2839 results about "Wheel and axle" patented technology

The invention discloses a pole climbing robot for a wind power tower pole, which is characterized in that the robot mainly comprises a robot body, 4-8 pole climbing mechanisms, a snake-shaped swing arm and a movable studio, wherein the snake-shaped swing arm and the movable studio are mounted on one side of the robot body; the robot body is an annular body formed by combining two semicircular cambered bodies or three equal cambered bodies; the diameter of an internal ring of the circular body is matched with the diameter of the wind power tower pole; the pole climbing mechanisms mainly comprise upper foot wheels, lower foot wheels, connecting arms, driving gears, thrust screw rods, nut gears and supporting seats; the upper foot wheels are connected with the lower foot wheels by the connecting arms through wheel shafts; the connecting arms are connected with the thrust screw rods by connecting pin shafts on the connecting arms, and form movable hinges; the 4-8 pole climbing mechanisms are distributed in the circular robot body uniformly; the snake-shaped swing arm consists of three swing arm parts, namely a large arm, a middle arm and a small arm; and the movable studio comprises two paralleled linear guide rails, a walk driving device and an operation room.

The invention relates to a locking device (1) for containers, doors, cabinets, furniture, or the like, which locking device has a lock plate (4), on which a combination lock (7), which has setting wheels (9), and a secondary lock (8) are arranged, and a stator (3), in relation to which the lock plate (4) having the combination lock (7) and the secondary lock (8) is rotatably arranged, the lock plate (4) having the combination lock (7) arranged thereon and with the secondary lock (8) arranged thereon being able to freely rotate 360 degrees relative to the stator (3) in the locked state of the locking device (1). In order to indicate opening of the locking device (1) by actuation of the secondary lock (8) to a person possessing the opening code of the combination lock (7), according to the invention, when the locking device (1) is opened by means of the secondary lock (8), the setting wheels (9) and coupling hubs (11) of the combination lock (7), which coupling hubs are associated with the setting wheels and can be axially moved relative to the setting wheels, can be uncoupled and an opening code of the combination lock (7) can be reset from an opening code set by means of the secondary lock (8) at the time of the opening of the locking device (1) to a specified factory code.

The invention discloses an aircraft landing gear shimmy test bed and a test method, the aircraft landing gear shimmy test bed comprises a main body rack, a hanging basket system, a large flywheel, a flywheel driving system, an excitation device and a follow-up displacement measurement system.The aircraft landing gear shimmy test bed can simulate the shimmy of an aircraft after undercarriages of different design configurations are subjected to interference excitation force or interference torque in the process of takeoff, taxiing, landing and the like of the aircraft; the control effect of the shimmy damping system on the stability of the undercarriage has short excitation time so as to simulate real working conditions, the shimmy stability performance of the undercarriage can be accurately detected, excitation is continuously carried out under the condition that the test state is continuously changed, and the working efficiency is greatly improved. The follow-up displacement measuring system designed by the invention can enable the exciting force and the center of the axle to be always kept on the same horizontal plane, can apply torque control and torque excitation control, is suitable for undercarriage shimmy tests with different axle heights, different tire diameters and different excitation modes, and has certain universality.

The utility model provides an automatic distance fixing device for material belts, and belongs to the technical field of coil stock processing equipment. The problems that slit metal material strips are tightly arranged, if the tightly arranged material strips are directly wound, the edges of every two adjacent metal material strips are overlapped, and winding fails are solved. The device comprises a mounting seat, a distance wheel rotationally arranged on the mounting seat, and a plurality of separation sheets sleeved on the distance wheel, the plurality of separation sheets are arranged along the axial direction of the distance wheel at intervals, and a guide clamping groove is enclosed between every two adjacent separation sheets; an adjusting device is further arranged on the mounting base and used for adjusting the distance between the partition pieces so that the width of the guide clamping groove can be matched with the width of the material belt. The utility model has the advantages that: before winding, the material belts are respectively placed in the independent guide clamping grooves to play a role in guiding, so that the material belts can be neater during winding, and the winding uniformity of the material belts is improved.

The mechanical clutch for the garden machine tool is applied to the technical field of clutches and comprises a support shell, a transmission shaft sleeve capable of being in transmission connection with an output shaft of an external engine is rotationally installed on the support shell, and the transmission shaft sleeve is sleeved with a driving wheel set; a driving disc is movably installed on the inner side of the support shell, a clutch disc is installed on the transmission shaft sleeve in the axial direction in a sliding mode, the clutch disc is arranged on the outer side of the driving disc, and the driving disc is used for pushing the clutch disc in the axial direction. The driving wheel set comprises a driving wheel and a friction disc capable of axially floating relative to the driving wheel, an elastic piece is installed between the friction disc and the driving wheel, and the friction disc is located on the outer side of the clutch disc. When the clutch disc is separated from the friction disc, the elastic piece can axially push the friction disc to enable the end face of the friction disc to abut against the support shell, and rapid braking of the driving wheel is achieved. The friction disc is designed in an axial floating mode, and after the clutch disc is separated, the elastic piece can push the friction disc to abut against the support shell to achieve rapid braking of the driving wheel.

The invention discloses a trailer and a trailer damping method.The trailer is applied to a wheel track type belt conveyor and used for supporting and dragging a conveying belt on a track of the wheel track type belt conveyor and walking along with the conveying belt, the trailer comprises a frame and a plurality of wheel assemblies distributed on the two sides of the frame, and the frame is provided with mounting seats corresponding to the wheel assemblies one to one; the wheel assembly comprises a wheel body, a wheel axle and a bearing, the wheel axle is in transmission connection with the wheel body through the bearing, at least part of the area of the wheel axle penetrates through a mounting hole formed in the mounting base and is in clearance fit with the mounting hole, and an elastic structure located between the mounting base and the wheel axle is arranged in the mounting hole. When the trailer transports a conveying belt and materials on the track, material loads and wheel-rail force are subjected to energy storage and energy consumption when passing through the elastic structure, so that the overall vibration of the trailer is attenuated, the vibration reduction effect of the trailer during operation on the track can be greatly improved, the peak value of a bearing vibration curve can be reduced, the peak clipping effect is achieved, and the service life of the bearing is prolonged.

Disclosed here is a landing gear support fixture for an aircraft under test having a landing gear. The disclosed landing gear support fixture includes: an axle attachment assembly that is compatibly shaped, sized, and configured to mate with and attach to at least one axle of the landing gear of the aircraft under test; a support platform to support the axle attachment assembly, wherein the support platform is in a fixed position relative to a stationary reference foundation; and a force sensor couplable between the axle attachment assembly and the support platform to provide sensor output associated with load imparted by the landing gear of the aircraft under test.

An off-road vehicle includes a frame; front and rear wheels; a front suspension assembly; a front torsion bar assembly, a rear suspension assembly and a rear torsion bar assembly. The front suspension assembly comprises a front lower rocker arm, a front upper rocker arm, and a front wheel shaft support assembly mounted between the front lower and the front upper rocker arms. The front torsion bar assembly is located above the front upper rocker arm, and is movably connected to the front upper rocker arm. The rear suspension assembly comprises a rear lower rocker arm, a rear upper rocker arm, a control arm assembly, and a rear wheel shaft support assembly mounted between the rear lower and rear upper rocker arms. The rear torsion bar assembly is located between the rear upper and lower rocker arms, and is movably connected to the rear upper rocker arm.

The utility model discloses corn bran rope braiding equipment which comprises a machine frame, a feeding mechanism and a sliding ring bearing are arranged at one end of the machine frame, a first bearing seat is arranged at the other end of the machine frame, a chain wheel shaft is installed in the first bearing seat, a first chain wheel is installed on the chain wheel shaft, and a first motor is arranged on the lower portion of the machine frame. A second chain wheel is mounted on a working shaft of the first motor, a chain is wound on the first chain wheel and the second chain wheel, a winding roller mechanism and a roller mechanism mounting frame are arranged in the middle of the rack, the winding roller mechanism comprises two end cover plates, and a rotating winding roller is arranged between the two end cover plates; and a roller driving motor for driving the winding roller to rotate is arranged in the winding roller, one end of the roller mechanism mounting frame is fixed to the side face of the first chain wheel, a protruding part is arranged at the other end of the roller mechanism mounting frame, and the protruding part is rotationally mounted in the sliding ring bearing. The corn bran rope braiding equipment is used for processing corn bran into ropes, and is high in automation degree and high in working efficiency.

The disclosure relates to an electromechanical rear derailleur for coaxial assembling on a rear wheel axle. The derailleur has a base element, a pivot mechanism, and a movable element having a chain guide assembly. The chain guide assembly is connected to the movable element so as to be rotatable about a rotation axis. A blocking device permits the chain guide assembly to be established relative to the movable element. The blocking device is able to be inserted into the movable element in two different positions.

The utility model relates to the technical field of pipe pile forming machines, in particular to a pinch roller mechanism convenient for distance control, and aims to solve the technical problems that in the prior art, the rotating resistance of a pipe die is large, and heat is easily accumulated on the surface of a pinch roller, the pinch roller mechanism specifically comprises a box body, and an inner cavity is formed in the box body; the rotating seat is fixedly arranged on the side plate of the box body; one end of the swing arm is rotationally connected with the rotating seat through a rotating shaft; the pressing wheel is arranged at the other end of the swing arm and is rotationally connected with the swing arm through a wheel shaft; the driving mechanism is arranged in the inner cavity and can drive the swing arm to swing up and down around the rotating seat; the driving mechanism comprises a movable arm, one end of the movable arm penetrates through a through opening formed in a side plate of the box body and is fixedly connected with the near end of a swing arm into a whole; by arranging the limiting device matched with the jacking device, accurate adjustment of the distance between the pressing wheel and the pipe die is achieved, the problems that due to the fact that a distance control mechanism is lacked in a traditional pressing wheel mechanism, continuous pressing fit between the pressing wheel and the pipe die is caused, and resistance is increased are solved, and the heat accumulation phenomenon of the wheel face of the pressing wheel is reduced.

A driver of an automatic guided vehicle includes a crown gear (turning gear) fixed to a bottom of a vehicle body, a support shaft penetrating a center of the crown gear and extending vertically from the vehicle body, a frame supported by the support shaft to be rotatable on a horizontal plane, a wheel axle rotatably and horizontally provided on the frame, and a wheel connected to the wheel axle. A first motor and a second motor, which are drive sources, and a first planetary gear mechanism and a second planetary gear mechanism are provided at both ends in an axial direction of the wheel axle, respectively. Each carrier of the first and second planetary gear mechanisms is connected to the wheel axle, and each ring gear of the first and second planetary gear mechanisms meshes with the crown gear.

The invention provides a heavy-duty truck vehicle-mounted safety monitoring method and device, and the method comprises the steps: obtaining the original monitoring data of a wheel-rail force through a wheel-rail force monitoring module which is installed on an axle and has a low power consumption characteristic, and carrying out the edge calculation of the original monitoring data, and obtaining a wheel load shedding rate, a derailment coefficient and a wheel axle transverse force; the framework acceleration and the bearing temperature are obtained through the low-power-consumption vibration acceleration sensing module and the bearing temperature sensing module; performing multi-modal fusion on each index to obtain a multi-modal operation state representation vector; obtaining a dynamic threshold value of each index based on an enhanced feature vector and a multi-modal operation state representation vector obtained by an offline self-learning model; and giving current situation analysis and trend analysis of safety monitoring based on a comparison result of each index and a dynamic threshold value. According to the invention, the limitation of independent analysis of single sensor data in the prior art is overcome, the dynamic adjustment of the safety threshold is realized, and the accuracy and reliability of safety monitoring are improved.

An active sealing plugging head belongs to the field of oil and gas pipeline maintenance equipment. The driving bracket is connected with a matched plugging cylinder; the driving rotating support comprises a connecting frame and a disc fixedly connected with the connecting frame. A connecting frame on the driving rotating bracket is rotationally connected with the driving bracket through a movable shaft; a movable shaft gland is fixedly connected to the outer side of the connecting frame on the driving rotating bracket; a contact assembly is fixedly connected to a disc of the driving rotating support. The contact assembly is connected with a guide wheel through a guide wheel shaft; an annular groove is formed in the outer circle face of a rotating disc of the driving rotating support, and a plurality of communicating holes communicating with one another are formed in the inner wall of the annular groove. The outer side of the disc of the driving rotating support is fixedly connected with a sealing leather cup. During plugging in the technical field of maintenance and repair of long-distance oil and gas pipelines, even if the leather cup is within the original compression amount or under other complex working conditions, medium micro-seepage can be prevented through active sealing, and the safety of the whole plugging process is improved.

The present invention relates to a transforming modular trolley and an adjustable axle device for office use, designed to enhance workspace flexibility and ergonomic comfort. The trolley features a modular top assembly with multiple surfaces, including a tilt-able primary work surface, dedicated surfaces for devices and personal items, and integrated storage options. It includes a vertically adjustable axle mechanism for height adjustments, an integrated power management system, and retractable anti-tip stabilizers. The adjustable axle device, available in both gas-spring and electric lift configurations, enables smooth height adjustments and secure locking at user-selected positions, with rotational coupling for customizable orientation. The trolley and axle device are intended for seamless integration into various office environments, offering enhanced usability, stability, and organization. This innovative design addresses the limitations of traditional workstations by providing a compact, mobile solution that supports seated and standing work positions while maintaining a clutter-free workspace.

A motorized landing gear including: a motor housing that encloses a motor; a gearbox; a controller; and a power source powering the motor and the controller. The gearbox attaches to an axle having two ends, with a first end of the axle connecting to a first landing gear leg and a second end of the axle connecting to a second landing gear leg. The motor connects to said gearbox and the controller instructs the motor to rotate. The rotation of the motor transfers power to the gearbox, which rotates the axle. The rotation of the axle in a first direction simultaneously telescopes the landing gear first leg and the landing gear second leg; and the rotation of the axle in a second direction simultaneously retracts the landing gear first leg and the landing gear second leg.

The utility model relates to the technical field of racing cars, in particular to a front suspension system for a cross-country racing car, which comprises a front cleat, a front axle and a front wheel core fixed on the front axle, the front wheel core comprises a cylindrical body and a flange plate located at the end of the body. The front cleat comprises a front cleat shaft, and the body is rotationally installed in the middle of the front cleat shaft. The flange plate is fixedly connected with a hub of the wheel; a brake disc is fixed on the flange plate; front wheel brake calipers matched with the brake disc are fixedly installed on the front cleat. The front cleat is installed on the front side portion of the racing car frame through the upper double-fork-arm suspension and the lower double-fork-arm suspension. The front cleat is further provided with a front connecting part used for being hinged to a racing car steering pull rod. The front suspension system for the cross-country racing car is good in stability and flexible in steering, facilitates improvement of racing results of the racing car, has the advantages of being simple and compact in structure, high in control sensitivity and the like, and better meets the requirement for light-weight design of the car under the condition that the braking performance is met.

The invention discloses a running and parking integrated electrically-driven rotary speed reducer which comprises a speed reducer box body, a first-stage planet assembly, a brake and a second-stage planet assembly. The first-stage planetary assembly is in transmission connection with the second-stage planetary assembly; the brake is used for controlling whether transmission connection between the first-stage planetary assembly and the second-stage planetary assembly is interrupted or not. A first closed cavity and a second closed cavity are formed in the speed reducer box body, the first-stage planetary assembly is installed in the first closed cavity, and the second-stage planetary assembly is installed in the second closed cavity; the first closed cavity and the second closed cavity are filled with lubricating oil; a second-stage sun wheel shaft in the second-stage planet assembly is provided with a first lubricating oil channel, the speed reducer box body is provided with a second lubricating oil channel, and the first lubricating oil channel and the second lubricating oil channel are communicated with the first closed cavity and the second closed cavity; the brake replaces a motor for temporary service braking, and the working efficiency is improved.

The disclosure describes an electromechanical rear derailleur for coaxial mounting on a rear wheel axis. The rear derailleur has a base member, a pivot mechanism, a movable member having a chain guiding arrangement, and an electromechanical drive for driving the pivot mechanism. The pivot mechanism connects the base member to the movable member. The chain guiding arrangement is connected to the movable member for rotation about an axis of rotation. The base member comprises a first connection end, which can be mounted coaxially with the rear wheel axis, and a second connection end for coupling with the pivot mechanism.

A steering drive includes an electric motor with a motor shaft and a steering lever rotatable about a pivot axis. A first planetary stage has a first sun gear, first planet gears, a first ring gear, and a first planet carrier. A final planetary stage has a final sun gear, final planet gears, a final ring gear, and a final planet carrier. A force flow runs from the motor shaft to the first sun gear, and from the first sun gear via the first planet gears to the first planet carrier and to the first ring gear. The force flow runs via the final sun gear and via the final planet gears to the final ring gear, runs from the first ring gear and from the final ring gear to the steering lever, and runs via a first sun gear shaft from the electric motor to the first sun gear.

The invention discloses an active suspension electro-hydraulic pump assembly, a chassis axle and a chassis system for a vehicle, an integrated motor shell and a controller cover plate are arranged, the integrated shell is provided with motor cavities located at the two ends in the axial direction, and the two motor cavities are respectively provided with two motors and corresponding hydraulic pumps; the controller cover plate covers the circuit board mounting surface of the integrated motor shell to form the controller cavity for mounting the circuit board, and only the sealant is arranged between the controller cover plate and the circuit board mounting surface for connection, so that the assembly process of the electro-hydraulic pump assembly is reconstructed and simplified; the design that the double motors are fixedly connected through bolts and the technology that the double motors are sealed through sealants are avoided, the overall road surface vibration resisting function of the product is improved, and the sealing reliability of the controller cavity of the product is improved.

The invention provides a control method and device, a storage medium and a computer program product, the control method is applied to a robot, and the robot comprises a moving chassis, a trunk part, a mechanical arm, a tail end executing mechanism and a sensor assembly; the movable chassis comprises a supporting plate assembly, a floating plate assembly and a driving wheel assembly. The driving wheel assembly comprises a driving wheel shaft, a driving wheel assembly and a suspension unit. The suspension unit comprises a swing rod unit and an adjustable shock absorber. The control assembly is connected with the adjustable shock absorber and used for adjusting damping of the adjustable shock absorber; the method comprises the steps that road condition information in the advancing direction of the robot is determined through a sensor assembly; according to the road condition information, target damping of the adjustable shock absorber is determined, and a first control signal is generated according to the target damping; and the damping of the adjustable shock absorber is adjusted to the target damping through the control assembly according to the first control signal.

The invention relates to a driving system for a hybrid tractor, which comprises an engine, a generator, a front motor and a rear motor, and the engine is in transmission connection with a PTO (Power Take Off); the front axle input shaft is in transmission connection with the front motor and the normally-combined clutch input shaft, a normally-combined clutch is arranged on the normally-combined clutch input shaft, a parking brake is arranged on the normally-combined clutch input shaft, and the parking brake is connected with the rear axle. An input shaft of the normally-combined clutch is in transmission connection with a small cone shaft, a mode switching clutch is arranged on the small cone shaft, the small cone shaft is in transmission connection with the input shaft of the normally-combined clutch and a rear motor, and one end of a sun wheel shaft is connected with a rear wheel through a planetary gear mechanism. And a service brake is arranged on the sun wheel shaft. The normally-combined clutch input shaft, the normally-combined clutch and the transmission mechanism are arranged between the front axle and the rear axle, so that the four-wheel braking function is achieved.

A driving wheel comprises an axle, a wheel body, and a driving assembly. The wheel body is of a hollow structure and is rotatably arranged on the axle. The driving assembly comprises a shell, a motor, and a transmission mechanism. The shell is fixedly arranged on the axle and located in the wheel body, and the motor is fixedly arranged in the shell and connected to the wheel body by the transmission mechanism. An output shaft of the motor is arranged perpendicular to the axle, which can reduce the space occupied by the motor and improve space utilization.

An electronic automatically decoupling hub assembly. The decoupling hub assembly has an axle and a hub shell rotationally positioned about the axle. A controller provides automatic activation / deactivation signals to an inductor. The decoupling hub assembly has a bearing rotationally positioned about the axle and a cassette body assembly, having a plurality of teeth, rotationally positioned about the bearing. One or more pawls are provided to engage with at least some of the teeth of the cassette body assembly and a seal is used to contain the pawls within the decoupling hub assembly. A cassette body assembly is coupled with the ratchet ring and an end cap is used to prevent a contaminant from entering into the decoupling hub assembly.

A bicycle wheel assembly structure includes an annular rim, a hub, nipples, and spokes. The annular rim includes multiple rim penetration sections, each of which includes a rim-side limiting part on a circumference. The hub is arranged at the center of the annular rim. The hub includes multiple hub penetration sections. The rim-side limiting part and the nipple limiting part, and also the hub-side limiting part and the spoke limiting part, are all made in a hexagonal pyramid form with apex truncated to form a planar surface and including bevel facets so as to provide an anti-sliding effect resulting from geometric constraint and high static friction at both the annular rim-side and the hub-side. The angle of the hexagonal pyramid of the nipple limiting part is 60°, 90°, or 120°, and an optimum arrangement can be made based on the material elongation of the spokes and the desired tension.

The invention discloses a train wheel set rapid detection and maintenance positioning device and method for a train factory, and belongs to the technical field of train wheel set detection. A rotary jacking mechanism abuts against a wheel shaft of a wheel set to jack the wheel set up from a rail of a maintenance platform and drive the wheel set to rotate, and a rim detection assembly is arranged between the rail and the wheel; the wheel rim detection assembly can conduct continuous inspection and probing through a mechanical probe rod and an ultrasonic probe, the wheel side detection assembly is arranged on the rotary jacking mechanism and detects the side face of a wheel through a laser scanning detector, and the wheel rim detection assembly and the wheel side detection assembly transmit probing results to the upper computer. A mechanical model of wheels on the two sides is formed in the upper computer, a damage point is displayed, the upper computer controls a stepping motor of the rotary jacking mechanism to move, the damage point can be selected through a screen of the upper computer, the rotary jacking mechanism is controlled to rotate slowly, and finally the damage point stays at a probing point of an ultrasonic probe or a laser scanning detector. And maintenance personnel can identify suspicious damage points conveniently.

The invention discloses a no-tillage planter and a sowing depth control method thereof. The planter comprises a rack, a ditching wheel, a depth limiting wheel, a press wheel, a soil covering mechanism and a seed feeding pipe, and is provided with a ditch depth detection device and a controller. A gap with a narrow front part and a wide rear part is formed between the two ditching wheels; the depth limiting wheels are separately arranged on the outer sides of the ditching wheels; and the heights of the depth limiting wheels are controlled through height adjusting mechanisms. The press wheel is rotationally connected with the middle of the axle through a connecting rod, a disc mechanism is mounted in the middle of the connecting rod and comprises a disc body and a connecting frame rotationally connected with the disc body, and an elastic element and a sensor are arranged between the connecting frame and the connecting rod. The tail end of the seed throwing pipe is located between the disc body and the press wheel, and an elastic pressing mechanism is arranged between the connecting rod and the rack. The soil density is judged in combination with sensor data, the sowing depth is adaptively adjusted, and the reasonability of the sowing depth is optimized. The thin grooves cut in the disc body are matched with the press wheel which is elastically pressed down to press and fix, so that the seeds are prevented from being pressed and damaged, and the seeding depth consistency is improved.

A single-motor-driven planetary gear train electric drive axle comprises a drive motor, a main speed reduction unit, a planetary speed reducer and a differential mechanism which are in transmission connection in sequence. A sun gear of the planetary reducer is connected with a sun gear shaft, an inner gear ring is fixed, and a planet carrier is in transmission connection with the differential. A gear shifting mechanism is further arranged between the main speed reduction unit and the planetary speed reducer and used for connecting power connection between the main speed reduction unit and the sun wheel shaft or power connection between the main speed reduction unit and the planet carrier. According to the electric drive axle, the gear shifting mechanism is arranged at the output end of the main speed reduction unit, the sun gear and the planet carrier are arranged, the inner gear ring is fixed, the occupied space is small, and the weight is lighter. When first-gear large-torque output is carried out, a transmission system has the requirements for high strength and high rigidity, the requirement for second-gear efficient operation is met, the part machining difficulty of a planet row gear shifting mechanism is lowered, the strength and reliability of an electric drive axle assembly for planet row gear shifting are effectively improved, and the product machining and assembling difficulty is effectively lowered.

The utility model discloses a walking wheel assembly and cleaning equipment, the walking wheel assembly comprises a wheel support, a rolling wheel and a guide extension piece, and the wheel support provides a first guide face which inclines upwards towards the front side of the advancing direction; the roller is mounted on the wheel bracket and can rotate around the wheel shaft; the guide extension piece is installed on the front side of the wheel support in the advancing direction, the guide extension piece can be switched between the folded state and the stretching state, in the stretching state, the guide extension piece provides a second guide face, and the second guide face is connected with the first guide face in the direction inclining upwards towards the front side in the advancing direction. The walking wheel assembly can switch the state of the guide extension piece according to the height of the obstacle, and the obstacle crossing ability can be improved.