Wheel-legged mechanism

Abstract

The application discloses a wheel-leg mechanism and relates to the technical field of wheel-leg vehicles.The wheel-leg mechanism comprises a wheel group mechanism, a thigh assembly, a shank assembly, a connecting rod transmission assembly and a linear driving mechanism, one end of the shank assembly is connected with the wheel group mechanism, the other end of the shank assembly is hingedly connected with the thigh assembly, the thigh assembly and the shank assembly are respectively connected with the linear driving mechanism through the connecting rod transmission assembly, and the linear driving mechanism and the connecting rod transmission assembly are respectively connected with a vehicle body.The wheel-leg mechanism has the advantages of small size, compact structure, suitability for both wheel type and leg type movement modes, realization of small end inertia and large movement range, arrangement of most of the weight mechanism on the upper end and the middle of the thigh, simple structure and space saving.

Description

Technical Field

[0001] This invention relates to the technical field of wheel-leg vehicles, and in particular to a wheel-leg mechanism. Background Technology

[0002] Wheel-legged vehicles are platforms that combine wheeled, legged, and hybrid mobility methods. They typically consist of one or more wheels and several movable legs, integrating the advantages of both wheeled and biomimetic legged platforms. They offer different solutions and strategies for various road conditions, making them more maneuverable and flexible than single-mode mobility. When a wheel-legged vehicle moves in wheeled mode, it resembles an intelligent vehicle or a small autonomous vehicle, requiring actuators to control the extension and retraction of the wheel-leg mechanism. When moving in legged mode, the movement of the legs can be adjusted by actuators to control the vehicle's forward movement. Common wheel-legged vehicle systems have a small range of motion and a large end-effector inertia, leading to complex control mechanisms.

[0003] Existing wheel-leg vehicles vary in leg design, drive, and transmission methods. Some are hydraulically driven, some are electrically driven, some use direct drive, and some use multi-link drive. The wheel-leg mechanisms of wheel-leg vehicles are generally driven by electric motors or hydraulics, with transmission methods including direct drive and multi-link drive. Electric motor-driven wheel-leg systems can achieve the desired leg movements, but they suffer from lower power density, less compact layout, greater weight, and larger end-effector inertia, leading to decreased control accuracy, robustness, and responsiveness. Hydraulically driven wheel-leg systems suffer from greater energy loss, low transmission efficiency, high susceptibility to temperature changes, and susceptibility to leakage. Multi-link drive systems are complex in design, have long kinematic chains, accumulate large errors, generate large inertial forces and dynamic loads, and have a smaller operating range. Summary of the Invention

[0004] The purpose of this invention is to provide a wheel-leg mechanism to solve the problems existing in the prior art, so that the center of gravity of the wheel-leg mechanism is moved upward and concentrated towards the vehicle body, the end rotational inertia is small, and there are two movement modes: wheel-type and leg-type.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] The present invention provides a wheel-leg mechanism, including a wheel assembly, a thigh assembly, a calf assembly, a linkage transmission assembly, and a linear drive mechanism. One end of the calf assembly is connected to the wheel assembly, and the other end is hinged to the thigh assembly. The thigh assembly and the calf assembly are respectively connected to the linear drive mechanism through the linkage transmission assembly. The linear drive mechanism and the linkage transmission assembly are respectively connected to the vehicle body.

[0007] Preferably, the thigh assembly includes a U-shaped thigh support, the lower end of which is hinged to both sides of the lower leg assembly, and a long shaft is rotatably connected to the upper two side plates.

[0008] Preferably, the linkage transmission assembly includes a thigh linkage mechanism and a calf linkage mechanism. The calf linkage mechanism is disposed on the long shaft and is connected to the linear drive mechanism and the calf push rod respectively. The thigh linkage mechanism is hinged to the upper end of the thigh support and the linear drive mechanism respectively.

[0009] Preferably, the thigh linkage mechanism includes a pair of arc-shaped links and a pair of linear links. The two sides of the linear drive mechanism are respectively connected to an arc-shaped link and a linear link. The other end of each linear link is used to hinge with the vehicle body, and the other end of each arc-shaped link is hinged with the upper end of the thigh support.

[0010] Preferably, the lower leg linkage mechanism includes a sleeve and a lower leg push rod. The sleeve is sleeved on the long shaft and has two connecting ears on its outer wall. The two connecting ears are respectively hinged to the linear drive mechanism and the lower leg push rod. The lower end of the lower leg push rod is hinged to the lower leg assembly.

[0011] Preferably, the linear drive mechanism and the connecting ear are respectively hinged to both ends of a movable head, and a pair of linear connecting rods are hinged to one end of the movable head that is hinged to the linear drive mechanism. The linear connecting rods are used to hinge with the vehicle body.

[0012] Preferably, the two connecting ears are staggered, and the central angle of the stagger is 20°-100°. The hinge axis between the lower leg push rod and the lower leg assembly is 10cm-20cm away from the hinge axis between the lower leg assembly and the thigh assembly.

[0013] Preferably, the calf assembly includes a calf support, which is a hollow frame. The lower end of the calf support is connected to the rotating shaft of the wheel assembly, and the upper end is hinged to the thigh assembly via a pin.

[0014] Preferably, the wheel assembly includes a wheel and a hub motor, the hub motor is mounted on the wheel and connected to the lower end of the lower leg assembly.

[0015] Preferably, the linear drive mechanism includes two electro-hydraulic actuators, which drive the thigh assembly and the lower leg assembly to move respectively through the linkage transmission assembly.

[0016] The present invention achieves the following technical effects compared to the prior art:

[0017] The wheel-leg mechanism of the present invention has a small size and compact structure, and is suitable for wheel-leg systems with both wheel and leg movement modes. It can achieve a small end inertia and a large range of motion. Most of the weight mechanism is arranged at the upper and middle of the thigh, which is simple in structure and saves space. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the wheel-leg mechanism in an embodiment of the present invention. Figure 1 ;

[0020] Figure 2 This is a schematic diagram of the wheel-leg mechanism in an embodiment of the present invention. Figure 2 ;

[0021] Figure 3 This is a schematic diagram of the wheel-leg mechanism in an embodiment of the present invention. Figure 3 ;

[0022] Figure 4 This is a schematic diagram of the wheel-leg mechanism in an embodiment of the present invention. Figure 4 ;

[0023] Figure 5 This is a schematic diagram of the structure of the wheel-leg mechanism before the legs extend in an embodiment of the present invention;

[0024] Figure 6 This is a schematic diagram of the structure of the wheel-leg mechanism after the legs are extended in an embodiment of the present invention;

[0025] Among them: 1-Electro-hydraulic actuator, 2-Thigh support, 3-Long shaft, 4-Arc-shaped connecting rod, 5-Linear connecting rod, 6-Lower leg support, 7-Sleeve, 8-Connecting ear, 9-Lower leg push rod, 10-Moving head, 11-Wheel hub motor, 12-Wheel. Detailed Implementation

[0026] 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 some embodiments of the present invention, and not all embodiments. Based on 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.

[0027] The purpose of this invention is to provide a wheel-leg mechanism to solve the problems existing in the prior art, so that the center of gravity of the wheel-leg mechanism is moved upward and concentrated towards the vehicle body, the end rotational inertia is small, and there are two movement modes: wheel-type and leg-type.

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] like Figures 1 to 6 As shown: This embodiment provides a wheel-leg mechanism, including a wheel assembly, a thigh assembly, a calf assembly, a linkage transmission assembly, and a linear drive mechanism. One end of the calf assembly is connected to the wheel assembly, and the other end is hinged to the thigh assembly. The thigh assembly and the calf assembly are respectively connected to the linear drive mechanism through the linkage transmission assembly. The linear drive mechanism and the linkage transmission assembly are respectively connected to the vehicle body.

[0030] As a preferred embodiment, the thigh assembly in this embodiment includes a U-shaped thigh support 2. The thigh support 2 adopts a hollow frame to reduce weight. The lower end of the thigh support 2 is hinged to both sides of the calf assembly, and a long shaft 3 is rotatably connected to the upper two side plates.

[0031] As a preferred embodiment, the linkage transmission assembly in this embodiment includes a thigh linkage mechanism and a calf linkage mechanism. The calf linkage mechanism is mounted on the long shaft 3 and is connected to the linear drive mechanism and the calf push rod 9 respectively. The thigh linkage mechanism is hinged to the upper end of the thigh support 2 and the linear drive mechanism (the push rod of the electro-hydraulic actuator 1) respectively.

[0032] As a preferred embodiment, the thigh linkage mechanism in this embodiment includes a pair of arc-shaped linkages 4 (or straight rods, as long as they serve to hinge and axially fix one end of the actuator) and a pair of linear linkages 5. An arc-shaped linkage 4 and a straight rod 5 are respectively connected to both sides of the linear drive mechanism (the top rod of the electro-hydraulic actuator 1). The other end of the straight rod 5 is used to hinge with the vehicle body, and the other end of the arc-shaped linkage 4 is hinged with the upper end of the thigh bracket 2.

[0033] The lower leg linkage mechanism includes a sleeve 7 and a lower leg push rod 9. The sleeve 7 is sleeved on the long shaft 3 and has two connecting ears 8 on its outer wall. The sleeve 7 is axially constrained on the long shaft 3 by a shoulder. There is a gap between the sleeve and the long shaft so that they can rotate relative to each other. The two connecting ears 8 are respectively hinged to the linear drive mechanism (the push rod of the electro-hydraulic actuator 1) and the lower leg push rod 9. The lower end of the lower leg push rod 9 is hinged to the lower leg assembly, thereby transmitting the motion to the lower leg bracket 6, causing it to rotate around the hinge axis.

[0034] In a preferred embodiment, the linear drive mechanism (the push rod of the electro-hydraulic actuator 1) and the connecting lug 8 are respectively hinged to both ends of a movable head 10. A pair of linear connecting rods 5 are hinged to one end of the movable head 10 that is hinged to the linear drive mechanism (the push rod of the electro-hydraulic actuator 1). The linear connecting rods 5 are used to hinge with the vehicle body.

[0035] In a preferred embodiment, the two connecting ears 8 are staggered, with a central angle of 20°-100° between them. The hinge axis between the calf push rod 9 and the calf assembly is 10cm-20cm away from the hinge axis between the calf assembly and the thigh assembly, facilitating the calf push rod 9 to push the calf support 6 to rotate around the hinge axis. This embodiment uses fewer connecting rods to drive the thigh and calf, resulting in a large range of motion. In this embodiment, the extension range of the actuator rods of the electro-hydraulic actuator 1 for the thigh and calf is 0-45cm. After the thigh actuator rod is directly connected to the thigh, the swing range of the thigh is 20°-70°. After the actuator rod of the electro-hydraulic actuator 1 for the calf is connected to the connecting ear, it moves translationally together with the electro-hydraulic actuator 1 for the thigh, thereby driving the calf push rods 9, which are interleaved on the connecting ear, to swing around the hinge axis. Even if the calf push rods 9 are not located on the hinge axis between the calf and thigh, the calf can still be driven to swing around the hinge axis. The swing range of the calf relative to the thigh is 30°-110°. Figure 6 As shown. The wheel-leg mechanism in this embodiment is simple (with relatively few linkage mechanisms), small in size, and compact in structure, enabling it to achieve a small end inertia and a large range of motion.

[0036] As a preferred embodiment, the calf assembly in this embodiment includes a calf support 6. The calf support 6 adopts a hollow frame to reduce weight. The lower end of the calf support 6 is connected to the rotating shaft of the wheel assembly, and the upper end is hinged to the thigh assembly through a pin.

[0037] In a preferred embodiment, the wheel assembly mechanism includes a wheel 12 and a hub motor 11. The hub motor 11 is mounted on the wheel 12 and is connected to the lower end of the lower leg assembly to enable the automatic rotation of the wheel 12.

[0038] In a preferred embodiment, the linear drive mechanism includes two electro-hydraulic actuators 1, which drive the thigh assembly and the lower leg assembly to move via a linkage transmission assembly. This embodiment achieves the movement of the wheel-leg type vehicle's legs using electro-hydraulic actuators 1 and fewer linkages. The electro-hydraulic actuators 1 are positioned on the upper side and in the middle of the thigh, resulting in a compact structure and space-saving design.

[0039] The specific working principle of the wheel-leg mechanism in this embodiment is as follows: When the wheel-leg vehicle performs leg movement, the vehicle sends a signal to the electro-hydraulic actuator 1 of the thigh (lower leg). After receiving the signal, the motor of the electro-hydraulic actuator 1 drives the plunger pump. The plunger pump outputs flow, creating a pressure difference between the two chambers of the electro-hydraulic actuator 1, thereby driving the thigh (lower leg). When the push rod of the electro-hydraulic actuator 1 of the thigh moves, due to the hinged relationship with the inner thigh plate, it pulls the inner thigh plate to achieve the corresponding movement of the thigh. When the push rod of the electro-hydraulic actuator 1 of the lower leg moves, due to the hinged relationships at various points, the push rod of the electro-hydraulic actuator 1 pulls the movable head 10. The movable head 10 pulls the sleeve 7 on the shaft. The sleeve 7 rotates around the shaft, further acting on the lower leg push rod 9, which pulls the lower leg to achieve the corresponding movement. When a wheel-leg vehicle is in wheeled motion, the vehicle sends a signal to the electro-hydraulic actuator 1 of the large (small) leg. The piston pump of the electro-hydraulic actuator 1 controls the movement of the large (small) leg actuator rod, thereby realizing the function of active suspension and increasing the smoothness of wheeled motion.

[0040] The wheel-leg system of this embodiment of the wheel-leg vehicle is installed on the upper part of the thigh. The main component, the hydraulic actuator, is robust, lightweight, and has fewer connection points. It is a complete unit with full functionality. After acting on a small number of linkage mechanisms, it completes the expected movement of the leg, which meets the layout and range of motion requirements of the wheel-leg vehicle. It solves the shortcomings and defects of most wheel-leg systems used in wheel-leg vehicles, can realize the movement requirements, and is reliable and durable.

[0041] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A wheel-leg mechanism, characterized in that: It includes a wheel assembly, a thigh assembly, a calf assembly, a linkage transmission assembly, and a linear drive mechanism. One end of the calf assembly is connected to the wheel assembly, and the other end is hinged to the thigh assembly. The thigh assembly and the calf assembly are respectively connected to the linear drive mechanism through the linkage transmission assembly. The linear drive mechanism and the linkage transmission assembly are respectively connected to the vehicle body. The thigh assembly includes a U-shaped thigh support. The lower end of the thigh support is hinged to both sides of the lower leg assembly, and a long shaft is rotatably connected to the upper two side plates. The linkage transmission assembly includes a thigh linkage mechanism and a lower leg linkage mechanism. The lower leg linkage mechanism is disposed on the long shaft and is respectively connected to the linear drive mechanism and the lower leg push rod. The thigh linkage mechanism is hinged to the upper end of the thigh support and the linear drive mechanism. The lower leg linkage mechanism includes a sleeve and a lower leg push rod. The sleeve is sleeved on the long shaft and has two connecting ears on its outer wall. The two connecting ears are respectively hinged to the linear drive mechanism and the lower leg push rod. The lower end of the lower leg push rod is hinged to the lower leg assembly. The linear drive mechanism and the connecting ears are respectively hinged to both ends of a movable head. A pair of linear connecting rods are hinged to the end of the movable head that is hinged to the linear drive mechanism. The linear connecting rods are used to hinge to the vehicle body.

2. The wheel-leg mechanism according to claim 1, characterized in that: The thigh linkage mechanism includes a pair of arc-shaped links and a pair of linear links. The two sides of the linear drive mechanism are respectively connected to an arc-shaped link and a linear link. The other end of each linear link is used to hinge with the vehicle body, and the other end of each arc-shaped link is hinged with the upper end of the thigh support.

3. The wheel-leg mechanism according to claim 1, characterized in that: The two connecting ears are staggered, and the central angle of the stagger is 20°-100°. The hinge axis between the lower leg push rod and the lower leg assembly is 10cm-20cm away from the hinge axis between the lower leg assembly and the thigh assembly.

4. The wheel-leg mechanism according to claim 1, characterized in that: The lower leg assembly includes a lower leg support, which is a hollow frame. The lower end of the lower leg support is connected to the rotating shaft of the wheel assembly, and the upper end is hinged to the thigh assembly via a pin.

5. The wheel-leg mechanism according to claim 1, characterized in that: The wheel assembly includes a wheel and a hub motor. The hub motor is mounted on the wheel and connected to the lower end of the lower leg assembly.

6. The wheel-leg mechanism according to claim 1, characterized in that: The linear drive mechanism includes two electro-hydraulic actuators, which drive the thigh assembly and the lower leg assembly to move respectively through the linkage transmission assembly.

Images