A chassis capable of wheel-track transformation

Abstract

The present invention discloses a chassis capable of wheel-track transformation, which includes a wheel-track power switching part, a wheel-track transformation part and a front rocker part. The wheel-track power switching part includes an axle coupler, an oil-pushing slider, a main axle, a main shaft gear, a front axle gear, a fixed-axis gear train, a lead screw, a driving motor, a guide rail and a lead screw driver; the wheel-track transformation part includes a crawler belt, a transformable wheel hub, a wheel hub hydraulic rod, a floating strip, an axle coupler, a crawler wheel and a main axle; the front rocker part includes a front rocker, a front crawler wheel, a front support rod and a front wheel, and the front rocker, the front crawler wheel, the front support rod and the front wheel form a robotic arm that can swing up and down. The present invention provides two different traveling mechanisms, uses the same power system, does not need to use hub motors, etc. to solve the problem of power system incompatibility, and is convenient to be applied to small explorers.

Description

Technical Field

[0001] The invention relates to a chassis structure, in particular to a wheel-track changing chassis with a hydraulic rod adjusting the shape of a wheel hub. Background Art

[0002] As an important component of the intelligent car, the chassis is mainly responsible for providing reliable and stable power for the intelligent car, as well as providing corresponding auxiliary functions. This chassis is suitable for unmanned express delivery vehicles, fire-fighting vehicles and various small robots that climb stairs. This deformable chassis can simultaneously meet the requirements of unmanned vehicles for climbing stairs and fast driving, and provides a reliable chassis for intelligent unmanned vehicles. The current application number is CN201310047258.2, and the name is "A four-link wheel-track conversion mechanism for a wheel-track variable structure mobile robot", which provides a structure that can perform wheel-track conversion. In this patent, the contour shape is changed by adjusting the follower, from a wheel type to a triangular track, and the corresponding two small wheels can flexibly adjust their positions to transform into more forms, which has the advantage of being able to adapt to a variety of terrains. However, this structure itself is highly dependent on the telescopic performance of the track, and it is difficult for general tracks to meet its requirements. There are also special requirements for tracks for special vehicles such as fire fighting (such as heat resistance and pressure resistance), which will limit the scope of application of the track. The application number is CN201110393359.6, and the name is "A wheel-track conversion mechanism". It provides a wheel-track conversion mechanism. The invention discloses a power switching device controlled by a shift fork, which can enable a vehicle or a traveling mechanism with this structure to switch between wheel type and track type according to road conditions, and can switch freely. However, this structure is four deformable wheels that work independently, and the power output is switched by shifting gears by the shift fork, which means that the larger the size of the shift fork, the more space it needs to occupy inside, otherwise it will not be able to shift the power transmission gear to the predetermined position. The overall structure occupies too much internal space, and the overall strength of small-volume vehicles is relatively reduced. The application number is CN201610677978.0 and the name is "Wheel-track transformable mobile chassis and fire detection robot having the same". It provides a fire-fighting robot that can be transformed into wheels and tracks. The invention is equipped with tracks and wheels at the same time, and the angle is adjusted by a rocker arm so that the wheeled walking devices on both sides can contact or leave the ground. Even during walking, the deformation can still be achieved, and the McKenna's wheel is used, which can rotate more flexibly, thereby greatly improving the work efficiency of on-site operations. However, this structure itself is equipped with tracks and wheels at the same time, which not only occupies a larger volume, but also in order to obtain sufficient power, the two sets of power devices will also have corresponding requirements, so the overall volume will be too large and not suitable for use with small prospectors. Summary of the invention

[0003] In order to solve the problem that the intelligent unmanned vehicle in the background needs to perform wheel-track transformation when facing different terrains and meet the market demand for a chassis that can perform wheel-track transformation, the present invention provides a chassis that can perform wheel-track transformation.

[0004] The object of the present invention is to provide a chassis that can perform wheel-track transformation. Different from many existing technologies, the present invention realizes the operation of two different walking mechanisms using the same power system, without the need to use hub motors or the like to solve the problem of power system incompatibility. The present invention uses the front wheel and the front support rod as the front wheel system in the wheeled state, and transforms into a crawler arm that can swing up and down in the tracked state. The crawler arm can be used to climb complex terrains such as stairs with a relatively high height. At this time, the deformable wheel hub is also in the tracked form, supporting the crawler. The internal crawler wheel obtains power through meshing with the main shaft gear through a gear set. When in the wheeled state, the gear set will disengage from the main shaft gear along the lead screw under the action of the lead screw driver, and then the crawler wheel loses power. At the same time, the secondary hydraulic rod pushes the push shaft slider to control the contraction of the crawler wheel. Immediately afterwards, the axle coupler moves towards the deformable wheel hub under the action of the hydraulic rod and meshes with the main shaft gear to complete the switching of the power system output end. Correspondingly, the deformable wheel hub is deformed into a wheeled form through the hub hydraulic rod. At this time, the crawler is completely attached to the deformable wheel hub in a circular shape and forms a tire together with the deformable wheel hub. In this way, the two different walking mechanisms can be supplied by a set of power systems. Compared with the prior art, such as the fork mechanism; in this power switching process, the secondary hydraulic rod is used in cooperation with the push shaft slider to control the movement of the crawler wheel, avoiding occupying too much working space and having a higher space utilization rate. Using this form to control the crawler wheel can avoid occupying the upper and lower spaces, reduce the height of the chassis, make the chassis have a lower center of gravity, good stability, and a larger ratio of length to height in the length, width, and height ratio of the chassis, making it less likely to tip over, and can climb relatively complex terrains. The deformable wheel hub of this system can be transformed into a wheeled form and a tracked form by itself, and the crawler will not be overly stretched in both states, which reduces the requirements for the crawler, facilitates the selection of crawlers for special equipment such as fire-fighting robots to a certain extent, and increases the universality.

[0005] Advantages of the present invention: (1) It can be applied to many small unmanned robots, such as various small robots like unmanned delivery vehicles and small exploration vehicles. Through the deformable wheels, it can be freely switched between wheeled and tracked vehicles. When traveling on the road in wheeled state, the speed will be faster than that of tracked vehicles and can greatly reduce the frictional loss of the tracks. When facing complex terrains such as stairs, it can be switched to a tracked vehicle. The extended tracked front arm is beneficial for climbing terrains higher than itself, and it can meet the requirements for dealing with a large number of complex terrains. Especially for small robots, it can help them climb stairs, cross obstacles for operation, and also ensure their own mobility. For example, fire reconnaissance robots often need to shuttle through ruins and quickly cross flat ground to reach the destination. Such a chassis is more suitable for robots with complex working conditions and limited self-volume. For robots that need to climb stairs frequently, the tracked chassis can help them climb stairs quickly and stably. However, considering that they mostly travel on flat ground, the wheeled chassis can help increase their moving speed and reduce the loss of rubber tracks. (2) Since the track does not have excessive length changes during the deformation of the deformable wheels, the requirements for the track are reduced. This is beneficial for special vehicles to install special tracks. For most special vehicles, their working conditions are often special and have relatively high requirements for track materials, avoiding the situation where they cannot be used due to material non-compliance, so it has wide universality. The structure of the deformable wheels is compact and does not have small load-bearing components. Since most vehicles require good load-bearing capacity, the existence of small components will affect the lifespan and the cost is relatively high. For example, using mechanisms such as shift forks to control load-bearing parts will greatly affect their own lifespan. (3) By adopting a set of power output systems and a low and long design, there are no overly long shafts or small components as a whole. Therefore, not only the cost is reduced, but also the internal space, center of gravity, and anti-tipping ability of the chassis are greatly reduced. The low and long overall design feature, combined with the supporting rods carried by itself, enables the chassis to withstand the torque caused by its own work in most working scenarios. For example, when a fire robot shoots water during work, it will also receive a reaction force. The low and long design can effectively offset the tipping torque without installing auxiliary devices. While the height of the chassis is reduced, its volume is also decreased, which is beneficial for small exploration vehicles to cross narrow terrains. For small robots, they often require a small self-volume and light weight, but also need to have sufficient anti-overturning ability. Therefore, this chassis is suitable for small robots. (4) Since a push shaft slider is used to control the movement of the track wheels, a large amount of space is saved as a whole compared to the shift fork that rotates around a fixed point. The overall power switching part has a compact structure and occupies less internal space, which is very suitable for small-sized robots to reduce their self-volume and avoid wasting the bottom space. There are no small components in the overall structure, which will make its working lifespan longer and be able to carry larger carriers. Such a linear motion can be driven hydraulically. Hydraulic drive not only requires a small volume but also has a large driving capacity.

[0006] The present invention will be further described below in conjunction with the accompanying drawings. Description of the Drawings

[0007] Figure 1 It is a schematic diagram of the overall structure of the present invention when using a wheeled chassis.

[0008] Figure 2 It is a schematic top view structure diagram of the present invention when using a wheeled chassis.

[0009] Figure 3 It is a schematic side view structure diagram of the present invention when using a wheeled chassis.

[0010] Figure 4 It is a schematic diagram of the overall structure of the present invention when using a tracked chassis.

[0011] Figure 5 It is a schematic top view structure diagram of the present invention when using a tracked chassis.

[0012] Figure 6 It is a schematic side view structure diagram of the present invention when using a tracked chassis.

[0013] Figure 7 It is a schematic bottom view structure diagram of the present invention when using a wheeled chassis.

[0014] Figure 8 It is a schematic diagram of the mechanism of the wheel-track switching device of the present invention.

[0015] Description of the reference numerals: 1 - crawler; 2 - deformable wheel hub; 3 - wheel hub hydraulic rod; 4 - floating strip; 5 - axle coupler; 6 - track wheel; 7 - push shaft slider; 8 - front rocker; 9 - front track wheel; 10 - front wheel support rod; 11 - front wheel; 12 - main axle; 13 - front axle; 14 - rear axle; 15 - main shaft gear; 16 - front axle gear; 17 - fixed-axis gear train; 18 - lead screw; 19 - belt; 20 - drive motor; 21 - coupler push plate; 22 – guide rail; 23 - lead screw drive; 24 - vehicle frame; 25 - secondary hydraulic rod; 26 - tertiary hydraulic rod. Detailed Embodiments

[0016] The present invention will be further described in detail below in conjunction with examples and the accompanying drawings.

[0017] Figure 1 As shown, a chassis of the present invention capable of wheel-track transformation includes a wheel hub deformation part, a power switching part, and a front rocker part.

[0018] Figure 1 and Figure 4As shown in the figure, the front rocker part mainly consists of a front rocker 8, a front crawler wheel 9, a front wheel support rod 10, and a front wheel 11. The front rocker 8 can swing up and down under the drive of a servo motor. The front crawler wheel 9 is connected to the front rocker 8 by a pin. The front wheel 11 and the front wheel support rod 10 are connected by a pin. The front wheel support rod 10 is connected to a servo motor fixed on the front crawler wheel and can swing up and down.

[0019] Figure 8 As shown in the figure, it includes deformable wheels 2, floating strips 4, an axle coupler 5, a main axle 12, a coupler push plate 21, a three-stage hydraulic rod 26, etc., which are important components of the wheel deformation part. Among them, the main axle 12 is connected to the vehicle frame 24 by a pin. The axle coupler 5 is connected to the main axle 12 by a slider connection. The deformable wheels 2 are rigidly connected to the axle coupler 5 through the floating strips 4. When the axle coupler 5 slides on the main axle 12, it is driven by the floating strips 4 to deform. When the axle coupler 5 is pushed to the farthest end (close to the deformable wheels 2) by the three-stage hydraulic rod 26, it is rigidly connected to the main axle 12 through the key on the main axle 12 and its own keyway. At this time, the deformable wheels 2 are in a wheeled state and rotate with the main axle 12. When the axle coupler approaches the middle of the main axle 12, the key and the groove withdraw from each other. At this time, the main axle 12 and the axle coupler 5 are in a cylindrical connection. The main axle 12 rotates, but the deformable wheels 2 and the axle coupler 5 do not rotate, that is, the axle coupler 5 and the main axle 12 are in relative sliding.

[0020] When the push axle connector 5 is close to the outer end face of the main axle 12, it is fixedly connected together by a key and can rotate. When it retreats to close to the midpoint of the main axle 12, it can slide relatively.

[0021] Figure 1 As shown in the figure, it is the form of the chassis in the wheeled state. The power switching part mainly consists of a crawler wheel 6, a push axle slider 7, a main axle 12, a front axle 13, a rear axle 14, a main shaft gear 15, a front axle gear 16, a fixed-axis gear train 17, a lead screw 18, a guide rail 22, a lead screw driver 23, and a two-stage hydraulic rod 25. Figure 1 As shown in the figure, it is in a wheeled state. At this time, the main shaft gear 15 is rigidly connected to the main axle 12. The two-stage hydraulic rod 25 is fixedly connected to the vehicle frame 24. Connected to the two-stage hydraulic rod 25 is the push axle slider 7. Among them, the push axle slider 7 is connected to the crawler wheel 6, the front axle 13, and the rear axle 14. The front axle 13 and the front axle gear 16 are fixedly connected together. At this time, the entire push axle slider 7 is in the position closest to the main shaft gear 15 (that is, the two-stage hydraulic rod 25 is in the contracted state) and the gear train 17 is close to the center line of the whole vehicle (that is, at this time, the two gear trains 17 are sandwiched inside the two front axle gears 16). The power is transmitted from the drive motor 20 to the main axle 12 by the belt 19. The main shaft gear 15 and the main axle 12 rotate together, but at this time, the front axle gear 16 is not meshed with the main shaft gear 16. Therefore, the power is only transmitted to the wheel deformation part.

[0022] The described push - shaft sliders 7 are divided into two parts, front and rear. The front push - shaft slider 7 is connected to the front axle 13 and the front - most track wheels 6, and the rear push - shaft slider 7 is connected to the rear axle 14 and the rear - most track wheels 6.

[0023] The front - axle gear 16 belongs to is rigidly connected to the front axle 13.

[0024] Figure 4 As shown, it is the form of the chassis in the tracked state. At this time, the components of the power - switching part have been switched from wheel - type output to tracked - type output. On the basis of the wheel - type, the secondary hydraulic rod 25 in the power - switching part pushes the push - shaft slider 7 to the maximum position at this time. The two front - and - rear track wheels 6 on one side are in close contact with the track 1 at this time. The front - axle gear 16 and the main - shaft gear 15 are the farthest apart at this time. The front - axle gear 16 and the main - shaft gear 15 are engaged with the gear set 17 at this time (in the wheel - type state, the gear set 17 is inside the front - axle gear 16 and close to the center line of the axle. At this time, the gear set 17 is driven by the lead - screw driver 23 along the lead - screw 18 and moves horizontally along the guide rail 22 to the current position). In the current state, the power still transmits from the drive motor 20 through the belt 19 to the main axle 12. However, since the hub - deformation part has changed from wheel - type to tracked - type at this time, the axle coupler 5 and the main axle 12 are in relative sliding, and the power cannot be transmitted to the deformable hub 2. It can only transmit from the main - shaft gear 15 to the gear set 17, then through the front - axle gear 16 and the front axle 13 to the track wheels 6, thus realizing the power switch.

[0025] Figure 1 、 2 As shown in FIGS. 3, etc., it is a wheel - type form of a chassis that can be switched between wheel and track. Here, in combination with the attached drawings (1 - 8), the power - switching part is introduced in detail from the wheel - type output state to the tracked - type output state. This chassis takes the frame 24 as the skeleton. The drive motor 20 is fixedly installed on the frame 24, and the power is transmitted to the main axle 12 through the belt 19. The main axle 12 is fixed on the frame 24. In the wheel - type state, the main - shaft gear 15 is not in contact and engagement with the front - axle gear 16. At this time, the front - axle gear 16 and the push - shaft slider 7 are in a position close to the main - shaft gear 15 because the secondary hydraulic rod 25 is in a contracted state, and at this time, the two sets of gear sets 17 are in the closest state, that is, far from the main - shaft gear 15. In the wheel - type state, the tertiary hydraulic rod 26 pushes the coupler push - plate 21, the coupler push - plate 21 pushes the axle coupler 5, and the groove of the axle coupler 5 is engaged with the key on the main axle 12 at this time and rotates together with the main shaft. In the wheel - type state, the hub hydraulic rod 3 contracts to the shortest, and at this time, the deformable hub 2 is in the wheel - type state (as Figure 3 ). This mechanism can be transformed into a tracked form through a series of motor drives and hydraulic - rod adjustments (refer to Figure 4 , FIGS. 5, 6), at this time, the hub hydraulic rod 3 extends, causing the deformable hub 2 to deform (it can be referred to Figure 3, 6), at this time, the secondary hydraulic rod 25 pushes the two track wheels 6 in two-way back-to-back directions, and the tertiary hydraulic rod 26 contracts, driving the coupler push plate 21 and the axle coupler 5 to disengage the key on the main shaft, so that the wheel hub loses power, and the main axle 12 is in idling. The secondary hydraulic rod 25 will push the push shaft slider 7 and the front axle gear 16 to the farthest position. At the same time, the fixed axis gear train 17 relies on the screw 18 to rotate and drive from a position away from the main shaft gear 15 to a position close to the main shaft gear 15 to complete the meshing with the main shaft gear 15 and the front axle gear 16. At this time, the main shaft gear 15 drives the front axle gear 16 to rotate, that is, at this time, the power of the drive motor 20 is transferred to the track wheel 6. While the internal transformation is in progress, the front rocker 8 remains stationary, but the front wheel 11 support rod 10 relies on the internal self-contained steering gear to rotate and retract the front wheel 11 (reference Figure 6 ), the entire change from crawler to wheeled form ends here. The process of changing from wheeled to crawler is the reverse process of the above process. In both forms, it is driven by a drive motor 20, so only one motor is needed for power. The deformation and its process do not over-stretch the crawler, which reduces the crawler requirements and prolongs the crawler life.

[0026] The above description is only a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Any simple modification, change and equivalent structural transformation made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A chassis capable of wheel-track transformation, characterized in that: it includes a vehicle frame (24), a wheel-track power switching unit, and a wheel-track transformation unit; The wheel-track power switching unit includes: an axle coupler (5), a push axle slider (7), a main axle (12), a main shaft gear (15), a front axle gear (16), a fixed-axis gear train (17), a lead screw (18), a drive motor (20), a guide rail (22), and a lead screw driver (23); wherein the drive motor (20) drives the main shaft gear (15) on the main axle (12) to rotate, and the meshing of the front axle gear (16) and the main shaft gear (15) is connected through the fixed-axis gear train (17) on the guide rail (22). In this process, the lead screw driver (23) is required to drive the fixed-axis gear train (17) to engage, and the position adjustment of the front axle gear (16) is also adjusted through the push axle slider (7) to complete the power output switching. Wherein the axle coupler (5) is connected to the main axle (12) through a keyway. When the form is track type, the axle coupler (5) is disengaged from the main axle (12) so that the main axle (12) only outputs power to the track wheels (6). When it is in wheel type, the main shaft gear (15) is rigidly connected to the main axle (12), the secondary hydraulic rod (25) is fixedly connected to the vehicle frame (24), and the push axle slider (7) is connected to the secondary hydraulic rod (25). The push axle slider (7) is connected to the track wheels (6), the front axle (13), and the rear axle (14), and the front axle (13) and the front axle gear (16) are fixedly connected together; at this time, the entire push axle slider (7) is in the position closest to the main shaft gear (15) and the fixed-axis gear train (17) is near the central axis of the whole vehicle. Power is transmitted from the drive motor (20) to the main axle (12) by a belt (19), and the main shaft gear (15) and the main axle (12) rotate together. However, at this time, the front axle gear (16) is not meshed with the main shaft gear (15), so the power is only transmitted to the hub deformation part. The form of the chassis in the tracked state. At this time, the components of the power switching unit have been switched from wheeled output to tracked output. On the basis of the wheeled state, the secondary hydraulic rod (25) in the power switching unit pushes the push shaft slider (7) to the maximum position at this time. The front and rear two tracked wheels (6) on one side are in close contact with the track (1) at this time. The front axle gear (16) and the main shaft gear (15) are the farthest apart at this time. The front axle gear (16) and the main shaft gear (15) are engaged with the fixed-axis gear train (17) at this time. In the current state, the power still transmits from the drive motor (20) to the main axle (12) through the belt (19). However, since the hub deformation part has changed from wheeled to tracked at this time, the axle coupler (5) and the main axle (12) are in relative sliding, and the power cannot be transmitted to the deformable hub (2). It can only transmit along the main shaft gear (15) to the fixed-axis gear train (17), and then through the front axle gear (16) and the front axle (13) to the tracked wheel (6), thus realizing the power switch; The wheel-track conversion part includes: track (1), deformable hub (2), hub hydraulic rod (3), floating strip (4), the axle coupler (5), the tracked wheel (6), the main axle (12); the track (1) is close to the deformable hub (2), the deformable hub (2) deforms by the telescopic movement of the hub hydraulic rod, the track (1) is driven by the tracked wheel (6) in the tracked state, the floating strip (4) is responsible for supporting the deformable hub (2), and its power source is transmitted to the floating strip (4) through the axle coupler (5). The axle coupler (5) and the main axle (12) are connected by a keyway. When the chassis is converted to the tracked state, the axle coupler (5) is disengaged from the main axle (12), causing the wheeled hub to lose power. Then, the power is transmitted to the tracked wheel (6) through gear meshing to complete the form conversion.

2. A wheel-track convertible chassis according to claim 1, characterized in that: The secondary hydraulic rod (25), the guide rail (22) and the lead screw drive (23) are all fixedly installed on the vehicle frame (24).

3. A wheel-track convertible chassis according to claim 1, characterized in that: The deformation structure of the deformable hub (2) is connected and driven by the key on the end of the main axle (12) and the keyway on the axle coupler (5).

4. A wheel-track convertible chassis according to claim 1, characterized in that: The front rocker (8), the front tracked wheel (9), the front support rod (10) and the front wheel (11) form a robotic arm that can swing up and down.

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