Differential steering wheel system with linear braking and speed changing functions

Abstract

The invention discloses a differential steering wheel system with linear braking and speed changing functions, which can solve the problem that a traditional steering wheel cannot give consideration to both high speed and heavy load through speed changing and torque changing, and can realize emergency braking of the steering wheel through linear braking when the steering wheel is at a high speed. The torque of a driving motor of the differential steering wheel is shunted through a speed change mechanism, a synchronous belt mechanism and a differential mechanism, and is transmitted to driving wheels on two sides through a speed reducer; when the differential steering wheel needs to steer, the steering motor actively controls steering, the driving wheels on the two sides automatically distribute rotating speed and torque through the differential mechanism, and stable steering is achieved. When a dangerous situation is encountered, the differential steering wheel achieves emergency braking through linear braking with adjustable braking force. Under the working conditions of high speed and light load, the speed of the differential steering wheel can be adjusted to a high-speed gear through the speed change mechanism, so that the speed range of the differential steering wheel is widened; under the working conditions of low speed and heavy load, the speed of the differential steering wheel can be adjusted to a low-speed gear through the speed change mechanism, so that the driving torque of the differential steering wheel is enhanced, and the traction capacity of the differential steering wheel is improved.

Description

Technical Field

[0001] This invention relates to the field of differential steering wheel system technology, specifically to a differential steering wheel system with linear braking and speed change functions. Background Technology

[0002] In recent years, with the development of intelligent manufacturing and intelligent logistics, the entire AGV industry has gradually shown a rapid evolution and maturity. Given the changing labor force, rising labor costs, and increasing demand from sectors such as express delivery and manufacturing, the application scenarios for AGVs are constantly expanding, and the application environments are becoming increasingly complex, ranging from indoors to outdoors, and from low-speed, heavy-load to high-speed, light-load. Users are placing increasingly higher demands on the environmental and operational adaptability of AGVs. As a core component of AGVs, the steering wheel system determines the performance of AGVs and plays a crucial role in their environmental and operational adaptability.

[0003] Currently, the speed ratio of the transmission mechanism in common steering wheel systems is generally fixed. With a fixed drive motor speed range, a steering wheel with a large transmission ratio, suitable for low-speed, heavy-load conditions, cannot simultaneously meet the requirements of high-speed, light-load conditions; conversely, a steering wheel with a small transmission ratio, suitable for high-speed, light-load conditions, cannot simultaneously meet the requirements of low-speed, heavy-load conditions.

[0004] Because common single-wheel steering wheels require complex algorithmic control to coordinate the rotational speeds of the inner and outer single-wheel steering wheels during multiple coordinated turns, dragging and slippage are still prone to occur even under these conditions. This dragging and slippage is even more severe and dangerous during high-speed turns. Furthermore, in situations requiring emergency braking at high speeds, relying on the motor-driven parking brake for emergency stopping is insufficient to bring the steering wheel to a complete stop within a short time and distance.

[0005] Therefore, with the increasing demands on the operating environment and complexity of steering wheels, it is necessary to provide a differential steering wheel system with linear braking and speed change functions. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention provides a differential steering wheel system with linear braking and speed change functions. This system can switch between low-speed, heavy-load and high-speed, light-load conditions, and can solve the problems of difficult control and instability of the steering wheel system during high-speed turning. It can also achieve controllable distance and time emergency stop at high speeds.

[0007] To achieve the above objectives, embodiments of the present invention employ the following technical solution: a differential steering wheel system with linear braking and speed change functions, comprising a speed change mechanism, a synchronous belt mechanism, a linear braking mechanism, a differential mechanism, a wheel assembly, and a steering swing mechanism. The speed change mechanism is connected to the synchronous belt mechanism and is used for speed and torque change of the steering wheel system. The gear of the speed change mechanism is adjusted according to the operating conditions of the steering wheel system to change the speed ratio of the drive mechanism of the steering wheel system, enabling the steering wheel system to adapt to low-speed, heavy-load or high-speed, light-load operating conditions. The synchronous belt mechanism is used to realize the transmission and amplification of driving torque. The linear braking mechanism is used to realize emergency stop. The input end of the differential mechanism is connected to the output end of the synchronous belt mechanism, and the output end of the differential mechanism is connected to the wheel assembly, used to realize load bearing, transmission, amplification, and splitting of driving torque. The steering swing assembly realizes the active steering of the steering wheel system through a steering motor and a steering mechanism, and makes the two drive wheels swing at a set angle.

[0008] Compared with the prior art, the beneficial effects of this application are as follows:

[0009] The speed change mechanism of this invention is connected to the synchronous belt mechanism via the output shaft and is integrated into the drive mechanism of the steering wheel system. When the steering wheel system faces low-speed, heavy-load or high-speed, light-load operating conditions, by adjusting the up and down position of the speed regulating fork, the axial position of the synchronizer is moved, causing the synchronizer to mesh with different gears on the output shaft, thereby changing the actual speed ratio of the steering wheel drive mechanism to meet the requirements of different operating conditions, thus greatly expanding the operating range of the AGV using this steering wheel.

[0010] The synchronous belt mechanism of this invention is connected to the transmission mechanism via the input end and to the differential mechanism via the bevel gear output shaft, and is integrated into the drive mechanism of the steering wheel system. The tension of the synchronous belt in the synchronous belt structure can be adjusted by the adjusting screw on the synchronous belt housing and the threaded hole on the gearbox housing. When the synchronous belt gradually loosens over time, it can be tightened by the adjusting screw to continue meeting the usage requirements, greatly reducing the maintenance and upkeep time of the synchronous belt mechanism.

[0011] The linear braking mechanism of this invention features an externally mounted linear brake pump, with the brake mounted on the synchronous belt housing and the brake disc mounted on the large pulley of the synchronous belt mechanism, thus connecting to the steering wheel system drive mechanism. A maximum oil pressure limit is set in the externally mounted linear brake pump according to the required emergency stopping safety distance. The oil pressure is transmitted to the brake via hydraulic lines through the oil port on the synchronous belt housing. The piston rod inside the brake, under the action of oil pressure, applies pressure to the central brake disc, generating a braking torque on the brake disc. This braking torque is amplified to the drive wheel via the differential mechanism and the hub reducer, achieving emergency braking of the steering wheel system. This linear braking mechanism allows the braking torque to be adjusted according to the oil pressure of the externally mounted linear brake pump, thereby making the braking distance and braking time of the steering wheel system controllable and meeting the braking distance requirements for different road surfaces.

[0012] The differential mechanism of this invention connects its input end to the output end of a synchronous belt, and its output end to the wheel assembly, thereby distributing the steering wheel drive torque across the wheel assembly. The differential housing is sealed via an O-ring and a rotary seal between the differential housing cover, the synchronous belt mechanism, and the wheel assembly. The differential mechanism incorporates four bevel gears mounted on a cross shaft, which distribute the torque. Two output bevel gears connect to the wheel assembly, serving as the differential mechanism's output, while the other two distribution bevel gears adjust the wheel assembly's speed and torque. This differential mechanism enables the steering wheel system to automatically distribute the speed and driving torque between the two drive wheels during cornering, especially at high speeds, preventing drag and slippage between the two drive wheels and ensuring smooth cornering. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in this invention, the accompanying drawings used in this invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 This is a front view of the structure in an embodiment of the present invention.

[0015] Figure 2 This is a structural back view of an embodiment of the present invention.

[0016] Figure 3 This is a front view of the structure in an embodiment of the present invention.

[0017] Figure 4 This is a side sectional view of the structure in an embodiment of the present invention.

[0018] Figure 5 This is a cross-sectional view of the speed change mechanism in an embodiment of the present invention.

[0019] Figure 6 This is a cross-sectional view of the linear braking mechanism in an embodiment of the present invention.

[0020] The markings in the diagram indicate:

[0021] 1-Drive motor; 2-Gearbox housing; 3-Input gear shaft; 4-Output gear shaft; 5-Intermediate gear shaft; 6-Gear A; 7-Gear B; 8-Gear C; 9-Gear D; 10-Gear 3; 11-Gear F; 12-Gear G; 13-Speed ​​control fork; 14-Synchronizer; 15-Synchronous belt housing; 16-Synchronous belt cover; 17-Angle gear; 18-Small pulley; 19-Large pulley; 20-Crankseter; 21-Synchronous belt ; 22-Baffle; 23-Adjusting screw; 24-Linear brake pump; 25-Brake; 26-Brake disc; 27-Oil pipe; 39-Tire; 40-Wheel hub reducer; 41-Steering motor; 42-Steering reducer; 43-Steering pinion; 44-Slewing bearing; 45-Mounting plate; 46-Horizontal plate; 47-Side plate; 48-Angle limit block; 49-Mechanical limit block; 50-Sliding bearing end cover; 51-Sliding bearing. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] A differential steering wheel system with linear braking and speed change functions includes a speed change mechanism, a synchronous belt mechanism, a linear braking mechanism, a differential mechanism, a wheel assembly, and a steering swing mechanism. Centered on the differential housing of the differential mechanism, the synchronous belt mechanism is fixed at the bottom of the differential housing, the linear braking mechanism is fixed inside the synchronous belt housing (15) of the synchronous belt mechanism, the linear brake pump (24) is fixed on the AGV body, the speed change mechanism is fixed on the synchronous belt housing (15) of the synchronous belt mechanism, the wheel assembly is hinged to both sides of the differential housing, and the steering swing mechanism is hinged to both sides of the lugs of the differential housing (28) of the differential mechanism. The speed change mechanism is connected to the small pulley (18) of the synchronous belt mechanism through the output gear shaft (4), the synchronous belt mechanism is connected to the differential mechanism through the bevel gear (17), and the differential mechanism is connected to the wheel hub reducer (40) of the wheel assembly through the output shaft.

[0024] The speed change mechanism is used for speed and torque change of the steering wheel system. The gear of the speed change mechanism is adjusted according to the working conditions of the steering wheel system to change the speed ratio of the drive mechanism of the steering wheel system, so that the steering wheel system can adapt to low speed, heavy load or high speed, light load working conditions. The speed change mechanism includes a drive motor (1), a gearbox body (2), an input gear shaft (3), an output gear shaft (4), an intermediate gear shaft (5), gear A (6), gear B (7), gear C (8), gear D (9), gear E (10), an external spline (11), a gear (G12), a speed adjustment fork (13), and a synchronizer (14).

[0025] The input gear shaft (3), output gear shaft (4), and intermediate gear shaft (5) are respectively mounted parallel to each other on the gearbox body (2) via bearings; gear D (9) is fixed on the input gear shaft (3), gears A (6), B (7), and C (8) are fixed sequentially on the intermediate gear shaft (5), the external spline (11) is fixed on the output gear shaft (4), and gears E (10) and G (G12) are mounted on the output gear shaft (4) via bearings; the pawl of the speed control fork (13) is engaged in the annular groove of the outer circle of the synchronizer (14) to control the axial position of the synchronizer (14) without restricting its circumferential rotation; the synchronizer (14) is mounted on the external spline via an internal spline. (11) The synchronizer (14) rotates at the same speed as the output gear shaft (4). By moving the speed adjustment fork (13), the axial position of the synchronizer (14) is adjusted. The synchronizer (14) contacts the gear E (10) or the gear (G12). Through the contact friction, the speed of the synchronizer (14) gradually synchronizes with the gear. After the speed is synchronized, the synchronizer (14) is fixed with the gear E (10) or the gear (G12) by the teeth with guide angles. The output gear shaft (4) (which rotates at the same speed as the synchronizer (14)) is also synchronized with the gear E (10) or the gear (G12), thereby changing the speed ratio between the input gear shaft (3) and the output gear shaft (4) of the transmission mechanism. The drive motor (1) is installed on the gearbox body (2) by screws and keys. Guide angles are machined on the teeth of the gear E (10), the external spline (11), the gear (G12), and the synchronizer (14) to ensure that the synchronizer (14) can mesh correctly with the gear E (10) or the gear (G12) when shifting gears.

[0026] Meshing relationships between gears: Gear D (9) is constantly meshed with gear A (6); Gear E (10) is constantly meshed with gear C (8) on the intermediate shaft; Gear G (12) is constantly meshed with gear A (6) on the intermediate shaft; Gear F (11) is constantly meshed with gear B (7) on the intermediate shaft.

[0027] When the synchronizer (14) is in the middle position, the torque of the input gear shaft (3) is transmitted to the intermediate gear shaft (5) through the meshing of gear D (9) and gear A (6). The torque of the intermediate gear shaft (5) drives gear (G12) to rotate through gear B (7), and gear C (8) drives gear E (10) to rotate. At this time, gear E (10) and gear (G12) do not synchronize their speed and torque with the output gear shaft (4) through the synchronizer (14), and the output gear shaft (4) has zero torque and zero speed.

[0028] When the synchronizer (14) is moved to the upper position by the speed adjustment fork (13), the torque of the input gear shaft (3) is transmitted to the intermediate gear shaft (5) through the meshing of gear D (9) and gear A (6). The torque of the intermediate gear shaft (5) drives the gear (G12) to rotate through gear B (7), and gear C (8) drives the gear E (10) to rotate. At this time, the gear (G12) is fixed to the output gear shaft (4) through the synchronizer (14), and the output gear shaft (4) and the gear (G12) have the same speed and torque.

[0029] When the synchronizer (14) is moved to the lower position by the speed adjustment fork (13), the torque of the input gear shaft (3) is transmitted to the intermediate gear shaft (5) through the meshing of gear D (9) and gear A (6). The torque of the intermediate gear shaft (5) drives gear F11 to rotate through gear B (7), and gear C (8) drives gear E (10) to rotate. At this time, gear E (10) is fixed to the output gear shaft (4) through the synchronizer (14), and the output gear shaft (4) and gear E (10) have the same speed and torque.

[0030] When the synchronizer (14) is in the upper or lower position, the transmission ratio between the input gear shaft (3) and the output gear shaft (4) of the transmission mechanism is changed, thereby realizing the speed change function.

[0031] The synchronous belt mechanism is used for the transmission and amplification of driving torque, and includes a synchronous belt housing (15), a synchronous belt cover plate (16), a bevel gear (17), a small pulley (18), a large pulley (19), a toothed disc (20), a synchronous belt (21), a baffle plate (22), and an adjusting screw (23).

[0032] The bevel gear (17) is mounted on the synchronous belt housing (15) via a bearing. A rotary seal is installed on the outside of the bearing to separate the synchronous belt mechanism from the differential mechanism. The large pulley (19) is mounted on the synchronous belt housing (15) via a bearing. The baffle (22) is mounted on the synchronous belt housing via screws and provides axial positioning for the bearings of the large pulley (19) and the bevel gear (17). The large pulley (19) and the bevel gear (17) are connected via a toothed disc (20) for power transmission. The small pulley (18) is mounted on the output gear shaft (4) of the transmission mechanism via a sleeve, baffle, screw, and key. The synchronous belt (21) is mounted on the small pulley (18) and the large pulley (19). The tension of the synchronous belt is adjusted by adjusting the screw (23) on the synchronous belt housing (15). After the tension is adjusted, the synchronous belt cover plate (16) is mounted on the synchronous belt housing (15) via screws.

[0033] When the output gear shaft (4) of the transmission mechanism outputs torque, the torque is amplified by the small pulley (18), the synchronous belt (21), and the large pulley (19), and the amplified torque is transmitted to the bevel gear (17) through the gear plate (20), and then the bevel gear (17) inputs the torque into the differential mechanism.

[0034] The linear braking mechanism is used for emergency stopping of the steering wheel system. It includes an external linear brake pump (24), a brake (25), a brake disc (26), and an oil pipe (27). The external linear brake pump (24) (which provides oil pressure) is installed on the AGV where the steering wheel system is located. The brake (25) is fixed to the synchronous belt housing (15) by adjusting shims and screws. The brake disc (26) is installed on the large pulley (19) by screws and a stop. When the steering wheel system needs to brake, the external linear brake pump (24) provides oil pressure, which is transmitted to the brake (25) through the oil pipe (27). The brake (25) has a built-in hydraulic piston rod. The piston rod is subjected to oil pressure and extends to the middle. The brake pads installed on the piston rod contact the brake disc (26) and transmit the pressure to the brake disc (26). A braking friction torque is generated on the brake disc (26). The brake disc (26) is fixed to the large pulley (19). The braking friction torque enters the steering wheel transmission system through the large pulley (19) of the synchronous belt mechanism. It is gradually amplified through the differential mechanism and wheel assembly, and finally acts on the tire (39), so that the tire (39) is in a state of sliding friction or a state of sliding and rolling mixed friction with the ground, thus achieving the braking effect.

[0035] The differential mechanism is used for bearing, transmitting, amplifying, and splitting the driving torque of the steering wheel system. The input end of the differential mechanism is connected to the output end of the synchronous belt mechanism, and the output end is connected to the wheel assembly, so as to realize the splitting of the steering wheel driving torque on the wheel assembly. The differential housing is sealed by setting O-rings and rotary seals between the differential housing cover plate, the synchronous belt mechanism, and the wheel assembly.

[0036] The wheel assembly is used for amplifying the drive torque of the steering wheel system and for bearing the load of the steering wheel system. It includes a tire (39) and a hub reducer (40). The hub reducer (40) is installed in the wheel core of the tire (39) by screws and cylindrical pins. The wheel assembly is installed on the differential mechanism by screws and long and short output spline shafts. The wheel assembly is connected to the differential mechanism through the long and short output spline shafts, forming the end of the steering wheel system drive mechanism.

[0037] The steering oscillation assembly can achieve active steering of the steering wheel system through the steering motor and steering mechanism, and can make the two drive wheels oscillate at a small angle to adapt to rough roads. The steering oscillation assembly includes a steering motor (41), a steering reducer (42), a steering pinion (43), a slewing bearing (44), a mounting plate (45), a cross plate (46), a side plate (47), an angle limiting block (48), a mechanical limiting block (49), a sliding bearing end cover (50), and a sliding bearing (51).

[0038] The angle limiting block (48) is fixed on the differential housing (28), the sliding bearing (51) is fixed on the differential housing lug, the side plate (47) is hinged to the differential housing (28) through the sliding bearing (51), the cross plate (46) is fixed to the two side plates (47) by screws, forming a U-shape to restrict its axial movement with the differential housing (28), the sliding bearing end cap (50) is fixed on the side plate (47) to restrict the axial movement of the sliding bearing (51); the mounting plate (45) is fixed on the cross plate (48) On 46), the inner ring of the slewing bearing (44) is fixed on the mounting plate (45), and the outer ring can slide relative to the mounting plate (45); the mechanical limit block (49) is fixed on the outer ring of the slewing bearing (44); the steering reducer (42) is fixed on the mounting plate (45), the steering motor (41) is mounted on the steering reducer (42) by screws and keys, and the steering pinion (43) is fixed to the output shaft of the steering reducer (42) by keys, baffles and screws, and forms a meshing relationship with the outer ring of the slewing bearing (44).

[0039] The steering wheel system is fixed to the AGV body via the outer ring of the slewing bearing. When the steering motor (41) outputs torque, the steering reducer (42) and the steering pinion (43) drive the inner ring of the slewing bearing (44) (the inner ring and the steering wheel body are fixed) to rotate relative to the AGV body, thus completing the steering function of the mechanism. The mechanical limit block (49) installed on the outer ring of the slewing bearing (44) and the mounting plate (45) are mechanically collided to prevent the differential steering wheel from losing control.

[0040] When the AGV travels over a bumpy road, the zigzag structure composed of the horizontal plate (46) and the side plate (47) swings relative to the differential housing (28) (including the wheel assembly) by rotating relative to the sliding bearing (51). The swing angle of the side plate (47) is limited by the angle limiting block (48) fixed on the side of the differential housing (28), thus completing the swing function of the mechanism.

[0041] The speed change mechanism of this invention is connected to the synchronous belt mechanism via the output gear shaft (4) and is integrated into the drive mechanism of the steering wheel system. When the steering wheel system faces low-speed, heavy-load or high-speed, light-load operating conditions, by adjusting the up and down position of the speed adjustment fork (13) and moving the axial position of the synchronizer (14), the synchronizer (14) meshes with different gears on the output gear shaft 4, thereby changing the actual speed ratio of the steering wheel drive mechanism so that it can meet the requirements of different operating conditions, thus greatly expanding the operating range of the AGV using this steering wheel.

[0042] The synchronous belt mechanism of this invention is connected to the transmission mechanism via the input end and to the differential mechanism via the output shaft of the bevel gear (17), and is connected to the drive mechanism of the steering wheel system. The tension of the synchronous belt (21) in the synchronous belt structure can be adjusted by the adjusting screw 23 on the synchronous belt housing and the threaded hole on the gearbox housing. When the synchronous belt gradually loosens over time, it can be tightened by the adjusting screw 23 to continue to meet the usage requirements, greatly reducing the maintenance and upkeep time of the synchronous belt mechanism.

[0043] The linear braking mechanism of the present invention has a brake (25) mounted on a synchronous belt housing (15) and a brake disc (26) mounted on a large pulley (19) of the synchronous belt mechanism, thereby connecting to the steering wheel system drive mechanism. A maximum oil pressure limit is set in the external linear brake pump (24) according to the required emergency stop safety distance. The oil pressure is transmitted to the brake (25) via hydraulic lines through the oil port on the synchronous belt housing (15). The piston rod inside the brake (25) is subjected to oil pressure, applying pressure to the brake disc (26) in the middle, forming a braking torque on the brake disc (26). This braking torque is amplified to the tire (39) via the differential mechanism and the wheel hub reducer (40), achieving emergency braking of the steering wheel system. In this linear braking mechanism, the braking torque can be adjusted according to the oil pressure of the external linear brake pump, thereby making the braking distance and braking time of the steering wheel system controllable, meeting the braking distance requirements of different road surfaces.

[0044] The differential mechanism of this invention connects its input end to the output end of a synchronous belt, and its output end to the wheel assembly, thereby distributing the steering wheel drive torque across the wheel assembly. The differential housing is sealed via an O-ring and a rotary seal between the differential housing cover, the synchronous belt mechanism, and the wheel assembly. The differential mechanism incorporates four bevel gears mounted on a cross shaft, which distribute the torque. Two output bevel gears connect to the wheel assembly, serving as the differential mechanism's output, while the other two distribution bevel gears adjust the wheel assembly's speed and torque. This differential mechanism enables the steering wheel system to automatically distribute the speed and driving torque between the two drive wheels during cornering, especially at high speeds, preventing drag and slippage between the two drive wheels and ensuring smooth cornering.

[0045] In this invention, the torque of the drive motor is transmitted to the two drive wheels through a transmission mechanism, a synchronous belt mechanism, a differential divider, and a reducer. When the differential steering wheel needs to turn, the steering motor actively controls the steering, and the two drive wheels automatically distribute speed and torque through the differential to achieve smooth steering. In dangerous situations, the differential steering wheel achieves emergency braking through linear braking with adjustable braking force. Under high-speed, light-load conditions, the speed of the differential steering wheel can be adjusted to a high-speed gear through the transmission mechanism, thereby widening the speed range of the differential steering wheel. Under low-speed, heavy-load conditions, the speed of the differential steering wheel can be adjusted to a low-speed gear through the transmission mechanism, thereby enhancing the driving torque of the differential steering wheel and increasing its traction capability.

[0046] The differential steering wheel system with linear braking and speed change functions provided by this invention can solve the problem of traditional steering wheels being unable to handle both high speed and heavy load by changing speed and torque. Furthermore, it can achieve emergency braking of the steering wheel through linear braking at high speeds. The torque of the differential steering wheel's drive motor is transmitted to the two drive wheels through a transmission mechanism, synchronous belt mechanism, differential shunt, and reducer. When the differential steering wheel needs to turn, the steering motor actively controls the steering, and the two drive wheels automatically distribute speed and torque through the differential to achieve smooth steering. In dangerous situations, the differential steering wheel achieves emergency braking through linear braking with adjustable braking force. Under high-speed, light-load conditions, the speed of the differential steering wheel can be adjusted to a high-speed gear through the transmission mechanism, thereby widening the speed range of the differential steering wheel. Under low-speed, heavy-load conditions, the speed of the differential steering wheel can be adjusted to a low-speed gear through the transmission mechanism, thereby enhancing the driving torque of the differential steering wheel and increasing its traction capability.

Claims

1. A differential steering wheel system with linear braking and variable speed function, characterized in that, The application relates to a steering gear system, which comprises a variable speed mechanism, a synchronous belt mechanism, a linear brake mechanism, a differential mechanism, a wheel assembly and a steering swing mechanism, wherein the variable speed mechanism is connected with the synchronous belt mechanism and is used for variable speed and variable torque of the steering gear system; the gear ratio of the variable speed mechanism is adjusted according to the working condition of the steering gear system, the driving mechanism speed ratio of the steering gear system is changed, and the steering gear system can adapt to low-speed heavy-load or high-speed light-load working conditions; the synchronous belt mechanism is used for realizing transmission and amplification of driving torque; the linear brake mechanism is used for realizing emergency stop; the input end of the differential mechanism is connected with the output end of the synchronous belt mechanism; the output end of the differential mechanism is connected with the wheel assembly and is used for realizing load bearing, driving torque transmission, amplification and flow distribution; the steering swing assembly realizes active steering of the steering gear system through a steering motor and a steering mechanism and makes two driving wheels swing at a set angle.

2. The differential rudder wheel system with linear braking and gear shifting function according to claim 1, characterized in that, The variable speed mechanism comprises a driving motor (1), a variable speed box body (2), an input gear shaft (3), an output gear shaft (4), an intermediate gear shaft (5), gear A (6), gear B (7), gear C (8), gear D (9), gear E (10), an outer spline (11), gear (G12), a speed regulating fork (13) and a synchronizer (14); the input gear shaft (3), the output gear shaft (4) and the intermediate gear shaft (5) are respectively installed in parallel on the variable speed box body (2) through bearings; gear D (9) is fixed on the input gear shaft (3); gear A (6), gear B (7) and gear C (8) are fixed in sequence on the intermediate gear shaft (5); the outer spline (11) is fixed on the output gear shaft (4); gear E (10) and gear (G12) are installed on the output gear shaft (4) through bearings; the pawl of the speed regulating fork (13) is clamped into the ring groove of the outer circle of the synchronizer (14) and is used for controlling the axial position of the synchronizer (14) and not limiting the circumferential rotation of the synchronizer (14); the synchronizer (14) is installed on the outer spline (11) through an inner spline and rotates at the same speed with the output gear shaft (4); gear D (9) is always engaged with gear A (6); gear E (10) is always engaged with gear C (8) on the intermediate shaft; gear G (12) is always engaged with gear A (6) on the intermediate shaft; gear F (11) is always engaged with gear B (7) on the intermediate shaft; the axial position of the synchronizer (14) is adjusted by pulling the speed regulating fork (13); the synchronizer (14) is in contact with gear E (10) or gear (G12); the rotational speed of the synchronizer (14) gradually synchronizes with that of gear E (10) or gear (G12) through contact friction; after the rotational speed is synchronized, the synchronizer (14) is fixed with gear E (10) or gear (G12) through a gear with a guide angle; the output gear shaft (4) is also synchronized with gear E (10) or gear (G12), so that the speed ratio between the input gear shaft (3) and the output gear shaft (4) of the variable speed mechanism is changed; the driving motor (1) is installed on the variable speed box body (2) through screws and keys.

3. The differential rudder wheel system with linear braking and gear shifting function according to claim 2, characterized in that, The guide angle is machined on the teeth of gear E (10), the outer spline (11), gear (G12) and the synchronizer (14), so that the synchronizer (14) can be correctly engaged with gear E (10) or gear (G12) during gear shifting.

4. The differential rudder wheel system with linear braking and gear shifting function according to claim 1, characterized in that, The synchronous belt mechanism comprises a synchronous belt box (15), a synchronous belt cover plate (16), a bevel gear (17), a small pulley (18), a large pulley (19), a toothed disc (20), a synchronous belt (21), a baffle (22), an adjusting screw (23), the bevel gear (17) is installed on the synchronous belt box (15) through a bearing, a rotary seal is installed outside the bearing, so that the synchronous belt mechanism is separated from the differential mechanism, the large pulley (19) is installed on the synchronous belt box (15) through a bearing, the baffle (22) is installed on the synchronous belt box through a screw and limits the bearings of the large pulley (19) and the bevel gear (17) in the axial direction, the large pulley (19) is connected with the bevel gear (17) through the toothed disc (20) to transmit power, the small pulley (18) is installed on the output gear shaft (4) of the speed change mechanism through a sleeve, a baffle, a screw and a key, the synchronous belt (21) is installed on the small pulley (18) and the large pulley (19), the tension of the synchronous belt is adjusted through the adjusting screw (23) on the synchronous belt box (15), and after the tension adjustment is completed, the synchronous belt cover plate (16) is installed on the synchronous belt box (15) through a screw. When the output gear shaft (4) of the speed change mechanism outputs a torque, the torque is amplified through the small pulley (18), the synchronous belt (21) and the large pulley (19), the amplified torque is transmitted to the bevel gear (17) through the toothed disc (20), and then the torque is input into the differential mechanism through the bevel gear (17).

5. The differential rudder wheel system with linear braking and gear shifting function according to claim 1, characterized in that, The linear brake mechanism comprises an external linear brake pump (24), a brake (25), a brake disc (26) and an oil pipe (27), the external linear brake pump (24) is installed on the AGV on which the steering wheel system is located, the brake (25) is fixed on the synchronous belt box (15) through adjusting shims and screws, and the brake disc (26) is installed on the large pulley (19) through screws and a stop. When the steering wheel system needs to be braked, the external linear brake pump (24) provides oil pressure, the oil pressure is transmitted to the brake (25) through the oil pipe (27), the brake (25) is internally provided with a hydraulic piston rod, the piston rod is extended to the middle under the action of the oil pressure, a brake pad installed on the piston rod contacts the brake disc (26) and transmits the pressure to the brake disc (26), a brake friction torque is generated on the brake disc (26), the brake disc (26) is fixed with the large pulley (19), the brake friction torque enters the steering wheel transmission system through the large pulley (19) of the synchronous belt mechanism, is gradually amplified through the differential mechanism and the wheel assembly and finally acts on the tire (39), so that the tire (39) is in a sliding friction state or a sliding and rolling mixed friction state with the ground, and a braking effect is achieved.

6. The differential steering wheel system with linear braking and gear shifting function according to claim 1, characterized in that, The wheel assembly comprises a tire (39) and a hub reduction machine (40). The hub reduction machine (40) is installed in the tire core of the tire (39) through screws and cylindrical pins, the wheel assembly is installed on the differential mechanism through screws, long and short output spline shafts, the wheel assembly is connected with the differential mechanism through the long and short output spline shafts, and the wheel assembly and the differential mechanism constitute the end of the steering wheel system driving mechanism.

7. The differential rudder wheel system with linear braking and gear shifting function according to claim 1, characterized in that, The steering swing assembly comprises a steering motor (41), a steering speed reducer (42), a steering pinion (43), a slewing bearing (44), a mounting plate (45), a cross plate (46), a side plate (47), an angle limiting block (48), a mechanical limiting block (49), a sliding bearing end cover (50) and a sliding bearing (51); The angle limiting block (48) is fixed on the differential case (28), the sliding bearing (51) is fixed on the differential case support lug, the side plate (47) is hinged to the differential case (28) through the sliding bearing (51), the cross plate (46) is fixed to the two side plates (47) through screws, forming a Chinese character-shaped structure to limit the axial movement of the differential case (28), the sliding bearing end cover (50) is fixed on the side plate (47) to limit the axial movement of the sliding bearing (51); the mounting plate (45) is fixed on the cross plate (46), the inner ring of the slewing bearing (44) is fixed on the mounting plate (45), and the outer ring can slide relative to the mounting plate (45); the mechanical limiting block (49) is fixed on the outer ring of the slewing bearing (44); the steering speed reducer (42) is fixed on the mounting plate (45), the steering motor (41) is installed on the steering speed reducer (42) through screws and keys, the steering pinion (43) is fixed to the output shaft of the steering speed reducer (42) through keys, retaining sheets and screws, and forms a meshing relationship with the outer ring of the slewing bearing (44); The steering wheel system is fixed to the AGV vehicle body through the outer ring of the slewing bearing, when the steering motor (41) outputs torque, the inner ring of the slewing bearing (44) (the inner ring is fixed to the steering wheel body) rotates relative to the AGV vehicle body through the steering speed reducer (42) and the steering pinion (43), and the steering function of the mechanism is completed; the mechanical limiting block (49) installed on the outer ring of the slewing bearing (44) and the mounting plate (45) mechanically collide, preventing the differential steering wheel from losing control; When the AGV drives over a bumpy road, the Chinese character-shaped structure composed of the cross plate (46) and the side plate (47) swings relative to the differential case (28) (including the wheel assembly) through the relative rotation of the sliding bearing (51), the swing angle of the side plate (47) is limited by the angle limiting block (48) fixed on the side of the differential case (28), and the swing function of the mechanism is completed.

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