Differential wheel set and transfer robot

Abstract

The invention relates to the technical field of differential wheel sets, and discloses a differential wheel set and a transfer robot, the differential wheel set comprises a slewing bearing unit and a differential driving unit, the slewing bearing unit comprises a fixed gear ring and a rotary disc, and the rotary disc and the fixed gear ring are connected and can rotate relatively; the differential driving unit is connected with the rotary disc and is embedded into an inner cavity of the rotary disc; the differential driving unit drives the slewing bearing unit to move through the rotary disk; wherein the differential driving unit is electrically connected with a wire harness, and the wire harness is attached to the lower side surface of the rotary disc, extends out and then is arranged around the peripheral side of the rotary disc. By means of the design, the wire harness can be wound and unwound on the circumferential side of the rotary disc along with rotation of the rotary disc, and the wire harness can be prevented from being excessively twisted and damaged when the rotary disc rotates. Meanwhile, the wire harness is attached to the lower side surface of the rotary disc, extends out of the rotary disc through the lower side surface of the rotary disc and then is wound around the peripheral side of the rotary disc, and the adverse effect of the wire harness on the height of the differential wheel set can be avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of differential wheel sets, and particularly to a differential wheel set and a handling robot. Background Art

[0002] In the field of modern logistics warehousing, logistics handling robots play a key role in improving logistics efficiency and reducing labor costs. They are mainly applied to the autonomous handling tasks of cage trucks or material cages in logistics warehouses. With the rapid development of the logistics industry, the downstream application fields of logistics handling robots are constantly expanding, which not only promotes the continuous increase in the market demand for logistics robots, but also puts forward more stringent requirements for their performance.

[0003] As an extremely important transfer tool in the logistics warehousing link, the cage truck has the characteristic of a low bottom height. Currently, in the autonomous handling operations for cage trucks, fork-lifting robots are widely used, such as typical unmanned forklifts and pallet jacks. However, with the pursuit of higher efficiency in space utilization in warehouses and the continuous increase in the weight of transported goods, logistics handling robots need to possess new characteristics such as high speed, omnidirectionality, and large load capacity to meet the increasingly complex logistics operation requirements.

[0004] Existing unmanned forklifts have certain limitations in structural design. Due to the low space under the fork arms, the layout space is severely restricted, so a single steering wheel or a single differential wheel set is often used in combination with driven wheels to form a moving chassis. However, in the actual application of this single-steering-wheel chassis design, its maneuverability is significantly restricted, and it is difficult to flexibly cope with the complex and changeable warehouse operation environment.

[0005] In the design of omnidirectional drive wheels, common steering wheels or differential wheel sets also have many problems. Taking the current layout method of the differential wheel set, the horizontal steering wheel drive assembly, and the slewing bearing unit as an example, they are usually arranged step by step upward, which results in a relatively large overall height of the assembly. At the same time, its wiring harness generally passes upward through the middle hollow hole, and in order to avoid damage to the wiring harness due to excessive torsion during the steering of the wheel set, a relatively large length has to be reserved for the upward-passing wiring harness, which further exacerbates the occupation of height space and is not conducive to efficient operation in the limited-space logistics warehouse environment.

[0006] In summary, existing logistics handling robots have obvious defects in both chassis design and the layout of drive wheels and wiring harnesses in the operation scenario of cage truck handling, and cannot fully meet the current requirements of the logistics warehousing industry for efficient, flexible, and large-load handling operations. There is an urgent need to develop a new technical solution for improvement. Summary of the Invention

[0007] In view of this, the present invention provides a differential wheel set and a handling robot to solve the problem that the existing logistics handling robots cannot adapt to the handling operation scenario of cage trucks.

[0008] In a first aspect, the present invention provides a differential wheel set, including a slewing bearing unit and a differential drive unit. The slewing bearing unit includes a fixed gear ring and a slewing disc. The slewing disc is connected to the fixed gear ring and the two can rotate relative to each other. The differential drive unit is connected to the slewing disc and is embedded in the internal cavity of the slewing disc. The differential drive unit drives the slewing bearing unit to move through the slewing disc. Among them, the differential drive unit is electrically connected with a wire harness. The wire harness extends out after fitting the lower surface of the slewing disc and is arranged around the circumference of the slewing disc.

[0009] Beneficial effects: The differential drive unit is tightly connected to the slewing disc and is embedded in the internal cavity of the slewing disc. This embedded design not only makes the structure of the differential wheel set more compact, reduces the overall volume, especially effectively reduces the overall height of the differential wheel set, so that the handling robot can adapt to the working conditions with a low bottom height of the cage truck. The slewing disc is connected to the fixed gear ring and the two can rotate relative to each other, so that the differential drive unit can adjust the traveling direction through the rotation of the slewing disc and the fixed gear ring, making the handling robot more flexible. The differential drive unit is electrically connected with a wire harness, and the other end of the wire harness is connected to the handling robot. The handling robot supplies power to the differential drive unit through the wire harness and controls the movement of the differential drive unit. In order to avoid adverse effects of the wire harness on the height of the differential wheel set, the wire harness is arranged to fit the lower surface of the slewing disc. After the wire harness extends out of the slewing disc through the lower surface of the slewing disc, it is wound around the circumference of the slewing disc, and then connected to the handling robot after being wound around the circumference of the slewing disc. By arranging the wire harness to extend out of the slewing disc through the lower surface of the slewing disc and then be wound around the circumference of the slewing disc, compared with passing the wire harness through the slewing disc and extending vertically, this design enables the wire harness to be retracted and released around the circumference of the slewing disc as the slewing disc rotates, and can avoid damage to the wire harness due to excessive torsion when the slewing disc rotates. At the same time, arranging the wire harness to fit the lower surface of the slewing disc, and the wire harness extends out of the slewing disc through the lower surface of the slewing disc and then is wound around the circumference of the slewing disc can avoid adverse effects of the wire harness on the height of the differential wheel set.

[0010] In an optional embodiment, the slewing disc is embedded inside the fixed gear ring, and rolling elements are movably arranged between the slewing disc and the fixed gear ring.

[0011] Beneficial effects: The rotating disk is embedded inside the fixed gear ring, making the space utilization of the entire differential gear set more compact and reasonable. This design not only effectively reduces the overall volume of the differential gear set, especially further reduces the height of the differential gear set, but also enhances the stability of its structure. During the actual operation of the differential gear set, when the differential drive unit drives the rotating disk to rotate, the rolling elements roll between the rotating disk and the fixed gear ring, converting the original sliding friction into rolling friction. The friction coefficient of rolling friction is much smaller than that of sliding friction, which enables the rotating disk to rotate more smoothly and easily inside the fixed gear ring, greatly reducing energy loss and improving the transmission efficiency of the differential gear set.

[0012] In an alternative embodiment, the differential gear set further includes an angle limiting assembly, which is disposed between the fixed gear ring and the rotating disk; the angle limiting assembly is configured to limit the rotation angle of the rotating disk relative to the fixed gear ring.

[0013] Beneficial effects: In the present invention, an angle limiting assembly is provided between the fixed gear ring and the rotating disk, which is precisely configured to limit the rotation angle of the rotating disk relative to the fixed gear ring. By setting a reasonable rotation angle range, it avoids the adverse effects on the wire harness caused by excessive rotation of the rotating disk. When the rotation of the rotating disk is about to exceed the safe angle range, the angle limiting assembly will act in time to prevent the rotating disk from continuing to rotate, thereby protecting the wire harness from being excessively twisted. This design not only improves the service life and reliability of the wire harness, but also enhances the overall stability and safety of the differential gear set, ensuring that the handling robot can operate continuously and stably in a complex working environment.

[0014] In an alternative embodiment, the angle limiting assembly includes two limit stoppers and a limit adapter. Both of the two limit stoppers are connected to the fixed gear ring, and the limit adapter is connected to the rotating disk; in the first direction of rotation of the rotating disk, the limit adapter is adapted to abut against one of the two limit stoppers to limit the rotation angle of the rotating disk in the first direction; in the opposite direction of the first direction of rotation of the rotating disk, the limit adapter is adapted to abut against the other of the two limit stoppers to limit the rotation angle of the rotating disk in the opposite direction of the first direction.

[0015] Beneficial effects: In the first direction of rotation of the turntable, the limiting adapter rotates synchronously with the turntable. As the turntable continues to rotate in the first direction, the limiting adapter gradually approaches one of the corresponding limiting stoppers. When the rotation angle of the turntable is about to reach the upper limit of the preset safe angle range, the limiting adapter is adapted to abut against the limiting stopper. Once the limiting adapter abuts against the limiting stopper, the rotation of the turntable in the first direction is effectively restricted and cannot continue to exceed the preset safe angle range, thus ensuring the stable operation of the differential wheel set and the safety of the wire harness connected thereto. When the turntable rotates in the opposite direction of the first direction, the limiting adapter also moves in the opposite direction with the turntable. As the reverse rotation angle of the turntable continuously increases, the limiting adapter gradually approaches the other limiting stopper. When the reverse rotation of the turntable is about to exceed the preset reverse safe angle range, the limiting adapter is adapted to abut against the other limiting stopper. In this way, the angle limiting component realizes the comprehensive and accurate limitation of the rotation angles of the turntable in both forward and reverse directions, enabling the differential wheel set to operate in a safe and stable state, and improving the reliability and service life of the entire system.

[0016] In an alternative embodiment, the line connecting the two limiting stoppers passes through the center of the fixed gear ring. That is, the rotation angle control range of the differential drive unit is 0° - 180°.

[0017] In an alternative embodiment, the differential wheel set further includes a swing shaft, which is horizontally arranged between the differential drive unit and the turntable, and the differential drive unit is configured to rotate relative to the turntable around the axis of the swing shaft.

[0018] Beneficial effects: In the design of the differential wheel set, the setting of the swing shaft greatly improves its adaptability to complex terrains, ensuring the stable operation of the handling robot under various working conditions. It ensures that the driving wheels of the differential drive unit can always maintain close contact with the slope surface, ensuring sufficient friction and grip, and preventing the handling robot from slipping or losing control on the slope surface.

[0019] In an alternative embodiment, the differential wheel set further includes a shaft mounting seat and a swing limiting block. The shaft mounting seat is fixed to the turntable, and the swing shaft is arranged at one end of the turntable and is located within the shaft mounting seat; the swing limiting block is connected to the upper connecting plate of the differential drive unit, and the swing limiting block is arranged on one side of the shaft mounting seat and is adapted to abut against the shaft mounting seat to limit the swing angle of the differential drive unit.

[0020] Beneficial effects: By providing a swing limit block, the swing limit block is connected to the upper connecting plate of the differential drive unit, that is, the swing limit block swings relative to the rotary disk together with the differential drive unit. The swing limit block is arranged on one side of the rotating shaft mounting seat and is adapted to abut against the rotating shaft mounting seat. The swing limit block is used to control the yaw angle of the differential drive unit, preventing the yaw angle from being too large and causing the handling robot to tip over.

[0021] In an alternative embodiment, the differential wheel set further includes a wear-resistant bushing and two rotating shaft spacers. The wear-resistant bushing is embedded in the connecting plate, and the swing shaft is arranged at one end of the differential drive unit and is arranged inside the wear-resistant bushing; the two rotating shaft spacers are respectively arranged on both sides of the wear-resistant bushing.

[0022] In an alternative embodiment, the differential wheel set further includes a drag chain. One end of the drag chain is wound around the circumferential side of the fixed gear ring, and this end is fixed to the rotary disk; the wire harness is arranged inside the drag chain.

[0023] Beneficial effects: In the design of the differential wheel set, the application of the drag chain further optimizes the protection and management of the wire harness, which plays a crucial role in the stable operation of the differential wheel set. One end of the drag chain equipped with the differential wheel set is cleverly wound around the circumferential side of the fixed gear ring, and this end is fixedly connected to the rotary disk. This connection method not only ensures that the drag chain can move flexibly with the rotation of the rotary disk, but also ensures that the winding state of the drag chain around the circumferential side of the fixed gear ring is stable and reliable, without loosening or falling off.

[0024] In an alternative embodiment, the differential wheel set further includes an angle detection member, which is arranged between the fixed gear ring and the rotary disk, and the angle detection member is configured to detect the rotation angle between the rotary disk and the fixed gear ring.

[0025] In a second aspect, the present invention further provides a handling robot, including a frame and a lifting arm. A steering wheel and a universal caster are arranged at the bottom of the frame, the lifting arm is connected to the frame, and a differential wheel set is arranged at the bottom of the lifting arm. The chassis of the handling robot adopts a three-point layout to ensure that all wheels are in contact with the ground. The differential wheel set is adopted below the lifting arm, and the steering wheel and the universal caster are distributed on both sides of the vehicle head; the differential wheel set cooperates with the steering wheel to realize the omnidirectional driving of the chassis. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1Schematic structural diagram of a slewing bearing unit and a differential drive unit in a differential wheel set according to an embodiment of the present invention;

[0028] Figure 2 Schematic structural diagram of the bottom of a slewing bearing unit and a differential drive unit in a differential wheel set according to an embodiment of the present invention;

[0029] Figure 3 Cross-sectional view of a swing shaft part of a differential wheel set according to an embodiment of the present invention;

[0030] Figure 4 Schematic structural diagram of a wire harness in a differential wheel set according to an embodiment of the present invention;

[0031] Figure 5 Schematic structural diagram of an overall differential wheel set according to an embodiment of the present invention;

[0032] Figure 6 Schematic structural diagram of a handling robot according to an embodiment of the present invention;

[0033] Figure 7 Top view of a handling robot according to an embodiment of the present invention.

[0034] Explanation of reference numerals:

[0035] 101, fixed gear ring; 102, slewing disc; 103, rolling element; 201, motor; 202, connecting plate; 203, speed reducer; 204, drive wheel; 301, limit stop; 302, limit adapter; 4, wire harness; 5, swing shaft; 6, shaft mounting seat; 7, swing limit block; 8, shaft spacer; 9, shaft end fixing part; 10, drag chain; 11, angle detection part; 12, frame; 13, lifting arm; 1301, steering wheel; 1302, caster wheel; 14, drag chain guide plate; 15, drag chain fixing part; 16, wear-resistant bushing. Detailed implementation manners

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] As an extremely important transfer tool in the logistics and warehousing process, the cage cart is characterized by a low bottom height. Currently, in the autonomous handling operations of cage carts, fork-lifting robots are widely used, such as typical automated forklifts and pallet jacks. However, with the pursuit of higher efficiency in space utilization in warehouses and the continuous increase in the weight of transported goods, logistics handling robots need to possess new characteristics such as high speed, omnidirectionality, and large load capacity to meet the increasingly complex logistics operation requirements.

[0038] Traditional automated forklifts have certain limitations in their structural design. Due to the low space under the fork arms, the layout space is severely restricted, so a single steering wheel or a single differential wheel set paired with a driven wheel is often used to form a moving chassis. However, in actual applications, the maneuverability of this single-steering chassis design is significantly restricted, making it difficult to flexibly handle complex and changing warehouse operation environments.

[0039] In the design of omnidirectional drive wheels, common steering wheels or differential wheel sets also have many problems. Taking the current layout of differential wheel sets and horizontal steering wheel drive components with a slewing bearing unit as an example, they are usually arranged step by step upwards, resulting in a relatively large overall height of the components. At the same time, their wiring harnesses generally pass through the middle hollow hole upwards, and to avoid damage to the wiring harness due to excessive torsion during wheel set steering, a relatively large length has to be reserved for the upward-passing wiring harness, which further exacerbates the occupation of height space and is not conducive to efficient operation in a logistics warehouse environment with limited space.

[0040] In summary, existing logistics handling robots have obvious defects in the operation scenarios for cage cart handling, whether in terms of chassis design or the layout of drive wheels and wiring harnesses, and cannot fully meet the current logistics and warehousing industry's requirements for efficient, flexible, and large-load handling operations. Therefore, this embodiment provides a differential wheel set.

[0041] The following combines Figures 1 to 5 , to describe the embodiments of the present invention.

[0042] According to an embodiment of the present invention, on the one hand, a differential wheel set is provided, which includes a slewing bearing unit and a differential drive unit. The slewing bearing unit includes a fixed gear ring 101 and a slewing disc 102. The slewing disc 102 is connected to the fixed gear ring 101 and the two can rotate relative to each other. The differential drive unit is connected to the slewing disc 102 and is embedded in the internal cavity of the slewing disc 102. The differential drive unit drives the slewing bearing unit to move through the slewing disc 102. Among them, the differential drive unit is electrically connected to a wiring harness 4, and the wiring harness 4 extends out along the lower surface of the slewing disc 102 and is arranged around the circumferential side of the slewing disc 102.

[0043] The fixed ring gear 101 is used to be fixed to the bottom of the body of the handling robot. The differential drive unit is the power core of the differential wheel set. It is closely connected to the rotary disk 102 and is embedded in the internal cavity of the rotary disk 102. This embedded design not only makes the structure of the differential wheel set more compact, reduces the overall volume, especially effectively reduces the overall height of the differential wheel set, so that the handling robot can adapt to the working condition requirements of the low bottom surface height of the cage truck. The rotary disk 102 is connected to the fixed ring gear 101 and the two can rotate relative to each other, so that the differential drive unit can adjust the traveling direction through the rotation of the rotary disk 102 and the fixed ring gear 101, making the handling robot more flexible. The differential drive unit is electrically connected to a wire harness 4, and the other end of the wire harness 4 is connected to the handling robot. The handling robot supplies power to the differential drive unit through the wire harness 4 and controls the movement of the differential drive unit. In order to avoid the wire harness 4 having an adverse impact on the differential wheel set in terms of height, the wire harness 4 is arranged to fit the lower surface of the rotary disk 102. After the wire harness 4 extends out of the rotary disk 102 through the lower surface of the rotary disk 102, it is wound around the circumferential side of the rotary disk 102, and then connected to the handling robot after being wound around the circumferential side of the rotary disk 102. By arranging the wire harness 4 to extend out of the rotary disk 102 through the lower surface of the rotary disk 102 and then be wound around the circumferential side of the rotary disk 102, compared with passing the wire harness 4 through the rotary disk 102 and extending vertically, this design enables the wire harness 4 to be retracted and released on the circumferential side of the rotary disk 102 as the rotary disk 102 rotates, and can avoid the wire harness 4 being excessively twisted and damaged when the rotary disk 102 rotates. At the same time, arranging the wire harness 4 to fit the lower surface of the rotary disk 102, and the wire harness 4 extending out of the rotary disk 102 through the lower surface of the rotary disk 102 and then being wound around the circumferential side of the rotary disk 102 can avoid the wire harness 4 having an adverse impact on the differential wheel set in terms of height.

[0044] In this embodiment, the differential drive unit is composed of a motor 201, a speed reducer 203, a connecting plate 202, and a driving wheel 204. Among them, one end of the speed reducer 203 is connected to the motor 201, and the other end is connected to the driving wheel 204. The left and right speed reducers 203 are fixed through the connecting plates 202 on both sides, and the differential drive unit components are arranged in central symmetry.

[0045] In one embodiment, a protective plate can be provided at the bottom of the wire harness 4 to protect the wire harness 4.

[0046] In one embodiment, the rotary disk 102 is embedded inside the fixed ring gear 101, and rolling elements 103 are movably provided between the rotary disk 102 and the fixed ring gear 101.

[0047] The rotating disk 102 is embedded and fixed inside the fixed gear ring 101, making the space utilization of the entire differential gear set more compact and reasonable. This design not only effectively reduces the overall volume of the differential gear set, especially further reduces the height of the differential gear set, but also enhances the stability of its structure. The fixed gear ring 101, as a relatively stationary component, provides a reliable support framework for the rotation of the rotating disk 102. The rolling elements 103 are made of high-strength and wear-resistant materials, such as high-quality bearing steel, to ensure that they can withstand huge pressure and friction during long-term use and are not easily damaged. These rolling elements 103 are distributed in the annular gap between the rotating disk 102 and the fixed gear ring 101 in a regular arrangement. Common arrangements include single-row ball, double-row ball or roller arrangement, etc. The specific arrangement will be selected according to the load requirements and usage scenarios of the differential gear set. During the actual operation of the differential gear set, when the differential drive unit drives the rotating disk 102 to rotate, the rolling elements 103 roll between the rotating disk 102 and the fixed gear ring 101, converting the original sliding friction into rolling friction. The friction coefficient of rolling friction is much smaller than that of sliding friction, which enables the rotating disk 102 to rotate more smoothly and easily inside the fixed gear ring 101, greatly reducing energy loss and improving the transmission efficiency of the differential gear set. At the same time, the rolling elements 103 can also evenly disperse the pressure between the rotating disk 102 and the fixed gear ring 101, avoiding excessive local pressure that may cause increased component wear and extending the service life of the rotating disk 102 and the fixed gear ring 101.

[0048] In one embodiment, the differential gear set further includes an angle limiting component, which is arranged between the fixed gear ring 101 and the rotating disk 102; the angle limiting component is configured to limit the rotation angle of the rotating disk 102 relative to the fixed gear ring 101.

[0049] During the operation of the differential wheel set, the safety and stability of the wire harness 4 are of utmost importance. Avoiding the twisting of the wire harness 4 is one of the key factors to ensure the normal operation of the differential wheel set. To further ensure that the wire harness 4 is not overly twisted, the differential wheel set is specifically provided with an angle limiting component. As described above, when the differential wheel set is working, the rotary disk 102 rotates relative to the fixed gear ring 101 to achieve the steering function of the differential wheel set. However, if the rotation angle of the rotary disk 102 is not restricted, during frequent steering operations, the wire harness 4 connected to the differential drive unit is likely to be twisted as the rotary disk 102 rotates excessively. Once the wire harness 4 is overly twisted, the internal wires may break, and the outer skin may also be damaged, resulting in a circuit failure, affecting the normal operation of the differential drive unit, and even causing the entire handling robot to malfunction. Therefore, in this embodiment, an angle limiting component is provided between the fixed gear ring 101 and the rotary disk 102, which is precisely configured to limit the rotation angle of the rotary disk 102 relative to the fixed gear ring 101. By setting a reasonable rotation angle range, it is possible to avoid the adverse effects caused by the excessive rotation of the rotary disk 102 on the wire harness 4. When the rotation of the rotary disk 102 is about to exceed the safe angle range, the angle limiting component will act in a timely manner to prevent the rotary disk 102 from continuing to rotate, thereby protecting the wire harness 4 from being overly twisted. This design not only improves the service life and reliability of the wire harness 4 but also enhances the overall stability and safety of the differential wheel set, ensuring that the handling robot can operate continuously and stably in a complex working environment.

[0050] In one embodiment, as Figure 2 shown, the angle limiting component includes two limit stoppers 301 and a limit adapter 302. Both limit stoppers 301 are connected to the fixed gear ring 101, and the limit adapter 302 is connected to the rotary disk 102. In the first direction of rotation of the rotary disk 102, the limit adapter 302 is adapted to abut against one of the two limit stoppers 301 to limit the rotation angle of the rotary disk 102 in the first direction. In the opposite direction of the first direction of rotation of the rotary disk 102, the limit adapter 302 is adapted to abut against the other of the two limit stoppers 301 to limit the rotation angle of the rotary disk 102 in the opposite direction of the first direction.

[0051] In the first direction of rotation of the rotary disk 102, for example, the first direction is Figure 2 the clockwise direction in []. The limit adapter 302 rotates synchronously with the rotary disk 102. As the rotary disk 102 continues to rotate in the first direction, the limit adapter 302 gradually approaches one of the corresponding limit stoppers 301 (in Figure 2The limiting stop 301 on the upper middle side). When the rotation angle of the rotary disk 102 is about to reach the upper limit of the preset safe angle range, the limiting adapter 302 is adapted to abut against the limiting stop 301. Once the limiting adapter 302 abuts against the limiting stop 301, the rotation of the rotary disk 102 in the first direction is effectively restricted and cannot continue to exceed the preset safe angle range, thus ensuring the stable operation of the differential wheel set and the safety of the wire harness 4 connected thereto. Further, the abutting surface of the limiting adapter 302 and the limiting stop 301 can be specially treated so that the abutting surface has good wear resistance and impact resistance to ensure that it can withstand a large force at the moment of abutment without damage. It is also possible to achieve buffering during abutment by setting an elastic material or a buffer structure on the abutting surface, thereby avoiding damage to the components of the differential wheel set due to excessive instantaneous impact force.

[0052] When the rotary disk 102 rotates in the opposite direction of the first direction, for example, if the first direction is Figure 2 the counterclockwise direction in, the limiting adapter 302 also moves in the opposite direction along with the rotary disk 102. As the reverse rotation angle of the rotary disk 102 continuously increases, the limiting adapter 302 gradually approaches another limiting stop 301 (the limiting stop 301 located at the Figure 2 lower middle side). When the reverse rotation of the rotary disk 102 is about to exceed the preset reverse safe angle range, the limiting adapter 302 is adapted to abut against the other limiting stop 301. In this way, the angle limiting component realizes the comprehensive and precise limitation of the rotation angles of the rotary disk 102 in both forward and reverse directions, enabling the differential wheel set to operate in a safe and stable state, and improving the reliability and service life of the entire system. Among them, the setting of the angle limiting component corresponds to the wire harness 4 extending from the lower side surface of the rotary disk 102 and being arranged around the circumferential side of the rotary disk 102. Through the angle limiting component, it is avoided that the rotation angle of the rotary disk 102 is too large, resulting in excessive pulling of the wire harness 4 wound around the rotary disk 102 due to the too large rotation angle of the rotary disk 102.

[0053] In one embodiment, the connection line of the two limiting stops 301 passes through the center of the fixed gear ring 101. That is, the rotation angle control range of the differential drive unit is 0° - 180°.

[0054] In one embodiment, as Figure 3 shown, the differential wheel set further includes a swing shaft 5, which is horizontally arranged between the differential drive unit and the rotary disk 102, and the differential drive unit is configured to rotate relative to the rotary disk 102 around the axis of the swing shaft 5.

[0055] In the design of the differential wheel set, the setting of the swing shaft 5 greatly improves its adaptability to complex terrains, ensuring that the handling robot can operate stably under various working conditions. As Figure 1 andFigure 3 As shown, the differential wheel set is equipped with two swing shafts 5, which are horizontally and symmetrically arranged between the differential drive unit and the rotary disk 102, and are respectively located on the opposite sides of the differential drive unit. The installation position of the swing shaft 5 is emphasized during the design process. Its horizontal setting ensures that when the differential drive unit rotates relative to the rotary disk 102, it can swing smoothly in the same plane, avoiding additional stress and wear caused by improper inclination angles. At the same time, the layout of the two swing shafts 5 on the opposite sides of the differential drive unit enables the differential drive unit to maintain good balance during movement and respond more stably regardless of the direction of the external force. During the movement of the differential drive unit, complex terrain conditions are a major challenge it faces, such as slopes. When the handling robot travels to a slope, the differential drive unit demonstrates its unique adaptability. At this time, the differential drive unit can rotate relative to the rotary disk 102 around the axis of the swing shaft 5. Due to the cooperative action of the two swing shafts 5, the differential drive unit can make adaptive adjustments according to the slope of the slope. When one side of the differential drive unit encounters a higher slope, the swing shaft 5 close to that side will serve as a fulcrum, causing the corresponding part of the differential drive unit to lift upward. At the same time, the other swing shaft 5 cooperates to adjust, making the overall differential drive unit present an inclination angle consistent with the slope. In this way, the drive wheels 204 of the differential drive unit can always maintain close contact with the slope, ensuring sufficient friction and grip to prevent the handling robot from slipping or losing control on the slope.

[0056] In one embodiment, as Figure 3 shown, the differential wheel set further includes a rotating shaft mounting seat 6 and a swing limiting block 7. The rotating shaft mounting seat 6 is fixed to the rotary disk 102, and the swing shaft 5 is disposed at one end of the rotary disk 102 and is arranged within the rotating shaft mounting seat 6; the swing limiting block 7 is connected to the upper connecting plate 202 of the differential drive unit, and the swing limiting block 7 is disposed on one side of the rotating shaft mounting seat 6 and is adapted to abut against the rotating shaft mounting seat 6 to limit the swing angle of the differential drive unit.

[0057] ​To install the swing rotation shaft 5, in this embodiment, a rotation shaft mounting seat 6 is fixed inside the rotary disk 102. A stepped through hole is provided inside the rotation shaft mounting seat 6. One end of the swing rotation shaft 5 is inserted into the stepped through hole inside the rotation shaft mounting seat 6. The other end of the swing rotation shaft 5 is provided with a stepped structure. The swing rotation shaft 5 realizes fitting abutment and limiting with the end of the stepped through hole through the stepped structure at this end. Further, the swing rotation shaft 5 is fixed inside the stepped through hole of the rotation shaft mounting seat 6. One end of the swing rotation shaft 5 extending out of the rotation shaft installation is movably connected to the upper connecting plate 202 of the differential drive unit, realizing the relative rotation of the differential drive unit with respect to the swing rotation shaft 5. By providing a swing rotation limiting block 7, the swing rotation limiting block 7 is connected to the upper connecting plate 202 of the differential drive unit, that is, the swing rotation limiting block 7 swings relative to the rotary disk 102 together with the differential drive unit. The swing rotation limiting block 7 is arranged on one side of the rotation shaft mounting seat 6 and is adapted to abut against the rotation shaft mounting seat 6. The swing angle of the differential drive unit is controlled by the swing rotation limiting block 7 to prevent the handling robot from tipping over due to excessive swing angle.

[0058] As Figure 1 shown, the swing rotation limiting block 7 is strip-shaped. The swing rotation limiting block 7 is arranged on the upper side of the rotation shaft mounting seat 6 and there is a gap between the two. When the rotation limiting block 7 rotates together with the differential drive unit, the abutment of the rotation limiting block 7 against the rotation shaft mounting seat 6 is utilized to control the swing angle of the differential drive unit.

[0059] In one embodiment, as Figure 3 shown, the differential wheel set further includes a wear-resistant bushing 16 and two shaft spacers 8. The wear-resistant bushing 16 is embedded in the connecting plate 202. One end of the swing rotation shaft 5 at the differential drive unit is arranged inside the wear-resistant bushing 16; the two shaft spacers 8 are respectively arranged on both sides of the wear-resistant bushing 16.

[0060] By providing the wear-resistant bushing 16, the wear-resistant bushing 16 is fixed to the upper connecting plate 202 of the differential drive unit. One end of the swing rotation shaft 5 at the differential drive unit is movably arranged inside the wear-resistant bushing 16, thereby realizing the relative rotation of the differential drive unit with respect to the swing rotation shaft 5. At the same time, shaft spacers 8 are provided on both opposite sides of the wear-resistant bushing 16. At the same time, an end fixing part 9 is also provided at the end of the swing rotation shaft 5, and a circlip can be specifically used.

[0061] In one embodiment, the differential wheel set further includes a drag chain 10. One end of the drag chain 10 is wound around the circumference of the fixed gear ring 101, and the end of this end is fixed to the rotary disk 102; the wire harness 4 is arranged inside the drag chain 10.

[0062] In the design of the differential wheel set, the application of the drag chain 10 further optimizes the protection and management of the wire harness 4, playing a crucial role in the stable operation of the differential wheel set. One end of the drag chain 10 equipped with the differential wheel set is cleverly wound around the circumferential side of the fixed gear ring 101, and this end is firmly fixedly connected to the rotary disk 102. This connection method not only ensures that the drag chain 10 can move flexibly with the rotation of the rotary disk 102, but also ensures that the winding state of the drag chain 10 around the circumferential side of the fixed gear ring 101 is stable and reliable, without loosening or falling off. When the rotary disk 102 rotates relative to the fixed gear ring 101, the drag chain 10 will perform corresponding winding and unwinding actions around the circumferential side of the fixed gear ring 101 with the movement of the rotary disk 102. This movement mode of the drag chain 10 closely cooperates with the rotation of the rotary disk 102, ensuring that the wire harness 4 is always in a safe and stable state during the rotation of the rotary disk 102. During the winding and unwinding process of the drag chain 10, the wire harness 4 inside it will not be excessively stretched or twisted, further guaranteeing the electrical and mechanical properties of the wire harness 4. For example, when the handling robot performs complex steering operations, the rotary disk 102 will rotate frequently. At this time, the drag chain 10 can flexibly adjust its position around the circumferential side of the fixed gear ring 101, keeping the wire harness 4 in a proper state at all times, and avoiding signal transmission failures or power supply interruptions caused by the twisting or stretching of the wire harness 4. In addition, the setting of the drag chain 10 also improves the overall aesthetics and neatness of the differential wheel set. Since the wire harness 4 is housed inside the drag chain 10, the internal structure of the differential wheel set appears clearer and more orderly, reducing the clutter caused by the exposure of the wire harness 4 and enhancing the appearance quality of the entire device.

[0063] As Figure 3 and Figure 5 shown, the rotary disk 102 is inside the fixed gear ring 101, and the lower part of the rotary disk 102 is not wrapped by the fixed gear ring 101. A drag chain fixing part 15 is fixed to the lower part of the rotary disk 102, and the drag chain fixing part 15 is used to fix with the drag chain 10. Further, the fixed gear ring 101 is sleeved outside the rotary disk 102, and after the drag chain 10 is fixed to the drag chain fixing part 15, it is wound around the outside of the fixed gear ring 101.

[0064] In one embodiment, as Figure 1 and Figure 2 shown, the differential wheel set further includes an angle detection part 11, which is arranged between the fixed gear ring 101 and the rotary disk 102. The angle detection part 11 is configured to detect the rotation angle between the rotary disk 102 and the fixed gear ring 101. In this embodiment, the angle detection part 11 adopts an absolute encoder. The fixed gear ring 101 is fixedly connected to the frame 12, the small gear is fixedly connected to the output shaft of the absolute encoder, the absolute encoder is fixedly installed on the rotary disk 102, and the small gear meshes with the fixed gear ring 101 for reading the rotation angle information of the differential drive unit.

[0065] According to an embodiment of the present invention, on the other hand, a handling robot is further provided, as Figure 6 and Figure 7 shown. The handling robot includes a frame 12 and a lifting arm 13. A steering wheel 1301 and universal casters are provided at the bottom of the frame 12. The lifting arm 13 is connected to the frame 12, and a differential wheel set is provided at the bottom of the lifting arm 13. The chassis of the handling robot adopts a three-point layout to ensure that all wheels are in contact with the ground. A differential wheel set is adopted below the lifting arm 13, and the steering wheel 1301 and universal casters are distributed on both sides of the vehicle head; the differential wheel set cooperates with the steering wheel 1301 to achieve omnidirectional driving of the chassis.

[0066] In one embodiment, as Figure 5 shown, the handling robot further includes a drag chain guide plate 14. The drag chain guide plate 14 is arranged outside the moving track of the drag chain 10, and the drag chain guide plate 14 is fixed on the frame 12 to restrict the running track of the drag chain 10.

[0067] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A differential wheel set, characterized in that: include: A slewing bearing unit comprises a fixed gear ring (101) and a slewing disc (102), wherein the slewing disc (102) is connected to the fixed gear ring (101) and the two can rotate relative to each other; A differential drive unit is connected to the rotating disk (102) and embedded in the internal cavity of the rotating disk (102); the differential drive unit drives the rotating support unit to move via the rotating disk (102); The differential drive unit is electrically connected to a wiring harness (4), and the wiring harness (4) is arranged around the circumference of the rotating disk (102) after extending out from the lower surface of the rotating disk (102).

2. The differential wheel set according to claim 1, characterized in that: The rotating disk (102) is embedded in the fixed gear ring (101), and a rolling body (103) is movably provided between the rotating disk (102) and the fixed gear ring (101).

3. The differential wheel set according to claim 2, characterized in that: It also includes an angle limiting component, which is arranged at the fixed gear ring (101) and the rotating disk (102); the angle limiting component is configured to limit the rotation angle of the rotating disk (102) relative to the fixed gear ring (101).

4. The differential wheel set according to claim 3, characterized in that: The angle limiting component comprises: Two limit stoppers (301), both connected to the fixed gear ring (101); A limit adapter (302) connected to the rotating disk (102); In the first direction in which the rotating disk (102) rotates, the limit adapter (302) is adapted to abut against one of the two limit stoppers (301) to limit the rotation angle of the rotating disk (102) in the first direction; In the direction opposite to the first direction in which the rotating disk (102) rotates, the limit adapter (302) is adapted to abut against the other of the two limit stops (301) to limit the rotation angle of the rotating disk (102) in the direction opposite to the first direction.

5. The differential wheel set according to claim 4, characterized in that: The connecting line of the two limit stoppers (301) passes through the center of the fixed gear ring (101).

6. The differential wheel set according to any one of claims 2 to 5, characterized in that: It also includes a swing shaft (5) which is horizontally arranged between the differential drive unit and the turntable (102), and the differential drive unit is configured to rotate around the axis of the swing shaft (5) relative to the turntable (102).

7. The differential wheel set according to claim 6, characterized in that: Also includes: A rotating shaft mounting seat (6) is fixed to the rotating disk (102), and the swing shaft (5) is located at one end of the rotating disk (102) and is arranged in the rotating shaft mounting seat (6); A swing limit block (7) is connected to the upper connecting plate (202) of the differential drive unit. The swing limit block (7) is arranged on one side of the rotating shaft mounting seat (6) and is suitable for abutting against the rotating shaft mounting seat (6) to limit the swing angle of the differential drive unit.

8. The differential wheel set according to claim 7, characterized in that: Also includes: A wear-resistant bushing (16) is embedded in the connecting plate (202), and the swing shaft (5) is located at one end of the differential drive unit and is arranged in the wear-resistant bushing (16); Two rotating shaft spacers (8) are respectively arranged on both sides of the wear-resistant bushing (16).

9. The differential wheel set according to any one of claims 2 to 5, characterized in that: It also includes a drag chain (10), one end of which is wound around the circumference of the turntable (102), and the end of which is fixed to the turntable (102); the wiring harness (4) is passed through the inside of the drag chain (10).

10. The differential wheel set according to any one of claims 2 to 5, characterized in that: It also includes an angle detection member (11) disposed between the fixed gear ring (101) and the rotating disk (102), and the angle detection member (11) is configured to detect a rotation angle between the rotating disk (102) and the fixed gear ring (101).

11. A transport robot, characterized in that: include: A frame (12) having a steering wheel (1301) and a universal caster (1302) at the bottom thereof; A lifting arm (13) is connected to the frame (12), and a differential wheel set according to any one of claims 1 to 10 is provided at the bottom of the lifting arm (13).

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