Linear cells and systems

Abstract

The present invention relates to a linear unit (10) and a system (100) comprising the linear unit (10). The linear unit comprises: i) a housing (12); ii) a screw (14) rotatably mounted in the housing (12); ii) a nut (16) cooperating with the screw (14); iv) a carriage (18) supported outside the housing (12) and movable along the housing (12) by means of a guide assembly (20); and v) a coupling element (30) coupling the carriage (18) with the nut (16) such that the carriage (18) is brought to move synchronously when the nut (16) is moved along the screw (14).

Description

[0001] The present invention relates to a linear unit and a system comprising the linear unit.

[0002] Linear units are known in the prior art for moving and positioning components such as machine parts. These linear units convert rotational motion, such as that of an electric motor, into linear motion. For this purpose, a rotatable screw engages with a nut. When the screw is driven to rotate (e.g., by an electric motor), the nut moves linearly along the screw. The movement of the nut is typically transmitted to the machine part via a push rod.

[0003] The lifespan of such linear units largely depends on the loads applied to the screw. Radial loads, in particular, that increase friction or even slightly deform the screw, can significantly reduce the lifespan of the screw and / or nut. A common solution to prevent such radial loads from acting on the screw is to ensure precise guidance of machine parts along the longitudinal axis of the linear unit. However, in some cases, this guidance is not feasible, such as when the movement of machine parts is not solely along the longitudinal axis of the linear unit.

[0004] Therefore, the object of the present invention is to improve the handling of radial loads acting on linear elements, and in particular to prevent or at least reduce radial loads acting on the screw of the linear element.

[0005] This objective is achieved by the linear unit and system described in the independent claims.

[0006] Preferred embodiments are given by the dependent claims and the following description.

[0007] According to a first aspect of the invention, a linear unit for converting rotational motion into linear motion comprises: i) a housing, ii) a screw rotatably mounted within the housing, iii) a nut cooperating with the screw, iv) a slide supported on the outside of the housing and movable along the housing by means of a guide assembly, and v) a connecting element connecting the slide to the nut such that when the nut moves along the screw, the slide is driven to move synchronously.

[0008] One aspect of this invention is that by connecting a nut that mates with the screw to a slide, the screw of the linear unit is at least partially decoupled from the radial load. Preferably, the slide is used to connect an external component that needs to move. The guiding arrangement for the slide thus absorbs the radial component of the load applied by the external component. The slide guided by this arrangement effectively separates the radial load from the axial load. Therefore, the axial load applied to the slide can be transmitted to the screw, while the radial load is guided to another transmission path.

[0009] Herein and below, "axial" preferably refers to a direction parallel to the longitudinal axis of the linear unit, especially a direction parallel to the screw or its axis of rotation.

[0010] Accordingly, "radial" preferably refers to a direction perpendicular to the longitudinal axis of the linear unit, especially a direction perpendicular to the screw or its axis of rotation. Optionally or additionally, "radial" may also refer to a direction perpendicular to the mounting surface of the guide arrangement.

[0011] Preferably, the guide arrangement is mounted on the outside of the linear unit housing. The housing effectively supports the guide arrangement and thus the slide under radial loads. Therefore, any radial load applied to the slide can be guided through the external structure of the linear unit without affecting the screw. Preferably, the radial load transmission path to the guide arrangement and housing is shorter than the radial load transmission path to the nut. Therefore, radial loads will be preferentially transmitted to the guide arrangement and housing rather than first applied to the nut.

[0012] A connecting element is provided to connect a nut disposed inside a housing to a slide disposed outside the housing. Preferably, the connecting element keeps the nut and the slide at the same axial height. More preferably, the connecting element provides a rigid connection between the nut and the slide in the axial direction, so that movement of the nut can immediately affect the axial position of the slide.

[0013] This structure also has the advantage of being compact. The connecting elements are easily integrated into the linear unit without significantly occupying space.

[0014] The nut and screw are preferably engaged by multiple planetary rollers disposed between them. Thus, the nut and screw form a planetary roller screw mechanism. Alternatively, the nut and screw can also be engaged by multiple balls, thereby forming a ball screw mechanism.

[0015] Preferred embodiments and further aspects of the present invention are described below. Unless explicitly excluded, the embodiments and aspects thereof may be combined with each other and with other aspects of the present invention in any way.

[0016] To achieve a safe and preferably axially rigid connection between the nut and the slide, the connecting element preferably at least partially surrounds the nut circumferentially. For example, the connecting element may include a receiving portion for at least partially receiving the nut. The receiving portion preferably forms a seat for the nut in the connecting element, and its basic shape may be a semi-tubular structure divided along a central axis.

[0017] Preferably, the connecting element, especially its receiving portion, is connected to the nut via two trunnions, preferably cylindrical. Preferably, the trunnions are housed in corresponding seats. Through the trunnions, axial loads can be directly and reliably transmitted between the nut and the connecting element.

[0018] For example, the trunnion can extend from opposite sides of the nut. Thus, the trunnion can be received by a slot in the connecting element, particularly in a receiving portion. This structure not only achieves a reliable mechanical connection between the nut and the connecting element but also facilitates assembly.

[0019] The two trunnions can be arranged coaxially. Preferably, the axis of the trunnion intersects the central axis of the screw. This avoids or at least reduces lever arm effects and nut rotation.

[0020] The groove in the connecting element, especially the receiving part, can be formed between two finger-like parts of the connecting element. Therefore, preferably, each trunnion is received by the groove formed between two finger-like parts of the connecting element (especially the receiving part).

[0021] Preferably, direct axial load transfer between the nut and the connecting element can be achieved by having the trunnion abut against the seat wall (e.g., the fingers of the connecting element) in a direction parallel to the screw. In other words, it is preferable that the trunnion has an axial tight fit in its seat.

[0022] On the other hand, to prevent or at least reduce the transmission of radial load from the connecting element to the nut, it is preferable that the trunnion has a clearance relative to its respective seat in the circumferential direction of the nut or receiving portion. In particular, the trunnion may maintain a distance from the end of its respective slot.

[0023] To absorb impacts such as vibration or (axial) loads, each seat preferably includes a damping element. The damping element preferably comprises two concentric sleeves with an elastic material disposed between them. Preferably, the trunnion is received in the innermost sleeve of the two concentric sleeves.

[0024] Alternatively, the trunnions can be rotatably mounted in their respective housings using bearings. This prevents or at least reduces friction and its associated loads when the connecting elements are slightly tilted around the trunnions in a plane parallel to the screw.

[0025] Similarly, other low-friction elements (such as bushings) can be used instead of bearings, and the trunnion can be rotatably mounted in the corresponding housing.

[0026] As an alternative to providing a cylindrical trunnion, a trunnion with a planar contact surface can also be provided, which contacts a mating planar seat surface. Preferably, the normals of both the contact surface and the seat surface are parallel to the screw, i.e., these surfaces are axially oriented. Preferably, the planar seat surface is formed by a seat wall, particularly a long sidewall defining the slot. By giving the trunnion a planar contact surface, the force acting on the trunnion or seat can be distributed over a larger area when axial loads are transferred between the nut and the connecting element. This effectively reduces contact pressure, decreases stress, and increases component life.

[0027] Another alternative or additional way to reduce the contact surface pressure between the trunnion and its respective seat is to have each seat include an insert. Preferably, the seat insert receives the corresponding trunnion. The seat insert is preferably movable between two opposing planar seat walls in a substantially tangential direction to the screw, for example, between two fingers of a connecting element. For this purpose, the seat insert may include a planar side surface, which preferably forms a sliding surface that slides on the seat wall. Preferably, the side surface contacts a mating planar seat surface. The side surface and the seat surface preferably each have a surface normal parallel to the screw.

[0028] The mounting insert also allows for radial movement of the trunnion. Preferably, the cylindrical trunnion is received by a mating hole in the mounting insert, thus allowing it to rotate relative to the mounting insert.

[0029] To convert the rotation of the screw into the linear movement of the nut, the nut must engage with the screw in an anti-rotation manner. For this purpose, it is preferable to have an anti-rotation fit between the nut and the connecting element, so that the nut cannot rotate relative to the connecting element. In particular, the nut and the connecting element can form an anti-rotation fit assembly that transmits torque between them. Designing the nut and connecting element as an anti-rotation fit is more advantageous in terms of space requirements compared to, for example, a common anti-rotation fit assembly formed by the nut and the housing. In particular, no additional space is required for arranging a dedicated anti-rotation fit assembly.

[0030] One method for preventing rotational engagement between a nut and a connecting element involves providing at least one elongated protrusion on the nut or connecting element in a direction parallel to the screw (i.e., axial direction). This elongated protrusion is preferably received by a corresponding mating groove in the connecting element or nut. The protrusion and groove must be respectively located on the opposing surfaces of the nut and the connecting element (especially the receiving portion). Therefore, forming this anti-rotational engagement assembly requires no additional space.

[0031] To improve the stability of the connecting element to pivoting motion, the nut and housing can also be fitted with an anti-rotation engagement. For this purpose, it is preferable to have at least one elongated protrusion on the housing or nut in a direction parallel to the screw, received by a corresponding groove in the nut or housing. This anti-rotation engagement of the nut with both the connecting element and the housing more effectively restricts the movement of the connecting element to the axial direction.

[0032] Preferably, the ribs of the connecting element are movably mounted to the slide. This further effectively decouples the nut from the radial load.

[0033] For example, the rib may be movable radially relative to the slide, i.e., perpendicular to the mounting surface of the screw and / or guide assembly. Optionally or additionally, the rib may be rotatable relative to the slide about its central axis, which preferably extends radially, i.e., perpendicular to the mounting surface of the screw and / or guide assembly.

[0034] For this purpose, the rib preferably includes a rib trunnion extending in a direction perpendicular to the screw (i.e., radially). Preferably, the rib trunnion extends along the central axis of the rib. Preferably, the rib trunnion is received in a floating manner in the slide seat hole, for example, allowing rotation and radial translation of the rib relative to the slide.

[0035] The system according to a second aspect of the invention includes a first component and a second component movable (especially pivotable) relative to the first component. Preferably, the linear unit described in the first aspect is mounted to the first component. Furthermore, it is preferable that the second component is coupled to a slide of the linear unit.

[0036] Therefore, a connection can be established between the second component and the nut via a connecting element, without transferring radial loads from the second component to the nut, or only to a very small extent. Instead, radial loads can be directed or absorbed to the guide assembly and housing. Making the nut and screw essentially unaffected by radial loads improves their service life.

[0037] The nature, features, and advantages of the invention described above, as well as the ways in which they are implemented, will be further detailed in the following description of embodiments in conjunction with the accompanying drawings. Where appropriate, identical or corresponding components are referred to by the same reference numerals in the drawings. The embodiments described are for the purpose of explaining the invention and do not limit the invention to the combinations of features shown therein, nor do they exclude the application of functional features. Furthermore, any feature disclosed in the foregoing description and the following embodiments can be considered alone and appropriately combined with features of any of the foregoing embodiments and their further aspects. In particular, each feature described above and below can be applied alone or in combination with other features to linear units according to the first aspect of the invention and systems according to the second aspect. Attached Figure Description

[0038] The accompanying drawings illustrate, in particular schematically: Figure 1 A cross-sectional side view of a linear element instance; Figure 2 Side view of an example of a connecting element; Figure 3 Figure 2 A cross-sectional view of the connecting element shown; Figure 4 Examples of forces acting on the slide; Figure 5 An example of a flexible mounting trunnion; Figure 6 An example of a rotatable mounting trunnion; Figure 7 System instance; Figure 8 Examples of seats including inserts; and Figure 9Examples of connecting elements that are movably mounted to a slide.

[0039] Figure 1 A cross-sectional side view is shown of an example of a linear unit 10 for converting rotational motion into linear motion. The linear unit 10 includes: a housing 12; a screw 14 rotatably mounted within the housing 12; a nut 16 cooperating with the screw 14; a slide 18 supported on the outside of the housing 12 by means of a guide assembly 20; and a connecting element 30 connecting the slide 18 to the nut 16. The screw 14 can be driven by a motor 22. When the screw 14 rotates, the nut 16 moves along the screw 14. Since the connecting element 30 connects the nut 16 to the slide 18, the slide 18 moves synchronously with the nut 16. The slide 18 includes a connecting structure 24 for connecting external components (e.g., machine parts to be moved).

[0040] The guide assembly 20 is preferably mounted on the outer side 12a (e.g., the top side) of the housing 12. To enable the connecting element 30 to engage the nut 16 with the slide 18, the housing 12 has at least a partial outward opening on this outer side 12a. For example, the housing 12 may include an opening 12b on the outer side 12a through which the connecting element 30 passes. This opening 12b... Figure 1 It is shown in dashed lines.

[0041] By movably arranging the slide 18 on the guide assembly 20 (e.g., a pair of guide rails) supported by the housing 12, radial loads applied to the slide 18 (e.g., applied by external components connected to the connecting structure 24) are not, or at least not entirely, transmitted to the nut 16, but are instead guided via the housing 12. Essentially only axial loads are transmitted between the nut 16 and the slide 18 via the connecting element 30. Figure 1 The linear unit 10 structure shown here effectively separates axial loads from radial loads.

[0042] Figure 2 A side view example of the connecting element 30 is shown. The connecting element 30 connects the nut 16 to the slide 18 such that when the nut 16 moves axially, the slide 18 is driven.

[0043] Nut 16 is accommodated in receiving portion 32 of connecting element 30. Receiving portion 32 thus forms a seat for nut 16 in connecting element 30. Receiving portion 32 is connected to slide 18 via rib 34. Preferably, receiving portion 32 and rib 34 are integrally formed, i.e., constitute a single piece.

[0044] To transmit axial load between the nut 16 and the connecting element 30, the connecting element 30 is connected to the nut 16 via trunnions 36 housed in respective seats 38. In this example, the trunnions 36 are arranged on opposite sides of the nut 16 and extend radially from the side surface 16a of the nut 16. Accordingly, the seats 38 are formed by the connecting element 30, particularly in the receiving portion 32. In this example, the seats 38 are formed by a groove 40a in the connecting element 30 (particularly the receiving portion 32). The groove 40a (and the finger-like portions 40) extends circumferentially along the receiving portion 32 and preferably opens at the lower end 42a of the connecting element 30. The lower end 42a is opposite to the upper end 42b. At the upper end 42b, the connecting element 30 is connected to the slide 18.

[0045] The trunnion 36 is cylindrical and preferably coaxially arranged. Therefore, the connecting element 30 can pivot about the trunnion 36 (i.e., the central axis of the trunnion 36) relative to the nut 16. This can be achieved by providing a bearing or other low-friction element in the housing 38, such as... Figure 6 As shown and described in detail below.

[0046] The trunnion 36 preferably has an axial tight fit in its respective seat 38, that is, it contacts the connecting element 30 in the axial direction. Therefore, axial loads can be immediately transmitted between the nut 16 and the connecting element 30 (and thus between the nut 16 and the slide 18).

[0047] On the other hand, the trunnion 36 preferably has a circumferential gap relative to the seat 38 in the nut 16 or the receiving portion 32. That is, the trunnion 36 preferably does not contact the connecting element 30 in the circumferential direction. This helps to more reliably decouple the nut 16 from radial loads, because even if a radial force is applied to the connecting element 30, the connecting element 30 can move perpendicular to the longitudinal axis of the nut 16 without applying any force to the nut 16.

[0048] Because the trunnion 36 is cylindrical and has a gap in its seat 38, the contact between the trunnion 36 and the connecting element 30 is essentially a line contact. This reduces friction when the connecting element 30 moves perpendicular to the longitudinal axis of the nut 16, thereby reducing the radial load acting on the nut 16; or when the connecting element 30 tilts about an axis parallel to the trunnion axis, it actually rotates about the trunnion 36, which also reduces friction.

[0049] Figure 3 Show Figure 2A cross-sectional view of the connecting element 30 is shown. A housing 12 with a nut 16 is also shown. The nut 16 engages with the screw 14 via a plurality of planetary rollers 14a disposed between the screw 14 and the nut 16. A guide assembly 20 is provided on the top side of the housing 12, which includes a pair of guide rails 20a movably mounted to the housing 12 by means of a slide 18. On the top side, the housing 12 includes an opening 12b to allow engagement between the slide 18 and the nut 16. For this purpose, a rib 34 of the connecting element 30 passes through the opening 12b.

[0050] The connecting element 30 (especially the receiving part 32) at least partially surrounds the nut 16. In particular, the inner surface 32a of the receiving part 32 may be formed to match the side surface 16a of the nut 16.

[0051] Preferably, the side surface 16a of the nut 16 does not contact the inner surface 32a. In particular, the nut 16 may have a radial clearance in the seat formed by the receiving portion 32. This allows for radial mechanical decoupling of the nut 16 from the connecting element 30.

[0052] To prevent rotation, the nut 16 is anti-rotationally locked and fitted with the connecting element 30. For this purpose, the nut 16 includes an elongated protrusion 16b extending axially (i.e., perpendicular to the drawing plane) and received by a corresponding mating groove 44 of the connecting element 30. Thus, the nut 16 is received in the receiving portion 32 in an anti-rotation manner. The protrusion 16b and the groove 44 form an anti-rotation fitting assembly.

[0053] In this example, the nut 16 also has an anti-rotation fit with the housing 12. Accordingly, the nut 16 also includes a second elongated protrusion 16b, which extends axially and is received by a corresponding mating groove 12c of the housing 12. Similarly, the second protrusion 16b and the groove 12c form an anti-rotation fit assembly.

[0054] Preferably, the two protrusions 16b of the nut 16 are provided on opposite sides of the nut 16. In particular, the two protrusions 16b may preferably extend in a plane perpendicular to the opening 12b.

[0055] In this example, the trunnion 36 extends radially from the nut 16 and is received by the seat 38 in the connecting element 30. However, it is also conceivable that the trunnion 36 extends from the connecting element 30 and is received by the seat 38 in the nut 16. In this case, the seat 38 may be formed by a recess in the nut body.

[0056] Figure 4 An example of a force F acting on the slide 18 is shown. The slide 18 is movably mounted on the housing (not shown) by means of a guide assembly 20 shown in dashed lines. The slide 18 is connected to the nut 16 by means of a connecting element 30, which includes a seat 38 for receiving two trunnions 36 that extend radially from opposite sides of the nut 16.

[0057] The force F has two components: an axial component Fa and a radial component Fr. The axial component Fa is transmitted to the nut 16 via the connecting element 30. In particular, the axial component Fa is transmitted to the nut 16 in the region where the trunnion 36 contacts the connecting element 30. However, the radial component Fr is guided to the housing at least partially via the guide assembly 20, as indicated by arrow A. Thus, the radial component Fr does not (substantially) act on the nut 16. This is achieved by means of a gap in the receiving portion 32 of the connecting element 30 within the nut 16, and a gap in the trunnion 36 relative to the seat 38 in the circumferential direction of the nut 16 or the receiving portion 32.

[0058] To achieve immediate axial load transfer between the nut 16 and the connecting element 30, the trunnion 36 preferably has an axial tight fit in its respective seat 38, i.e., in contact with the connecting element 30. In the illustrated example, the trunnion 36 is not cylindrical, but has two planar contact surfaces 36a. These contact surfaces 36a contact the mating planar seat surface 38a. Thus, the axial component Fa can be transferred to the nut 16 over a larger area (i.e., the area of ​​the contact surfaces 36a), reducing stress compared to transmission via line contact.

[0059] Figure 5 An example is shown of a trunnion 36 resiliently mounted within a seat 38 of a connecting element 30. For this purpose, the seat 38 includes a damping element 46, such as two concentric sleeves with an elastic material 46a disposed between them. Preferably, the trunnion 36 is received within the innermost sleeve. This not only reduces vibration but also prevents or at least reduces load peaks during axial load transmission.

[0060] Figure 6 An example of a trunnion 36 rotatably mounted within a seat 38 of a connecting element 30 is shown. To facilitate rotation of the trunnion 36 relative to its seat 38, the trunnion 36 may be mounted within the seat 38 by means of a bearing 48. Alternatively, other types of low-friction elements, such as bushings, may be used. Rotatably mounting the trunnion 36 within the seat 38 allows the connecting element 30 to pivot about the trunnion 36 (i.e., perpendicular to the central axis of the drawing) relative to the nut containing the trunnion 36.

[0061] Figure 7An example of system 100 is shown, which includes a first component 102 and a second component 104 pivotally mounted relative to the first component 102. System 100 also includes a linear unit 10 mounted to the first component 102. A slide 18 of the linear unit 10 is coupled to the second component 104 such that the second component 104 pivots relative to the first component 102 about a joint 106 when the nut moves linearly. The connection between the slide 18 and the second component 104 can be established by a connector 108, one end of which is connected to a connection structure 24 of the slide 18, and the other end of which is connected to the second component 104.

[0062] Preferably, the slide 18 is movably mounted on the housing (not shown) of the linear unit 10 by means of a guide assembly and is guided in a direction parallel to the longitudinal axis of the linear unit 10. The movement of the slide 18 is driven by a nut (not shown) that engages with a rotatable screw, and the connection between the nut and the slide 18 is established by a connecting element (not shown).

[0063] This structure allows the load, for example, applied to the slide 18 by the connector 108 in a direction perpendicular to the slide 18’s movement, to be at least partially decoupled from the nut.

[0064] Figure 8 An example of a seat 38 including a seat insert 50 that receives the trunnion 36 of a nut 16 is shown. The seat insert 50 is received between two fingers 40 of a connecting element 30. The seat insert 50 is preferably rectangular and is movably arranged within a groove 40b formed by the two fingers 40. In particular, the seat insert 50 includes two opposing planar side surfaces 50a that are in planar contact with the mating plane seat surface 38a of the seat wall, i.e., in contact with the plane of the side wall of the fingers 40.

[0065] The insert 50 includes a central hole 52 for receiving the trunnion 36. In the illustrated example, the trunnion 36 is cylindrical and therefore rotatable relative to the insert 50.

[0066] Figure 9An example of a connecting element 30 movably mounted to a slide 18 is shown, the slide 18 being movable along the outside of the housing (not shown) of a linear unit by means of a guide assembly 20. The connecting element 30 connects a nut 16, which mates with a screw 14, to the slide 18. For this purpose, the connecting element 30 includes a receiving portion 32 forming a seat for the nut 16. The nut 16 is connected to the receiving portion 32 via a trunnion 36 housed in a respective seat 38. If the trunnion 36 is cylindrical as in this example, the connecting element 30 can pivot about the longitudinal axis of the trunnion 36 (i.e., the axis perpendicular to the drawing). The connecting element 30 extends from the receiving portion 32 (i.e., from the nut 16) to the slide 18 via a rib 34. The rib 34 preferably extends perpendicular to the longitudinal axis of the screw 14 and / or the receiving portion 32 and / or the nut 16.

[0067] At its end opposite to the receiving part 32, the rib 34 includes a rib trunnion 54. The rib trunnion 54 extends along the central axis 30a of the connecting element 30, which is perpendicular to the screw 14 and perpendicular to the sliding block 18 in the direction of movement of the guide assembly 20.

[0068] Preferably, the rib trunnion 54 is cylindrical and is received by a corresponding slide seat hole 56. The slide seat hole 56 is preferably located on the bottom side of the slide 18 facing the nut 16. The slide seat hole 56 may be formed, for example, by a cylindrical recess on the bottom side of the slide 18.

[0069] Preferably, the rib trunnion 54 has an axial clearance within the slide seat hole 56. This allows the connecting element 30 to move axially relative to the slide 18. Here, "axial" refers to the direction parallel to the rib's central axis 30a, i.e., perpendicular to the screw 14.

[0070] If the rib trunnion 54 is cylindrical, it can also be rotatably accommodated in the slide seat hole 56, so that the connecting element 30 can rotate relative to the slide 18 around the central axis 30a of the rib.

[0071] If the connecting element 30 is also not tightly fitted at the nut 60, for example... Figure 2 and Figure 8 By receiving the trunnion 36 between the two finger-shaped portions of the connecting element 30 as shown, the connecting element 30 effectively establishes a floating connection between the nut 16 and the slide 18.

[0072] The mechanical decoupling between the nut 16 and the slide 18 achieved by this structure can effectively and reliably prevent radial loads from acting on the nut 16.

[0073] Explanation of reference numerals in the attached figures 10 Linear Units 12. Shell 12a Outer side 12b Opening 12c slot 14 Screw 14a Planetary Roller 16 nuts 16a Side surface 16b protrusion 18 Slides 20 guide components 20a guide rail 22 Electric motors 24 Connection Structure 30 Connecting elements 32 Receiving Section 32a Inner Surface 34 Ribs 36 trunnions 36a Contact surface 38 seats 38a seat surface 40. Finger-like part 40a slot 42a lower end 42b upper end 44 slots 46 Damping elements 46a Elastic Material 48 bearings 50 inserts 50a side surface 52 holes 54 Rib Trunnions 56 Slide seat hole 100 System 102 First Component 104 Second Component 106 connector 108 Connector F force Fa axial component Fr radial component A arrow

Claims

1. A linear unit (10) for converting rotational motion into linear motion, comprising: Shell (12); A screw (14) rotatably mounted inside the housing (12); a nut (16) cooperating with the screw (14); a slide (18) disposed on the outside (12a) of the housing (12) and movable along the housing (12) via a guide assembly (20); and a connecting element (30) that connects the slide (18) and the nut (16) such that when the nut (16) moves along the screw (14), the slide (18) is driven to move synchronously.

2. The linear unit (10) according to claim 1, wherein, The connecting element (30) at least partially surrounds the nut (16) circumferentially.

3. The linear unit (10) according to claim 1 or 2, wherein, The connecting element (30) is connected to the nut (16) via two trunnions (36), which are housed in corresponding seats (38).

4. The linear unit (10) according to claim 3, wherein, The trunnions (36) extend from opposite sides of the nut (16), and each trunnion (36) is accommodated between two fingers (40) of the connecting element (30).

5. The linear unit (10) according to claim 3 or 4, wherein, The trunnion (36) abuts against the seat wall in a direction parallel to the screw (14), and there is a gap in the circumferential direction of the nut (16) relative to the seat (38).

6. The linear unit (10) according to any one of claims 3 to 5, wherein, Each of the seats (38) includes a damping element (46) comprising two concentric sleeves with an elastic material (46a) disposed therebetween.

7. The linear unit (10) according to any one of claims 3 to 5, wherein, The trunnions (36) are rotatably mounted in their respective seats (38) via bearings (48).

8. The linear unit (10) according to any one of claims 3 to 5, wherein, The trunnion (36) has a planar contact surface (36a) that mates with the planar seat surface (38a), and the normals of the contact surface (36a) and the seat surface (38a) are both parallel to the screw (14).

9. The linear unit (10) according to any one of claims 3 to 6, wherein, Each of the said seats (38) includes a seat insert (50) for receiving a corresponding trunnion (36), the seat insert (50) being movable between two opposing and planar seat walls in a direction substantially tangential to the screw (14), and including a planar side surface (50a) in contact with a mating planar seat surface (38a), the normals of the side surface (50a) and the seat surface (38a) being parallel to the screw (14).

10. The linear unit (10) according to any one of the preceding claims, wherein, The nut (16) and the connecting element (30) are anti-rotationally engaged, so that the nut (16) cannot rotate relative to the connecting element (30).

11. The linear unit (10) according to claim 9, wherein, The nut (16) or the connecting element (30) includes at least one elongated protrusion (16b) extending in a direction parallel to the screw (14), the elongated protrusion (16b) being received in a corresponding mating groove (44) of the connecting element (30) or the nut (16).

12. The linear unit (10) according to any one of claims 9 or 10, wherein, In addition to the anti-rotation fit between the connecting element (30) and the nut (16), the housing (12) or the nut (16) also includes at least an elongated protrusion (16b) extending in a direction parallel to the screw (14), the elongated protrusion (16b) being received in a corresponding mating groove (12c) of the nut (16) or the housing (12).

13. The linear unit (10) according to any one of the preceding claims, wherein, The rib (34) of the connecting element (30) is movably mounted on the slide (18).

14. The linear unit (10) according to claim 13, wherein, The rib (34) includes a rib trunnion (54) that extends in a direction perpendicular to the screw (14) and is received in a floating manner in a slide seat hole (56).

15. A system (100) comprising a first component (102) and a second component (104) movable relative to the first component (102), wherein, The linear unit (10) according to any of the preceding claims is mounted to the first component (102), and the second component (104) is connected to the slide (18) of the linear unit (10).

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