A tractor front wheel speed increasing steering device and steering system

Abstract

The invention relates to a tractor front wheel speed-increasing steering device and a steering system. The steering device comprises a rear axle housing, an input shaft, an idler shaft and a transfer case output shaft. The input shaft, the idler shaft and the transfer case output shaft are parallel to each other and are rotatably connected in the rear axle housing respectively. A transfer case driving gear is splined on the input shaft, a non-multiple-speed idler and a double-speed idler are splined on the idler shaft respectively, a non-multiple-speed passive gear and a double-speed passive gear are movably connected on the transfer case output shaft respectively, the transfer case driving gear meshes with the non-multiple-speed idler, the non-multiple-speed idler meshes with the non-multiple-speed passive gear, and the double-speed idler meshes with the double-speed passive gear. A first clutch and a second clutch are arranged on the transfer case output shaft, the first clutch cooperates with the non-multiple-speed passive gear correspondingly and drives the transfer case output shaft to enter a four-wheel drive mode or a two-wheel drive mode, and the second clutch cooperates with the double-speed passive gear correspondingly and drives the transfer case output shaft to enter a double-speed mode or a two-wheel drive mode.

Description

Technical Field

[0001] The present invention relates to the technical field related to tractors, and in particular to a front wheel speed increasing steering device and a steering system for a tractor. Background Art

[0002] At present, domestic tractors are all two-wheel drive or four-wheel drive. Two-wheel drive tractors have no driving force constraints on the front wheels, and the steering is more flexible, but they are not suitable for working conditions that require large traction; four-wheel drive tractors have large traction, strong climbing ability, and good engine braking effect, but because the front-wheel drive is mandatory, the front wheel speed does not increase with the increase of the turning angle, but instead generates resistance, which will cause the turning radius to increase, the turning time to increase, and the turning marks to damage the land. Summary of the invention

[0003] In order to solve one or more of the above-mentioned technical problems, the present invention provides a tractor front wheel speed-increasing steering device and a steering system.

[0004] The technical solution of the present invention to solve the above technical problems is as follows: a tractor front wheel speed-increasing steering device comprises a rear axle housing, an input shaft, an idler shaft and a transfer case output shaft, the input shaft, the idler shaft and the transfer case output shaft are parallel to each other and are rotatably connected in the rear axle housing respectively; the input shaft is splined with a transfer case driving gear, the idler shaft is splined with a non-double-speed idler and a double-speed idler respectively, the transfer case output shaft is movably connected with a non-double-speed passive gear and a double-speed passive gear respectively, the transfer case driving gear is meshed with the non-double-speed idler, the non-double-speed idler is meshed with the non-double-speed passive gear, and the double-speed idler is meshed with the double-speed passive gear; a first clutch and a second clutch are provided on the transfer case output shaft, the first clutch is correspondingly matched with the non-double-speed passive gear, and drives the transfer case output shaft to enter a four-wheel drive mode or a two-wheel drive mode by contacting or separating with the non-double-speed passive gear, and the second clutch is correspondingly matched with the double-speed passive gear, and drives the transfer case output shaft to enter a double-speed mode or a two-wheel drive mode by contacting or separating with the double-speed passive gear.

[0005] The beneficial effects of the present invention are as follows: the steering device of the present invention provides another speed driving mode in addition to the two-wheel drive and four-wheel drive modes of the tractor. When the tractor is operating normally while driving in a straight line, the driver can select two-wheel drive or four-wheel drive. When steering is required, the tractor automatically switches to the front wheel speed-increasing state, the front wheel speed increases, quick steering is achieved, the turning circle radius is reduced, the crushing of the land is reduced, and the operating efficiency is improved.

[0006] Based on the above technical solution, the present invention can also be improved as follows.

[0007] Furthermore, the transfer case output shaft is provided with oil passages respectively connected with the first clutch and the second clutch, one end of the oil passages extends to an end surface of one end of the transfer case output shaft, and one end of the oil passages is provided with an oil plug.

[0008] The beneficial effect of adopting the above further solution is that by arranging the oil passage on the transfer case output shaft, it is beneficial to perform oil pressure driving on the two clutches.

[0009] Further, the first clutch includes a first housing, a first piston, a first friction plate assembly and a first spring. The first housing is sleeved on the transfer case output shaft and fixedly connected to the transfer case output shaft. A first annular structure is extended on the end surface of the non-speed passive gear. The first friction plate assembly is sleeved on the first annular structure and spline-matched with it. The first piston can be axially slidably assembled in the first housing and spline-matched with the transfer case output shaft. The first spring is sleeved on the transfer case output shaft and respectively abuts against the first piston and the first retaining ring on the transfer case output shaft; the first piston frictionally cooperates with the first friction plate assembly to realize clutch transmission between the non-speed passive gear and the transfer case output shaft.

[0010] The beneficial effect of adopting the above further scheme is: in the four-wheel drive mode, the first piston can be driven to move axially, so that the first piston contacts and frictionally cooperates with the first friction plate, thereby realizing synchronous transmission between the transfer case output shaft and the non-multiple-speed passive gear, that is, realizing the four-drive force output of the transfer case output shaft. In the two-wheel drive mode, the first piston is no longer driven to move axially, and under the action of the first spring, the friction cooperation between the first piston and the first friction plate is released, realizing the relative movement between the transfer case output shaft and the non-multiple-speed passive gear, and the transfer case output shaft no longer outputs power, that is, realizing the two-drive force output mode.

[0011] Furthermore, a main oil channel and a first branch oil channel are provided on the transfer case output shaft, one end of the main oil channel extends to an end surface of one end of the transfer case output shaft, one end of the first branch oil channel is connected to the main oil channel, and the other end is connected to the first oil chamber between the first piston and the first housing.

[0012] The beneficial effect of adopting the above further solution is that the first piston can be driven by hydraulic oil to move axially along the transfer case output shaft.

[0013] Furthermore, the second clutch includes a second housing, a second piston, a second friction plate assembly and a second spring. The second housing is sleeved on the transfer case output shaft and fixedly connected to the transfer case output shaft. A second annular structure is extended on the end surface of the multi-speed passive gear. The second friction plate assembly is sleeved on the second annular structure and spline-matched with the transfer case output shaft. The second piston can be axially slidably assembled in the second housing and spline-matched with the transfer case output shaft. The second spring is sleeved on the transfer case output shaft and respectively abuts against the second piston and the second retaining ring on the transfer case output shaft; the second piston frictionally cooperates with the second friction plate assembly to realize clutch transmission between the multi-speed passive gear and the transfer case output shaft.

[0014] The beneficial effect of adopting the above further scheme is that: in the double-speed mode, the second piston can be driven to move axially, so that the second piston contacts and frictionally engages with the second friction plate assembly, thereby realizing synchronous transmission between the transfer case output shaft and the double-speed passive gear, that is, realizing the double-speed power output of the transfer case output shaft. In the two-drive mode, the second piston is no longer driven to move axially, and under the action of the second spring, the friction engagement between the second piston and the second friction plate assembly is released, thereby realizing relative movement between the transfer case output shaft and the double-speed passive gear, and the transfer case output shaft no longer outputs power, that is, realizing the two-drive force output mode.

[0015] Furthermore, a main oil channel and a second branch oil channel are provided on the transfer case output shaft, one end of the main oil channel extends to an end surface of one end of the transfer case output shaft, one end of the second branch oil channel is connected to the main oil channel, and the other end is connected to the second oil chamber between the second piston and the second housing.

[0016] The beneficial effect of adopting the above further solution is that the second piston can be driven by hydraulic oil to move axially along the transfer case output shaft.

[0017] Furthermore, the transmission ratio between the non-multiple-speed idler gear and the non-multiple-speed driven gear is smaller than the transmission ratio between the multiplied-speed idler gear and the multiplied-speed driven gear.

[0018] The beneficial effect of adopting the above further solution is that different mode conversions between the four-wheel drive mode and the double-speed mode are achieved by designing different transmission ratios.

[0019] A tractor front wheel speed-increasing steering system comprises the tractor front wheel speed-increasing steering device, and further comprises: a front axle angle sensor, a rotation speed sensor and a controller, wherein the front axle angle sensor is mounted on the front axle and used to send the detected front axle steering angle to the controller, and the rotation speed sensor is mounted on the tractor chassis and used to send the detected tractor speed to the controller;

[0020] The controller is used to control the second clutch to contact the multi-speed passive gear when the steering angle of the front axle is not less than a preset angle and when the speed of the tractor is not greater than a preset speed, so that the output shaft of the transfer case enters the multi-speed mode;

[0021] The controller is used to control the second clutch to separate from the multi-speed driven gear when the steering angle of the front axle is not less than a preset angle and when the tractor speed is greater than the preset speed, so that the transfer case output shaft enters the two-wheel drive mode.

[0022] The beneficial effect of the present invention is that the steering system of the present invention can control different mode switching through parameters detected by the front axle angle sensor and the rotation speed sensor.

[0023] Furthermore, the controller is also used to control the first clutch to contact or disengage with the non-double-speed passive gear when the steering angle of the front axle is less than a preset angle, and drive the transfer case output shaft to enter the four-wheel drive mode or the two-wheel drive mode.

[0024] The beneficial effect of adopting the above further solution is that when the steering angle of the front axle does not reach the preset angle, the double-speed mode is not performed, and the control is more flexible and reliable.

[0025] Furthermore, it also includes a speed switch and a four-wheel drive switch, and the speed switch and the four-wheel drive switch are respectively connected to the controller.

[0026] The beneficial effect of adopting the above further solution is that different mode control instructions can be input through relevant switches. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the internal structure of the front wheel speed increasing steering device of the tractor of the present invention;

[0028] Figure 2 The control principle diagram of the tractor front wheel speed increasing steering system of the present invention.

[0029] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0030] 1. Rear axle housing;

[0031] 2. Input shaft; 21. Transfer case driving gear; 22. Thrust washer; 23. Spacer; 24. Tapered roller bearing;

[0032] 3. Idle shaft; 31. Non-speed idler; 32. Speed ​​idler; 33. Cylindrical roller bearing; 34. Deep groove ball bearing;

[0033] 4. Transfer case output shaft; 40. Transfer case end cover; 41. Non-speed driven gear; 42. Speed ​​driven gear; 43. First annular structure; 44. Second annular structure; 45. First retaining ring; 46. Second retaining ring; 47. Main oil channel; 48. Second oil channel; 49. Oil plug;

[0034] 5. First clutch; 51. First housing; 52. First piston; 53. First friction plate assembly; 54. First spring;

[0035] 6. Second clutch; 61. Second housing; 62. Second piston; 63. Second friction plate assembly; 64. Second spring; 7. Sealing ring; 8. Needle roller assembly. DETAILED DESCRIPTION

[0036] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0037] Example 1

[0038] like Figure 1 As shown, a tractor front wheel speed-increasing steering device of this embodiment comprises a rear axle housing 1, an input shaft 2, an idler shaft 3 and a transfer case output shaft 4, wherein the input shaft 2, the idler shaft 3 and the transfer case output shaft 4 are parallel to each other and are rotatably connected in the rear axle housing 1; a transfer case driving gear 21 is splined on the input shaft 2, a non-multiple-speed idler 31 and a multi-speed idler 32 are splined on the idler shaft 3, a non-multiple-speed passive gear 41 and a multi-speed passive gear 42 are movably connected on the transfer case output shaft 4, and the transfer case driving gear 21 is meshed with the non-multiple-speed idler 31. The non-double-speed idler gear 31 is meshed with the non-double-speed driven gear 41, and the double-speed idler gear 32 is meshed with the double-speed driven gear 42; the transfer case output shaft 4 is provided with a first clutch 5 and a second clutch 6, the first clutch 5 corresponds to the non-double-speed driven gear 41, and drives the transfer case output shaft 4 to enter the four-wheel drive mode or the two-wheel drive mode by contacting or separating with the non-double-speed driven gear 41, and the second clutch 6 corresponds to the double-speed driven gear 42, and drives the transfer case output shaft 4 to enter the double-speed mode or the two-wheel drive mode by contacting or separating with the double-speed driven gear 42.

[0039] The first clutch 5 and the second clutch 6 of the present embodiment are wet clutches.

[0040] Among them, the non-speed driven gear 41 and the speed driven gear 42 are respectively arranged on the transfer case output shaft 4 so as to be rotatable circumferentially through the needle roller assembly 8, and the non-speed driven gear 41 and the speed driven gear 42 are also axially limited on the transfer case output shaft 4 through thrust washers.

[0041] Specifically, Figure 1 As shown, the input shaft 2 of this embodiment is respectively assembled in the rear axle housing 1 through a tapered roller bearing 24, the transfer case driving gear 21 and the tapered roller bearing 24 are arranged in intervals through a spacer 23, and the tapered roller bearing 24 can be axially limited on the input shaft 2 through a thrust washer 22. The two ends of the idler shaft 3 are respectively assembled in the rear axle housing 1 through a cylindrical roller bearing 33 and a deep groove ball bearing 34. The transfer case output shaft 4 is assembled in the rear axle housing 1 through a deep groove ball bearing 34, and the deep groove ball bearing 34 can be assembled on the transfer case output shaft 4 through a transfer case end cover 40. The transfer case output shaft 4 of this embodiment can be sealed and connected with the rear axle housing 1, etc. through a sealing ring.

[0042] A specific solution of this embodiment is that the transfer case output shaft 4 is provided with oil passages corresponding to the first clutch 5 and the second clutch 6, one end of the oil passage extends to an end surface of one end of the transfer case output shaft 4, and one end of the oil passage is provided with an oil plug 49. By providing the oil passage on the transfer case output shaft, it is beneficial to hydraulically drive the two clutches.

[0043] like Figure 1 As shown, an optional scheme of the present embodiment is that the first clutch 5 includes a first housing 51, a first piston 52, a first friction plate engaging member 53 and a first spring 54, the first housing 51 is sleeved on the transfer case output shaft 4 and fixedly connected to the transfer case output shaft 4, a first annular structure 43 is extended and formed on the end face of the non-speed driven gear 41, the first friction plate engaging member 53 is sleeved on the first annular structure 43 and spline-matched therewith, the first piston 52 can be axially slidably assembled in the first housing 51 and spline-matched with the transfer case output shaft 4, the first spring 54 is sleeved on the transfer case output shaft 4 and respectively abuts against the first piston 52 and the first retaining ring 45 on the transfer case output shaft 4; the first piston 52 frictionally cooperates with the first friction plate engaging member 53 to realize the clutch transmission between the non-speed driven gear 41 and the transfer case output shaft 4. In the four-wheel drive mode, the first piston can be driven to move axially, so that the first piston contacts and frictionally engages with the first friction plate, thereby realizing synchronous transmission between the transfer case output shaft and the non-multiple-speed passive gear, that is, realizing the four-drive force output of the transfer case output shaft. In the two-wheel drive mode, the first piston is no longer driven to move axially, and under the action of the first spring, the frictional engagement between the first piston and the first friction plate is released, realizing relative movement between the transfer case output shaft and the non-multiple-speed passive gear, and the transfer case output shaft no longer outputs power, that is, realizing the two-drive force output mode.

[0044] like Figure 1As shown, a specific solution of this embodiment is that the transfer case output shaft 4 is provided with a main oil passage 47 and a first branch oil passage (not shown in the figure), one end of the main oil passage 47 extends to one end face of the transfer case output shaft 4, one end of the first branch oil passage is connected to the main oil passage 47, and the other end is connected to the first oil chamber between the first piston 52 and the first housing 51. The first piston can be driven to move axially along the transfer case output shaft by hydraulic oil.

[0045] like Figure 1 As shown, an optional scheme of the present embodiment is that the second clutch 6 includes a second housing 61, a second piston 62, a second friction plate engaging member 63 and a second spring 64, the second housing 61 is sleeved on the transfer case output shaft 4 and fixedly connected to the transfer case output shaft 4, a second annular structure 44 is extended on the end surface of the multi-speed passive gear 42, the second friction plate engaging member 63 is sleeved on the second annular structure 44 and spline-matched therewith, the second piston 62 can be axially slidably assembled in the second housing 61 and spline-matched with the transfer case output shaft 4, the second spring 64 is sleeved on the transfer case output shaft 4 and respectively abuts against the second piston 62 and the second retaining ring 46 on the transfer case output shaft 4; the second piston 62 and the second friction plate engaging member 63 frictionally cooperate to realize the clutch transmission between the multi-speed passive gear 42 and the transfer case output shaft 4. In the double-speed mode, the second piston can be driven to move axially, so that the second piston contacts and frictionally engages with the second friction plate, thereby realizing synchronous transmission between the transfer case output shaft and the double-speed passive gear, that is, realizing the double-speed power output of the transfer case output shaft. In the two-wheel drive mode, the second piston is no longer driven to move axially, and under the action of the second spring, the frictional engagement between the second piston and the second friction plate is released, realizing relative movement between the transfer case output shaft and the double-speed passive gear, and the transfer case output shaft no longer outputs power, that is, realizing the two-drive force output mode.

[0046] like Figure 1 As shown, a specific solution of this embodiment is that the transfer case output shaft 4 is provided with a main oil passage 47 and a second branch oil passage 48, one end of the main oil passage 47 extends to an end surface of one end of the transfer case output shaft 4, one end of the second branch oil passage 48 is connected to the main oil passage 47, and the other end is connected to the second oil chamber between the second piston 62 and the second housing 61. The second piston can be driven to move axially along the transfer case output shaft by hydraulic oil.

[0047] Specifically, the first piston 52 and the second piston 62 of this embodiment are respectively sealed and connected in the corresponding first housing 51 and second housing 61 through the sealing ring 7, and the first piston 52 and the second piston 62 are also respectively sealed and connected to the transfer case output shaft 4 through the sealing ring 7.

[0048] like Figure 1 As shown, a specific solution of this embodiment is that the transmission ratio between the non-speed idler 31 and the non-speed driven gear 41 is smaller than the transmission ratio between the speed idler 32 and the speed driven gear 42. By designing different transmission ratios, different mode conversions between the four-wheel drive mode and the speed mode are achieved.

[0049] The working process of a tractor front wheel speed-increasing steering device of this embodiment is to use the transfer case driving gear 21 on the input shaft 2 to drive the non-multiple-speed idler 31 to rotate, and then drive the idler shaft 3 and the double-speed idler 32 to rotate, the double-speed idler 32 can drive the double-speed passive gear 42 to rotate, and the non-multiple-speed idler 31 can drive the non-multiple-speed passive gear 41 to rotate. In the two-wheel drive mode, the first clutch and the second clutch are not working, and the non-multiple-speed passive gear 41 and the double-speed passive gear 42 are idling. In the four-wheel drive mode, the first clutch is working, the second clutch is not working, the non-multiple-speed idler 31 drives the non-multiple-speed passive gear 41 to rotate, and at the same time, under the operation of the second clutch 6, drives the transfer case output shaft 4 to output power. In the double-speed mode, the first clutch is not working, the second clutch is working, the double-speed idler 32 drives the double-speed passive gear 42 to rotate, and at the same time, under the operation of the first clutch 5, drives the transfer case output shaft 4 to output power.

[0050] The steering device of this embodiment provides another speed driving mode in addition to the two-wheel drive and four-wheel drive modes of the tractor. When the tractor is operating normally in a straight line, the driver can choose two-wheel drive or four-wheel drive. When steering is required, the tractor automatically switches to the front wheel speed-up state, the front wheel speed increases, and rapid steering is achieved, the turning circle radius is reduced, the crushing of the land is reduced, and the working efficiency is improved.

[0051] Example 2

[0052] like Figure 1 and Figure 2 As shown, a tractor front wheel speed-increasing steering system of this embodiment includes the tractor front wheel speed-increasing steering device, and also includes: a front axle angle sensor, a speed sensor and a controller, wherein the front axle angle sensor is installed on the front axle and is used to send the detected front axle steering angle to the controller, and the speed sensor is installed on the tractor chassis and is used to send the detected tractor speed to the controller;

[0053] The controller is used to control the second clutch to contact the multi-speed passive gear when the steering angle of the front axle is not less than a preset angle and when the tractor speed is not greater than a preset speed, so that the transfer case output shaft 4 enters the multi-speed mode;

[0054] The controller is used to control the second clutch 6 to separate from the multi-speed driven gear 42 when the steering angle of the front axle is not less than a preset angle and when the tractor speed is greater than the preset speed, so that the transfer case output shaft 4 enters the two-wheel drive mode.

[0055] The controller is also used to control the first clutch 5 to contact or disengage with the non-speed driven gear 41 when the front axle steering angle is less than a preset angle, and drive the transfer case output shaft 4 to enter the four-wheel drive mode or the two-wheel drive mode. When the front axle steering angle does not reach the preset angle, the speed mode is not performed, and the control is more flexible and reliable.

[0056] An optional solution of this embodiment is that the first clutch and the second clutch are connected to the first solenoid valve and the second solenoid valve respectively, and the first solenoid valve and the second solenoid valve are controlled by a controller to control the clutching action of the first clutch and the second clutch respectively.

[0057] The preset angle can be selected according to different models or needs, for example, it can be 25° to 55°, specifically 30°, 35°, 40°, etc. The preset speed can also be selected according to different models or needs, for example, it can be 5km / h to 15km / h, specifically 10km / h, 12km / h, etc.

[0058] The tractor front wheel speed-increasing steering system of this embodiment further comprises a speed switch and a four-wheel drive switch, wherein the speed switch and the four-wheel drive switch are respectively connected to the controller. Different mode control instructions can be input through the relevant switches.

[0059] When the steering system of this embodiment is working, it first enters the two-wheel drive mode. When the steering angle is less than the preset angle and the vehicle speed is greater than the preset speed, the four-wheel drive switch is turned on to enter the four-wheel drive mode. When the steering angle is not less than the preset angle and the vehicle speed is not greater than the preset speed, the double-speed switch is turned on to enter the double-speed mode.

[0060] The steering system of this embodiment can control different mode switching through parameters detected by the front axle angle sensor and the rotation speed sensor.

[0061] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0062] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0063] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0065] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0066] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A tractor front wheel speed increasing steering device, characterized in that: It includes a rear axle housing, an input shaft, an idler shaft and a transfer case output shaft, the input shaft, the idler shaft and the transfer case output shaft are parallel to each other and are rotatably connected in the rear axle housing respectively; the input shaft is splined with a transfer case driving gear, the idler shaft is respectively splined with a non-speed idler and a speed idler, the transfer case output shaft is respectively movably connected with a non-speed passive gear and a speed passive gear, the transfer case driving gear is meshed with the non-speed idler, the non-speed idler is meshed with the non-speed passive gear, and the speed idler is meshed with the speed passive gear; a first clutch and a second clutch are provided on the transfer case output shaft, the first clutch is correspondingly matched with the non-speed passive gear, and drives the transfer case output shaft to enter a four-wheel drive mode or a two-wheel drive mode by contacting or separating with the non-speed passive gear, the second clutch is correspondingly matched with the speed passive gear, and drives the transfer case output shaft to enter a speed mode or a two-wheel drive mode by contacting or separating with the speed passive gear.

2. A tractor front wheel speed increasing steering device according to claim 1, characterized in that: The transfer case output shaft is provided with oil passages respectively connected with the first clutch and the second clutch, one end of the oil passages extends to an end surface of one end of the transfer case output shaft, and one end of the oil passages is provided with an oil plug.

3. A tractor front wheel speed increasing steering device according to claim 1, characterized in that: The first clutch includes a first housing, a first piston, a first friction plate assembly and a first spring. The first housing is sleeved on the transfer case output shaft and fixedly connected to the transfer case output shaft. A first annular structure is extended on the end surface of the non-double-speed passive gear. The first friction plate assembly is sleeved on the first annular structure and spline-matched with it. The first piston can be axially slidably assembled in the first housing and spline-matched with the transfer case output shaft. The first spring is sleeved on the transfer case output shaft and respectively abuts against the first piston and the first retaining ring on the transfer case output shaft; the first piston frictionally cooperates with the first friction plate assembly to realize clutch transmission between the non-double-speed passive gear and the transfer case output shaft.

4. A tractor front wheel speed increasing steering device according to claim 3, characterized in that: The transfer case output shaft is provided with a main oil passage and a first branch oil passage, one end of the main oil passage extends to an end surface of one end of the transfer case output shaft, one end of the first branch oil passage is connected to the main oil passage, and the other end is connected to the first oil chamber between the first piston and the first housing.

5. The tractor front wheel speed increasing steering device according to claim 1, characterized in that: The second clutch includes a second housing, a second piston, a second friction plate assembly and a second spring. The second housing is sleeved on the transfer case output shaft and fixedly connected to the transfer case output shaft. A second annular structure is extended on the end surface of the multi-speed passive gear. The second friction plate assembly is sleeved on the second annular structure and spline-matched with it. The second piston can be axially slidably assembled in the second housing and spline-matched with the transfer case output shaft. The second spring is sleeved on the transfer case output shaft and respectively abuts against the second piston and the second retaining ring on the transfer case output shaft; the second piston frictionally cooperates with the second friction plate assembly to realize clutch transmission between the multi-speed passive gear and the transfer case output shaft.

6. A tractor front wheel speed increasing steering device according to claim 5, characterized in that: The transfer case output shaft is provided with a main oil passage and a second branch oil passage, one end of the main oil passage extends to an end surface of one end of the transfer case output shaft, one end of the second branch oil passage is connected to the main oil passage, and the other end is connected to the second oil chamber between the second piston and the second housing.

7. A tractor front wheel speed increasing steering device according to claim 1, characterized in that: The transmission ratio between the non-multiple-speed idler gear and the non-multiple-speed driven gear is smaller than the transmission ratio between the multi-speed idler gear and the multi-speed driven gear.

8. A tractor front wheel speed increasing steering system, characterized in that: The tractor front wheel speed-increasing steering device comprises any one of claims 1 to 7, and further comprises: a front axle angle sensor, a rotation speed sensor and a controller, wherein the front axle angle sensor is mounted on the front axle and is used to send the detected front axle steering angle to the controller, and the rotation speed sensor is mounted on the tractor chassis and is used to send the detected tractor speed to the controller; The controller is used to control the second clutch to contact the multi-speed passive gear when the steering angle of the front axle is not less than a preset angle and when the speed of the tractor is not greater than a preset speed, so that the output shaft of the transfer case enters the multi-speed mode; The controller is used to control the second clutch to separate from the multi-speed driven gear when the steering angle of the front axle is not less than a preset angle and when the tractor speed is greater than the preset speed, so that the transfer case output shaft enters the two-wheel drive mode.

9. A tractor front wheel speed increasing steering system according to claim 8, characterized in that: The controller is also used to control the first clutch to contact or disengage with the non-double-speed passive gear when the steering angle of the front axle is less than a preset angle, and drive the transfer case output shaft to enter a four-wheel drive mode or a two-wheel drive mode.

10. A tractor front wheel speed increasing steering system according to claim 8, characterized in that: It also includes a multiple speed switch and a four-wheel drive switch, and the multiple speed switch and the four-wheel drive switch are respectively connected to the controller.

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