Device for preventing rotation of a spindle nut of an electric actuator

Abstract

Device for preventing rotation of a spindle nut of an electric actuator, wherein the electric actuator comprises an actuator body (2) and the spindle nut (5), wherein the actuator body (2) has an inner connecting section (21) formed on its inside, and the spindle nut (5) has an outer connecting section (51) formed on its outside, wherein the device for preventing rotation of a spindle nut (5) of the electric actuator comprises: two rotation limiting elements (6) for arrangement between the actuator body (2) and the spindle nut (5), wherein the rotation limiting elements (6) are designed for connection with the spindle nut (5), wherein each of the rotation limiting elements (6) has a base wall (61), an outer connecting section (62) and an inner connecting section (63), wherein the base wall (61) has an outer surface (611) and an inner surface (612) which are arranged radially opposite each other, wherein the outer connecting section (62) is formed on the outer surface (611) of the base wall (61) and is designed for positive engagement with the inner connecting section (21) of the actuator body (2), and wherein the inner connecting section (63) is formed on the inner surface (612) of the base wall (61) and is designed for positive engagement with the outer connecting section (51) of the spindle nut (5).

Description

[0001] The disclosure relates to a device for preventing rotation, in particular a device for preventing rotation of a spindle nut of an electric actuator.

[0002] As in the Fig. 1 and Fig. Figure 2 shows an actuator disclosed in Japanese Patent Publication No. JP 6570114 B2, comprising a hollow housing 11, a spindle 12 arranged in the hollow housing 11, a ball-bearing threaded spindle 13 extending into the spindle 12, a cylindrical spindle nut receptacle 14 pushed onto the spindle 12, and a conventional rotation limiting element 15 engaging with an outer circumferential surface of the spindle nut receptacle 14. An inner wall of the hollow housing 11 is provided with a plurality of limiting grooves 111. The spindle 12 is adjustable forwards and backwards relative to the hollow housing 11, allowing it to protrude from or retract into the hollow housing 11. The spindle nut receptacle 14 has a plurality of engagement projections 141 spaced apart in the circumferential direction.The rotation limiting element 15 according to the prior art has a substantially C-shaped cross-section and comprises a main body 151, a plurality of connecting projections 152 formed around the perimeter and spaced apart from each other, a plurality of engagement grooves 153 formed in the connecting projections 152 and a plurality of limiting projections 154 formed around the perimeter and spaced apart from each other.

[0003] The engagement projections 141 of the spindle nut receiving element 14 can each engage with the engagement grooves 153 of the rotation limiting element 15 according to the prior art, and the limiting projections 154 of the rotation limiting element 15 according to the prior art can each engage with the limiting grooves 111 of the hollow housing 11, so that the effect of limiting the rotation of the spindle nut receiving element 14 is achieved.

[0004] Because the rotation limiting element 15 is C-shaped and formed in one piece according to the prior art, and has a circumference similar to that of the spindle nut receiving element 14, the rotation limiting element 15 must first be pulled upwards during assembly of the actuator, and the engagement grooves 153 must each be aligned with the engagement projections 141 of the spindle nut receiving element 14 in order to engage with them, so that the rotation limiting element 15 completely surrounds the spindle nut receiving element 14. Subsequently, the limiting projections 154 are each aligned with the limiting grooves 111 of the hollow housing 11 and inserted into them. Thus, the assembly of the actuator is relatively complicated and difficult to carry out.

[0005] Therefore, it is an object of the present disclosure to provide a device for preventing rotation of a spindle nut of an electric actuator, which can eliminate at least one of the disadvantages of the prior art.

[0006] According to one aspect of the disclosure, a device for preventing the rotation of the spindle nut of an electric actuator is provided. The electric actuator comprises an actuator body and a spindle nut. The actuator body has an inner connecting section formed on its inside, and the spindle nut has an outer connecting section formed on its outside. The device for preventing the rotation of the spindle nut of the electric actuator comprises two rotation limiting elements designed for arrangement between the actuator body and the spindle nut. The rotation limiting elements are designed for connection with the spindle nut. Each of the rotation limiting elements has a base wall, an outer connecting section, and an inner connecting section.The base wall has an outer surface and an inner surface arranged radially opposite each other. The outer connecting section of each of the rotation limiting elements is formed on the outer surface of the base wall and serves to engage positively with the inner connecting section of the actuator body. The inner connecting section of each of the rotation limiting elements is formed on the inner surface of the base wall and serves to engage positively with the outer connecting section of the spindle nut.

[0007] Further features and advantages of the disclosure will become clear from the following detailed description of embodiment(s) with reference to the accompanying drawings. It should be noted that various features may not be shown to scale. Fig. Figure 1 is a sectional view of an actuator with a rotation limiting element according to the prior art, which is disclosed in Japanese patent publication No. 6570114 B2. Fig. Figure 2 is a perspective view of the rotation limiting element of a state-of-the-art actuator. Fig. Figure 3 is a schematic sectional view of a device for preventing rotation of the spindle nut of an electric actuator according to an embodiment as disclosed herein. Fig. Figure 4 is a perspective exploded view of the embodiment and the electric actuator. Fig. Figure 5 is another perspective exploded view of the embodiment and the electric actuator from a different angle than in the Fig. 4. Fig. 6 is a sectional view along line VI-VI in the Fig. 3. Fig. Figure 7 is a perspective view of a rotation limiting element of the rotation lock according to the embodiment. Fig. 8 is a side view of the [image / description] in the Fig. 7 shown rotation limiting element. Fig. Figure 9 is a partial perspective view of the embodiment and the electric actuator. Fig. 10 shows a part of Fig. 3 in an enlarged view.

[0008] Before describing the revelation in more detail, it should be noted that, where deemed appropriate, reference signs or terminal parts of reference signs have been repeated in the figures to denote corresponding or equivalent elements which may optionally have similar properties.

[0009] It should be noted here that, for the purpose of clarifying the description, spatial relative terms such as "above", "below", "above", "on", "over", "downwards", "upwards", and the like may be used throughout the disclosure when referring to the features depicted in the drawings. These features may be oriented differently (e.g., rotated by 90 degrees or in other orientations), and the spatial reference terms used subsequently may be interpreted accordingly.

[0010] As in the Fig. Figures 3 to 5 show a device for preventing rotation of the spindle nut of an electric actuator according to an embodiment as disclosed herein. The electric actuator comprises an actuator body 2, a threaded spindle 3 arranged on the actuator body 2 and extending along an axis (X), a sensor 4 attached to the actuator body 2, and the spindle nut 5, which is pushed onto the threaded spindle 3 and installed or inserted into the actuator body 2. The actuator body 2 is an extruded aluminum body and defines a receiving space 20 extending along the axis (X).The actuator body 2 has an inner connecting section 21 formed on its inside, an outer fastening section 22 formed on its outside, and a fastening element 23 connected to the outer fastening section 22.

[0011] In this embodiment, the actuator body 2 is designed as a square body. The inner connecting section 21 has a plurality of recessed grooves 211 extending along the axis (X) and spaced apart from one another. The recessed grooves 211 are rectangular. The outer mounting section 22 has a plurality of grooves 221 spaced apart from one another and extending inwards towards the receiving space 20. The mounting element 23 extends along the axis (X) and is inserted into a selected groove 221. The threaded spindle 3 is arranged in and extends into the receiving space 20 and has an outer circumferential surface 31 that surrounds the axis (X). It can be seen that the outer circumferential surface 31 of the threaded spindle 3 is formed with an external thread (not shown in the drawings). The sensor 4 is arranged in one of the grooves 221.In this embodiment, the fastening element 23 is embedded in the groove 221 in which the sensor 4 is arranged, in order to fasten the sensor 4.

[0012] As in the Fig. As shown in Figures 4 to 6, the spindle nut 5 surrounds the axis (X), which is pushed onto the outer circumferential surface 31 of the threaded spindle 3. The spindle nut 5 has an outer circumferential surface 52 and an inner circumferential surface 53, which is radially opposite the outer circumferential surface 52 and faces the threaded spindle 3, respectively. The spindle nut 5 has an outer connecting section 51 formed on its outer surface. The outer connecting section 51 has a plurality of recessed holes 511, which are spaced apart from each other in the circumferential direction and extend from the outer circumferential surface 52 to the inner circumferential surface 53. In this embodiment, each of the recessed holes 511 is designed as an elliptical hole.

[0013] The device for preventing rotation of the spindle nut 5 of the electric actuator is arranged in the receiving space 20 and comprises two rotation limiting elements 6 and a plurality of magnetic elements 7. In this embodiment, the number of magnetic elements 7 is two, but the present disclosure is not limited to this example.

[0014] The rotation limiting elements 6 are designed to be attached to the outer circumferential surface 52 of the spindle nut 5 and to be arranged between the actuator body 2 and the spindle nut 5. The rotation limiting elements 6 are connected independently and individually to the outer circumferential surface 52 of the spindle nut 5 on two diametrically opposite sides of the outer circumferential surface 52. In this embodiment, the actuator body 2 defines a diagonal (L) that runs through two diagonal edges of the actuator body 2. The rotation limiting elements 6 are symmetrical with respect to the diagonal (L).

[0015] As in the Fig. As shown in Figures 7 to 9, each of the rotation limiting elements 6 defines a receiving opening 60 that faces or is opposite the outer circumferential surface 52 of the spindle nut 5, and this opening has a base wall 61, an outer connecting section 62, and an inner connecting section 63. The base wall 61 of each of the rotation limiting elements 6 has an outer surface 611 and an inner surface 612 that are arranged radially opposite each other, and further has two end edge surfaces 613 that are arranged at opposite ends of the rotation limiting element 6 along the axis (X), as well as a mounting opening 610 that extends radially through the outer surface 611 and the inner surface 612. In this embodiment, the base wall 61 of each of the rotation limiting elements 6 has a substantially C-shaped cross-section in a plane perpendicular to the axis (X).The end edge surfaces 613 of each of the rotation limiting elements 6 are spaced apart in a direction perpendicular to the diagonal (L) from the end edge surfaces 613 of another of the rotation limiting elements 6. For each of the rotation limiting elements 6, the mounting opening 610 is designed as a square opening and serves to attach a respective magnetic element 7. Each of the magnetic elements 7 is a magnet, and the sensor 4 is designed to detect the position of each of the magnetic elements 7.

[0016] It should be noted that, since the structures of the rotation limiting elements 6 and the structures of the magnetic elements 7 are identical, the following description refers only to one of the rotation limiting elements 6 and the associated magnetic element 7 attached to one of the rotation limiting elements 6. Because the magnetic element 7 is driven by the rotation limiting element 6 to move or be adjusted along the axis (X) together with it, the sensor 4 can detect the positions of the magnetic element 7 to obtain information about the axial adjustment of the spindle nut 5, thus making the embodiment relatively practical.It should be noted that in this embodiment the mounting opening 610 is designed as a through hole, but that in other embodiments the mounting opening 610 may be designed as a blind hole or another type of groove structure, as long as this can position the magnetic element 7 and secure its position.

[0017] The outer connecting section 62 is formed on the outer surface 611 of the base wall 61 and serves to engage with the inner connecting section 21 of the actuator body 2 by means of a positive fit. In this embodiment, the outer connecting section 62 projects from the outer surface 611 in a direction away from the inner surface 612 and has a plurality of projecting blocks 621, which are spaced apart from one another and each serve to engage in one of the recessed grooves 211. The number of projecting blocks 621 is equal to the number of recessed grooves 211 of the actuator body 2.

[0018] Each of the projecting blocks 621 of the outer connecting section 62 has a surface 622 radially spaced from the outer surface 611, two end surfaces 623 each connected to two opposite ends of the surface 622 along the axis (X), two side surfaces 624 extending along the axis (X) and each connected to the two opposite sides of the surface 622, an airflow slot 625 extending along the axis (X) and recessed from the surface 622, and a plurality of recesses 626 recessed from the surface 622 and spaced apart from one another. The airflow slot 625 is connected to the receiving chamber 20 to form a flow and has two opposite end sections, each formed in the end surfaces 623.The recessed sections 626 are spatially connected to the airflow slot 625, and the latter is connected to the receiving chamber 20 to form an airflow. Each of the recessed sections 626 extends from one of the side surfaces 624 to the airflow slot 625.

[0019] In this embodiment, the recessed structures of the airflow slot 625 and the recessed sections 626 form a plurality of gaps (not shown) between the outer connecting section 62 and the inner connecting section 21 of the actuator body 2 for each of the rotation limiting elements 6. In this way, the airflow generated during the movement of the threaded spindle 3 can be discharged or circulated through the gaps. The gaps can not only promote pressure equalization around the spindle nut 5, but also serve as a retention area for lubricating oil (or lubricant), thus preventing the plastic components of the embodiment from drying out due to lack of lubrication.

[0020] The inner connecting section 63 is formed on the inner surface 612 of the base wall 61 and serves to engage positively with the outer connecting section 51 of the spindle nut 5. In this embodiment, the inner connecting section 63 projects from the inner surface 612 in a direction away from the outer surface 611 and has a plurality of projecting ribs 631, which are spaced apart from each other in the circumferential direction and each serve to engage in the recessed holes 511. The number of projecting ribs 631 of the rotation limiting elements 6 is equal to the number of recessed holes 511 of the spindle nut 5, and the projecting ribs 631 are designed as elliptical projections whose shape is complementary to the recessed holes 511.

[0021] In this embodiment, the rotation limiting elements 6 are positioned on the spindle nut 5 in a double clamping arrangement due to the positive engagement of the projecting ribs 631 of the inner connecting section 63 of each rotation limiting element 6 into the recessed holes 511 of the spindle nut 5 and due to the positive engagement of the projecting blocks 621 of the outer connecting section 62 into the recessed grooves 211 of the actuator body 2. This clamping action occurs on both the inner surface 612 and the outer surface 611 of each rotation limiting element 6. In this way, rotation or displacement of the spindle nut 5 can be effectively prevented, and the overall structural stability is improved.

[0022] In this embodiment, the projecting ribs 631 are each oriented radially to the projecting blocks 621, but the present disclosure is not limited thereto. The projecting ribs 631 can alternate radially with the projecting blocks 621, as long as the rotation limiting element 6 can be securely connected to the spindle nut 5 and the actuator body 2.

[0023] It should be noted that in this embodiment, the outer connecting section 62 and the inner connecting section 63 are each designed as projections, and the inner connecting section 21 of the actuator body 2 and the outer connecting section 51 of the spindle nut 5 are each designed as recesses. In other variants, however, the structures of the outer connecting section 62 and the inner connecting section 63 can be designed as recesses, and the inner connecting section 21 and the outer connecting section 51 can be designed as projections, but are not limited to these configurations.

[0024] As in the Fig. 6, Fig. 9 and Fig. As shown in Figure 10, during assembly of the embodiment, the rotation limiting elements 6 are arranged such that they are opposite each other and secured along the diagonal (L) on the outer circumferential surface 52 of the spindle nut 5, so that the projecting ribs 631 are each inserted into the recessed holes 511. Subsequently, the projecting blocks 621 are aligned with the recessed grooves 211 of the actuator housing 2, thus completing the assembly process of the embodiment.

[0025] The advantages of the embodiment described above can be summarized as follows.

[0026] 1. Because the rotation limiting elements 6 are two independent structures, each connected to radially opposite sides of the spindle nut 5, this design offers better ease of assembly compared to the rotation limiting element 15 according to the prior art (see Fig. 1 and Fig. 2), which is a one-piece structure that completely surrounds the outer circumferential surface of the spindle nut receiving element 14 and is less easy to assemble. In this embodiment, a two-piece clamping or positive-locking arrangement can be realized by arranging the rotation limiting elements 6 on the two radially opposite sides of the spindle nut 5, thereby improving ease of assembly.

[0027] 2. In each of the rotation limiting elements 6, the projecting ribs 631 of the inner connecting section 63 serve to engage positively in the recessed holes 511 of the spindle nut 5, and the projecting blocks 621 of the outer connecting section 62 serve to engage positively in the recessed grooves 211 of the actuator body 2, so that the rotation limiting element 6 is positioned on the spindle nut 5 in a manner of double clamping or double positive locking, both on the inner surface 612 and on the outer surface 611 of the rotation limiting element 6. This not only effectively prevents the spindle nut 5 from being rotated or adjusted, but also significantly improves the overall structural stability.

[0028] 3. Due to the recessed structures of the airflow slot 625 and the recessed sections 626, which form the gap (not shown) between the outer connecting section 62 of the rotation limiting element 6 and the inner connecting section 21 of the actuator body 2, the airflow generated during the movement of the threaded spindle 3 can be discharged through or circulated within the gap. The gaps not only facilitate pressure equalization in the area around the spindle nut 5, but also serve as a retention area for lubricating oil, thus preventing the plastic components of the embodiment from drying out due to lack of lubrication.

[0029] 4. For each of the rotation limiting elements 6, the respective magnetic element 7 is driven by the rotation limiting element 6 to be adjusted together with it along the axis (X), and the sensor 4 can detect the position of the magnetic element 7 to obtain information about the axial adjustment of the spindle nut 5, thereby achieving relatively good practicality.

[0030] In the preceding description, numerous specific details have been provided for illustrative purposes, in order to provide a thorough understanding of the embodiment(s). However, it is obvious to a person skilled in the art that one or more other embodiments can be realized without some of these specific details. It should be noted that references in this description to "an embodiment," "an embodiment," an embodiment with a specific ordinal number, etc., mean that a particular feature, structure, or property may be included in the practical implementation of the disclosure.It should also be noted that in the description, various features are sometimes combined in a single embodiment, figure, or description to streamline the disclosure and facilitate understanding of different aspects of the invention; however, this does not mean that each of these features must be implemented in conjunction with all the other features. In other words, in each described embodiment, if the implementation of one or more features or special details does not interfere with the implementation of one or more other features or special details, the one or more features can be selected and implemented independently.It should also be noted that one or more features or special details from one embodiment may be implemented together with one or more features or special details from another embodiment in the implementation of the disclosure.

[0031] In summary, the disclosure relates to a device for preventing rotation of a spindle nut of an electric actuator, comprising an actuator body 2 and the spindle nut 5. The actuator body 2 has an inner connecting section 21, and the spindle nut 5 has an outer connecting section 51. The anti-rotation device comprises two rotation limiting elements 6, which are arranged between the actuator body 2 and the spindle nut 5 and connected to the spindle nut 5.Each of the rotation limiting elements 6 comprises a base wall 61 with an outer surface 611 and an inner surface 612, which are arranged radially opposite each other, wherein an outer connecting section 62 is formed on the outer surface 611 of the base wall 61 and engages with the inner connecting section 21 by engagement of projection and recess, and an inner connecting section 63 is formed on the inner surface 612 and engages with the outer connecting section 51 by engagement of projection and recess. 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] JP 6570114 B2

[0002] JP 6570114 B2

[0007]

Claims

[1] Device for preventing rotation of a spindle nut of an electric actuator, wherein the electric actuator comprises an actuator body (2) and the spindle nut (5), wherein the actuator body (2) has an inner connecting section (21) formed on its inside, and the spindle nut (5) has an outer connecting section (51) formed on its outside, wherein the device for preventing rotation of a spindle nut (5) of the electric actuator comprises: two rotation limiting elements (6) for arrangement between the actuator body (2) and the spindle nut (5), wherein the rotation limiting elements (6) are designed for connection with the spindle nut (5), wherein each of the rotation limiting elements (6) has a base wall (61), an outer connecting section (62) and an inner connecting section (63), wherein the base wall (61) has an outer surface (611) and an inner surface (612) which are arranged radially opposite each other, wherein the outer connecting section (62) is formed on the outer surface (611) of the base wall (61) and is designed for positive engagement with the inner connecting section (21) of the actuator body (2), and wherein the inner connecting section (63) is formed on the inner surface (612) of the base wall (61) and is designed for positive engagement with the outer connecting section (51) of the spindle nut (5). [2] Device for preventing rotation of the spindle nut of an electric actuator according to claim 1, wherein the outer connecting section (62) of each of the rotation limiting elements (6) projects from the outer surface (611). [3] Device for preventing rotation of the spindle nut of an electric actuator according to claim 1 or 2, wherein the inner connecting section (63) of each of the rotation limiting elements (6) projects from the inner surface (612). [4] Device for preventing rotation of the spindle nut of an electric actuator according to one of the preceding claims, wherein the inner connecting section (21) of the actuator body (2) has a plurality of spaced-apart recessed grooves (211), wherein the outer connecting section (62) of each of the rotation limiting elements (6) has a plurality of projecting blocks (621) which are spaced apart from each other and each engage in the recessed grooves (211), wherein the number of projecting blocks (621) of the rotation limiting elements (6) corresponds to the number of recessed grooves (211). [5] Device for preventing rotation of the spindle nut of an electric actuator according to claim 4, wherein the actuator body (2) defines a receiving space (20), wherein each of the protruding blocks (621) of the outer connecting section (62) of each of the rotation limiting elements (6) has a surface (622) which is spaced radially apart from the outer surface (611) and an airflow slot (625) which is recessed from the surface (622), wherein the airflow slot (625) extends along an axis (X) and is connected to the receiving space (20) to form a flow. [6] Device for preventing rotation of the spindle nut of an electric actuator according to claim 4, wherein the actuator body (2) defines a receiving space (20), wherein each of the protruding blocks (621) of the outer connecting section (62) of each of the rotation limiting elements (6) has a surface (622) which is radially spaced from the outer surface (611), and has a plurality of recesses (626) which are recessed from the surface (622), wherein the recesses (626) are designed to be connected to the receiving space (20) to form a flow. [7] Device for preventing rotation of the spindle nut of an electric actuator according to one of the preceding claims, wherein the outer connecting section (51) of the spindle nut (5) has a plurality of recessed holes (511) which are spaced apart from each other in the circumferential direction, wherein the inner connecting section (63) of each of the rotation limiting elements (6) has a plurality of projecting ribs (631) which are spaced apart from each other in the circumferential direction and each engage in the recessed holes (511), wherein the number of projecting ribs (631) of the rotation limiting elements (6) is equal to the number of recessed holes (511). [8] Device for preventing rotation of the spindle nut of an electric actuator according to one of the preceding claims, wherein the actuator body (2) is designed as a square body which defines a diagonal (L) which passes through two diagonal edges of the actuator body (2), wherein the rotation limiting elements (6) are arranged symmetrically to the diagonal (L). [9] Device for preventing rotation of the spindle nut of an electric actuator according to one of the preceding claims, further comprising two magnetic elements (7), wherein the base wall (61) of each of the rotation limiting elements (6) has a mounting opening (610) in which one of the magnetic elements (7) is inserted. [10] Device for preventing rotation of the spindle nut of an electric actuator according to claim 9, wherein the mounting opening (610) of the base wall (61) extends radially through the outer surface (611) and the inner surface (612) of each of the rotation limiting elements (6).

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