CN216472002U

CN216472002U - Self-adaptive lifting mechanism and car lifting jack

Info

Publication number: CN216472002U
Application number: CN202122928273.0U
Authority: CN
Inventors: 黎莎; 闫颖辉
Original assignee: Beijing Railway Institute of Mechanical and Electrical Engineering Group Co Ltd
Current assignee: Beijing Railway Institute of Mechanical and Electrical Engineering Group Co Ltd
Priority date: 2021-11-26
Filing date: 2021-11-26
Publication date: 2022-05-10
Anticipated expiration: 2031-11-26

Abstract

The utility model belongs to the technical field of jacking equipment and discloses a self-adaptive lifting mechanism and a car lifting jack. Through setting up elastic support, when the unilateral unbalance loading of bearing subassembly, the lead screw can produce with the axis skew of bearing subassembly with the trend adaptively, has reduced the skew volume of the relative lead screw axis of bearing subassembly axis, has improved transmission efficiency.

Description

Self-adaptive lifting mechanism and car lifting jack

Technical Field

The utility model relates to the technical field of jacking equipment, in particular to a self-adaptive lifting mechanism and a car lifting jack.

Background

Jacking equipment is widely applied in the mechanical industry, and the core of the jacking equipment is a lifting mechanism capable of being driven. The lifting mechanism can support the mechanism to be jacked so as to enable a certain operation space to be formed below the mechanism to be jacked, and meanwhile, the supporting mechanism can stably descend to the original position.

For example, in the transportation industry, vehicles are serviced periodically. When the transportation vehicle enters a workshop for maintenance, the vehicle body needs to be supported by the vehicle lifting jack so as to carry out maintenance operation on the locomotive vehicle. The lifting mechanism of the car lifting jack comprises a vertically arranged lead screw and a nut sleeved on the lead screw, and a bracket is connected to the nut. When jacking, support the bracket in the below of automobile body to the drive lead screw rotates around self axis, can make the nut drive the bracket and shift up, realizes the jacking to the automobile body. Because the lifted vehicle has a heavy weight, the load borne by the bracket and the nut is also large, and the car lifting jack is subjected to unilateral unbalance loading operation, the nut bears a large unbalance loading torque, and the axis of the nut deflects relative to the axis of the lead screw, so that the transmission is not smooth, and the friction and abrasion phenomena of the nut are serious.

In the prior art, the upper end of a screw rod is fixed on a shell of a car lifting jack through a thrust bearing and a radial bearing, and the other end of the screw rod is fixed on a base through a sliding type simple support mode. And the mode that simply supports provides the confining force for the lower extreme of lead screw on the horizontal direction for the lead screw produces comparatively serious bending deformation, produces great radial displacement promptly, has further aggravated the skew of the relative lead screw axis of nut axis, leads to nut wearing and tearing aggravation, and transmission efficiency is low, easily appears going up and down to crawl, phenomenon such as jamming, and car lifting jack working property is poor.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a self-adaptive lifting mechanism and a car lifting jack, wherein the lower end of a lead screw can move adaptively in the unilateral unbalance loading operation process, so that the inclination of the axis of a nut relative to the axis of the lead screw is effectively reduced, and the lifting transmission process is stable and reliable.

In order to achieve the purpose, the utility model adopts the following technical scheme:

in a first aspect, an adaptive lift mechanism is provided, comprising:

the mounting frame body comprises a top plate and a base which are arranged in parallel and at intervals;

the upper end of the screw rod is rotatably connected to the top plate;

the bearing component is sleeved on the lead screw and is in threaded connection with the lead screw;

the elastic support is connected to the base, a limiting hole is formed in the elastic support, the lower end of the lead screw rotatably penetrates through the limiting hole and can move along the axial direction of the limiting hole, and when the bearing assembly is subjected to unilateral unbalance loading, the lower end of the lead screw can move along the radial direction.

As a preferable scheme of the self-adaptive lifting mechanism provided by the utility model, the elastic support comprises a support component and an elastic component, the support component is connected to the base, an installation cavity is formed in the support component, the elastic component is arranged in the installation cavity, and the limiting hole is formed in the elastic component.

As a preferable scheme of the self-adaptive lifting mechanism provided by the utility model, the elastic component comprises a rigid shaft sleeve and an elastic bushing, the outer wall of the elastic bushing is matched with the wall of the installation cavity, the rigid shaft sleeve penetrates through the elastic bushing, and the inner cavity of the rigid shaft sleeve is the limiting hole.

As a preferred scheme of the self-adaptive lifting mechanism provided by the utility model, the rigid shaft sleeve comprises a copper sleeve, a plurality of through holes are arranged on the side wall of the copper sleeve at intervals, and a graphite structure is embedded in each through hole.

As a preferable scheme of the adaptive lifting mechanism provided by the present invention, the elastic bushing is a rubber bushing vulcanized on a cavity wall of the mounting cavity.

As a preferable scheme of the self-adaptive lifting mechanism provided by the utility model, the support assembly comprises a limiting sleeve, an inner cavity of the limiting sleeve is the installation cavity, the bottom end of the limiting sleeve is outwards protruded to form a flange, and the flange is detachably connected to the base.

As a preferable scheme of the self-adaptive lifting mechanism provided by the utility model, a limit ring is convexly arranged on the inner wall of the limit sleeve, the lower end of the lead screw penetrates through a ring opening of the limit ring and extends into the limit hole, a gap is formed between the outer wall of the lead screw and the inner wall of the limit ring, and the elastic component is limited between the limit ring and the base.

The adaptive lifting mechanism provided by the utility model preferably further comprises a plurality of fasteners, the plurality of fasteners are distributed at intervals along the circumferential direction of the flange, and each fastener penetrates through the flange and is in threaded connection with the base.

As a preferable scheme of the adaptive lifting mechanism provided by the present invention, the supporting assembly includes a lifting nut, a nut connecting seat, and a cantilever bracket, the lifting nut is connected to the lead screw by a thread, the cantilever bracket is connected to the lifting nut by the nut connecting seat, and the cantilever bracket is configured to be used for supporting the mechanism to be lifted.

In a second aspect, a car lifting jack is provided, which comprises the adaptive lifting mechanism.

The utility model has the beneficial effects that:

the utility model provides a self-adaptive lifting mechanism which comprises an installation frame body, a screw rod and a bearing component, wherein the installation frame body comprises a top plate and a base which are arranged in parallel at intervals, the upper end of the screw rod is rotatably connected to the top plate, the bearing component is sleeved on the screw rod and is in threaded connection with the screw rod, when a mechanism to be jacked needs to be jacked, the bearing component is supported on the bottom surface of the mechanism to be jacked, and then the screw rod is driven to rotate, so that the bearing component drives the mechanism to be jacked to ascend under the transmission action of the screw rod. Be provided with the elastic support on the base, seted up spacing hole on the elastic support, the lower extreme of lead screw is rotationally worn to locate spacing downthehole to make the lead screw rotate around self axis smoothly, and the axial displacement in spacing hole can be followed to the lower extreme of lead screw. When the unilateral unbalance loading operation of bearing subassembly, the bearing subassembly receives perpendicular decurrent pressure and the moment of flexure load of clockwise, and pressure and load transfer are to the lead screw on to make the lead screw along the axial micro-displacement in spacing hole, and the lower extreme of lead screw can be followed its radial production micro-displacement. That is to say, through setting up elastic support, when the unilateral unbalance loading of bearing subassembly, the lead screw can produce with the axis skew of bearing subassembly with the trend adaptively to effectively reduce the relative lead screw axis's of bearing subassembly axis deflection volume, alleviate the wearing and tearing when going up and down the transmission, improve transmission efficiency.

The utility model also provides a car lifting jack, which comprises the self-adaptive lifting mechanism, wherein the elastic support provides certain constraint for the lower end of the lead screw, and simultaneously can enable the lead screw to generate axis deviation with the same trend as that of the bearing assembly in a self-adaptive manner.

Drawings

Fig. 1 is a schematic structural diagram of an adaptive lifting mechanism according to an embodiment of the present invention;

FIG. 2 is a schematic view of the lower end of the lead screw engaged with the elastic support according to the embodiment of the present invention;

fig. 3 is a schematic diagram of a screw provided in an embodiment of the present invention, deformed in three support states.

In the figure:

1. installing a frame body; 2. a lead screw; 3. a holding assembly; 4. an elastic support;

11. a top plate; 12. A base; 13. A vertical plate;

31. a nut; 32. A nut connecting seat; 33. A cantilever bracket;

41. a seat assembly; 411. a limiting sleeve; 412. a flange; 413. a limiting ring;

42. an elastic component; 421. a rigid shaft sleeve; 4211. a limiting hole; 422. an elastic bushing.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not limiting of the utility model. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used based on the orientations and positional relationships shown in the drawings only for convenience of description and simplification of operation, and do not indicate or imply that the referred device or element must have a specific orientation, be configured and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

As shown in fig. 1, the present embodiment provides an adaptive lifting mechanism, which includes a mounting frame body 1, a screw rod 2, a supporting assembly 3, and an elastic support 4.

Referring to fig. 1, the mounting frame body 1 includes a top plate 11 and a base 12 which are parallel and spaced apart from each other. The upper end of the screw rod 2 is rotatably connected to the top plate 11. The bearing component 3 is sleeved on the screw rod 2 and is in threaded connection with the screw rod 2. When the mechanism to be jacked needs to be jacked up, the bearing component 3 is supported on the bottom surface of the mechanism to be jacked up. Subsequently, the screw rod 2 is driven to rotate, so that the bearing component 3 drives the mechanism to be jacked to ascend under the transmission action of the screw rod 2. Exemplarily, a driving motor is arranged on the top plate 11, a housing of the driving motor is fixedly mounted on the top plate 11, and an output end of the driving motor is in transmission connection with an upper end of the screw rod 2. During jacking, start driving motor, lead screw 2 can be rotatory around self axis, and simultaneously, bearing subassembly 3 shifts up 2 relative lead screws, treats that climbing mechanism shifts up under the jacking force effect of bearing subassembly 3 in step.

Optionally, the mounting bracket 1 further comprises a vertical plate 13. Roof 11 and base 12 all connect on riser 13, and riser 13 can play the effect of stable stay roof 11 and base 12.

Referring to fig. 1, the elastic support 4 is disposed on the base 12. The elastic support 4 is provided with a limiting hole 4211, the lower end of the lead screw 2 is rotatably arranged in the limiting hole 4211 in a penetrating manner, so that the lead screw 2 can smoothly rotate around the axis of the lead screw, and the lower end of the lead screw 2 can move along the axial direction of the limiting hole 4211. When the unilateral unbalance loading operation of bearing subassembly 3, bearing subassembly 3 receives perpendicular decurrent pressure and the moment of flexure load of clockwise, and pressure and load transfer are to lead screw 2 on to make lead screw 2 along spacing hole 4211's axial micro-displacement, and lead screw 2's lower extreme can be followed its radial production micro-displacement. That is to say, through setting up elastic support 4, when the unilateral unbalance loading of bearing subassembly 3, lead screw 2 can produce the axis skew with the trend with bearing subassembly 3 adaptively to effectively reduce the skew volume of the relative lead screw 2 axis of bearing subassembly 3 axis, alleviate the wearing and tearing when going up and down the transmission, improve transmission efficiency.

Alternatively, referring to fig. 1, elastomeric mount 4 includes a mount assembly 41 and an elastomeric assembly 42. The seat assembly 41 is fixedly attached to the base 12. The support assembly 41 is a rigid member with a mounting cavity defined therein. The elastic component 42 is arranged in the mounting cavity, and the limiting hole 4211 is arranged on the elastic component 42. Set up elastic component 42 in the installation cavity, can increase elastic component 42 and support component 41's area of contact to make support component 41 can provide stable supporting role for elastic component 42, thereby the restriction wears to locate the lead screw 2 lower extreme displacement in elastic component 42 and is excessive.

Referring to fig. 2, in the present embodiment, the elastic assembly 42 includes a rigid bushing 421 and an elastic bushing 422. The rigid bushing 421 and the elastic bushing 422 are both sleeve-shaped. The outer wall of the elastic bushing 422 is matched with the wall of the installation cavity, the rigid shaft sleeve 421 penetrates through the elastic bushing 422, and the inner cavity of the rigid shaft sleeve 421 is the limiting hole 4211. That is, the lower end of the screw 2 is rotatably inserted into the inner cavity of the rigid sleeve 421, and can move slightly in the vertical direction in the inner cavity. The elastic bushing 422 is clamped between the rigid shaft sleeve 421 and the inner wall of the support assembly 41, the inner wall of the elastic bushing 422 abuts against the outer wall of the rigid shaft sleeve 421, and the outer wall abuts against the wall of the installation cavity. When the bearing assembly 3 is biased on a single side, the elastic bushing 422 can be elastically deformed to allow the lower end of the screw rod 2 to move in compliance.

It is understood that in this embodiment, the rigid bushing 421 and the elastic bushing 422 are split. Of course, in other embodiments, the elastic assembly 42 may also only include the elastic bushing 422, that is, the lower end of the screw 2 is rotatably disposed through the inner cavity of the elastic bushing 422 and can move slightly in the vertical direction in the inner cavity. That is, in this case, the inner wall of the elastic bushing 422 abuts against the outer wall of the lower end of the screw 2, and the outer wall abuts against the wall of the installation chamber. When the supporting member 3 is biased to be loaded on one side, the elastic bushing 422 can also be elastically deformed to make the lower end of the screw rod 2 generate a compliant displacement.

Further, in the present embodiment, the elastic bushing 422 is a rubber bushing. Namely, the elastic bushing 422 is made of a rubber material. Preferably, the rubber bushing is vulcanized to the wall of the mounting cavity. When the rubber bushing is processed, an unformed rubber material is directly formed on the wall of the mounting cavity of the support assembly 41 through a vulcanization process and in combination with a mould pressing mode, so that the support assembly 41 and the rubber bushing form an integrated component, the rubber bushing can be prevented from moving when being subjected to adaptive compression deformation, and the stability is improved.

Optionally, in this embodiment, the rigid sleeve 421 includes a copper sleeve. The lateral wall interval of copper sheathing is provided with a plurality of through-holes, and all inlays in every through-hole and is equipped with the graphite structure. The copper sleeve has the advantages of good wear resistance, small friction coefficient and long service life. The lower extreme of lead screw 2 is worn to locate in the steel bushing, can rotate and along the axial displacement of steel bushing relative to the copper sheathing, inlays the graphite structure on the copper sheathing and can provide the lubrication action for between lead screw 2 and the copper sheathing, reduces the frictional resistance when lead screw 2 removes relative to the copper sheathing. In addition, when the copper bush slides relative to the elastic bushing 422 under the driving of the lead screw 2, the graphite structure can provide a lubricating effect between the copper bush and the elastic bushing 422, and reduce the frictional resistance when the copper bush slides relative to the elastic bushing 422. By embedding the graphite structure in the copper sleeve, the whole rigid shaft sleeve 421 has a self-lubricating function, lubricating grease does not need to be injected, and maintenance times are reduced. During processing, graphite can be sintered in the through hole of the copper sleeve.

Referring to fig. 2, the support assembly 41 optionally includes a limiting sleeve 411, and an inner cavity of the limiting sleeve 411 is the installation cavity. The bottom end of the position-limiting sleeve 411 is protruded outwards to form a flange 412, and the flange 412 is detachably connected to the base 12. The flange 412 is arranged on the outer wall of the limiting sleeve 411, so that the support assembly 41 can be conveniently installed and fixed on the base 12. The removable connection between the flange 412 and the base 12 may facilitate servicing or replacement of the seat assembly 41 and the spring assembly 42.

Illustratively, the flange 412 is coupled to the base 12 by a plurality of fasteners. A plurality of fasteners are distributed at intervals along the circumferential direction of the flange 412, and each fastener penetrates through the flange 412 and is in threaded connection with the base 12, so that the connection reliability is guaranteed, and looseness is avoided. The fasteners are preferably bolts.

Referring to fig. 2, a limiting ring 413 is protruded on the inner wall of the limiting sleeve 411. The lower end of the lead screw 2 passes through the ring opening of the limit ring 413 and extends into the limit hole 4211 (the inner cavity of the rigid shaft sleeve 421). The resilient member 42 is captured between the stop collar 413 and the base 12. In the embodiment, the elastic bushing 422 and the rigid bushing 421 are both limited between the limiting ring 413 and the base 12 to prevent the two from separating from the installation cavity. As can be seen from fig. 2, there is a gap between the outer wall of the screw 2 and the inner wall of the retainer ring 413, and this gap allows the screw 2 to have a certain adaptive displacement space, so as to avoid limiting the same-trend displacement of the screw 2 along with the supporting member 3. Meanwhile, the ring wall of the limiting ring 413 can play a limiting role, and excessive displacement of the lead screw 2 is avoided.

In this embodiment, the limiting sleeve 411, the flange 412 and the limiting ring 413 are integrally formed, that is, the whole support assembly 41 is an integrally formed component, which ensures that it has sufficient strength.

Referring to fig. 1, the supporting member 3 includes a lifting nut 31, a nut coupling base 32, and a cantilever bracket 33. The lifting nut 31 is sleeved on the screw rod 2 and is in threaded connection with the screw rod 2. The overhanging bracket 33 is connected with the lifting nut 31 through a nut connecting seat 32, and the overhanging bracket 33 is used for supporting a mechanism to be jacked, such as a vehicle body to be overhauled. As shown in FIG. 1, taking the lifting of the car body to be overhauled as an example, the load on the overhanging bracket 33 is the gravity load F of the car body to be overhauled_PThe gravity load F_PThe elevating nut 31 fitted over the lead screw 2 is subjected to a vertically downward pressure F and a clockwise bending moment M, so that the axis of the elevating nut 31 is deflected. Due to the arrangement of the elastic support 4, the screw rod 2 can generate axis deviation which is in the same trend with the lifting nut 31 in a self-adaptive manner, so that the deviation of the axis of the lifting nut 31 relative to the axis of the screw rod 2 is effectively reduced, the abrasion of the lifting nut 31 during transmission is reduced, and the transmission efficiency is improved.

In this embodiment, the stiffness of the elastomeric bushing 422 is determined based on finite element calculation analysis. After a finite element model of the lifting mechanism is established, a deformation and displacement schematic diagram of the screw rod 2 under three states of no supporting constraint at the lower end, movable simple support supporting constraint and elastic support 4 supporting constraint can be simulated. Referring to fig. 3, a curve a represents a displacement curve of the screw rod 2 when the lower end of the screw rod 2 is not constrained by a support. The displacement of the lowest end of the screw rod 2 is delta, and the a curve shows that when jacking operation is carried out under the condition that the lower end of the screw rod 2 lacks of supporting constraint, the dynamically changed load can cause excessive deflection of the axis of the lifting nut 31 and the axis of the screw rod 2, so that the transmission system is unstable, and the lifting process is unstable. And the curve b represents the displacement curve of the screw rod 2 when the lower end of the screw rod 2 is restrained by adopting a movable simple support. The mode of activity letter support provides the confining force for the lower extreme of lead screw 2 on the horizontal direction, and lead to 2 self to take place great bending deformation, has aggravated the deflection volume of the relative lead screw 2 axis of lifting nut 31 axis, easily appears going up and down to creep, card phenomenon such as dead. The curve c represents the displacement curve of the screw rod 2 when the lower end of the screw rod 2 is supported and restrained by the elastic support 4. The displacement of the lowest end of the screw rod 2 is reduced by gamma when no supporting constraint exists, at the moment, the deflection angle of the axis of the lifting nut 31 relative to the vertical direction under the action of deflection load is theta, and the deflection angle of the axis of the matched part of the screw rod 2 and the lifting nut 31 relative to the vertical direction is also close to theta, namely, the deflection amount of the axis of the lifting nut 31 relative to the axis of the screw rod 2 is obviously reduced, the abrasion of the lifting nut 31 can be reduced, and the transmission condition is improved. After the lower end of the screw 2 is constrained by the elastic support 4 in the finite element model and optimized, the maximum allowable displacement value of the lower end of the screw 2 can be determined, and further the rigidity value of the elastic bushing 422 can be determined.

This embodiment still provides a car lifting jack, contains foretell adaptive elevating system, and wherein, elastic support 4 can make 2 self-adaptations ground of lead screw produce with the axis skew of lift nut 31 trend when providing certain restraint for 2 lower extremes of lead screw, and this car lifting jack can adapt to dynamic change's automobile body load at jacking automobile body in-process, keeps reliable and stable's lifting motion, avoids appearing phenomenons such as lift crawl, jamming, improves car lifting jack working property.

It can be understood that the self-adaptive lifting mechanism provided by the embodiment is not limited to be used in the car lifting jack, and can be applied to other jacking equipment with unbalance loading, so that the effects of improving the transmission condition and ensuring the stability of the lifting process can be achieved.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Numerous obvious variations, adaptations and substitutions will occur to those skilled in the art without departing from the scope of the utility model. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An adaptive lift mechanism, comprising:

the mounting frame body (1) comprises a top plate (11) and a base (12) which are arranged in parallel and at intervals;

the upper end of the screw rod (2) is rotatably connected to the top plate (11);

the bearing component (3) is sleeved on the lead screw (2) and is in threaded connection with the lead screw (2);

the elastic support (4) is connected to the base (12), a limiting hole (4211) is formed in the elastic support (4), the lower end of the lead screw (2) rotatably penetrates through the limiting hole (4211) and can move along the axial direction of the limiting hole (4211), and when the bearing component (3) is subjected to unilateral unbalance loading, the lower end of the lead screw (2) can move along the radial direction.

2. The self-adaptive lifting mechanism according to claim 1, wherein the elastic support (4) comprises a support component (41) and an elastic component (42), the support component (41) is connected to the base (12), a mounting cavity is formed in the support component (41), the elastic component (42) is arranged in the mounting cavity, and the limiting hole (4211) is formed in the elastic component (42).

3. The self-adaptive lifting mechanism according to claim 2, wherein the elastic assembly (42) comprises a rigid shaft sleeve (421) and an elastic bushing (422), the outer wall of the elastic bushing (422) is matched with the wall of the installation cavity, the rigid shaft sleeve (421) is arranged in the elastic bushing (422) in a penetrating manner, and the inner cavity of the rigid shaft sleeve (421) is the limiting hole (4211).

4. The adaptive lifting mechanism according to claim 3, wherein the rigid shaft sleeve (421) comprises a copper sleeve, a plurality of through holes are arranged at intervals on the side wall of the copper sleeve, and a graphite structure is embedded in each through hole.

5. The adaptive lift mechanism of claim 3, wherein the elastomeric bushing (422) is a rubber bushing vulcanized to a wall of the mounting cavity.

6. The adaptive lifting mechanism according to claim 2, wherein the support assembly (41) comprises a limiting sleeve (411), an inner cavity of the limiting sleeve (411) is the installation cavity, a bottom end of the limiting sleeve (411) is protruded outwards to form a flange (412), and the flange (412) is detachably connected to the base (12).

7. The self-adaptive lifting mechanism according to claim 6, wherein a limiting ring (413) is convexly arranged on the inner wall of the limiting sleeve (411), the lower end of the lead screw (2) penetrates through the ring opening of the limiting ring (413) and extends into the limiting hole (4211), a gap exists between the outer wall of the lead screw (2) and the inner wall of the limiting ring (413), and the elastic component (42) is limited between the limiting ring (413) and the base (12).

8. The adaptive lift mechanism of claim 7, further comprising a plurality of fasteners spaced circumferentially about the flange (412), each fastener passing through the flange (412) and threadably engaging the base (12).

9. The adaptive lifting mechanism according to any one of claims 1 to 8, characterized in that the racking assembly (3) comprises a lifting nut (31), a nut connection seat (32), and a cantilever bracket (33), the lifting nut (31) being screwed to the lead screw (2), the cantilever bracket (33) being connected with the lifting nut (31) through the nut connection seat (32), the cantilever bracket (33) being configured for jacking the mechanism to be jacked.

10. A car lifting jack, characterized by comprising an adaptive lifting mechanism according to any one of claims 1 to 9.