Brake assembly and lifting column with this brake assembly

Abstract

Brake assembly (2) comprising a connecting element (21), a mounting seat (22) and a self-locking spring (23), characterized in that the connecting element (21) comprises a first multi-seam section (211), a connecting section (212) and a second multi-seam section (213) arranged one after the other, wherein the connecting section (212) comprises a cylindrical surface and a limiting structure arranged on the cylindrical surface, wherein the first multi-seam section (211) extends through the mounting seat (22), and the mounting seat (22) is placed on the cylindrical surface on one side of the limiting structure and bears against the limiting structure, such that the connecting element (21) and the mounting seat (22) are rotatable relative to each other in the circumferential direction; and wherein the self-locking spring (23) is placed on the cylindrical surface on the other side of the limiting structure, with one end of the self-locking spring (23) being limited at the mounting seat (22).

Description

[0001] The present utility model relates to the technical field of lifting columns, in particular a brake assembly and a lifting column with this brake assembly.

[0002] Lifting columns comprise sleeve assemblies, drive gears, and motor drive units. The motor drives the drive gears to achieve the telescopic movement of the sleeve assembly. They are widely used in height-adjustable furniture and office equipment such as beds, chairs, tables, etc. Typically, lifting columns tend to slip after the motor stops due to the load, compromising user safety and normal use. This necessitates that lifting columns possess a certain self-locking force.

[0003] To address the aforementioned problem, research revealed that CN 1 06966345A discloses an extendable drive assembly and a lifting column in which a drive device is connected to a drive spindle (i.e., a fully threaded spindle). The drive spindle is mounted to a mounting plate by means of a fourth bearing placed on its upper part to achieve axial positioning between the drive spindle and the mounting plate. A mounting seat is attached to the end of the drive spindle, to which a torsion spring is attached. The torsion spring engages with the mounting plate via pins. When the drive spindle rotates, the mounting seat and the torsion spring can rotate with it. During the lowering of the lifting column, the torsion spring can exert a torsional force on the drive spindle, thus providing a self-locking function for the drive spindle when no force is applied.However, this solution still has significant shortcomings: 1) Due to the load on the lifting column, the drive spindle is extremely susceptible to bending deformation after absorbing axial forces, especially at maximum stroke, which impairs straightness. During operation of the lifting column, the oscillation of the drive spindle easily leads to vibrations of the lifting column, with the torsion spring oscillating along with the drive spindle and the self-locking force becoming unstable; 2) The self-locking force of the lifting column can only be measured after complete assembly. If the self-locking force value does not meet the requirements, the lifting column must be disassembled to replace or adjust the self-locking spring, which is extremely impractical.

[0004] CN208532163U discloses a drive device and a lifting column. To increase the self-locking force of the entire drive device, a first brake torsion spring is arranged on the drive spindle (i.e., a fully threaded spindle) and a second brake torsion spring is arranged on the hollow shaft (i.e., a hollow threaded spindle). This solution has the same disadvantages as CN106966345A, namely: 1) the structure of this solution is complex and the installation impractical; 2) due to the arrangement of two brake torsion springs with differing resistance values, this can also lead to vibrations of the lifting column.

[0005] To solve the aforementioned technical problems, the present utility model aims to provide a brake assembly whose self-locking force value can be determined before assembly and which exhibits high self-locking stability after installation in the lifting column.

[0006] Another objective is to provide a lifting column with the aforementioned brake assembly.

[0007] To achieve the aforementioned objectives, the present utility model employs a solution according to independent claim 1. The dependent claims relate to further developments of this solution.

[0008] The first aspect provides a brake assembly comprising a connecting element, a mounting seat, and a self-locking spring, wherein the connecting element comprises a first splined section, a connecting section, and a second splined section arranged sequentially, wherein the connecting section comprises a cylindrical surface and a limiting structure arranged on the cylindrical surface, the first splined section passing through the mounting seat, and the mounting seat being placed on the cylindrical surface at one side of the limiting structure and bearing against the limiting structure, such that the connecting element and the mounting seat are rotatable circumferentially relative to each other; and wherein the self-locking spring is placed on the cylindrical surface at the other side of the limiting structure, with one end of the self-locking spring being limited at the mounting seat.In use, the self-locking spring is first inserted from the side of the first splined section. The self-locking spring penetrates the first splined section and rests on the second cylindrical surface. Subsequently, the mounting seat is inserted from the side of the first splined section. The mounting seat rests on the first cylindrical section and engages the self-locking spring with the mounting seat, with the connecting element, mounting seat, and self-locking spring forming an integrated unit.

[0009] The brake assembly not only allows its self-locking force to be determined before assembly, but also, by installing it after this determination, the self-locking force values ​​of lifting columns from the same batch can be standardized. This effectively prevents vibrations between different lifting columns due to varying self-locking force values ​​when two or more lifting columns are operating simultaneously. Furthermore, when used in lifting columns, the mounting seat can limit the connecting element longitudinally, effectively preventing bending or oscillation of the connecting element. The self-locking spring engages with the mounting seat to improve the stability and consistency of the lifting column's self-locking performance.

[0010] According to one embodiment, the solution for facilitating quick assembly of the mounting seat from the side of the first splined section comprises a first cylindrical surface and a second cylindrical surface, wherein the outer diameter of the first cylindrical surface is smaller than the outer diameter of the second cylindrical surface, wherein the limiting structure is a first limiting step surface located at the junction between the first cylindrical surface and the second cylindrical surface, wherein the mounting seat is placed on the first cylindrical surface and the self-locking spring is placed on the second cylindrical surface. According to one embodiment, a second limiting step surface is formed between the second cylindrical surface and the second splined section, wherein the self-locking spring is limited between the mounting seat and the second limiting step surface.

[0011] According to one embodiment, the mounting seat has a mounting bore along the central axis, wherein an arcuate surface is formed circumferentially on the inside of the mounting bore, which extends outwards and forms a step-shaped projection; wherein a projecting circular platform is formed around the outside of the mounting bore; wherein the inner wall of the projecting circular platform abuts the first cylindrical surface and the step-shaped projection abuts the boundary step surface.

[0012] It should be explained that the inside and outside of the mounting bore represent relative positional relationships along the axis of the mounting bore. The projecting circular platform rests against the first cylindrical surface, thereby increasing the contact area between the two and ensuring longitudinal concentricity between the fastener and the mounting seat. The stepped projection rests against the limiting step surface, with the arc-shaped surface design reducing the contact area between the mounting seat and the limiting step surface. Simultaneously, the stepped projection and the limiting step surface form a line or even point contact, thus reducing the frictional force between the mounting seat and the fastener in the transverse direction and effectively minimizing engine power losses.

[0013] According to one embodiment, a support plate is formed around the stepped projection, wherein the end face height of the support plate does not exceed the end face height of the stepped projection, thereby increasing the strength of the stepped projection.

[0014] According to one embodiment, the limiting structure is a projection arranged on the cylindrical surface, wherein the projection is located near the first multi-wedge section.

[0015] According to one embodiment, a mounting bore is formed in the mounting seat along the central axis, wherein an arcuate surface is formed circumferentially on the inside of the mounting bore, the arcuate surface extending outwards forming a step-shaped projection; wherein a projecting circular platform is formed around the outside of the mounting bore; wherein the step-shaped projection abuts the shoulder.

[0016] According to one embodiment, the mounting seat has several circumferential walls, wherein at least one of the circumferential walls is provided with an outer collar at its upper edge and at least one of the circumferential walls has an undercut.

[0017] According to one embodiment, to ensure the relative rest position between the self-locking spring and the mounting seat, a limiting groove is further arranged at the angular point between two adjacent circumferential walls, wherein the self-locking spring protrudes outwards to form a bending hook, and which engages in the limiting groove.

[0018] According to one embodiment, the mounting seat has four circumferential walls, wherein the upper edge edges of each pair of opposing circumferential walls are provided with outer collars and the other pair of opposing circumferential walls are provided with undercuts.

[0019] According to one embodiment, an additional deflection groove is formed on the circumferential wall provided with the undercut, wherein the undercut is arranged obliquely upwards along the lower edge of the deflection groove.

[0020] According to one embodiment, the aforementioned circular platform has a height of 0.5–1.5 mm and a thickness of 0.5–1.5 mm. The arc surface has, in particular, a curvature of 1–3 mm, and the stepped projection has, in particular, a height of 0.1–0.3 mm.

[0021] According to one embodiment, the mounting seat has several circumferential walls, with at least one of the circumferential walls being provided with an outer collar at its upper edge and at least one of the circumferential walls being provided with an undercut. The mounting housing is provided with a mounting bore adapted to the outer shape of the circumferential wall, and the undercut returns to its original position after being pressed into the mounting bore and is firmly locked to the mounting housing. The circumferential wall ensures the stability of the mounting seat after installation, the outer collar serves to limit its position, the undercut allows for further fastening after installation, and the mounting bore serves for connecting the fastener.

[0022] The present utility model provides, in a second aspect, a lifting column comprising a mounting housing, an inner tube assembly, an outer tube assembly, a round tube, a threaded spindle, and a brake assembly according to the first aspect, wherein the mounting seat of the brake assembly engages with the mounting housing. The inner tube assembly is fixedly connected to the mounting housing, the round tube is arranged within the inner tube assembly, one end of the round tube is connected to the brake assembly, a spindle nut is fixedly attached to the other end of the round tube, the spindle nut is fixedly connected to the inner tube assembly, one end of the threaded spindle penetrates the spindle nut and is located inside the round tube, and the other end of the threaded spindle is fixedly connected to the outer tube assembly.

[0023] The brake assembly comprises a connecting element, a mounting seat, and a self-locking spring. The connecting element comprises a first splined section, a connecting section, and a second splined section arranged sequentially. The connecting section comprises a cylindrical surface and a limiting structure. The mounting seat is placed on the cylindrical surface at one side of the limiting structure and rests against said limiting structure, allowing the connecting element and the mounting seat to rotate circumferentially relative to each other. The self-locking spring is placed on the cylindrical surface at the other side of the limiting structure, with one end of the self-locking spring being limited by the mounting seat.

[0024] According to any embodiment, the limiting structure is a projection located on the cylindrical surface, wherein the projection is arranged near the first multi-wedge section; the self-locking spring is limited between the projection and the end face of the round tube.

[0025] Compared to the prior art, the advantageous effects of the present utility model are one or more of the following: (1) In the proposed brake assembly, the mounting seat is supported against the limiting structure of the connecting element, allowing its self-locking force value (numerical value) to be determined before assembly. Installation after determination can ensure that the self-locking force values ​​of lifting columns from the same batch become uniform. When two or more lifting columns are operated simultaneously, vibrations between different lifting columns due to inconsistent self-locking force values ​​can be effectively avoided. (2) When used in the proposed lifting column, the self-locking spring is mounted on the connecting element. Compared to mounting the self-locking spring on the threaded spindle, the connecting element is not axially affected by alternating load forces; therefore, the connecting element does not tend to bend or easily wobble, resulting in a more uniform self-locking force. (3) When used in the proposed lifting column, the connecting element in the brake assembly only transmits torque and does not absorb any axial force, so that the connecting element is not easily damaged or deformed and the self-locking spring is not easily unstable, so that the self-locking force value of the brake assembly is not easily disturbed by external forces and the lifting column has a uniform self-locking force and stable operating performance.

[0026] The technical solution and its context are described in more detail below with reference to the figures and exemplary embodiments. However, it should be understood that these figures are designed for illustrative purposes only and therefore do not serve to limit the scope of protection of this utility model. Furthermore, unless otherwise stated, these drawings are intended solely to conceptually illustrate the structural designs described herein and need not necessarily be drawn to scale. Fig. Figure 1 is a schematic structural view of the brake assembly according to embodiment 1 of the present utility model; Fig. Figure 2 is a sectional view of the brake assembly according to embodiment 1 of the present utility model; Fig. Figure 3 is a schematic structural view of the connecting element of the brake assembly according to embodiment 1 of the present utility model; Fig. Figure 4 is a schematic structural view of the self-locking spring of the brake assembly according to embodiment 1 of the present utility model; Fig. Figure 5 is a schematic structural view of the mounting seat of the brake assembly according to embodiment 1 of the present utility model from one angle; Fig. Figure 6 is a schematic structural view of the mounting seat of the brake assembly according to embodiment 1 of the present utility model from an alternative viewpoint; Fig. Figure 7 is a schematic front view of the structure of the mounting seat of the brake assembly according to embodiment 1 according to the present utility model; Fig. Figure 8 is a schematic sectional view of the structure of the mounting seat of the brake assembly according to embodiment 1 of the present utility model; Fig. Figure 9 is a schematic structural view of the lifting column of the present utility model with the brake assembly mounted according to embodiment 1; Fig. Figure 10 is a schematic structural view of the connecting element of the brake assembly according to embodiment 2 of the present utility model; Fig. Figure 11 shows a schematic structural representation of the lifting column according to the present utility model with the brake assembly mounted from embodiment 2.

[0027] The present disclosure can be more easily understood by referring to the following description in conjunction with the drawings and examples, all of which form an integral part of the present disclosure. It is understood that the present disclosure is not limited to the specific products, processes, conditions, or parameters described and / or illustrated herein. Furthermore, the terms used herein serve only to illustrate certain embodiments and are not intended to be limiting unless otherwise stated.

[0028] It should also be understood that, for the sake of clarity, certain features of the present disclosure may be described herein in the context of separate embodiments, but may also be provided in combination within a single embodiment. That is to say, unless obviously incompatible or expressly excluded, each individual embodiment is considered to be combinable with every other embodiment, and this combination is regarded as a further distinct embodiment. Conversely, for the sake of clarity, various features of the present disclosure that are described in the context of a single embodiment may also be provided individually or in any subcombination.Finally, although specific embodiments can be described as part of a series of steps or as part of more general structures, each step or substructure can also be considered an independent embodiment.

[0029] Unless otherwise specified, each individual element in the list and each combination of individual elements in that list is to be understood as a different embodiment. For example, a list of embodiments presented as "A, B or C" is to be interpreted as including embodiments "A", "B", "C", "A or B", "A or C", "B or C", or "A, B or C".

[0030] In the present revelation, the singular forms of the articles "a," "an," and "the" also include corresponding plural references, and references to specific numerical values ​​include at least that specific value, unless the context clearly indicates otherwise. Therefore, for example, a reference to "substance" is a reference to at least one such substance and its equivalents.

[0031] Terms containing ordinal numbers such as "first" and "second" may be used to explain different components or fluids; however, these components and fluids are not limited by these terms. Therefore, these terms merely serve to distinguish this component / fluid from another component / fluid without deviating from the teachings of the present disclosure.

[0032] When items are described using linking terms such as "...and / or...", the description should be understood to include each of the associated listed items as well as all combinations of one or more of them.

[0033] In general, the use of the term "approximately" indicates approximate values ​​that may vary according to the desired properties achieved by the disclosed subject matter and are interpreted in a function-based, context-dependent manner. Therefore, the person skilled in the art will be able to interpret a certain degree of deviation on a case-by-case basis. In some cases, the number of significant figures used when specifying particular values ​​may be a representative technique for determining the permissible deviation by the term "approximately". In other cases, a gradation in a series of values ​​may be used to determine the range of permissible deviation by the term "approximately". Furthermore, all ranges in the present disclosure, including and combining them, are available, and reference to values ​​specified in the range includes any value within that range.Unless otherwise defined, all technical and scientific terms used in this document have the same meaning as they are normally understood by persons skilled in the technical field of the present utility model. The terms and / or used in this document include any and all combinations of one or more related items listed. Example 1

[0034] As in Fig. 1 and Fig. As shown in Figure 2, the brake assembly 2 of this embodiment comprises a connecting element 21, a mounting seat 22 and a self-locking spring 23.

[0035] This includes, as in Fig. Figure 3 shows the connecting element 21 comprising a first multi-wedge section 211, a connecting section 212, and a second multi-wedge section 213, arranged successively. The connecting section 212 includes a cylindrical surface and a boundary structure. The cylindrical surface comprises a first cylindrical surface 2121 and a second cylindrical surface 2122, with the outer diameters of the first cylindrical surface 2121, the second cylindrical surface 2122, and the second multi-wedge section 213 increasing successively. The boundary structure is a first boundary step surface 2123 located at the junction between the first cylindrical surface 2121 and the second cylindrical surface 2122.At the junction between the second cylindrical surface 2122 and the second multi-wedge section 213, a second limiting step surface 2124 is formed, wherein the self-locking spring 23 is placed on the second cylindrical surface 2122, the mounting seat 22 is placed on the first cylindrical surface 2121 and engages with the self-locking spring 23.

[0036] In use, the self-locking spring 23 is first mounted from the side of the first multi-seam section 211, then the mounting seat 22 is mounted from the side of the first multi-seam section 211, whereby the self-locking spring 23 is confined between the mounting seat 22 and the second limiting step surface 2124 and is brought into engagement with the mounting seat 22 in such a way that the connecting element 21, the mounting seat 22 and the self-locking spring 23 form an integral assembly.

[0037] The structural design described above makes it possible to determine the self-locking force of the brake assembly before installation. Following this determination, installation ensures that the self-locking force values ​​of lifting columns from the same batch are aligned. This effectively prevents vibrations between different lifting columns with varying self-locking force values ​​when two or more lifting columns are operating simultaneously.

[0038] As in the Fig. 2, Fig. 5 and Fig. As shown in Figure 6, the mounting seat 22 has a mounting bore 221 along its central axis, with an arcuate surface 2211 formed on the inside around the mounting bore 221, extending outwards and forming a stepped projection 2212. A projecting circular platform 2213 is formed around the outside of the mounting bore 221. The inside and outside of the mounting bore 221 are in a relative positional relationship along the axis of the mounting bore 221.

[0039] The inner wall of the projecting circular platform 2213 rests against the first cylindrical surface 2121, thereby increasing the contact area between the two and ensuring longitudinal concentricity between the connecting element 21 and the mounting seat 22. The stepped projection 2212 bears against the limiting step surface 2123, the design of the arcuate surface 2211 reducing the contact area between the mounting seat 22 and the limiting step surface 2123, while simultaneously the stepped projection 2212 and the limiting step surface 2123 form a line contact or even a point contact, as shown in Fig. 2 shown, which reduces the frictional force between mounting seat 22 and connecting element 21 in the transverse direction and effectively reduces the power loss of the motor.

[0040] Furthermore, as in Fig. 2 shown, for simplified assembly of the mounting seat 22 from the side of the first multi-seam section 211, the inner diameter of the mounting bore 221 is larger than the outer diameter of the first multi-seam section 211.

[0041] With reference to Fig. 5 To increase the strength of the stepped projection 2212, support plates 2214 are formed around the stepped projection 2212, wherein the support plates 2214 are arranged radially distributed in the circumferential direction, and the end face height of the support plates 2214 does not exceed the end face height of the stepped projection 2212 in order to avoid interference of movement between the support plates 2214 and the boundary step surface 2123.

[0042] The connecting element 21 in this embodiment is fully press-molded, wherein the height of the projecting circular platform 2213 is 0.5 mm, the thickness is 1 mm, and simultaneously the corresponding length of the connecting element is increased, the change in length of the connecting element resulting in a slightly longer stroke; and the curvature of the arcuate surface 2211 is 1.5 mm, the height of the stepped projection 2212 is 0.2 mm, in order to achieve point contact and reduce the frictional force. To ensure that the self-locking spring 23 is stationary relative to the mounting seat 22, as in Fig. 4 and Fig. As shown in Figure 5, a limiting groove 2224 is provided at the angle between two adjacent circumferential walls 222, wherein the self-locking spring 23 projects outwards to form a bending hook 231, the bending hook 231 engaging in the limiting groove 2224.

[0043] Preferably, as in the Fig. 5, Fig. 6, Fig. 7 to Fig. As shown in Figure 8, the mounting seat 22 has four circumferential walls 222, wherein the upper edges of each pair of opposing circumferential walls 222 are provided with outer collars 2221, and the other two opposing circumferential walls 222 are provided with undercuts 2222. Furthermore, a clearance groove 2223 is additionally formed on the circumferential wall 222 that is provided with the undercut 2222, wherein the undercut 2222 is arranged obliquely upwards along the lower edge of the clearance groove 2223.

[0044] As in Fig. As shown in Figure 9, this embodiment provides a lifting column comprising a mounting housing 1, an inner tube assembly 3, an outer tube assembly 4, a round tube 5, a threaded spindle 6, and a brake assembly 2, wherein the mounting seat 22 of the brake assembly 2 is engaged in the mounting housing 1. One end of the inner tube assembly 3 is fixedly connected to the mounting housing 1, the round tube 5 is arranged in the inner tube assembly 3, one end of the round tube 5 is connected to the mounting housing 1 via the brake assembly, a spindle nut 7 is fixedly attached to the other end of the round tube 5, the spindle nut 7 is fixedly connected to the other end of the inner tube assembly 3, one end of the threaded spindle 6 penetrates the spindle nut 7 and is located inside the round tube 5, the other end of the threaded spindle 6 is fixedly connected to the outer tube assembly 4.

[0045] Furthermore, the mounting housing 1 has a mounting bore adapted to the outer contour of the circumferential wall 222, whereby the undercut 2222 returns to its original position after press-fit insertion into the mounting bore and is clamped to the mounting housing 1. The circumferential wall 222 ensures the stability of the mounting seat 22 after assembly, the outer collar 2221 allows for easy position limitation, the undercut 2222 allows for further fixing after assembly, and the mounting bore enables the connection of the connecting element 21.

[0046] When the outer tube assembly 4 is loaded, the outer tube assembly 4 first transmits the force to the threaded spindle 6, then via the spindle nut 7 mounted on the threaded spindle 6 to the inner tube assembly 3 and the mounting housing 1, whereby the round tube 5 essentially does not absorb any axial force or load force, but merely transmits torque, whereby the connecting element 21 of the brake assembly 2 connected to the round tube 5 also does not absorb any axial force, thus the connecting element 21 is not easily damaged or deformed; the self-locking spring 23 is mounted on the connecting element 21, the connecting element 21 has small axial dimensions, so that no uneven self-locking force or failure of the self-locking force due to bending, oscillation or similar phenomena occurs;and the self-locking spring 23 does not tend to fluctuate, so that the self-locking force value of the brake assembly 2 is not easily disturbed by external forces, the self-locking force of the lifting column is uniform and the operating performance is stable.; Example 2

[0047] As in Fig. 10 and Fig. As shown in Figure 11, the brake assembly of this embodiment differs from embodiment 1 in that the limiting structure is a projection 2125 located on the cylinder surface, wherein the projection 2125 is arranged near the first multi-seam section 211. The self-locking spring 23 is limited between the projection 2125 and the end face of the round tube 5.

[0048] In this embodiment, the projecting circular platform 2213 of the mounting seat 22 aligns with the cylindrical surface, thereby increasing the contact area between the two and ensuring longitudinal concentricity between the connecting element 21 and the mounting seat 22. The stepped projection 2212 abuts the extension 2125, with the shape of the arcuate surface 2211 reducing the contact area between the mounting seat 22 and the extension 2125. Simultaneously, the stepped projection 2212 and the extension 2125 form a line contact or even a point contact, thus reducing the frictional force between the mounting seat 22 and the connecting element 21 in the transverse direction and effectively reducing the engine's power losses.

[0049] It is obvious to those skilled in the art that the present utility model is not limited to the details of the exemplary embodiments mentioned above, but that it can be implemented in other specific forms. Therefore, the exemplary embodiment should be considered exemplary and non-limiting from any point of view; the scope of protection of the present utility model is limited by the attached claims and not by the foregoing description. No reference numerals in the claims should be considered as limiting the claim in question. Reference symbol list 1 Mounting housing 2 Brake assembly 21 Connecting element 211 First multi-wedge section 212 Connecting section 2121 First cylindrical surface 2122 Second cylinder surface 2123 First boundary step area 2124 Second boundary step area 2125 Approach 213 Second multi-wedge section 22 assembly seat 221 Mounting hole 2211 arc area 2212 Stepped projection 2213 Outstanding circular platform 2214 Support plate 222 Perimeter wall 2221 Outer collar 2222 Undercut 2223 Evasive groove 2224 Limit groove 23 Self-locking spring 231 Bending hooks 3 Inner tube assembly 4 Outer pipe assembly 5 round tube 6 threaded spindle 7 Spindle nut QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 1 06966345A [0003, 0004] CN 208532163U

[0004]

Claims

[1] Brake assembly (2) comprising a connecting element (21), a mounting seat (22) and a self-locking spring (23), characterized by , that the connecting element (21) comprises a first multi-seam section (211), a connecting section (212) and a second multi-seam section (213) arranged sequentially, wherein the connecting section (212) comprises a cylindrical surface and a limiting structure arranged on the cylindrical surface, wherein the first multi-seam section (211) extends through the mounting seat (22), and the mounting seat (22) is placed on the cylindrical surface at one side of the limiting structure and bears against the limiting structure, such that the connecting element (21) and the mounting seat (22) are rotatable in the circumferential direction relative to each other; and wherein the self-locking spring (23) is placed on the cylindrical surface at the other side of the limiting structure, with one end of the self-locking spring (23) being limited at the mounting seat (22). [2] Brake assembly (2) according to claim 1, characterized by , that the cylindrical surface comprises a first cylindrical surface (2121) and a second cylindrical surface (2122), wherein the outer diameter of the first cylindrical surface (2121) is smaller than the outer diameter of the second cylindrical surface (2122), the boundary structure is designed as a first boundary step surface (2123) which is located at the connection point between the first cylindrical surface (2121) and the second cylindrical surface (2122), the mounting seat (22) is placed on the first cylindrical surface (2121) and the self-locking spring (23) is placed on the second cylindrical surface (2122). [3] Brake assembly (2) according to claim 2, characterized by , that a second limiting step surface (2124) is formed between the second cylindrical surface (2122) and the second multi-wedge section (213), wherein the self-locking spring (23) is limited between the mounting seat (22) and the second limiting step surface (2124). [4] Brake assembly (2) according to claim 2, characterized by , that the mounting seat (22) has a mounting bore (221) along the central axis, wherein an arcuate surface (2211) is formed circumferentially on the inside of the mounting bore (221), and the arcuate surface (2211) extends outwards to form a step-shaped projection (2212); wherein a projecting circular platform (2213) is formed around the outside of the mounting bore (221); wherein the inner wall of the projecting circular platform (2213) abuts the first cylindrical surface (2121), and the step-shaped projection (2212) abuts the boundary step surface (2123). [5] Brake assembly (2) according to claim 4, characterized by , that a support plate (2214) is formed around the stepped projection (2212), wherein the end face height of the support plate (2214) does not exceed the end face height of the stepped projection (2212). [6] Brake assembly (2) according to claim 1, characterized by, that the limiting structure is a projection (2125) provided on the cylindrical surface, wherein the projection (2125) is located near the first multi-wedge section (211). [7] Brake assembly (2) according to claim 6, characterized by , that a mounting bore (221) is formed in the mounting seat (22) along the central axis, wherein an arcuate surface (2211) is formed circumferentially on the inside of the mounting bore (221), and the arcuate surface (2211) extends outwards to form a step-shaped projection (2212); wherein a projecting circular platform (2213) is formed around the outside of the mounting bore (221), wherein the step-shaped projection (2212) abuts the shoulder (2125). [8] Brake assembly (2) according to any one of claims 1 to 7, characterized by, that the mounting seat (22) has several circumferential walls (222), wherein at least one of the circumferential walls (222) is provided with an outer collar (2221) at its upper edge and at least one of the circumferential walls (222) has an undercut (2222). [9] Brake assembly (2) according to claim 8, characterized by , that a limiting groove (2224) is arranged at the angle between two adjacent circumferential walls (222), wherein the self-locking spring (23) protrudes outwards to form a bending hook (231), and the bending hook (231) engages in the limiting groove (2224). [10] Brake assembly (2) according to claim 9, characterized by , that the mounting seat (22) has four circumferential walls (222), wherein the upper edge edges of each pair of opposing circumferential walls (222) are provided with an outer collar (2221) and the other pair of opposing circumferential walls (222) are provided with an undercut (2222). [11] Brake assembly (2) according to claim 10, characterized by , that an additional deflection groove (2223) is formed on the circumferential wall (222) provided with the undercut (2222), wherein the undercut (2222) is arranged obliquely upwards along the lower edge of the deflection groove (2223). [12] Brake assembly (2) according to claim 4 or 7, characterized by , that the projecting circular platform (2213) has a height of 0.5-1.5 mm and a thickness of 0.5-1.5 mm; the arc surface (2211) has a curvature of 1-3 mm, the stepped projection (2212) has a height of 0.1-0.3 mm. [13] Lifting column comprising a mounting housing (1), an inner tube assembly (3), an outer tube assembly (4), a brake assembly (2), a round tube (5) and a threaded spindle (6), wherein a mounting seat (22) of the brake assembly (2) engages with the mounting housing (1); the inner tube assembly (3) is fixedly connected to the mounting housing (1), the round tube (5) is arranged in the inner tube assembly (3), one end of the round tube (5) is connected to the brake assembly (2), the other end of the round tube (5) is fixedly connected to a spindle nut (7), the spindle nut (7) is fixedly connected to the inner tube assembly (3), one end of the threaded spindle (6) penetrates the spindle nut (7) and is located inside the round tube (5), the other end of the threaded spindle (6) is fixedly connected to the outer tube assembly (4); characterized by, that the connecting element (21) comprises a first multi-seam section (211), a connecting section (212) and a second multi-seam section (213) arranged sequentially, wherein the connecting section (212) comprises a cylindrical surface and a boundary structure, wherein the mounting seat (22) is placed on the cylindrical surface at one side of the boundary structure and bears against the boundary structure, such that the connecting element (21) and the mounting seat (22) are rotatable relative to each other in the circumferential direction; and wherein the self-locking spring (23) is placed on the cylindrical surface at the other side of the boundary structure, with one end of the self-locking spring (23) being bounded at the mounting seat (22). [14] Lifting column according to claim 13, characterized by , that the boundary structure is a projection (2125) provided on the cylindrical surface, wherein the projection (2125) is located near the first multi-wedge section (211). [15] Lifting column according to claim 14, characterized by , that the self-locking spring (23) is limited between the extension (2125) and the end face of the round tube (5).

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