speed change gear 12 are adjacent, and the I-speed speed change gear 12 is provided with I-speed mating teeth 122. A I-speed shift sleeve 211 is selectively engaged with the outer rings of the I-speed spline hub 15 and the I-speed mating teeth 122. When the I-speed shift sleeve 211 is engaged only with the outer ring of the I-speed spline hub 15, the first neutral gear is engaged. When the I-speed shift sleeve 211 is engaged simultaneously with the I-speed spline hub 15 and the outer rings of the I-speed mating teeth 122, the I-speed is engaged, and the power on the input shaft 3 is transmitted through the meshing of the I-speed speed change gear 12 and the I-speed output gear 41.

[0027] like Figure 2 、 Figure 3As shown, the II-III gear spline hub 16 is located between the II gear speed change gear 13 and the III gear speed change gear 14 , the II gear speed change gear 13 is provided with II gear matching teeth 132 , and the III gear speed change gear 14 is provided with III gear matching teeth 142 . The II-III gear shift sleeve 221 is selectively engaged with the II-III gear mating teeth 132, the II-III gear spline hub 16 and the outer ring of the III gear mating teeth 142. When the II-III gear shift sleeve 221 is only engaged with the outer ring of the II-III gear spline hub 16, it is the second neutral gear; when the II-III gear shift sleeve 221 is simultaneously engaged with the II gear mating teeth 132 and the outer ring of the II-III gear spline hub 16, the II gear is opened, and the power on the input shaft 3 is transmitted through the engagement of the II gear speed change gear 13 and the II gear output gear 42; when the II-III gear shift sleeve 221 is simultaneously engaged with the III gear mating teeth 142 and the outer ring of the II-III gear spline hub 16, the III gear is opened, and the power on the input shaft 3 is transmitted through the engagement of the III gear speed change gear 14 and the III gear output gear 43.

[0028] like Figure 2 、 Figure 3 As shown, one end of the I-gear shift fork 212 is inserted into the circumferential surface of the I-gear shift sleeve 211, and the other end is fixed to the I-gear shift rod 213. The I-gear shift rod 213 is slidably set on the gearbox housing 10 and one end of it extends out of the housing 10. The I-gear shift handle 214 is fixed to the end of the I-gear shift rod 213 extending out of the housing 10.

[0029] like Figure 2 、 Figure 3 As shown, one end of the II-III gear shift fork 222 is inserted into the circumferential surface of the II-III gear shift sleeve 221, and the other end is fixed to the II-III gear shift rod 223. The II-III gear shift rod 223 is slidably set on the gearbox housing 10 and one end thereof extends out of the housing 10. A II-III gear shift handle 224 is fixed to the end of the II-III gear shift rod 223 extending out of the housing 10.

[0030] Furthermore, the distance when the I gear shift lever 213 moves from the first neutral gear to the I gear is set to be equal to the distance when the II-III gear shift lever 223 moves from the second neutral gear to the II gear or the III gear, and the action time is the same to ensure that the response time of each gear shift is consistent.

[0031] like Figure 3 、 Figure 4As shown, the drum box also includes an anti-slip mechanism 5 that cooperates with the shift mechanism 2. The anti-slip mechanism 5 includes an adjusting component 51 and an adjusting plate 52. The adjusting component 51 includes a steel ball 511, a pressure block 512, a shift spring 513 located between the steel ball 511 and the pressure block 512, and an adjusting screw 514 threadedly connected to the adjusting plate 52 and resting on the pressure block 512. The steel ball 511 is pressed against the shift lever of the shift mechanism 2. The pressure of the shift spring 513 is adjusted by screwing in and out the adjusting screw 514, thereby adjusting the force on the shift lever.

[0032] In this embodiment, the adjustment assembly 51 has two groups, which cooperate with the I-gear shift lever 213 and the II-III-gear shift lever 223 respectively, and are used to lock the position of the I-gear shift lever 213 and the II-III-gear shift lever 223 relative to the housing 10 to prevent shifting. The steel ball 511 is pressed against the I-gear shift lever 213 or the II-III-gear shift lever 223, and the I-gear shift lever 213 is provided with two fixing grooves corresponding to the steel balls 511, such as Figure 3 As shown, they are the first neutral groove 2131 and the I gear groove 2132. The II-III gear shift lever 223 is provided with three fixed grooves corresponding to the steel balls 511, as shown in FIG. Figure 3 As shown, they are the II gear groove 2231, the second neutral gear groove 2232, and the III gear groove 2233 in sequence.

[0033] When the steel ball 511, the shift spring 513 and the pressure block 512 are sequentially installed into the box body 10, the adjustment plate 52 is fixed on the top of the box body 10, and the adjustment screw 514 is screwed into the threaded hole of the adjustment plate 52 to press on the pressure block 512. The pressure of the shift spring 513 is adjusted by screwing in and out the adjustment screw 514.

[0034] In this embodiment, an annular groove for installing a sealing ring 515 is provided on the outer ring of the pressing block 512. The provision of the sealing ring 515 can prevent the leakage of lubricating oil and eliminate the defects of oil leakage and environmental pollution.

[0035] Please continue reading Figures 1 to 4 The working principle of the anti-disengagement mechanism of the wheat machine drum box described in the utility model is:

[0036] like Figure 3 、 Figure 4 As shown, when the drum box is in the initial position, the drum box is in the first neutral position and the second neutral position, and the steel ball 511 presses on the first neutral groove 2131 and the second neutral groove 2232.

[0037] When it is necessary to shift into gear I, operate the gear I shift handle 214 to pull out the gear I shift rod 213. During the pulling process, the circumferential surface of the gear I shift rod 213 squeezes the shift spring 513. Then, the steel ball 511 that cooperates with the gear I shift rod 213 presses on the gear I groove 2132. The gear I shift rod 213 drives the gear I shift fork 212 and the gear I shift sleeve 211 to slide toward the gear I speed change gear 12. When the gear I shift sleeve 211 is simultaneously engaged with the gear I spline hub 15 and the outer ring of the gear I matching tooth 122, the gear I is opened and the gear I shift handle 214 is in the Figure 3 In the middle "I gear" position, the power on the input shaft 3 is transmitted to the output shaft 4 through the synchronous movement of the I gear speed change gear 12 and the I gear spline hub 15.

[0038] When it is necessary to engage the II gear, operate the I gear shift handle 214 to push the I gear shift rod 213 back to its initial position, i.e., to the first neutral gear. Then operate the II-III gear shift handle 224 to pull out the II-III gear shift rod 223. The II-III gear shift rod 223 drives the II-III gear shift fork 222 and the II-III gear shift sleeve 221 to slide toward the II gear speed change gear 13. When the II-III gear shift sleeve 221 is simultaneously engaged with the II gear matching teeth 132 and the outer ring of the II-III gear spline hub 16, the II gear is engaged. The II-III gear shift handle 224 is located at Figure 3 In the middle "Ⅱ gear" position, the steel ball 511 matched with the Ⅱ-Ⅲ gear shift lever 223 rests in the Ⅱ gear groove 2231. The power on the input shaft 3 is transmitted to the output shaft 4 through the synchronous movement of the Ⅱ gear speed change gear 13 and the Ⅱ-Ⅲ gear spline hub 16.

[0039] When it is necessary to shift to gear III, operate the gear II-III shift handle 224 to push the gear II-III shift lever 223 back to its initial position, i.e., back to the second neutral gear. Then operate the gear II-III shift handle 224 to push the gear II-III shift lever 223 further in, and the gear II-III shift lever 223 drives the gear II-III shift fork 222 and the gear II-III shift sleeve 221 to slide toward the gear III transmission gear 14. When the gear II-III shift sleeve 221 is simultaneously engaged with the gear III mating teeth 142 and the outer ring of the gear II-III spline hub 16, gear III is on, and the gear II-III shift handle 224 is in the Figure 3 In the "III gear" position, the steel ball 511 that cooperates with the II-III gear shift lever 223 rests in the III gear groove 2233. The power on the input shaft 3 is transmitted to the output shaft 4 through the synchronous movement of the III gear speed change gear 14 and the II-III gear spline hub 16.

[0040] To sum up, during the entire operation, the wheat machine drum box can be shifted by simply pulling out or pushing the I gear shift handle 214 or the II-III gear shift handle 224. When the gear is loose, the gear can be re-engaged and the adjusting screw 514 can be rotated to readjust the pressure of the shift spring 513 to give the I gear shift lever 213 or the II-III gear shift lever 223 sufficient clamping force. The operation is simple and the gear shifting is smooth.

Claims

1. A wheat harvester drum box anti-disengagement mechanism, wherein the drum box has a multi-speed speed, specifically comprising a box body (10), a speed change gear shaft (1), a shift mechanism (2), an input shaft (3), and an output shaft (4), wherein the input shaft (3) and the speed change gear shaft (1) are engaged with each other through gears, and the shift mechanism (2) comprises a shift lever, and the multi-speed change gears on the speed change gear shaft (1) are selectively matched and engaged with the multi-speed output gears on the output shaft (4) under the drive of the shift lever, and the power from the input shaft (3) is changed and then transmitted through the output shaft (4) to supply external equipment with power, characterized in that: The drum box further comprises an anti-slip mechanism (5) cooperating with the shift mechanism (2), the anti-slip mechanism (5) comprising an adjusting assembly (51) and an adjusting plate (52), the adjusting assembly (51) comprising a steel ball (511), a pressure block (512), a shift spring (513) located between the steel ball (511) and the pressure block (512), and an adjusting screw (514) threadedly connected to the adjusting plate (52) and resting on the pressure block (512), the steel ball (511) being pressed against the shift lever of the shift mechanism (2), and the pressure of the shift spring (513) being adjusted by screwing in and out the adjusting screw (514), thereby adjusting the force on the shift lever.

2. The anti-disengagement mechanism for the drum box of a wheat harvester according to claim 1, characterized in that: The adjustment plate (52) is fixed on the box body (10).

3. The anti-disengagement mechanism for the drum box of a wheat harvester according to claim 1, characterized in that: The outer ring of the pressing block (512) is provided with an annular groove for installing a sealing ring (515).

4. The anti-disengagement mechanism for the drum box of a wheat harvester according to claim 1, characterized in that: The shift mechanism (2) includes a first gear shift mechanism (21) and a second-third gear shift mechanism (22). The shift lever on the first gear shift mechanism (21) is a first gear shift lever (213), and the shift lever on the second-third gear shift mechanism (22) is a second-third gear shift lever (223). The adjustment component (51) has two groups, which respectively cooperate with the first gear shift lever (213) and the second-third gear shift lever (223) to lock the positions of the first gear shift lever (213) and the second-third gear shift lever (223) relative to the box body (10).

5. The anti-disengagement mechanism for the drum box of a wheat harvester according to claim 4, characterized in that: The I-gear shift lever (213) is provided with two fixed grooves corresponding to the steel ball (511), namely the first neutral gear groove (2131) and the I-gear groove (2132); the II-III-gear shift lever (223) is provided with three fixed grooves corresponding to the steel ball (511), namely the II-gear groove (2231), the second neutral gear groove (2232), and the III-gear groove (2233). When the drum box is in the first neutral gear and the second neutral gear, the steel ball (511) presses against the first neutral gear groove. At the groove (2131) and the second neutral groove (2232), when the drum box is in gear I, the steel ball (511) matched with the gear I shift lever (213) presses on the gear I groove (2132); when the drum box is in gear II, the steel ball (511) matched with the gear II-III shift lever (223) presses against the gear II groove (2231); when the drum box is in gear III, the steel ball (511) matched with the gear II-III shift lever (223) presses against the gear III groove (2233).

6. The anti-disengagement mechanism for the drum box of a wheat harvester according to claim 4, characterized in that: The speed change gear shaft (1) is provided with a first gear speed change gear (12), a second gear speed change gear (13), a third gear speed change gear (14), a first gear spline hub (15), and a second-third gear spline hub (16). The first gear spline hub (15) and the second-third gear spline hub (16) are fixedly installed on the speed change gear shaft (1). The first gear speed change gear (12), the second gear speed change gear (13), and the third gear speed change gear (14) are rotatably installed on the speed change gear shaft (1). The output shaft (4) is provided with a first gear output gear (41), a second gear output gear (42), and a third gear output gear (43). The first gear output gear (41) is engaged with the first gear speed change gear (12), the second gear output gear (42) is engaged with the second gear speed change gear (13), and the third gear output gear (43) is engaged with the third gear speed change gear (14).

7. The anti-disengagement mechanism for the drum box of a wheat harvester according to claim 6, characterized in that: The I-speed shift mechanism (21) includes an I-speed shift sleeve (211), the I-speed spline hub (15) and the I-speed speed change gear (12) are adjacent, the I-speed speed change gear (12) is provided with an I-speed matching tooth (122), the I-speed spline hub (15) and the I-speed matching tooth (122) are selectively engaged with the I-speed shift sleeve (211) on the outer ring, when the I-speed shift sleeve (211) is only engaged with the outer ring of the I-speed spline hub (15), it is the first neutral gear; when the I-speed shift sleeve (211) is simultaneously engaged with the I-speed spline hub (15) and the outer ring of the I-speed matching tooth (122), it is the I-speed on.

8. The anti-disengagement mechanism for the drum box of a wheat harvester according to claim 6, characterized in that: The II-III gear shift mechanism (22) includes a II-III gear shift sleeve (221), the II-III gear spline hub (16) is located between the II gear speed change gear (13) and the III gear speed change gear (14), the II gear speed change gear (13) is provided with a II gear matching tooth (132), the III gear speed change gear (14) is provided with a III gear matching tooth (142), the II-III gear shift sleeve (221) selectively engages with the II gear matching tooth (132), the II-III gear spline hub (16), and the III gear matching tooth (142). 6) and the outer ring of the gear III matching teeth (142), when the II-III gear shift sleeve (221) is only engaged with the outer ring of the gear II-III spline hub (16), it is the second neutral gear; when the II-III gear shift sleeve (221) is simultaneously engaged with the gear II matching teeth (132) and the outer ring of the gear II-III spline hub (16), the gear II is opened; when the II-III gear shift sleeve (221) is simultaneously engaged with the gear III matching teeth (142) and the outer ring of the gear II-III spline hub (16), the gear III is opened.

9. The anti-disengagement mechanism for the drum box of a wheat harvester according to claim 7, characterized in that: The I-gear shift mechanism (21) further comprises an I-gear shift fork (212) and an I-gear shift handle (214), one end of the I-gear shift fork (212) being inserted into the circumferential surface of the I-gear shift sleeve (211), and the other end being fixed to the I-gear shift rod (213), the I-gear shift rod (213) being slidably arranged on the case (10) of the transmission case and one end extending out of the case (10), the I-gear shift handle (214) being fixed to the end of the I-gear shift rod (213) extending out of the case (10); the II-III gear shift mechanism The mechanism (22) comprises a II-III gear shift fork (222) and a II-III gear shift handle (224), one end of the II-III gear shift fork (222) is inserted into the circumferential surface of the II-III gear shift sleeve (221), and the other end is fixed to the II-III gear shift rod (223), the II-III gear shift rod (223) is slidably arranged on the case (10) of the transmission case and one end thereof extends out of the case (10), and the II-III gear shift handle (224) is fixed to the end of the II-III gear shift rod (223) extending out of the case (10).

Images