An automatic unlocking drive device

Abstract

This invention provides an automatic unlocking drive device to improve the problem that existing devices cannot automatically enter the unlocking state when the power component is turned off or the input torque of the drive shaft is less than the resistance torque of the traveling wheel. The automatic unlocking drive device includes a locking member and an elastic member. The locking member is mounted on the drive shaft driven by the power component and has a first position, a second position, and a third position; wherein the first and second positions are locking positions connecting the traveling wheel to the drive shaft, and the third position is an unlocking position disengaging the traveling wheel from the drive shaft; the elastic member accumulates elastic potential energy when the locking member moves from the third position to the first or second position, and releases the elastic potential energy when the drive device is turned off or the input torque is less than the resistance torque of the traveling wheel, causing the locking member to reset from the first or second position to the third position.

Description

Technical Field

[0001] This invention relates to the field of self-propelled device drives, and more specifically to an automatic unlocking drive device. Background Technology

[0002] A push-type self-propelled lawn mower is a lawn mowing device equipped with a self-propelled function. The drive unit drives the walking wheels to rotate, so that the push-type self-propelled lawn mower can move automatically on the ground. It has the advantages of being labor-saving, efficient, and easy to operate, and is very suitable for mowing lawns in sanitation, grasslands, and green areas.

[0003] Traditional self-propelled lawnmowers typically connect their power unit and wheels via a drive mechanism. However, existing drive mechanism structures cannot automatically unlock the wheels from the power unit when the drive is off. If the device is pulled after the drive is off, the wheels will cause the power unit to rotate along with them, requiring considerable force to pull the device backward. This increases the user's burden. Therefore, it is necessary to provide an automatic unlocking drive mechanism that allows the wheels to automatically unlock when the power unit is off or when the input torque to the drive shaft is less than the resistance torque of the wheels, enabling the wheels to rotate freely relative to the drive shaft of the power unit. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the present invention provides an automatic unlocking drive device to improve the problem that existing drive devices, self-propelled equipment and lawnmowers cannot automatically enter the unlocking state when the power component is turned off or the input torque of the drive shaft is less than the resistance torque of the walking wheels.

[0005] To achieve the above and other related objectives, the present invention provides an automatic unlocking drive device for driving a walking wheel. The automatic unlocking drive device includes a locking member and an elastic member. The locking member is mounted on a drive shaft driven by a power component and has a first position, a second position, and a third position; wherein the first and second positions are locking positions connecting the walking wheel to the drive shaft, and the third position is an unlocking position disengaging the walking wheel from the drive shaft; the elastic member accumulates elastic potential energy when the locking member moves from the third position to the first or second position, and releases the elastic potential energy when the drive device is closed or the input torque is less than the resistance torque of the walking wheel, causing the locking member to reset from the first or second position to the third position.

[0006] In one example of the present invention, the drive member is detachably mounted on the drive shaft, and a steering buffer structure is provided between the drive shaft and the drive member to buffer the force exerted by the drive shaft on the drive member when turning.

[0007] In one example of the present invention, the driving member is provided with a through hole, the transmission shaft is inserted into the through hole, and the steering buffer structure includes at least one clearance structure provided on the transmission shaft and a protrusion corresponding to the clearance structure provided in the through hole, and a circumferential gap provided between the clearance structure and the corresponding protrusion for buffering; when the clearance structure rotates to the corresponding protrusion, it drives the driving member to rotate.

[0008] In one example of the present invention, the avoidance structure is a flat surface disposed on the drive shaft, and a mating surface is provided on the side of the protrusion that meets the flat surface when the drive shaft rotates.

[0009] In one example of the present invention, a drive member is provided on the transmission shaft, and the elastic member includes a first reset elastic body; the first reset elastic body is installed between the locking member and the drive member, and accumulates circumferential reset energy when the locking member rotates relative to the drive member.

[0010] In one example of the present invention, the first reset elastic body includes a torsion spring, one end of which is mounted on the drive member and the other end of which is mounted on the locking member.

[0011] In one example of the present invention, the automatic unlocking drive device further includes a power output component, which is mounted on a drive shaft on the side of the locking component facing the walking wheel and can rotate relative to the drive shaft. A clutch insertion structure is provided between the output component and the locking component, and a drive structure is provided between the output component and the walking wheel.

[0012] In one example of the present invention, the elastic element includes a second reset elastic body; the second reset elastic body is installed between the traveling wheel and the locking element, and accumulates axial reset energy when the locking element moves toward the traveling wheel side.

[0013] In one example of the present invention, the second reset elastic body includes a spring, one end of which abuts against the locking member, and the other end of which abuts against the power output member.

[0014] In one example of the present invention, a driving member is provided on the drive shaft, a rolling element is provided on the driving member, and a sliding groove is provided on the locking member. During the rotation of the drive shaft, the rolling element rolls in the sliding groove, driving the locking member to switch between a first position, a second position, and a third position.

[0015] In one example of the present invention, the slide includes a first spiral groove and a second spiral groove with opposite directions of rotation. One end of the first spiral groove and the second spiral groove intersect, and the other end extends away from the side of the traveling wheel. When the rolling body reaches the intersection of the first spiral groove and the second spiral groove, the locking member is in a third position. When the rolling body reaches the end of the first spiral groove away from the intersection, the locking member is in a first position. When the rolling body reaches the end of the second spiral groove away from the intersection, the locking member is in a second position.

[0016] In one example of the present invention, there are two slides, which are evenly distributed along the circumference on the inner wall of the locking member, and the number of rolling elements corresponds to the slides, which are evenly distributed along the circumference on the driving member.

[0017] In one example of the present invention, the driving component and the transmission shaft are separately arranged, with the driving component mounted on the transmission shaft and rotating with the transmission shaft.

[0018] In one example of the present invention, the driving component and the transmission shaft are an integral structure.

[0019] In one example of the present invention, the rolling element is a ball; the driving member is provided with a groove that matches the ball, the ball is partially housed in the groove, and the portion exposed in the groove rolls along the groove.

[0020] In one example of the present invention, the clutch engagement structure includes a plurality of first engagement teeth disposed on the locking member and a plurality of second engagement teeth disposed on the power output member, wherein the plurality of first engagement teeth and the plurality of second engagement teeth are engaged when the locking member is in the locked position.

[0021] In one example of the present invention, the drive structure includes a gear assembly.

[0022] In one example of the present invention, the locking member is provided with a first insertion tooth, which drives a second insertion tooth provided on the walking wheel to rotate the walking wheel.

[0023] The automatic unlocking drive device of the present invention can drive the drive shaft to the walking wheel when the locking member is in the first position and the second position. Moreover, the locking member can be automatically reset to the third position, which unlocks the drive shaft from the walking wheel, by the elastic member when the power component is turned off or the input torque is less than the resistance torque of the walking wheel. This can meet the various drive connection needs of users. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0025] Figure 1 This is a structural diagram of the automatic unlocking drive device of the present invention mounted on the drive shaft;

[0026] Figure 2 This is an exploded view of the automatic unlocking drive device of the present invention on the transmission shaft;

[0027] Figure 3An exploded view of the automatic unlocking drive device of the present invention at another angle on the transmission shaft;

[0028] Figure 4 This is a three-dimensional schematic diagram of the automatic unlocking drive device of the present invention when the drive shaft starts to rotate;

[0029] Figure 5 This is a three-dimensional schematic diagram of the locking element in the automatic unlocking drive device of the present invention reaching the locking position under the drive of the drive element;

[0030] Figure 6 This is a schematic diagram of the forces acting on the locking component after the transmission shaft stops rotating in the automatic unlocking drive device of the present invention.

[0031] Figure 7 This is a three-dimensional schematic diagram of the locking element in the automatic unlocking drive device of the present invention being reset to the unlocked position under the action of the elastic element;

[0032] Figure 8 This is a schematic diagram of the automatic unlocking drive device of the present invention when there is a circumferential gap between the transmission shaft and the drive component in the initial state;

[0033] Figure 9 This is a schematic diagram of the structure of the transmission shaft and the driving component after the flat surface of the transmission shaft contacts the mating surface of the driving component in the automatic unlocking drive device of the present invention;

[0034] Figure 10 This is a schematic diagram of the structure of the automatic unlocking drive device of the present invention when the drive component rotates with the drive shaft and drives the locking component to the locking position;

[0035] Figure 11 This is a schematic diagram showing the rotation angle of the transmission shaft relative to the driving component and the rotation angle between the unlocking position and the locking position of the locking component in the automatic unlocking drive device of the present invention.

[0036] Figure 12 This is a three-dimensional cross-sectional view of the locking component in the automatic unlocking drive device of the present invention;

[0037] Figure 13 This is a front sectional view of the locking component in the automatic unlocking drive device of the present invention;

[0038] Figure 14 This is a schematic diagram showing the positions of the ball bearings in the automatic unlocking drive device of the present invention when the locking member is in the first, second, and third positions.

[0039] Figure 15 A schematic diagram showing the installation relationship between the walking wheels and the automatic unlocking drive device;

[0040] Figure 16 This diagram illustrates the installation relationship between the walking wheels and the automatic unlocking drive device after the walking wheel cover has been removed.

[0041] Figure 17 This is a diagram showing the mounting structure of the drive shaft on the drive unit.

[0042] Figure 18 This is an exploded view of the driving device in this invention;

[0043] Figure 19 This is a schematic diagram of gear meshing in the drive device of the present invention.

[0044] Component designation explanation:

[0045] 100. Wheel; 200. Wheel cover; 300. Driven gear; 400. Power assembly; 410. Drive shaft; 411. Circumference; 412. Flat surface; 420. Gearbox; 421. Double gear; 422. Large gear; 430. Motor assembly; 431. Motor housing; 432. Self-propelled motor; 433. Motor gear; 500. Automatic unlocking drive device; 510. Drive component; 511. Second through hole; 512. Groove; 513. Rolling element; 514. Spring mounting section; 515. First torsion spring slot; 516. Torsion spring mounting section; 517. End face; 518. 519. Protrusion; 520. Mating surface; 521. First reset elastic body; 522. First end; 523. Second end; 530. Locking member; 531. Slide groove; 5311. First spiral groove; 5312. Second spiral groove; 532. First insertion tooth; 533. Spring mounting groove on the locking member; 534. First through hole; 535. Second torsion spring slot; 540. Second reset elastic body; 550. Power output member; 551. Inner end face; 552. Second insertion tooth; 553. Spring mounting groove on the power output member; 554. Drive gear; 560. Washer; 570. Shaft retaining ring. Detailed Implementation

[0046] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. It should also be understood that the terminology used in the embodiments of the present invention is for describing specific implementation schemes and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0047] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" used in this specification are only for clarity of description and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as part of the scope of the invention.

[0048] Please see Figures 1 to 19 The present invention provides an automatic unlocking drive device 500, which can improve the problem that existing drive devices, self-propelled equipment or lawnmowers cannot automatically enter the unlocking state when the power component is turned off or the input torque of the drive shaft 410 is less than the resistance torque of the walking wheel.

[0049] Please see Figures 2 to 4The automatic unlocking drive device 500 includes a locking member 530 and an elastic member. The locking member 530 is mounted on a drive shaft 410 driven by a power component and has a first position, a second position, and a third position. The power component 400 drives the drive shaft 410 to rotate, and the drive shaft 410 drives the locking member 530 to switch between the first position, the second position, and the third position via the drive member 510. The first position is a locking position in which the locking member 530 is driven to connect with the traveling wheel when the drive shaft 410 rotates in the forward direction. When the locking member 530 is in the first position, the power component 400 rotates in the forward direction and drives the traveling wheel to rotate in the forward direction. The second position is a locking position in which the locking member 530 is driven to connect with the traveling wheel when the drive shaft 410 rotates in the reverse direction. When the locking member 530 is in the second position, the power component 400 rotates in the reverse direction and drives the traveling wheel to rotate in the reverse direction. The third position is an unlocking position in which the connection between the drive shaft 410 and the traveling wheel is disconnected. When the locking member 530 is in the third position, the traveling wheel can rotate freely relative to the drive shaft 410. The locking member 530 can switch between a third position and a first position when the drive shaft 410 rotates in the forward direction, and it can also switch between a third position and a second position when the drive shaft 410 rotates in the reverse direction. The automatic unlocking drive device 500 of this invention can automatically switch the position of the locking member 530 through the bidirectional rotation of the power component 400 to achieve bidirectional drive of the traveling wheel. The elastic member accumulates elastic potential energy when the locking member 530 moves from the third position to the first or second position. When the power component 400 is closed or the input torque is less than the resistance torque of the traveling wheel, the elastic potential energy is released, causing the locking member 530 to reset from the first or second position to the third position. The aforementioned automatic unlocking drive device 500 can automatically unlock the traveling wheel from the drive shaft 410 regardless of whether the drive shaft is in the forward or reverse direction, when the power component 400 is closed or the input torque is less than the resistance torque of the traveling wheel. The automatic unlocking drive device 500 of the present invention can not only achieve bidirectional drive of the walking wheel through the bidirectional rotation of the power component 400, but also automatically unlock the walking wheel from the drive shaft 410 when the power component 400 is turned off or the input torque is less than the resistance torque of the walking wheel.

[0050] Please see Figures 2 to 4In one example of the present invention, a driving member 510 is provided on the drive shaft 410. When the drive shaft 410 rotates, the driving member 510 drives the locking member 530 to move from a third position to a first position or a second position, so as to realize the forward or reverse drive connection between the drive shaft 410 and the traveling wheel. In the present invention, the driving member 510 can be integrally provided with the drive shaft 410 or separately provided. In one example of the present invention, the driving member 510 and the drive shaft 410 are separately provided. The driving member 510 is provided with a second through hole 511 that matches the drive shaft 410. The drive shaft 410 is inserted into the second through hole 511 and extends to the outside of the driving member 510. The driving member 510 is fitted on the drive shaft 410 and rotates with the drive shaft 410. The driving component 510 is provided with a rolling element 513, and the locking component 530 is provided with a sliding groove 531. During the rotation of the drive shaft 410, the rolling element 513 rolls in the sliding groove 531, driving the locking component 530 to switch between the first position, the second position and the third position.

[0051] Please see Figures 8 to 14 In one example of the present invention, the slide groove 531 includes a first spiral groove 5311 and a second spiral groove 5312 with opposite rotation directions. One end of the first spiral groove 5311 and the second spiral groove 5312 intersects, and the other end of the first spiral groove 5311 and the second spiral groove 5312 extends away from the side of the traveling wheel, respectively. The first spiral groove 5311 and the second spiral groove 5312 are arranged symmetrically in an approximately "V" shape, and the rotation angles are ±X°, respectively. The drive shaft 410 drives the drive member 510 and the rolling element 513 to rotate. The locking member 530 can rotate relative to the drive member 510 by an angle of forward rotation of X° and reverse rotation of X°. It should be noted that the specific value of X can be set according to design requirements. The axial extension distance of the first spiral groove 5311 and the second spiral groove 5312 is the same, and the maximum value is M, so as to realize that the locking member 530 locks with the traveling wheel at the same axial position. It should be noted that the specific value of M can be set according to design requirements. Specifically, when the rolling element 513 reaches the intersection of the first spiral groove 5311 and the second spiral groove 5312, the locking member 530 is in the third position; when the rolling element 513 reaches the end of the first spiral groove 5311 away from the intersection, the locking member 530 is in the first position; and when the rolling element 513 reaches the end of the second spiral groove 5312 away from the intersection, the locking member 530 is in the second position.

[0052] Considering that one groove 531 is sufficient to drive the rolling element 513 to the locking element 530, the number of grooves 531 in this invention can be at least one. However, considering the uniformity of force distribution, preferably, in one example of this invention, there are two grooves 531, evenly distributed along the circumference 411 on the inner wall of the locking element 530. The number of rolling elements 513 corresponds to and matches the number of grooves 531, and they are evenly distributed along the circumference 411 on the driving element 510 at positions corresponding to the grooves 531. In this invention, the rolling element 513 can also be other rotating body structures, as long as it matches the rotation direction of the spiral groove and rolls within the spiral groove to drive the locking element 530. Preferably, please refer to [reference needed]. Figures 2 to 7 In one example of the present invention, the rolling element 513 is a ball, such as a steel ball. The driving member 510 is provided with a groove 512 that matches the ball. The groove 512 is a spherical groove, and the radius of the sphere matches the radius of the ball. Part of the ball is housed in the groove 512, and the other part is exposed outside the groove 512. The ball rolls in the groove 512, and the part exposed in the groove 512 drives the slide groove 531 on the locking member 530 to move.

[0053] In this invention, the locking member 530 can be directly engaged with the traveling wheel to achieve drive. For example, in one example of this invention, the traveling wheel is rotatably mounted on the vehicle body, and a clutch engagement structure is directly provided between the locking member 530 and the traveling wheel. The clutch engagement structure includes a plurality of first engagement teeth 532 disposed on the locking member 530 and a plurality of second engagement teeth 552 disposed on the traveling wheel. The locking member 530 switches between an unlocked position and a locked position under the action of the driving member 510. When the locking member 530 is in the locked position, the plurality of first engagement teeth 532 and the plurality of second engagement teeth 552 are engaged to drive the traveling wheel to rotate. When the locking member 530 is in the unlocked position, the plurality of first engagement teeth 532 and the plurality of second engagement teeth 552 are separated.

[0054] Although drive can be achieved by directly engaging the locking element 530 with the travel wheel, it is preferable to refer to [the following text is missing from the original] Figures 2 to 4In one example of the present invention, the automatic unlocking drive device 500 further includes a power output component 550. The power output component 550 is mounted on the drive shaft 410 of the locking component 530 facing the traveling wheel and is rotatable relative to the drive shaft 410. One side of the power output component 550 abuts against the end face 517 of the drive component 510, and the other side is axially fixed by a washer 560 and a shaft retaining ring 570. A clutch engagement structure is provided between the output component and the locking component 530, and a drive structure is provided between the output component and the traveling wheel. The clutch engagement structure includes a plurality of first engagement teeth 532 disposed on the locking component 530 and a plurality of second engagement teeth 552 disposed on the power output component 550. When the locking component 530 is in the locked position, the plurality of first engagement teeth 532 and the plurality of second engagement teeth 552 are engaged to drive the traveling wheel to rotate. When the locking component 530 is in the unlocked position, the plurality of first engagement teeth 532 and the plurality of second engagement teeth 552 are disengaged.

[0055] In this invention, the drive structure can be any suitable form that drives the traveling wheels to rotate via the rotation of the power output component 550, such as multiple gear sets, belt drives, chain drives, etc. However, considering transmission efficiency, please refer to [the relevant documentation]. Figure 2 , Figure 3 , Figure 15 and Figure 16 In one example of the present invention, the drive structure includes a gear assembly, which includes a drive gear 554 disposed on the power output component 550 and a driven gear 300 disposed on the traveling wheel. The drive gear 554 and the driven gear 300 mesh to drive the traveling wheel to rotate. A traveling wheel cover 200 is disposed on the outside of the driven gear 300 to protect the drive gear 554 and the driven gear 300. When the power input to the transmission shaft 410 is released or the input torque of the transmission shaft 410 is less than the resistance torque of the traveling wheel, the first insertion tooth 532 and the second insertion tooth 552 are separated under the action of the elastic member.

[0056] Please see Figures 2 to 3In one example of the present invention, the locking member 530 drives the walking wheel through the power output member 550, the drive member 510 is provided on the transmission shaft 410, and the elastic member includes a first reset elastic body 520 and a second reset elastic body 540; the first reset elastic body 520 is installed between the locking member 530 and the drive member 510, and accumulates circumferential reset energy when the locking member 530 rotates relative to the drive member 510; the first reset elastic body 520 includes a torsion spring, and a cylindrical torsion spring mounting section 516 and a first reset elastic body 540 are provided on the side of the drive member 510 facing the locking member 530. The outer diameter of the torsion spring mounting section 516 matches the inner diameter of the torsion spring in the torsion spring slot 515. The locking member 530 has a first through hole 534, which is fitted onto the outside of the driving member 510, the torsion spring, and the transmission shaft 410, and can rotate relative to these components. A second torsion spring slot 535 is provided on the inner end face 551 of the first through hole 534. The torsion spring is fitted onto the torsion spring mounting section 516, with its first end 521 inserted into the first torsion spring slot 515 and its second end 522 inserted into the second torsion spring slot 535. A second reset elastic body 540 is installed between the power output member 550 and the locking member 530, and accumulates axial reset energy when the locking member 530 moves towards the power output member 550. The second reset elastic body 540 can be any suitable structural form that pushes the locking member 530 to move axially when restoring elastic deformation, such as a bent spring, a spring pad with a certain elasticity, etc. In this embodiment, the second reset elastic body 540 is a spring. The power output member 550 and the locking member 530 are respectively provided with spring mounting grooves. One end of the spring abuts against the spring mounting groove 553 on the power output member, and the other end of the spring abuts against the spring mounting groove 533 on the locking member. The transmission shaft 410 is provided with a corresponding spring mounting section 514. The outer diameter of the spring mounting section 514 is smaller than the inner diameter of the spring, and the spring is fitted on the spring mounting section 514.

[0057] In another example of the invention, the locking member 530 directly engages with the traveling wheel to achieve drive. The second reset elastic body 540 is installed between the traveling wheel and the locking member 530, and accumulates axial reset energy when the locking member 530 moves toward the traveling wheel. The second reset elastic body 540 can be any suitable structural form that can push the locking member 530 to move axially when restoring elastic deformation, such as a bent spring, a spring pad with a certain elasticity, etc. In this embodiment, the second reset elastic body 540 is a spring. The traveling wheel and the locking member 530 are respectively provided with spring mounting grooves. One end of the spring abuts against the spring mounting groove on the traveling wheel, and the other end of the spring abuts against the spring mounting groove 533 on the locking member.

[0058] Please see Figures 8 to 11 and Figures 2 to 3Considering that the inner and outer wheels rotate at different speeds when the driving wheels are manually operated, resulting in greater steering resistance, in order to achieve easy steering, in one example of the present invention, the driving component 510 is detachably mounted on the transmission shaft 410, and a steering speed regulating structure is provided between the transmission shaft 410 and the driving component 510. In one example of the present invention, the drive member 510 is provided with a second through hole 511, the transmission shaft 410 is inserted into the second through hole 511, and the steering speed regulating structure includes at least one clearance structure provided on the transmission shaft 410 and a corresponding protrusion 518 provided in the second through hole 511 corresponding to the clearance structure, as well as a circumferential gap provided between the clearance structure and the corresponding protrusion 518. When the steering device is used to operate the driving wheel to turn, the driving wheel rotates relative to the transmission shaft 410, so that the protrusion 518 is temporarily separated from the transmission shaft 410. During the process of the protrusion 518 being temporarily separated from the transmission shaft 410, the transmission shaft 410 cannot drive the driving wheel to rotate until the clearance structure rotates to the corresponding protrusion 518 again, so as to drive the drive member 510 to rotate again, thereby achieving the deceleration of the driving wheel when turning. The clearance structure can be any suitable structure that forms a gap between the drive shaft 410 and the protrusion 518, such as a groove. Preferably, in one example of the invention, the clearance structure is a flat surface 412 provided on the circumference 411 of the drive shaft 410, and a mating surface 519 is provided on the side of the protrusion 518 that meets the flat surface 412 when the drive shaft 410 rotates. A circumferential gap is provided between the flat surface 412 and the mating surface 519, so that the power assembly 400 can be normally driven to rotate when the flat surface 412 rotates past the circumferential gap and reaches the mating surface 519.

[0059] Please see Figures 8 to 11 In one example of the present invention, the power assembly 400 can drive the transmission shaft 410 to rotate in the forward and reverse directions. The protrusion 518 has mating surfaces 519 on both sides along the circumference 411. During the forward or reverse rotation of the transmission shaft 410, the flat surface 412 engages with the mating surfaces 519 on both sides of the protrusion 518, thereby driving the power assembly 400 to rotate in the forward or reverse direction.

[0060] Please see Figure 11 Considering the balance of force, preferably, in one example of the present invention, there are two (or more) avoidance structures, which are evenly distributed along the circumference 411 of the drive shaft 410. The number of protrusions 518 is the same as that of the avoidance structures, and they are evenly distributed along the circumference 411 on the inner wall of the through hole to form an approximately figure-eight shaped shaft hole. The protrusions and the avoidance structures on both sides have a maximum avoidance gap of Y°. The specific value of the avoidance gap Y can be set during the design and manufacturing process according to the diameter of the traveling wheel and the turning speed.

[0061] Please see Figures 2 to 7 and Figures 15 to 19The working principle of the automatic unlocking drive device 500 of the present invention is as follows: the self-propelled motor 432 is started, and the torque is transmitted to the transmission shaft 410 through the motor gear 433, the double gear 421, and the large gear 422. When the transmission shaft 410 drives the drive component 510 and the ball to rotate, the ball drives the locking component 530 to generate a force in the herringbone spiral groove. When the generated forces T2 and F1 are greater than the torsion of the torsion spring and the elasticity of the spring, the locking component 530 will rotate around the axis Z and move along the axis Z. When the distance between the locking component 530 and the power output component 550 moves from N1 to N2, the first insertion tooth 532 of the locking component 530 and the second insertion tooth 552 of the power output component 550 mesh, and the transmission shaft 410 drives the power output component 550 to rotate synchronously, realizing the self-propelled function of the device. When the torque and axial force input to the self-propelled motor 432 or drive shaft 410 are less than the force of the torsion spring and the spring restoring deformation, the locking member 530, under the action of the torsion of the torsion spring and the elasticity of the spring, has its herringbone groove 512 pressing against the ball. The locking member 530 produces the opposite movement to when it is driven by the self-propelled motor 432, that is, the locking member 530 rotates and moves in the opposite direction around axis Z. The distance between the locking member 530 and the power output member 550 moves from N2 to N1. The first insertion tooth 532 of the locking member 530 and the second insertion tooth 552 of the power output member 550 disengage. The power output member 550 disengages from the drive shaft 410, and the traveling wheel 100 can rotate freely relative to the power assembly 400.

[0062] It should be noted that if there is no elastic element in this invention, the locking element can be switched between the first and second positions by the bidirectional rotation of the power component 400. While this allows for unlocking between the drive shaft and the driving wheel through bidirectional drive of the same power component 400, it does not enable automatic unlocking via the elastic element without any external force input. In this case, compared to the embodiments described above, the drive device includes a drive shaft 410 and a locking element 530, but does not include an elastic element (i.e., it does not include the first reset elastic body 520 and the second reset elastic body 540). The drive shaft 410 is connected to the power assembly 400; the locking member 530 is mounted on the drive shaft 410 and has a first position, a second position, and a third position; wherein, the power assembly 400 drives the locking member to switch between the first position, the second position, and the third position; when the locking member 530 is in the first position, the power assembly 400 drives the traveling wheel to rotate in the forward direction; when the locking member 530 is in the second position, the power assembly 400 drives the traveling wheel to rotate in the reverse direction; when the locking member 530 is in the third position, the traveling wheel rotates freely relative to the drive shaft 410. This drive structure not only enables bidirectional drive but also allows the traveling wheel to rotate freely relative to the power assembly 400 when the moving part is in the third position, and also meets the user's need to unlock and disengage the traveling wheel from the drive unit's power shaft.

[0063] The automatic unlocking drive device of this invention enables the drive shaft to drive the walking wheels when the locking member is in the first and second positions. Furthermore, an elastic element allows the locking member to automatically reset to a third position, unlocking the drive shaft from the walking wheels, when the drive device is closed or the input torque is less than the resistance torque of the walking wheels. This satisfies various user drive connection needs. In this self-propelled device and lawnmower, the elastic element allows the locking member to automatically reset to the third position, unlocking the drive shaft from the walking wheels. This effectively improves the problem in existing self-propelled devices and lawnmowers where the walking wheels and drive shaft cannot rotate relative to each other when the power component is closed or the input torque of the drive shaft is less than the resistance torque of the walking wheels. Therefore, this invention effectively overcomes some practical problems in the prior art, thus having high utilization value and practical significance.

[0064] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. An automatic unlocking driving device for driving a walking wheel to walk, characterized in that, The automatic unlocking driving device comprises: a locking member mounted on a transmission shaft driven by a driving assembly and having a first position, a second position and a third position; wherein the first position and the second position are locking positions connecting the walking wheel with the transmission shaft, and the third position is an unlocking position disconnecting the walking wheel from the transmission shaft; a resilient member accumulating elastic potential energy when the locking member moves from the third position to the first position or the second position, and releasing the elastic potential energy to reset the locking member from the first position or the second position to the third position when the driving assembly is turned off or the input torque is less than the resistance torque of the walking wheel; wherein the transmission shaft is provided with a driving member, the driving member is provided with a rolling body, the locking member is provided with a sliding groove, and the transmission shaft drives the locking member to switch between the first position, the second position and the third position through the rolling of the rolling body in the sliding groove during rotation; the sliding groove comprises first and second helical grooves with opposite rotation directions, and one end of each of the first and second helical grooves intersects, and the other end of each of the first and second helical grooves extends to a side away from the walking wheel, respectively; when the rolling body reaches the intersection of the first and second helical grooves, the locking member is in the third position; when the rolling body reaches one end of the first helical groove away from the intersection, the locking member is in the first position; when the rolling body reaches one end of the second helical groove away from the intersection, the locking member is in the second position; the resilient member comprises a first reset elastic body, and the first reset elastic body comprises a torsional spring, one end of the torsional spring is mounted on the driving member, the other end of the torsional spring is mounted on the locking member, and the torsional spring accumulates circumferential reset energy when the locking member rotates relative to the driving member.

2. The automatic unlocking drive device according to claim 1, characterized by The driving member is detachably mounted on the transmission shaft, and a steering buffering structure is arranged between the transmission shaft and the driving member to buffer the force of the transmission shaft acting on the driving member during steering.

3. The automatic unlocking drive device according to claim 2, characterized in that The driving member is provided with a through hole, the transmission shaft is fitted into the through hole, the steering buffering structure comprises at least one avoiding structure arranged on the transmission shaft, a corresponding protruding portion arranged in the through hole corresponding to the avoiding structure, and a circumferential gap arranged between the avoiding structure and the corresponding protruding portion for buffering; the avoiding structure drives the driving member to rotate when it rotates to the corresponding protruding portion.

4. The automatic unlocking drive device according to claim 3, characterized by The avoiding structure is a flat surface arranged on the transmission shaft, and the side of the protruding portion facing the flat surface is provided with a matching surface when the transmission shaft rotates.

5. The automatic unlocking drive apparatus according to claim 1, characterized by The automatic unlocking driving device further comprises a power output member mounted on the transmission shaft on the side of the locking member facing the walking wheel and rotatable relative to the transmission shaft, a clutch plug-in structure is arranged between the output member and the locking member, and a driving structure is arranged between the output member and the walking wheel.

6. The automatic unlocking drive device according to claim 5, characterized in that The elastic member comprises a second reset elastic body; the second reset elastic body is installed between the walking wheel and the locking member and accumulates axial reset energy when the locking member moves to the walking wheel side.

7. The automatic unlocking drive device according to claim 6, characterized in that The second reset elastic body comprises a spring, one end of the spring abuts against the locking member, and the other end of the spring abuts against the power output member.

8. The automatic unlock drive apparatus according to claim 1, wherein The sliding grooves are even in number and are circumferentially and evenly arranged on the inner wall of the locking member, the number of the rolling bodies corresponds to the number of the sliding grooves, and the rolling bodies are circumferentially and evenly arranged on the driving member.

9. The automatic unlock drive apparatus according to claim 1, wherein The driving member is separately arranged from the transmission shaft, the driving member is sleeved on the transmission shaft and rotates with the transmission shaft.

10. The automatic unlocking drive apparatus according to claim 1, characterized by The driving member and the transmission shaft are in an integrated structure.

11. The automatic unlocking drive apparatus according to claim 1, characterized by The rolling bodies are rolling balls; the driving member is provided with grooves matched with the rolling balls, the rolling balls are partially accommodated in the grooves, and the parts exposed from the grooves roll along the sliding grooves.

12. The automatic unlocking drive apparatus according to claim 5, characterized by The clutch plug-in structure comprises a plurality of first plug-in teeth arranged on the locking member and a plurality of second plug-in teeth arranged on the power output member, and the plurality of first plug-in teeth and the plurality of second plug-in teeth are plugged when the locking member is in the locking position.

13. The automatic unlocking drive apparatus according to claim 5, characterized by The driving structure comprises a gear driving assembly.

14. The automatic unlocking drive apparatus according to claim 1, characterized by The locking member is provided with a first plug-in driving structure, the first plug-in driving structure drives a second plug-in driving structure arranged on the walking wheel, so as to rotate the walking wheel.

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