Gearbox

Abstract

The utility model relates to the technical field of agricultural harvesters, in particular to a gearbox. A gearbox comprises a shell and a box cover, the upper portion of the shell is connected with a fork shaft, the lower portion of the shell is connected with a gear shaft, and the fork shaft is connected with a gear shifting fork; a first-gear gear, a second-gear gear and a third-gear gear are sequentially arranged on the intermediate gear shaft, a first-gear gear hub sleeve and a second-gear and third-gear gear hub sleeve are connected to the gear shaft, the first-gear gear hub sleeve and the first-gear gear are arranged adjacently, and the second-gear and third-gear gear hub sleeve is arranged between the second-gear gear and the third-gear gear. The hydraulic input gearbox is provided with three gears (the first gear, the second gear and the third gear), the gear structure is simple and compact, operation and control are easy, and the problem that double gears are engaged or the gear cannot be engaged due to the fact that gear selection is not in place due to interlocking is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of agricultural harvesters, in particular to a gearbox. Background Art

[0002] Currently, there are many types of general-purpose harvesters, such as grain combine harvesters, corn harvesters, peanut harvesters, and rice harvesters. The traditional travel drive mode is that the engine outputs power through a V-belt pulley and a V-belt to drive a mechanical gearbox. The gearbox generally has four gears (one, two, three, and reverse). The power input to the gearbox is selected and shifted through the shift cover assembly installed on the top of the gearbox, thereby achieving power output at different speeds and torques, and then the power is transmitted to the left and right side reducers through the left and right half shafts of the gearbox, and the left and right side reducers drive the tires to rotate.

[0003] This type of gearbox is usually equipped with two fork shafts, and the gear selection and shifting operation mode is frequently required during use, which makes it easy for the operator to select the wrong gear and fail to engage in gear, or engage in double gears. Therefore, the present application provides a gearbox with simplified gear positions, and solves the problem of engaging in double gears or failing to engage in gears due to the interlocking problem of the double fork shaft gearbox in the prior art. Utility Model Content

[0004] In order to solve the above problems, the utility model provides a gearbox.

[0005] The technical solution adopted by the utility model to solve the technical problem is: a gearbox, comprising a housing and a housing cover, the upper part of the housing is connected to a fork shaft, the lower part of the housing is connected to a gear shaft, and the fork shaft is connected to a shift fork;

[0006] The gear shaft is provided with a first gear, a second gear and a third gear in sequence, and the gear shaft is connected with a first gear hub sleeve and a second and third gear hub sleeve. The first gear hub sleeve is arranged adjacent to the first gear, and the second and third gear hub sleeve is arranged between the second gear and the third gear.

[0007] As an optimization, the length of the first gear hub sleeve is 56.5 mm, and the length of the meshing teeth of the second gear is 33.5 mm.

[0008] As an optimization, two shift forks are provided, namely a first gear fork and a second and third gear fork, the fork foot spacing of the two forks is 151 mm, and a shift block is provided between the two forks.

[0009] As an optimization, five gears are included, namely, third gear, neutral gear, second gear, neutral gear, and first gear. The gear shifting distance between two adjacent gears is 11.5 mm. Five self-locking grooves are provided at one end of the fork shaft, and the center distance between two adjacent self-locking grooves is 11.5 mm.

[0010] As an optimization, a shift assembly is connected to the interior of the case cover, and the shift assembly comprises an outer shift rocker arm, a thrust bearing and an inner shift rocker arm from top to bottom, and the outer shift rocker arm is located on the upper side of the gearbox.

[0011] As an optimization, the lever arm length of the inner shift rocker arm is 65 mm, and the lever arm length of the outer shift rocker arm is 130 mm;

[0012] When the length direction of the outer shift rocker arm is set along the length direction of the gearbox, it is the second gear. When the outer shift rocker arm is offset to the left by 10.2° and 20.7° along the length direction of the gearbox, it is neutral and the third gear respectively. When the outer shift rocker arm is offset to the right by 10.2° and 20.7° along the length direction of the gearbox, it is neutral and the first gear respectively.

[0013] As an optimization, based on the space required for the shifting stroke and the strength of the gears and shafts, the housing needs to be widened from the original width of 278mm to 323mm.

[0014] The gearbox of this scheme has the following advantages:

[0015] The hydraulic input gearbox has three gears (first gear, second gear, and third gear). The gear structure is simple and compact, and the operation is simple, eliminating the problem of engaging double gears or not being able to engage gears due to interlocking problems;

[0016] Widen the gearbox housing and calculate the minimum required width of the gearbox housing according to the gear parameters; lengthen the first gear hub and calculate the minimum required length of the first gear hub according to the gear stroke parameters; lengthen the second gear meshing tooth length and calculate the minimum length of the second gear meshing tooth according to the gear stroke parameters; fix the second and third gear shift forks and the first gear shift fork on the same fork shaft to realize a one-rod-tube three-gear structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Attached Figure 1 It is a schematic diagram of the internal structure of the gearbox of the utility model.

[0018] Attached Figure 2 This is a schematic diagram of the gear structure of the gearbox of the utility model.

[0019] Among them, 1. housing, 2. case cover, 3. fork shaft, 4. gear shaft, 5. first gear gear, 6. second gear gear, 7. third gear gear, 8. first gear hub sleeve, 9. second and third gear hub sleeves, 10. first gear shift fork, 11. second and third gear shift forks, 12. shift block, 13. outer shift rocker arm, 14. thrust bearing, 15. inner shift rocker arm. DETAILED DESCRIPTION

[0020] like Figure 1-2As shown, a gearbox includes a housing 1 and a housing cover 2, wherein the upper portion of the housing 1 is connected to a fork shaft 3, the lower portion of the housing 1 is connected to a gear shaft 4, and the fork shaft 3 is connected to a shift fork;

[0021] The gear shaft 4 is provided with a first gear 5, a second gear 6 and a third gear 7 in sequence. The gear shaft 4 is connected to a first gear hub sleeve 8 and a second- and third-gear hub sleeve 9. The first gear hub sleeve 8 is arranged adjacent to the first gear 5, and the second- and third-gear hub sleeve 9 is arranged between the second gear 6 and the third gear 7.

[0022] When assembling the gearbox, the shift fork and the fork shaft 3 are fixed together by a pin shaft;

[0023] The length of the first gear hub sleeve 8 is 56.5 mm, and the length of the meshing teeth of the second gear 6 is 33.5 mm.

[0024] like Figure 1 As shown, there are two shift forks, namely a first gear shift fork 10 and a second and third gear shift fork 11, the fork foot spacing of the two shift forks is 151 mm, and a shift block 12 is provided between the two shift forks.

[0025] It includes five gears, namely, third gear, neutral gear, second gear, neutral gear and first gear. The gear engagement distance between two adjacent gears is 11.5 mm. Five self-locking grooves are provided at one end of the fork shaft 3, and the center distance between two adjacent self-locking grooves is 11.5 mm.

[0026] like Figure 1 As shown, the interior of the case cover 2 is connected with a shift assembly, and the shift assembly comprises an outer shift rocker arm 13, a thrust bearing 14 and an inner shift rocker arm 15 from top to bottom, and the outer shift rocker arm 13 is located on the upper side of the gearbox.

[0027] The lever arm length of the inner shift rocker arm 15 is 65 mm, and the lever arm length of the outer shift rocker arm 13 is 130 mm;

[0028] like Figure 2 As shown, when the length direction of the outer shift rocker arm 13 is set along the length direction of the gearbox, it is the second gear; when the outer shift rocker arm 13 is offset to the left by 10.2° and 20.7° along the length direction of the gearbox, it is the neutral gear and the third gear respectively; when the outer shift rocker arm 13 is offset to the right by 10.2° and 20.7° along the length direction of the gearbox, it is the neutral gear and the first gear respectively.

[0029] During the gear shifting process, the outer shift rocker arm 13 is directly moved, and the inner shift rocker arm 15 is driven to move through the outer shift rocker arm 13. The shift dial head at the lower end of the shift rocker arm drives the shift block 12 to swing left and right, and the fork shaft 3 drives the first gear shift fork 10 and the second and third gear shift forks 11 to slide left and right together. The shift fork simultaneously drives the first gear gear hub sleeve 8 and the second and third gear gear hub sleeve 9 (referred to as gear hub sleeves) to slide on the gear shaft 4, and the gear shifting can be achieved by meshing the inner spline of the gear hub sleeve with the outer spline of the first gear gear 5, the second gear gear 6 or the third gear gear 7.

[0030] According to the space required for the shifting stroke and the strength of the gears and shafts, the housing 1 needs to be widened from the original width of 278 mm to 323 mm.

[0031] The present application is for a fork shaft 3 to control three gears, and a neutral gear must be set between every two adjacent gears. Therefore, the gear shifting mechanism needs to have a total of five gear positions (three gear positions plus two neutral positions). After gear shifting simulation and calculation, it is necessary to lengthen the first gear hub to 56.5mm and the second gear meshing tooth to 33.5mm. After such parameter improvement, it can meet the gear shifting requirements of five gears and the strength requirements of the shaft and gears.

[0032] After calculation, two shift forks are fixed to a fork shaft 3, the distance between the fork feet of the two shift forks is 151mm, and the shift block 12 is fixed to the middle of the two shift forks. The gear positions at this time are: third gear, neutral second gear, neutral, first gear. The gear engagement distance between each two adjacent gear positions is 11.5mm. According to the gear position and the gear engagement distance, five self-locking grooves need to be processed at one end of the fork shaft 3, and the center distance between two adjacent self-locking grooves is 11.5mm.

[0033] The above-mentioned specific implementations are only specific cases of the present utility model. The patent protection scope of the present utility model includes but is not limited to the product form and style of the above-mentioned specific implementations. Any gearbox that complies with the claims of the present utility model and any appropriate changes or modifications made thereto by ordinary technicians in the corresponding technical field shall fall within the patent protection scope of the present utility model.

Claims

1. A gearbox, comprising a housing (1) and a cover (2), characterized in that: The upper part of the housing (1) is connected to a fork shaft (3), the lower part of the housing (1) is connected to a gear shaft (4), and the fork shaft (3) is connected to a shift fork; The gear shaft (4) is provided with a first gear (5), a second gear (6) and a third gear (7) in sequence, and the gear shaft (4) is connected with a first gear hub sleeve (8) and a second and third gear hub sleeve (9), the first gear hub sleeve (8) is arranged adjacent to the first gear (5), and the second and third gear hub sleeve (9) is arranged between the second gear (6) and the third gear (7); The shift forks are provided with two, namely a first gear shift fork (10) and a second and third gear shift fork (11), the fork foot spacing of the two shift forks is 151 mm, and a shift block (12) is provided between the two shift forks; It comprises five gears, namely, the third gear, neutral gear, the second gear, neutral gear and the first gear, and the gear engagement distance between two adjacent gears is 11.5 mm. One end of the fork shaft (3) is provided with five self-locking grooves, and the center distance between two adjacent self-locking grooves is 11.5 mm. The interior of the gearbox cover (2) is connected with a gear shift assembly, which comprises, from top to bottom, an outer gear shift rocker arm (13), a thrust bearing (14) and an inner gear shift rocker arm (15), wherein the outer gear shift rocker arm (13) is located on the upper side of the gearbox; The lever arm length of the inner shift rocker arm (15) is 65 mm, and the lever arm length of the outer shift rocker arm (13) is 130 mm; When the length direction of the outer shift rocker arm (13) is arranged along the length direction of the gearbox, it is the second gear; when the outer shift rocker arm (13) is offset to the left by 10.2° and 20.7° along the length direction of the gearbox, it is the neutral gear and the third gear respectively; when the outer shift rocker arm (13) is offset to the right by 10.2° and 20.7° along the length direction of the gearbox, it is the neutral gear and the first gear respectively.

2. A gearbox according to claim 1, characterized in that: The length of the first gear hub sleeve (8) is 56.5 mm, and the length of the meshing teeth of the second gear (6) is 33.5 mm.

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