Linear Actuator, Hydraulic Bearing, and Motor Vehicle with such a Hydraulic Bearing or Linear Actuator

Abstract

The invention relates to an electromagnetic linear actuator (16) with a stator (18) and an armature (20) which can be moved relative to the stator (18). The stator (18) has at least one permanent magnet (22) and at least one coil (24), the stator (18) has a conductive element (26) made of a ferromagnetic material, the conductive element (26) extends over the at least one permanent magnet (22) and/or the at least one coil (26), and the armature (18) forms a yoke (34) made of a ferromagnetic material in the longitudinal direction L for the conductive element (26). The invention further relates to a hydraulic bearing (2) with a support spring (36), a working chamber (4), which is filled with a hydraulic fluid, a compensating chamber (6), a partition (8) which is arranged between the working chamber (4) and the compensating chamber (6), a throttle channel (10) which is formed between the working chamber (4) and the compensating chamber (6) for exchanging hydraulic fluid, and a control membrane (12) which is paired with the partition (8) and which is designed to change a working chamber volume (14) of the working chamber (4). The hydraulic bearing (2) has an electromagnetic linear actuator (16) according to the invention, and the armature (20) is mechanically connected to the control membrane (12). The invention additionally relates to a motor vehicle with such a hydraulic bearing (2).

Claims

1.-25. (canceled)

26. An electromagnetic linear actuator comprising: a stator comprising at least one permanent magnet and at least one coil; and, an armature which is movable relative to the stator; wherein the stator further comprises a conductive element composed of ferromagnetic material, wherein the conductive element engages over the at least one permanent magnet and/or the at least one coil, and wherein the armature forms, in a longitudinal direction L, a yoke composed of the ferromagnetic material for the conductive element.

27. The linear actuator as claimed in claim 26, wherein the conductive element comprises a longitudinal section extending in the longitudinal direction L of the linear actuator, a lower collar extending in a transverse direction Q of the linear actuator, and an upper collar extending in the transverse direction Q of the linear actuator, and wherein the lower collar is spaced apart from the upper collar in the longitudinal direction L.

28. The linear actuator as claimed in claim 27, wherein each of the lower collar and the upper collar projects beyond the longitudinal section in the same transverse direction Q, and wherein the at least one permanent magnet and/or the at least one coil are/is arranged between the lower collar and the upper collar.

29. The linear actuator as claimed in claim 26 comprising at least two permanent magnets, wherein the at least one coil is arranged between the at least two permanent magnets in the longitudinal direction L.

30. The linear actuator as claimed in claim 26 comprising at least two coils, wherein the at least one permanent magnet is arranged between the at least two coils in the longitudinal direction L.

31. The linear actuator as claimed in claim 26, wherein at least one of the at least one permanent magnet is arranged behind or in front of the at least one coil in the transverse direction Q.

32. The linear actuator as claimed in claim 26, wherein the at least one coil directly adjoins at least one of the at least one permanent magnets.

33. The linear actuator as claimed in claim 26, wherein the armature is mounted by way of a slide bearing arrangement.

34. The linear actuator as claimed in claim 33, wherein the slide bearing arrangement is at least substantially free from ferromagnetic material.

35. The linear actuator as claimed in claim 33, wherein the armature forms, on an associated side facing toward the stator, a bearing surface of the slide bearing arrangement, and wherein a slide element of the slide bearing arrangement is fastened to a stator side facing toward the armature, the slide element, by way of an associated side facing toward the armature, forms a counterpart bearing surface of the slide bearing arrangement.

36. The linear actuator as claimed in claim 35, wherein the slide element is arranged between an upper collar and a lower collar in the longitudinal direction L of the linear actuator.

37. The linear actuator as claimed in claim 36, wherein the slide element is enclosed in the stator between the lower collar and the upper collar.

38. The linear actuator as claimed in claim 36, wherein the slide element projects in transverse direction Q beyond stator pole surfaces formed by the lower collar and the upper collar.

39. The linear actuator as claimed in claim 35, wherein the bearing surface of the slide bearing arrangement and armature pole surfaces provided for the yoke are formed on a common, uninterrupted armature side.

40. The linear actuator as claimed in claim 35, wherein a stator pole surface of the stator and an armature pole surface of the armature arranged opposite the stator pole surface, are spaced apart from one another in the transverse direction Q of the linear actuator by a gap, wherein a gap width B of the gap is smaller than a slide element width G of the slide element.

41. A hydraulic mount comprising a load-bearing spring, a working chamber filled with a hydraulic fluid, an equalization chamber, a partition which is arranged between the working chamber and the equalization chamber, a throttle duct formed between the working chamber and the equalization chamber, which serves for exchange of hydraulic fluid, and a control diaphragm which is assigned to the partition and which is designed for the variation of a working chamber volume of the working chamber; wherein the hydraulic mount comprises an electromagnetic linear actuator comprising: a stator comprising at least one permanent magnet and at least one coil; and, an armature which is movable relative to the stator; wherein the stator further comprises a conductive element composed of ferromagnetic material; wherein the conductive element engages over the at least one permanent magnet and/or the at least one coil; wherein the armature forms, in a longitudinal direction L, a yoke composed of the ferromagnetic material for the conductive element; and, wherein the armature is mechanically connected to the control diaphragm.

42. The hydraulic mount as claimed in claim 41, where the armature is composed of one of the yoke or the yoke and a holder, for the connection of the yoke to the control diaphragm.

43. The hydraulic mount as claimed in claim 41, wherein the hydraulic mount is used as an engine mount for a motor vehicle, and wherein the motor vehicle comprises a vehicle frame, an engine, and the engine mount which produces a connection, with mounting action, between the engine and the vehicle frame.

44. An electromagnetic linear actuator comprising a stator comprising a conductive element composed of ferromagnetic material, and an armature which is movable relative to the stator; wherein the armature is mounted by way of a slide bearing arrangement; wherein the armature forms, on an associated side facing toward the stator, a bearing surface of the slide bearing arrangement; and, wherein a slide element of the slide bearing arrangement is fastened to a stator side facing toward the armature, the slide element, by way of an associated side facing toward the armature, forms a counterpart bearing surface of the slide bearing arrangement.

45. The linear actuator as claimed in claim 44, wherein the slide bearing arrangement is at least substantially free from ferromagnetic material.

46. The linear actuator as claimed in claim 44, wherein the stator comprises at least one permanent magnet and at least one coil, and wherein the conductive element engages over the at least one permanent magnet and/or the at least one coil, and wherein the armature forms, in a longitudinal direction L, a yoke composed of the ferromagnetic material for the conductive element.

Description

[0060] The invention will be described below, without restriction of the general concept of the invention, on the basis of exemplary embodiments and with reference to the drawings. In the drawings:

[0061] FIG. 1 shows a schematic cross-sectional view of a hydraulic mount,

[0062] FIG. 2 shows a schematic cross-sectional view of a first embodiment of a linear actuator,

[0063] FIG. 3 shows a schematic cross-sectional view of a second embodiment of a linear actuator,

[0064] FIG. 4 shows a schematic cross-sectional view of a third embodiment of a linear actuator, and

[0065] FIG. 5 shows a schematic cross-sectional view of a further embodiment of a linear actuator.

[0066] FIG. 1 shows a hydraulic mount 2. The hydraulic mount 2 comprises a load-bearing spring 36 in the form of a rubber element. Said load-bearing spring 36 is, in the conventional manner, in the form of a hollow body, wherein the top side of the load-bearing spring 36 has a cover 38. A connection element (not illustrated) for the fastening of an engine is normally attached to the cover 38. In a simple embodiment, the connection element is a threaded bolt which can be screwed to the engine. The bottom side of the load-bearing spring 36 is adjoined by the partition 8. The working chamber 4 is formed between the load-bearing spring 36, the cover 38 and the partition 8. The working chamber 4 is filled with a hydraulic fluid. This is preferably a mixture of oil and water. Situated adjacently below the partition 8 in the longitudinal direction L is the hollow cylindrical base housing 40, the interior space of which is divided by a flexible separating body 48. The space enclosed by the partition 8, the separating body 48 and the base housing 40 forms the equalization chamber 6 of the hydraulic mount 2. The equalization chamber 6 is preferably likewise filled with hydraulic fluid. Said hydraulic fluid may likewise be a mixture of oil and water. It can thus be seen from FIG. 1 that the partition 8 is arranged between the working chamber 4 and the equalization chamber 6. For the damping of low-frequency vibrations which are exerted by the engine on the load-bearing spring 36 via the cover 38 and which thus also act on a working chamber volume 14 of the working chamber 4, a throttle duct 10 is provided which is formed between the working chamber 4 and the equalization chamber 6 and which serves for the exchange of hydraulic fluid. If the load-bearing spring 36 is compressed as a result of the vibrations, this normally leads to an increase of the pressure of the hydraulic fluid in the working chamber 4 and/or to a decrease in size of the working chamber volume 14 of the working chamber 4. Here, in both alternatives, a volume flow of the hydraulic fluid takes place from the working chamber 4 through the throttle duct 10 into the equalization chamber 6. Here, dissipation occurs in the throttle duct 10, such that the vibrations acting on the load-bearing spring 36 can be damped. The damping by way of the throttle duct 10 is however effective only for low-frequency vibrations. In the presence of relatively high-frequency vibrations, for example above 20 Hz, virtually no damping or isolation of vibrations whatsoever is effected by way of the throttle duct 10.

[0067] For the isolation of vibrations with a frequency of greater than 20 Hz, the hydraulic mount 2 has a control diaphragm 12. Said control diaphragm 12 is assigned to the partition 8. For this purpose, the control diaphragm 12 may be formed by the partition 8 itself or may be inserted into the partition 8. It is thus possible for the partition 8 to enclose the control diaphragm 12. The control diaphragm 12 is designed to be elastically deformable in the longitudinal direction L of the hydraulic mount 2. In accordance with its elastic deformability in the longitudinal direction L, the working chamber volume 14 of the working chamber 4 increases or decreases in size. Said deformability of the control diaphragm 12 is utilized advantageously to isolate relatively high-frequency vibrations. For this purpose, the control diaphragm 12 is, at its side averted from the working chamber 4, mechanically connected to an armature 20 of an electromagnetic linear actuator 16 of the hydraulic mount 2. The linear actuator 16 furthermore has a stator 18, with the armature 20 being arranged so as to be mounted movably with respect to said stator. The armature is fastened to the base housing 40 of the hydraulic mount 2 or is at least partially formed by the base housing 40. To restrict the movement direction of the armature 20 to a movement direction in the longitudinal direction L, the linear actuator 16 has a corresponding bearing arrangement. It is thus possible for the elastic deformation of the control diaphragm 12 to be electrically controlled by way of the electromagnetic linear actuator 16.

[0068] Furthermore, FIG. 1 shows an advantageous embodiment of the hydraulic mount 2 according to the invention in which the armature 20 is mechanically connected to the control diaphragm 12 by way of a mechanical plunger 46 which is assigned to the armature 20. By way of the plunger, the stator 18 of the linear actuator 16 can be arranged so as to be spaced apart from the control diaphragm 12, such that the equalization chamber 6 can form in the region between the stator 18 and the partition 8. Such an embodiment of the hydraulic mount 2 has proven to be particularly expedient in practice. Other embodiments which do not have a plunger 46 or which, instead of the plunger 46, have some other articulated mechanism for the transmission of forces of the linear actuator 16 to the control diaphragm 12 are therefore likewise intended to be regarded as a mechanical connection between the armature 20 and the control diaphragm 12.

[0069] FIG. 2 illustrates a design variant of the electromechanical linear actuator 16 in more detail. In such an embodiment, the the linear actuator 16 may also be used for other purposes and/or devices, for example a chassis mount. The linear actuator 16 comprises a stator 18 with a stator housing 50, multiple permanent magnets 22 and a coil 24. The linear actuator 16 is of symmetrical form with respect to an axis A in the longitudinal direction L.

[0070] The further explanations therefore relate initially to the right-hand half of the linear actuator 16. Owing to the symmetry, the linear actuator 16 has analogous features, embodiments and/or advantages in its opposite half.

[0071] As viewed in the longitudinal direction L, the linear actuator 16 has a lower permanent magnet 22a and an upper permanent magnet 22b. The coil 24, or at least a part of the coil 24, is arranged between the lower permanent magnet 22a and the upper permanent magnet 22b. A longitudinal section 30 of a conductive element 26 composed of ferromagnetic material is arranged radially at the outside with respect to the two permanent magnets 22a, 22b and the coil 24. The conductive element 26 is part of the stator 18. The conductive element 26 serves for concentrating a coil magnetic field of the coil 24. For this purpose, the conductive element 26 furthermore has a lower collar 28 and an upper collar 32 which extend each case in the transverse direction Q from the longitudinal section 30. As emerges from FIG. 2, the lower collar 28 engages between the lower permanent magnet 22a and the coil 24. By contrast, the upper collar 32 engages between the upper permanent magnet 22b and the coil 24. By way of the longitudinal section 30 and the two collars 28, 32, the conductive element 26 is of comb-like form. By way of the corresponding opening between the two collars 28, 32, the conductive element 26 engages of the coil 24. By way of its outer L-shaped sections which comprise in each case one of the two collars 28, 32 and a respectively adjacent end of the longitudinal section 30, the conductive element 26 engages over the two permanent magnets 22a, 22b.

[0072] The armature 20 according to the invention composed of ferromagnetic material forms a yoke 34 for the conductive element 26. The armature 20 requires neither a permanent magnet nor a coil for this purpose. The armature 20 is thus free from permanent magnets and/or coils. In practice, it has proven to be expedient if the yoke 34 formed by the armature 20 extends in the longitudinal direction L from a lower web 54 via a middle section 56 to an upper web 58. Here, each of the two webs 54 projects beyond the middle section 56 in the transverse direction Q. In a rest position of the armature 20, the upper web 58 is aligned opposite the upper collar 32 and the lower web 54 is aligned opposite the lower collar 28. In other words, the upper web 58 and the upper collar 32 are arranged in a common upper plane, and the lower web 54 and the lower collar 28 are arranged in a common lower plane. The webs 54, 58 and the collars 28, 32 thus define an air gap 60 which is formed between the armature 20 and the stator 18 in the transverse direction Q.

[0073] To ensure that the armature 20 performs the desired movement only in the longitudinal direction L, the armature 20 is arranged so as to be mounted at its top side by way of an upper guide spring 61, and at its bottom side by way of a lower guide spring 63, on the stator 18. The two guide springs 61, 63 prevent the armature 20 from being able to perform a movement in the transverse direction Q.

[0074] To effect a deflection of the armature 20 in the longitudinal direction, the coil 24 is energized. Here, a coil magnetic field is generated which is concentrated by the conductive element 26 and the yoke 34, such that circular magnetic field lines are generated. These also lead through the two collars 28, 34. The two permanent magnets 22a, 22b are arranged adjacent to the collars 28, 32, which permanent magnets have in each case a common magnetic field orientation in the transverse direction Q. Thus, in the event of an energization of the coil 24, the concentrated coil magnetic field has a permanent magnetic field of the lower permanent magnet 22a constructively superposed thereon in the lower collar 28, whereas the concentrated coil magnetic field has a permanent magnetic field of the upper permanent magnet 22b destructively superposed thereon in the upper collar 32, or vice versa. Depending on the configuration of said superposition, the armature 20 moves upward or downward in the longitudinal axial direction.

[0075] For the transmission of said movement in the longitudinal direction, the armature 20 may, in the case of the corresponding linear actuator 16 being used for a hydraulic mount 2, be fastened directly to the control diaphragm 12. The armature 20 may however also be assigned a holder 65 by way of which the armature 20 is mechanically connected to the control diaphragm 12. Said holder 65 may also be adjoined radially at the outside by the leaf springs 68 illustrated in FIG. 2, which leaf springs extend as far as the stator 18 for the purposes of mounting the armature 20 relative to the stator 18.

[0076] FIG. 3 schematically illustrates a further embodiment of the linear actuator 16. The linear actuator 16 is of substantially identical construction to the linear actuator 16 described above, as has been discussed with reference to FIG. 2. Analogous explanations, features and/or advantages thus apply. The linear actuator 16 from FIG. 3 however differs in terms of the embodiment of the conductive element 26 and the associated arrangement of the permanent magnets 22a, 22b and the coil 24. To explain the differences and the associated effects, reference is also made, as above, to the fact that the linear actuator 16 is of symmetrical construction with respect to the axis A. Therefore, the construction of the right-hand half of the linear actuator 16 will be discussed below, wherein analogous features, advantages and effects apply to the rest of the linear actuator 16.

[0077] The conductive element 26 extends from a lower collar 28 via a longitudinal section 30 to an upper collar 32. The conductive element is thus of C-shaped form. The lower permanent magnet 22a, the coil 24 and the upper permanent magnet 22 are inserted into a corresponding opening of the C-shaped form. The coil 24 is arranged between the two permanent magnets 22a, 22b. The conductive element 26 is thus designed so as to engage over the entire grouping composed of permanent magnets 22a, 22b and of the at least one coil 24. For this purpose, the collars 28, 32 engage over the longitudinally pointing face sides and the longitudinal section 30 engages over a transversely pointing face side of the abovementioned grouping. The permanent magnets 22a, 22b and the coil 24 are thus enclosed by the conductive element 26. If the coil 26 is now energized, it is the case, as before, that a coil magnetic field is generated, wherein the magnetic field lines thereof are concentrated in ring-shaped fashion by the conductive element 26 and by the yoke 34 formed by the armature 20. Furthermore, the permanent magnets are again arranged directly adjacent to the collars 28, 32, such that an analogous constructive or destructive superposition with the associated permanent magnetic field respectively occurs. The armature 20 can thus be deflected in the longitudinal direction L in controlled fashion by way of the energization of the coil 24.

[0078] FIG. 4 schematically illustrates a further embodiment of the linear actuator 16. The linear actuator 16 is of substantially identical construction to the linear actuators 16 described above, as have been discussed with reference to FIGS. 2 and 3. Analogous explanations, features and/or advantages thus apply. The linear actuator 16 from FIG. 4 however differs in terms of the embodiment of the conductive element 26 and the associated arrangement of the permanent magnets 22a, 22b and the coil 24. To explain the differences and the associated effects, reference is also made, as above, to the fact that the linear actuator 16 is of symmetrical construction with respect to the axis A. Therefore, the construction of the right-hand half of the linear actuator 16 will be discussed below, wherein analogous features, advantages and effects apply to the rest of the linear actuator 16.

[0079] As in FIG. 3, the conductive element 26 of the linear actuator 16 from FIG. 4 is of C-shaped form. However, a permanent magnet 22 and at least a part of a coil 24 have been inserted into the corresponding opening, wherein the permanent magnet 22 and the coil 24 are arranged one behind the other in the transverse direction Q. As viewed in the transverse direction Q, the permanent magnet 22 is arranged at the armature side and the coil 24 is arranged at the longitudinal section side. Thus, the conductive element 26 engages over both the permanent magnets 22 and the coil 24. In the longitudinal direction L, the permanent magnet 22 extends over the entire longitudinal extent of the coil 22 and preferably beyond. Thus, the permanent magnet 22 adjoins both the lower collar 28 and the upper collar 32. If the coil 26 is now energized, a coil magnetic field with correspondingly ring-shaped magnetic field lines is generated, which magnetic field lines are concentrated by the conductive element 26 and by the yoke formed by the armature 20. Owing to the arrangement of the permanent magnet 22 adjacent to the two collars 28, 32, the magnetic field will be constructively superposed in the lower collar 28 and will be destructively superposed in the upper collar 32, or vice versa. The armature 20 is thus subjected to a pulling force in the longitudinal direction L.

[0080] FIG. 5 schematically illustrates a further embodiment of the linear actuator 16. The linear actuator 16 is of substantially identical construction to the linear actuators 16 described above, as have been discussed with reference to FIGS. 2 to 4. Analogous explanations, features and/or advantages thus apply. The linear actuator 16 from FIG. 5 however differs in terms of the embodiment of the bearing arrangement of the armature 20.

[0081] To ensure that the armature 20 performs the desired movement only in the longitudinal direction L, it has been discussed above by way of example on the basis of exemplary embodiments that the armature 20 is fastened at its top side by way of an upper guide spring 61, and at its bottom side by way of a lower guide spring 63, to the stator 18. The two guide springs 61, 63 prevent the armature 20 from being able to perform a movement in the transverse direction Q. For this purpose, the guide springs 61, 63 must often be configured with a high stiffness. Said high stiffness can however have the disadvantage, during a movement of the armature in the longitudinal direction, that the armature 20 must bend the guide springs 61, 63 in the longitudinal direction L, such that corresponding reaction forces act on the armature 20. Said forces that arise during a movement of the armature 20 give rise to a loss of power, which does not serve for deflection, for example of the control diaphragm 12.

[0082] To avoid or at least considerably reduce said loss of power and at the same time restrict the movement direction of the armature 20 to a movement direction in the longitudinal direction L, the armature 20 may be mounted by way of a slide bearing arrangement 62. For this purpose, the slide bearing arrangement 62 has a degree of freedom in the longitudinal direction L. It can thus transmit forces in the transverse direction Q of the actuator 16. Owing to the preferred mechanical connection of the armature 20 to the control diaphragm 12, it is possible for the precision of the guidance of the armature in the longitudinal direction L to be further improved, in particular if the control diaphragm 12 is designed for accommodating forces in the transverse direction Q. The slide bearing arrangement 62 ensures that, even in the event of a deflection in the longitudinal direction L, the armature 20 has a radially outside spacing, characterized in particular by the air gap 60, with respect to the stator 18.

[0083] The slide bearing arrangement 62 particularly preferably has a very low coefficient of friction, such that a loss of power that arises as a result of the friction during a movement of the armature 20 in the longitudinal direction L is negligibly small. Under this assumption, no additional power reserves have to be allowed for in terms of construction in the actuator 16, which power reserves would otherwise be necessary in the case of known actuators in order to perform as large as possible a deflection in the longitudinal direction L. Therefore, the actuator 16 can be made altogether more compact and smaller, which furthermore makes it possible to realize a weight reduction of the actuator 16 and of the hydraulic mount 2.

[0084] As can be seen from FIG. 5, the conductive element 26 of the linear actuator 16 is again of C-shaped form in cross section. A permanent magnet 22 and a coil 24 have been inserted into the corresponding opening, which is also referred to as receiving region, wherein the permanent magnet 22 and the coil 24 are arranged one behind the other in the transverse direction Q. As viewed in the transverse direction Q, the permanent magnet 22 is arranged at the armature side and the coil 24 is arranged at the longitudinal section side. Thus, the conductive element 26 engages over both the permanent magnets 22 and the coil 24. In the longitudinal direction L, the permanent magnet 22 extends over the entire longitudinal extent of the coil 22 and preferably beyond. In other words, the permanent magnet 22 adjoins both the lower collar 28 and the upper collar 32. The lower collar 28 forms, by way of the associated side facing toward the armature 20, a stator pole surface 82, in particular a lower stator pole surface. A corresponding situation applies to the upper collar 32, which, by way of the associated side facing toward the armature 20, forms a further stator pole surface 82, in particular an upper stator pole surface. If the coil 26 is now energized, a coil magnetic field with correspondingly ring-shaped magnetic field lines is generated, which magnetic field lines are concentrated by the conductive element 26 and by the yoke 34 formed by the armature 20. Owing to the arrangement of the permanent magnet 22 adjacent to the two collars 28, 32, the magnetic field will be constructively superposed in the lower collar 28 and will be destructively superposed in the upper collar 32, or vice versa. The armature 20 is thus subjected to a pulling force in the longitudinal direction L.

[0085] The armature 20 composed of or comprising ferromagnetic material forms, as mentioned above, a yoke 34 for the conductive element 26. The armature 20 requires neither a permanent magnet nor a coil for this purpose. The armature 20 is thus free from permanent magnets and/or coils. In practice, it has proven to be expedient if the yoke 34 formed by the armature 20 extends in the longitudinal direction L from a lower section 84 via a middle section 56 to an upper section 86. In a rest position of the armature 20, the upper section 84 is aligned opposite the upper collar 32 and the lower section 86 is aligned opposite the lower collar 28. In other words, the upper section 84 and the upper collar 32 are arranged in a common upper plane, and the lower section 86 and the lower collar 28 are arranged in a common lower plane. The lower section 84 of the armature 20 forms, by way of the associated side facing toward the stator 18, an armature pole surface 80, in particular a lower armature pole surface. A corresponding situation applies to the upper section 86, which, by way of the associated side facing toward the stator 18, forms a further armature pole surface 80, in particular an upper armature pole surface. The lower armature section 84, the upper armature section 86 and the collars 28, 32 thus define an air gap 60 which forms in each case in the region between one of the armature pole surfaces 80 and a stator pole surface 82, arranged opposite said one of the armature pole surfaces, in the transverse direction Q. Here, the air gap 60 has a gap width B in the transverse direction Q.

[0086] It can be seen from FIG. 5 that the slide element 70 is enclosed in the longitudinal direction L in a depression 88 of the stator 18 between the lower collar 28 and the upper collar 32. The slide element 70 is thus arranged between the upper collar 32 and the lower collar 28 in the longitudinal direction L of the linear actuator 16. Thus, the slide element 70 does not overlap the stator pole surfaces 82 of the stator 18. It is thus possible for the stator pole surfaces 82 and the armature pole surfaces 80 to be arranged opposite one another in pairwise fashion in a rest position of the linear actuator 16. As discussed above, the armature pole surfaces 80 are formed on a respective side, facing toward the stator 18, of the lower armature section 84 and of the upper armature section 86. The middle section 56 of the armature 20 is between the lower armature section 84 and the upper armature section 86. Here, that side of the middle section 56 of the armature 20 which faces toward the stator 18 forms a bearing surface 90 of the slide bearing arrangement 62. The armature 20 lies by way of the bearing surface 90 directly against the slide element 70. The slide element 70 thus forms, with the side facing toward the armature 20, a counterpart bearing surface 92 of the slide bearing arrangement 62.

[0087] To prevent the armature pole surfaces 80 from abutting against the stator pole surfaces 82 and thus giving rise to undesired mechanical friction, the slide element 70 projects in the transverse direction Q beyond the stator pole surfaces 82 formed by the collars 28, 32. The height in the transverse direction Q by which the slide element 70 projects beyond the stator pole surfaces 82 simultaneously defines the gap width B of the air gap 60. As can also be seen from FIG. 5, it is however also the case that a part of the slide element 70 is enclosed in the depression 88, such that the gap width B is smaller than the slide element width G. This has the further advantage that the slide element 70 can have an adequately large slide element width G which ensures adequately high structural stability of the slide element 70. Despite the relatively large slide element width G, the air gap width B can be kept particularly small, which reduces the magnetic resistance at the air gap 60. The arrangement of the slide element 70 between the collars 28, 32 of the stator 18, with partial enclosure in the depression 88 of the stator 18, thus makes it possible to realize an advantageous bearing arrangement of the armature 20 with simultaneous low magnetic resistance at the air gap 60.

[0088] Furthermore, it can be seen from FIG. 5 that the lower armature section 84, the middle section 56 of the armature 20 and the upper armature section 86 are of uninterrupted form. This permits particularly simple production of the armature 20. Furthermore, the bearing surface 90 of the slide bearing arrangement 62 and the armature pole surfaces 80 provided for the yoke 34 can be formed on a common, uninterrupted armature side 94. With this embodiment, a particularly compact construction of the linear actuator 16 can be ensured. This is because, in the event of a deflection of the armature 20 in the longitudinal direction L, the armature 20 can slide with the upper armature section 86 or the lower armature section 84 over the counterpart bearing surface 92 without problems. This is the case in particular if the armature pole surfaces 80 and the bearing surface 90 are arranged in alignment with one another. If a corresponding deflection of the armature 20 now occurs, the bearing surface 90 formed by the armature 20 is displaced into the upper armature section 86 or into the lower armature section 84. A corresponding situation applies to the armature pole surfaces 80, which may now be formed partially by the middle section 56 of the armature 20. In other words, the various sections 28, 84, 86 of the armature 20 perform dual functions and simultaneously permit a deflection of the armature 20 with low resistance.

LIST OF REFERENCE SIGNS

Part of the Description

[0089] A Axis [0090] L Longitudinal direction [0091] Q Transverse direction [0092] B Gap width [0093] G Slide element width [0094] 2 Hydraulic mount [0095] 4 Working chamber [0096] 6 Equalization chamber [0097] 8 Partition [0098] 10 Throttle duct [0099] 12 Control diaphragm [0100] 14 Working chamber volume [0101] 16 Linear actuator [0102] 18 Stator [0103] 20 Armature [0104] 22 Permanent magnet [0105] 22a Lower permanent magnet [0106] 22b Upper permanent magnet [0107] 24 Coil [0108] 26 Conductive element [0109] 28 Lower collar [0110] 30 Longitudinal section [0111] 32 Upper collar [0112] 34 Yoke [0113] 36 Load-bearing spring [0114] 38 Cover [0115] 40 Base housing [0116] 46 Plunger [0117] 48 Separating body [0118] 50 Stator housing [0119] 54 Lower web [0120] 56 Middle section [0121] 58 Upper web [0122] 60 Air gap [0123] 61 Upper guide spring [0124] 62 Slide bearing arrangement [0125] 63 Lower guide spring [0126] 65 Holder [0127] 70 Slide element [0128] 80 Armature pole surface [0129] 82 Stator pole surface [0130] 84 Lower section [0131] 86 Upper section [0132] 88 Depression [0133] 90 Bearing surface [0134] 92 Counterpart bearing surface [0135] 94 Armature side