A single-track stair climbing wheelchair based on a linkage mechanism

Abstract

The application relates to a single-track type stair climbing wheelchair based on a connecting rod mechanism, which comprises a frame, a wheelchair main body, a track climbing mechanism, a connecting rod mechanism and a flat ground walking mechanism; wherein the wheelchair main body is arranged on the upper part of the frame, the track climbing mechanism is installed on the lower part of the frame on both sides, the connecting rod mechanism is symmetrically arranged on both sides of the frame, and the flat ground walking mechanism is installed on the connecting rod mechanism. When climbing stairs, the wheelchair realizes conversion from wheel driving to track driving through the connecting rod mechanism. The connecting rod mechanism and a hydraulic rod are used to replace a motor, the wheelchair can realize mutual conversion between the flat ground walking state and the track climbing state, vibration and noise caused by the motor in the conversion process are avoided, the stability of the machine in the stair climbing process is effectively improved, and the application has the advantages of safety and reliability, stability and comfort, economy and practicality and the like.

Description

Technical Field

[0001] This invention relates to stair-climbing wheelchairs, and more particularly to a single-track stair-climbing wheelchair based on a linkage mechanism. Background Technology

[0002] 1. Wheelchairs provide convenience for the elderly, the frail, and people with disabilities, but ordinary wheelchairs cannot go up and down stairs, which limits their mobility and seriously affects their daily lives. Furthermore, with the increasing aging of my country's population, wheelchairs have become an indispensable means of transportation for the elderly. However, due to limitations in regional economic development or other constraints, stairs remain prevalent in our daily lives.

[0003] 2. The invention patent with publication number CN105726232B discloses a double-section double-track stair-climbing wheelchair based on the swing of the walking wheels and a method for going up and down stairs. It mainly includes a wheelchair body, two large walking wheels, a track stair-climbing mechanism and a large wheel swing arm mechanism. The structure is relatively simple and the cost is relatively low. However, the swing arm mechanism is driven by a motor, which is prone to noise and vibration, and it will also affect the stability during the swing arm process.

[0004] 3. The invention patent with publication number CN107361934A discloses a new type of six-degree-of-freedom automatic stair-climbing wheelchair. The wheelchair achieves a smooth transition when going up and down stairs and does not tilt suddenly. However, it occupies a large space and is not easy to change direction at the corner of the stairs. Moreover, the center of gravity of the stair-climbing wheelchair is high, which can easily cause safety problems if the rider does not operate it properly.

[0005] 4. While theoretical research on stair-climbing wheelchairs is well-established and numerous related products exist on the market, they generally suffer from low safety, poor stability, and high production costs. For tracked stair-climbing wheelchairs, existing products primarily use electric motors for power transitions between walking and stair-climbing modes, resulting in poor stability and a tendency to generate vibration and noise. Therefore, this invention aims to develop a more stable stair-climbing wheelchair that can be reliably used in daily life. Summary of the Invention

[0006] To address the aforementioned problems, this invention aims to propose a single-track stair-climbing wheelchair based on a linkage mechanism, so as to effectively improve the stair-climbing performance and stability of the wheelchair.

[0007] The technical solution adopted in this invention is as follows:

[0008] The present invention proposes a single-track stair-climbing wheelchair based on a linkage mechanism. The tracked stair-climbing wheelchair includes a frame, a wheelchair body, a tracked stair-climbing mechanism, a linkage mechanism, and a flat-ground walking mechanism. The wheelchair body is disposed on the upper part of the frame. The tracked stair-climbing mechanism is installed on both sides of the lower part of the frame. The linkage mechanism is symmetrically disposed on both sides of the frame. The flat-ground walking mechanism is mounted on the linkage mechanism.

[0009] The wheelchair body includes a wheelchair mechanism, a posture adjustment mechanism, an auxiliary motion mechanism, and a support frame. The wheelchair body is fixedly mounted on the tracked stair-climbing mechanism via the support frame. The wheelchair mechanism includes foot pedals, leg rests, a seat, armrests, and a backrest. The posture adjustment mechanism includes a front seat posture adjustment mechanism, a backrest posture adjustment mechanism, a rear seat posture adjustment mechanism, a leg rest posture adjustment mechanism, and a foot pedal posture adjustment mechanism. The auxiliary motion mechanism includes a first hydraulic rod, a second hydraulic rod, a mounting box, a third hydraulic rod, a rotating shaft, and a fixed platform.

[0010] Furthermore, the backrest adjustment mechanism is fixedly connected to the backrest, with its middle position connected to the end of the first hydraulic rod, and its end hinged to the rear seat adjustment mechanism; the rear seat adjustment mechanism is hinged to the front seat adjustment mechanism; the front seat adjustment mechanism is fixedly connected to the seat and leg rest adjustment mechanism; the leg rest adjustment mechanism is fixedly connected to the leg rest and footrest adjustment mechanism; the footrest adjustment mechanism is fixedly connected to the footrest; the fixed platform is fixedly mounted on the support frame to fix the wheelchair body; the fixed platform has a hinge support... The seat is hinged to the third hydraulic rod to control the rotation of the wheelchair body; the fixed platform is connected to the rotating shaft via bearings; the rotating shaft is connected to the mounting box via bearings; the mounting box is fixedly connected to the posture adjustment mechanism at the rear end of the seat; the interior of the mounting box is hinged to the first hydraulic rod, the second hydraulic rod, and the end of the third hydraulic rod respectively; wherein the first hydraulic rod and the second hydraulic rod control the posture adjustment mechanism to keep the seat horizontal; the third hydraulic rod allows the wheelchair body to rotate slightly to maintain the stability of the wheelchair operation;

[0011] The tracked stair-climbing mechanism includes a track mechanism and a track drive motor and its reduction mechanism; the track mechanism includes a drive wheel axle, a drive wheel, a load-bearing wheel, a guide wheel axle, a guide wheel, a tension wheel, a positioning plate, a limiter, and a track;

[0012] Furthermore, the drive wheel meshes with the track, thereby driving the track to rotate. The drive wheel is mounted on a drive wheel shaft. The drive wheel shaft is mounted at the rear end of the track mechanism, below the frame. The load-bearing wheel is mounted between the frame and the positioning plate via a limiter and can rotate relative to it. The load-bearing wheels are evenly distributed on the bottom edge of the track to distribute the weight of the wheelchair, making the pressure of the wheelchair on the entire track uniform and improving the stability of the track during operation. The guide wheel is used to guide the track to rotate normally and prevent the track from deviating or going off track during operation. The guide wheel is mounted on a guide wheel shaft. The guide wheel shaft is mounted at the front end of the track mechanism, below the frame. The tension wheel is mounted via a limiter, meshes with the track, and tensions the track outward to maintain a constant path during track rotation. The positioning plate is elongated and has holes that mate with the limiter for positioning the load-bearing wheel and the tension wheel.

[0013] The linkage mechanism includes a connecting rod, a main rod connecting shaft, a main rod, a hydraulic rod connecting shaft, a fourth hydraulic rod, a small rod, a universal wheel support rod, a small rod connecting shaft, a fixed seat, a bearing seat for the main rod connecting shaft, a bearing seat for the small rod connecting shaft, and a pad.

[0014] Furthermore, the main rod connecting shaft is mounted on the frame via a main rod connecting shaft bearing seat and is hinged to the main rod; the upper end of the main rod is hinged to the connecting rod, and the lower end is fixedly mounted with a large wheel drive motor and its reduction mechanism; the large wheel drive motor and its reduction mechanism are connected to the large wheel to drive it; the small rod connecting shaft is connected to a small rod connecting shaft bearing seat, and the small rod connecting shaft bearing seat is fixed to the frame via a pad, so the small rod connecting shaft is vertically higher than the main rod connecting shaft; the small rod connecting shaft is hinged to the small rod; a connecting shaft is welded to the outer side of the lower end of the small rod to hinge the other end of the connecting rod; the lower end of the small rod is hinged to the universal wheel support rod; the lower middle position of the universal wheel support rod is hinged to the end of the fourth hydraulic rod; the fixed seat is fixedly connected to the frame, providing a connection position for the hydraulic rod connecting shaft; the hydraulic rod connecting shaft is connected to the fixed seat via a bearing and a locking cap; the fourth hydraulic rod is hinged to the hydraulic rod connecting shaft.

[0015] The positive effects of this invention are as follows:

[0016] 1. By combining the wheelchair with the tracked stair-climbing mechanism, there is no need to disassemble or reassemble it under specific circumstances, making it more convenient for practical applications; the wheelchair can be electrically driven when walking on flat ground, making it more convenient and labor-saving compared to ordinary wheelchairs.

[0017] 2. With the cooperation of the tracked crawling mechanism and the linkage mechanism, this invention can ensure the overall stability of the wheelchair at the beginning and end of the stair climbing process. Furthermore, by operating the linkage mechanism, the tracked stair climbing wheelchair can be flexibly switched between flat ground walking and stair climbing modes. The structure is relatively simple and has great potential for widespread application.

[0018] 3. The linkage mechanism in this invention has the advantages of easy manufacturing and long transmission distance, which greatly saves production costs and also satisfies the transmission distance between the large wheel and the universal wheel.

[0019] 4. The power source for the linkage mechanism in this invention is hydraulic drive, not electric motor drive. Electric motor drive will generate vibration and noise to a certain extent, which is not conducive to the riding experience. In addition, the electric motor control system is susceptible to electromagnetic interference, and the transition between the wheelchair's walking state and stair-climbing state will become unstable, thus affecting the overall stability of the tracked stair-climbing wheelchair during stair climbing. Hydraulic drive avoids the problems caused by electric motor drive and improves the riding experience. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a single-track stair-climbing wheelchair based on a linkage mechanism proposed in this invention;

[0021] Figure 2 This is a schematic diagram of the structure of the wheelchair body of the present invention;

[0022] Figure 3 This is a schematic diagram of the tracked stair-climbing mechanism of the present invention;

[0023] Figure 4 This is a schematic diagram of the linkage mechanism of the present invention;

[0024] Figure 5 This is a schematic diagram of the connection structure between the universal wheel support rod and the small rod of the present invention;

[0025] Figure 6 This is a schematic diagram of the connection structure between the linkage mechanism and the flat-ground walking mechanism of the present invention.

[0026] Legend:

[0027] 1-Rack;

[0028] 2-Wheelchair body, 21-Wheelchair mechanism, 22-Posture adjustment mechanism, 23-Assistive motion mechanism, 24-Support frame, 211-Foot pedal, 212-Leg rest, 213-Seat, 214-Armrest, 215-Backrest, 221-Front seat posture adjustment mechanism, 222-Backrest posture adjustment mechanism, 223-Rear seat posture adjustment mechanism, 224-Leg rest posture adjustment mechanism, 225-Foot pedal posture adjustment mechanism, 231-First hydraulic rod, 232-Second hydraulic rod, 233-Mounting box, 234-Third hydraulic rod, 235-Rotation shaft, 236-Fixed platform;

[0029] 3-Crawler climbing mechanism, 31-Crawler mechanism, 32-Crawler drive motor and its reduction mechanism, 311-Drive wheel axle, 312-Drive wheel, 313-Bearing wheel, 314-Guide wheel axle, 315-Guide wheel, 316-Tension wheel, 317-Positioning plate, 318-Limiter, 319-Crawler;

[0030] 4-Linkage mechanism, 41-Linkage, 42-Main rod connecting shaft, 43-Main rod, 44-Hydraulic rod connecting shaft, 45-Fourth hydraulic rod, 46-Small rod, 47-Universal wheel support rod, 48-Small rod connecting shaft, 49-Fixed seat, 401-Main rod connecting shaft bearing seat, 402-Small rod connecting shaft bearing seat, 403-Padded block;

[0031] 5-Flat-ground walking mechanism, 51-Large wheel, 52-Small wheel, 53-Large wheel drive motor and its reduction mechanism. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the present invention clear and complete, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some, not all, embodiments of the present invention, and are merely illustrative of the embodiments of the present invention. They are not intended to limit the embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] In the description of this invention, it should be noted that the terms "center," "middle," "upper," "lower," "left," "right," "inner," "outer," "top," "bottom," "side," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "a," "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] For purposes of simplicity and illustration, the principles of the embodiments are described primarily by way of example. In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments. These embodiments may not be limited to these specific details in practice by those skilled in the art.

[0036] The embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0037] like Figure 1-6 As shown:

[0038] The present invention proposes a single-track stair-climbing wheelchair based on a linkage mechanism, which mainly includes a frame 1, a wheelchair body 2, a tracked stair-climbing mechanism 3, a linkage mechanism 4, and a flat-ground walking mechanism 5;

[0039] The wheelchair body 2 is a seat structure that carries the passenger, the track climbing mechanism 3 is used for the wheelchair to climb when it is on the stairs, and the linkage mechanism 4 is used to retract the flat walking mechanism 5 when climbing stairs.

[0040] The wheelchair body 2 is as follows Figure 2 As shown, it includes a wheelchair mechanism 21, a posture adjustment mechanism 22, an assistive motion mechanism 23, and a support frame 24;

[0041] The wheelchair mechanism 21 includes a footrest 211, a leg rest 212, a seat 213, armrests 214, and a backrest 215;

[0042] The posture adjustment mechanism 22 includes a front seat posture adjustment mechanism 221, a back seat posture adjustment mechanism 222, a rear seat posture adjustment mechanism 223, a leg rest posture adjustment mechanism 224, and a foot pedal posture adjustment mechanism 225.

[0043] The auxiliary action mechanism 23 includes a first hydraulic rod 231, a second hydraulic rod 232, a mounting box 233, a third hydraulic rod 234, a rotating shaft 235, and a fixed platform 236;

[0044] The chair back posture adjustment mechanism 222 is fixedly connected to the chair back 215; its middle position is connected to the end of the first hydraulic rod 231, thereby adjusting the posture; its end is connected to the chair seat rear posture adjustment mechanism 223 through a shaft and bearing, and the two can rotate relative to each other.

[0045] Furthermore, the rear end posture adjustment mechanism 223 of the chair seat is hinged to the front end posture adjustment mechanism 221 of the chair seat;

[0046] Furthermore, the chair seat front end posture adjustment mechanism 221 is fixedly connected to the chair seat 213 and the leg rest posture adjustment mechanism 224;

[0047] Furthermore, the leg support posture adjustment mechanism 224 is fixedly connected to the leg support 212 and the foot pedal posture adjustment mechanism 225;

[0048] Furthermore, the foot pedal posture adjustment mechanism 225 is fixedly connected to the foot pedal 211;

[0049] The fixed platform 236 is fixedly installed on the support frame 24 to fix the wheelchair body 2; the fixed platform 236 has a hinge support, which is hinged to the third hydraulic rod 234 to control the rotation of the wheelchair body 2; and the fixed platform 236 is connected to the rotating shaft 235 through a bearing.

[0050] Furthermore, the rotating shaft 235 is connected to the mounting box 233 via a bearing;

[0051] Furthermore, the mounting box 233 is fixedly connected to the posture adjustment mechanism 223 at the rear end of the seat; the interior of the mounting box 233 is respectively hinged to the first hydraulic rod 231, the second hydraulic rod 232, and the end of the third hydraulic rod 234; wherein the first hydraulic rod 231 and the second hydraulic rod 232 control the posture adjustment mechanism 22 to keep the seat 213 horizontal; the third hydraulic rod 234 can make the wheelchair body 2 rotate slightly to maintain the stability of the wheelchair operation;

[0052] The wheelchair body 2 is fixed to the tracked stair climbing mechanism 3 by a support frame 24;

[0053] The tracked stair-climbing mechanism 3, as described in Figure 3 As shown, it includes a track mechanism 31 and a track drive motor and its reduction mechanism 32;

[0054] The track mechanism 31 includes a drive wheel axle 311, a drive wheel 312, a load-bearing wheel 313, a guide wheel axle 314, a guide wheel 315, a tension wheel 316, a positioning plate 317, a limiter 318, and a track 319.

[0055] The drive wheel 312 meshes with the track 319, thereby driving the track 319 to rotate. The drive wheel 312 is mounted on the drive wheel shaft 311, and the drive wheel shaft 311 is connected to the track drive motor and its reduction mechanism 32 for transmission. The drive wheel shaft 311 is mounted at the rear end of the track mechanism 31 and at the lower part of the frame 1.

[0056] Furthermore, the track drive motor and its reduction mechanism 32 are fixedly mounted on the cross plate in the middle of the frame 1;

[0057] Preferably, the drive wheel 312 is a spur gear;

[0058] The load-bearing wheels 313 are multiple symmetrical wheels. The load-bearing wheels 313 are installed between the frame 1 and the positioning plate 317 through the limiter 318 and can rotate relative to each other. The load-bearing wheels 313 are evenly distributed on the bottom edge of the track 319 to distribute the weight of the wheelchair, so that the wheelchair exerts uniform pressure on the entire track 319 and improves the stability of the track during operation.

[0059] The guide wheel 315 is used to guide the track 319 to rotate normally and prevent the track 319 from deviating or going off track during operation. The guide wheel 315 is mounted on the guide wheel shaft 314. The guide wheel shaft 314 is mounted on the front end of the track mechanism 31 and the lower part of the frame 1.

[0060] Preferably, the radial cross-section of the guide wheel 315 is box-shaped;

[0061] The tensioning wheel 316 is symmetrically arranged on the left and right sides. The tensioning wheel 316 is installed between the frame and the positioning plate 317 through the limiter 318 and can rotate relative to each other. The tensioning wheel 316 contacts the track 319 and tensions the track 319 outward to keep the track 319's path unchanged during rotation.

[0062] The positioning piece 317 is elongated and has holes that mate with the limiter 318 for positioning the load-bearing wheel 313 and the tensioning wheel 316.

[0063] Furthermore, the positioning piece 317 is located outside the load-bearing wheel 313 and the tensioning wheel 316 to ensure that the track crawling mechanism 3 is not easily affected by the environment;

[0064] The inner side of the track 319 is provided with a groove that meshes with the drive wheel 312. The width of the track 319 is greater than the thickness of the drive wheel 312, and the thickness of the drive wheel 312 is greater than the thickness of the tension wheel 316, so that the track 319 can cover the drive wheel 312, the load-bearing wheel 313 and the tension wheel 316. In this way, the track crawling mechanism 3 is not easily affected by the environment during operation.

[0065] Preferably, the load-bearing roller 313 and the tensioning roller 316 have the same thickness;

[0066] The linkage mechanism 4 is as follows Figure 4 As shown, it includes a connecting rod 41, a large rod connecting shaft 42, a large rod 43, a hydraulic rod connecting shaft 44, a fourth hydraulic rod 45, a small rod 46, a universal wheel support rod 47, a small rod connecting shaft 48, a fixed seat 49, a large rod connecting shaft bearing seat 401, a small rod connecting shaft bearing seat 402, and a pad 403;

[0067] The main rod connecting shaft 42 is mounted on the frame 1 via the main rod connecting shaft bearing seat 401 and is hinged to the main rod 43;

[0068] Furthermore, the upper end of the large rod 43 is hinged to the connecting rod 41;

[0069] Furthermore, a large wheel drive motor and its reduction mechanism 53 are fixedly installed at the lower end of the large rod 43;

[0070] Furthermore, the large wheel drive motor and its reduction mechanism 53 are connected to the large wheel 51 to drive the large wheel;

[0071] The small rod connecting shaft 48 is connected to the small rod connecting shaft bearing seat 402. The small rod connecting shaft bearing seat 402 is fixed to the frame 1 by a pad 403. Therefore, compared with the large rod connecting shaft 42, the small rod connecting shaft 48 is higher in the vertical direction. The small rod connecting shaft 48 is hinged to the small rod 46.

[0072] Furthermore, a connecting shaft is welded to the outer side of the lower end of the small rod 46 for hinged connection to the other end of the connecting rod 41;

[0073] Furthermore, the lower end of the small rod 46 is hinged to the universal wheel support rod 47;

[0074] Furthermore, the lower part of the universal wheel support rod 47 is hinged to the end of the fourth hydraulic rod 45;

[0075] The fixed base 49 is fixedly connected to the frame 1, providing a connection position for the hydraulic rod connecting shaft 44;

[0076] Furthermore, the hydraulic rod connecting shaft 44 is connected to the fixed seat 49 via a bearing and a locking cap;

[0077] Furthermore, the fourth hydraulic rod 45 is hinged to the hydraulic rod connecting shaft 44.

[0078] The specific working method of the stair-climbing wheelchair of the present invention (taking climbing stairs as an example) is as follows:

[0079] 1. When the passenger rides the stair-climbing wheelchair to the stairs, first adjust the direction so that the large wheel 51 faces the stairs and rests on the edge of the first step. Then, operate the linkage mechanism 4 to retract the universal wheel 52 so that it is above the track 319. The process is as follows: Initially, the large wheel 51 and the universal wheel 52 provide support for the entire stair-climbing wheelchair. Then, under the drive of the fourth hydraulic rod 45, the universal wheel support rod 47 retracts. The universal wheel support rod 47 drives the universal wheel 52 to retract, and the entire stair-climbing wheelchair tilts. The rear end of the track mechanism 31 tilts up and rests on the edge of the step. At this time, the support point of the entire stair-climbing wheelchair becomes the large wheel 51 and the front end of the track mechanism 31.

[0080] 2. Afterwards, as the rear end of the track mechanism 31 rests on the upper edge of the step, the universal wheel support rod 47 and the small rod 46 are locked together. At this time, the universal wheel support rod 47 and the small rod 46 can be regarded as a rigid body, and the linkage mechanism 4 can be regarded as a four-bar linkage. Under the drive of the fourth hydraulic rod 45, the linkage mechanism 4 will drive the large rod 43 to retract the large wheel 51. At this time, the large wheel 51 and the universal wheel 52 have been completely retracted. The entire support point of the stair climbing wheelchair is provided by the track mechanism 31. At this time, the entire stair climbing wheelchair tilts down. Then, the track climbing mechanism 3 is operated to reverse and start climbing the stairs. After crossing the second step, it switches to normal track climbing state.

[0081] 3. When the tracked stair-climbing mechanism 3 climbs to the edge of the last step, in order to avoid the stair-climbing wheelchair from tilting suddenly, the tracked stair-climbing mechanism 3 should be temporarily stopped. At this time, the rider should operate the linkage mechanism 4 to make the large wheel 51 just touch the ground to provide a support point for the entire stair-climbing wheelchair. Then, the tracked stair-climbing mechanism 3 should be operated to continue climbing the stairs. During this process, the center of gravity completes the transition from the stair slope to the flat ground. When the stair-climbing wheelchair is completely off the step, the linkage mechanism 4 should be operated again to make the flat ground walking mechanism 5 swing to the walking state. At this time, the stair-climbing wheelchair can walk on the flat ground.

[0082] 4. Repeat steps 1, 2, and 3 above until you reach the desired floor.

Claims

1. A single-track stair-climbing wheelchair based on a linkage mechanism, characterized in that: The stair-climbing wheelchair includes a frame (1), a wheelchair body (2), a tracked stair-climbing mechanism (3), a linkage mechanism (4), and a flat-ground walking mechanism (5). The wheelchair body (2) is located on the upper part of the frame (1). The wheelchair body (2) includes a wheelchair mechanism, a posture adjustment mechanism, and an auxiliary action mechanism with a first hydraulic rod (231), a second hydraulic rod (232), and a third hydraulic rod (234). The first hydraulic rod (231) and the second hydraulic rod (232) work together to control the posture adjustment mechanism to keep the seat horizontal. The third hydraulic rod (234) can drive the wheels. The main body of the chair rotates slightly; the track climbing mechanism (3) is symmetrically fixed on both sides of the lower part of the frame (1) and does not rise or fall with the linkage mechanism throughout the entire process. The track climbing mechanism (3) is a left-right symmetrical single track mechanism, including a drive wheel, multiple sets of evenly distributed load-bearing wheels, guide wheels, tension wheels, limiters and tracks. The load-bearing wheels are evenly distributed at the bottom of the tracks to bear the weight of the whole machine; the linkage mechanism (4) is symmetrically arranged on both sides of the frame (1). The linkage mechanism (4) is a hydraulically driven four-bar structure, including a connecting rod (41), a large rod (43), and a small rod (46). The universal wheel support rod (47) and the fourth hydraulic rod (45), which serves as the sole switching power, are connected by a large rod (43) hinged to the frame via a large rod connecting shaft bearing seat (401) and a small rod (46) hinged via a small rod connecting shaft bearing seat (402) with a pad (403) for elevation. The universal wheel support rod (47) can rotate 0 to 30° relative to the small rod (46). When the two are locked together, the linkage mechanism forms a rigid four-bar linkage. The fourth hydraulic rod (45) is hinged between the frame fixed seat (49) and the universal wheel support rod (47) and is driven solely by hydraulic extension. The flat-ground walking mechanism is stepped up and down without a switching motor; the flat-ground walking mechanism (5) is mounted on the linkage mechanism (4), and the flat-ground walking mechanism (5) includes a large wheel (51) installed at the lower end of the large rod (43) and a small universal wheel (52) installed at the bottom end of the universal wheel support rod (47). The large wheel (51) and the small universal wheel (52) can be retracted step by step by the fourth hydraulic rod (45); this stair-climbing wheelchair relies on the fourth hydraulic rod (45) to drive the linkage mechanism (4) to complete the conversion between flat-ground walking and tracked stair climbing modes. Its specific working method is as follows: S1 Flat ground walking state: The fourth hydraulic rod (45) extends, driving the universal wheel support rod (47) and the large rod (43) to swing down, so that the large wheel (51) and the universal small wheel (52) are completely on the ground, the track climbing mechanism (3) is lifted off the ground, and the large wheel is driven by the large wheel drive motor to drive the large wheel to travel on the flat ground; S2 First stage switch: The fourth hydraulic rod (45) retracts for the first time, first driving the universal wheel support rod (47) to retract upwards, the universal small wheel (52) is raised to above the track, the support point of the whole machine is converted to the large wheel (51) and the front end of the track mechanism, and the rear end of the track rests on the edge of the step; S3 Stair Climbing Second Stage Switching: After the universal wheel support rod (47) and the small rod (46) are locked to the limit and the linkage mechanism forms a rigid body, the fourth hydraulic rod (45) continues to retract and pulls the large rod (43) upward to flip up. The large wheel (51) is completely retracted, and the entire load of the machine is borne by the track climbing mechanism (3). S4 Track Climbing Process: The track drive motor drives the track to move and climb along the steps. During the climbing process, the first hydraulic rod (231) and the second hydraulic rod (232) continuously maintain the chair level, and the third hydraulic rod (234) slightly rotates the main body of the wheelchair to counteract the lateral tilt of the stairs. S5 Step to Flat Ground Buffer Transition: Before the track climbs to the edge of the last step, the track operation is paused, and the fourth hydraulic rod (45) extends and lowers the enlarged wheel (51) slightly to pre-land as an auxiliary support, smoothly completing the center of gravity transition from the stairs to the flat ground; S6 Reset to Flat Ground Mode: After the machine has completely left the step, the fourth hydraulic rod (45) gradually extends, and the large wheel (51) and the omnidirectional small wheel (52) are lowered in sequence. The track climbing mechanism (3) is lifted off the ground and the wheeled flat ground walking mode is restored.

2. The single-track stair-climbing wheelchair based on a linkage mechanism according to claim 1, characterized in that: The wheelchair mechanism (21) in the wheelchair body (2) includes foot pedals (211), leg rests (212), seat (213), armrests (214), and backrest (215); the posture adjustment mechanism (22) includes a front seat posture adjustment mechanism (221), a backrest posture adjustment mechanism (222), a rear seat posture adjustment mechanism (223), a leg rest posture adjustment mechanism (224), and a foot pedal posture adjustment mechanism (225); the auxiliary action mechanism (23) includes a first hydraulic rod (231), a second hydraulic rod (232), a mounting box (233), a third hydraulic rod (234), a rotating shaft (235), and a fixed platform (236); the wheelchair body (2) is fixed to the tracked stair climbing mechanism (3) by a support frame (24).

3. The single-track stair-climbing wheelchair based on a linkage mechanism according to claim 2, characterized in that: The chair back adjustment mechanism (222) is connected to the chair back (215), the first hydraulic rod (231), and the rear seat adjustment mechanism (223); the rear seat adjustment mechanism (223) is hinged to the front seat adjustment mechanism (221); the front seat adjustment mechanism (221) is connected to the chair seat (213) and the leg rest adjustment mechanism (224); the leg rest adjustment mechanism (224) is connected to the leg rest (212) and the foot pedal adjustment mechanism (225). The foot pedal adjustment mechanism (225) is connected to the foot pedal (211); the fixed platform (236) is connected to the support frame (24), and to the third hydraulic rod (234) and the rotating shaft (235); the mounting box (233) is connected to the rotating shaft (235) and the seat rear end adjustment mechanism (223), and its interior is hinged to the first hydraulic rod (231), the second hydraulic rod (232), and the third hydraulic rod (234).

4. The single-track stair-climbing wheelchair based on a linkage mechanism according to claim 1, characterized in that: The track mechanism (31) of the tracked stair climbing mechanism (3) includes a drive wheel axle (311), a drive wheel (312), a load-bearing wheel (313), a guide wheel axle (314), a guide wheel (315), a tension wheel (316), a positioning plate (317), a limiter (318), and a track (319).

5. The single-track stair-climbing wheelchair based on a linkage mechanism according to claim 4, characterized in that: The drive wheel (312) is mounted on the drive wheel shaft (311) and meshes with the track (319); the load-bearing wheel (313) is mounted through the limiter (318); the guide wheel (315) is mounted on the guide wheel shaft (314); the tension wheel (316) is mounted through the limiter (318) and contacts the track (319); the positioning piece (317) is long and has a hole that mates with the limiter (318); the inner side of the track (319) is provided with a groove that meshes with the drive wheel (312).

6. The single-track stair-climbing wheelchair based on a linkage mechanism according to claim 1, characterized in that: The linkage mechanism (4) further includes a connecting rod (41), a large rod connecting shaft (42), a hydraulic rod connecting shaft (44), a small rod (46), a universal wheel support rod (47), a small rod connecting shaft (48), a fixed seat (49), a large rod connecting shaft bearing seat (401), a small rod connecting shaft bearing seat (402), and a pad (403).

7. The single-track stair-climbing wheelchair based on a linkage mechanism according to claim 6, characterized in that: The main rod connecting shaft (42) is mounted on the frame (1) through the main rod connecting shaft bearing seat (401) and is hinged to the main rod (43); the main rod (43) is connected to the connecting rod (41) and the large wheel drive motor and its reduction mechanism (53) connected to the large wheel (51); the small rod connecting shaft (48) is connected to the small rod connecting shaft bearing seat (402), and the small rod connecting shaft bearing seat (402) is fixed to the frame (1) through the pad (403); the small rod connecting shaft (48) is hinged to the small rod (46); the lower end of the small rod (46) is connected to the connecting rod (41) and the universal wheel support rod (47); the universal wheel support rod (47) is connected to the fourth hydraulic rod (45); the fixed seat (49) is fixed on the frame (1); the hydraulic rod connecting shaft (44) is connected to the fixed seat (49); the fourth hydraulic rod (45) is connected to the hydraulic rod connecting shaft (44).

8. A single-track stair-climbing wheelchair based on a linkage mechanism according to claim 6, characterized in that: The angle of the caster support rod (47) relative to the small rod (46) can vary from 0 to 30°. When the caster support rod (47) and the small rod (46) are locked together, the angle of the caster support rod (47) relative to the vertical direction changes to 30°.

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