Electromagnetic drive unit

Abstract

For an electromagnetic drive unit (2) having an armature (3), a yoke (4) and a first coil (24), the armature (3) is mounted in a pivotal manner and comprises a first armature magnetic contact region (5), the yoke (4) comprises a first yoke magnetic contact region (7) and a second yoke magnetic contact region (8), the first yoke magnetic contact region (7) comprises a first contact region (9) and the second yoke magnetic contact region (8) comprises a second contact region (10), the first yoke magnetic contact region (5) being in contact with the first contact region (9) in a first state of the electromagnetic drive unit (2) and the second yoke magnetic contact region (8) being in contact with the second contact region (10) in a second state of the electromagnetic drive unit (2). The first yoke magnetic contact region (5) is in contact with the second contact region (10), and it is proposed that the first yoke magnetic contact region (7) and the second yoke magnetic contact region (8) are formed such that a first magnetic latching torque in a first state is higher than a second magnetic latching torque in a second state.

Description

[0001] The present disclosure relates to an electromagnetic drive unit according to the preamble of claim 1 .

[0002] Electromagnetic relays are well known and are part of many electrical devices. Even in the age of semiconductor switching elements, the classic mechanical relay has the advantages of lower resistance and lower dissipated energy.

[0003] Electromagnetic relays are part of hybrid switchgear, particularly hybrid circuit breakers (HCBs). Hybrid switchgear includes a semiconductor switching unit that is shunted by a relay. This relay is often called a bypass relay. During normal operation, the bypass relay's contacts are closed, and the semiconductor switching unit is typically in a non-conducting mode. Current flowing through the switchgear flows through the low-resistance bypass relay. Applicants describe a hybrid circuit breaker based on this concept in WO 2015 / 028634.

[0004] In the event of a short-circuit interruption, the bypass relay's contacts must open as quickly as possible. The faster the contacts open, the faster the current is diverted to the semiconductor switching unit. Compared to slower contact opening, a fast-opening bypass relay enables the semiconductor switching unit to interrupt rising currents at a lower level. If the semiconductor switching unit does not require the ability to interrupt high currents, the entire semiconductor switching unit can be implemented using semiconductor components with a lower maximum current capability. Such semiconductors are physically smaller than high-current semiconductors. They have lower resistance and heat dissipation, resulting in lower loop inductance in the semiconductor switching unit and, consequently, shorter current diversion times.

[0005] The bypass relay's contact opening time or speed is a key factor in hybrid circuit breaker design. This time and / or speed limits the overall miniaturization of the switchgear. The bypass relay's actual contact opening time directly impacts most other components, particularly the required power rating of the semiconductors. Slow bypass relays require semiconductor switching units with high power ratings. Because semiconductors with high power ratings are larger, the bypass relay's contact opening time is the largest factor influencing the overall size of the hybrid switchgear.

[0006] The contact opening time is partly affected by the electromagnetic drive unit of the relay and the mechanical design of the relay. Applicant's WO 2021 / 008991 A1 shows a special design of the mechanical connection between the electromagnetic drive unit of the relay and the movable electrical contacts of the relay.

[0007] The object of the present invention is to overcome the disadvantages of the prior art by providing an electromagnetic drive unit for a relay, in particular a bypass relay of an HCB, the electromagnetic drive unit having a shortened and / or very short contact opening time.

[0008] According to the invention, this object is achieved by the features of claim 1 .

[0009] The holding torque of the electromagnetic drive unit influences the relay's tripping time. Therefore, this holding torque can be used to shorten tripping time. Design changes to the yoke's magnetic contact area are easier to implement and more cost-effective in manufacturing than using stronger permanent magnets.

[0010] Therefore, the electromagnetic drive unit can disconnect the relay in a very short time. The electromagnetic drive unit according to the present invention does not require more space than the electromagnetic drive unit according to WO 2021 / 008991 A1, but the disconnection time is shortened by 10%-20%.

[0011] The dependent claims describe further preferred embodiments of the invention.

[0012] The invention is described with reference to the accompanying drawings, which merely illustrate exemplary embodiments of the invention.

[0013] Figure 1 shows the open front side of a relay for an electromagnetic drive unit according to the present invention;

[0014] Figure 2 The axonometric diagram shows the Figure 1 relays;

[0015] Figure 3 A first preferred embodiment of the electromagnetic drive unit is shown in a first state;

[0016] Figure 4 Shown according to Figure 3 Details of the electromagnetic drive unit;

[0017] Figure 5 The axonometric diagram shows the Figure 3 electromagnetic drive unit;

[0018] Figure 6 The second preferred embodiment with an electromagnetic drive unit is shown according to Figure 1 Rear view of the relay;

[0019] Figure 7 Based on the axonometric drawing Figure 6 relays;

[0020] Figure 8 The electromagnetic drive unit is shown in an on state;

[0021] Figure 9 shows the electromagnetic drive unit in a disconnected state;

[0022] Figure 10 A second preferred embodiment of the electromagnetic drive unit is shown in a first state; and

[0023] Figure 11 Shown according to Figure 10 Details of the electromagnetic drive unit.

[0024] Figures 3 to 7 、 Figure 10 and Figure 11 At least some preferred embodiments of an electromagnetic drive unit 2, in particular for a relay 1, are shown. The electromagnetic drive unit 2 comprises an armature 3, a yoke 4, a first permanent magnet 19, and a first coil 24. The armature 3 is pivotally mounted about a predetermined rotation axis 6. The armature 3 comprises a first armature magnetic contact region 5. The yoke 4 comprises a first yoke magnetic contact region 7 and a second yoke magnetic contact region 8. The first yoke magnetic contact region 7 comprises a first contact region 9, and the second yoke magnetic contact region 8 comprises a second contact region 10. In a first state of the electromagnetic drive unit 2, the first armature magnetic contact region 5 is in contact with the first contact region 9, and in a second state of the electromagnetic drive unit 2, the first armature magnetic contact region 5 is in contact with the second contact region 10. The first yoke magnetic contact region 7 and the second yoke magnetic contact region 8 are formed such that a first magnetic holding torque in the first state is higher than a second magnetic holding torque in the second state.

[0025] The holding torque of the electromagnetic drive unit influences the relay's tripping time. Therefore, this holding torque can be used to shorten tripping time. Design changes to the yoke's magnetic contact area are easier to implement and more cost-effective in manufacturing than using stronger permanent magnets.

[0026] Therefore, the electromagnetic drive unit can disconnect the relay in a very short time. The electromagnetic drive unit according to the present invention does not require more space than the electromagnetic drive unit according to WO 2021 / 008991 A1, but the disconnection time is shortened by 10% to 20%.

[0027] The electromagnetic drive unit 2 is preferably part of a relay 1, particularly a relay 1 for low-voltage applications. The relay 1 is particularly intended for use as a bypass relay in a hybrid circuit breaker, which comprises at least a semiconductor switching unit and a bypass relay, wherein the bypass relay is arranged in parallel with the semiconductor switching unit. A hybrid circuit breaker according to this concept is described, for example, by the applicant in WO 2015 / 028634. The bypass relay is preferably implemented as the relay 1 according to the present invention.

[0028] The electromagnetic drive unit 2 includes an armature 3 and a yoke 4 .

[0029] The yoke 4 comprises a first yoke magnetic contact area 7 and a second yoke magnetic contact area 8. The first yoke magnetic contact area 7 comprises a first contact area 9, and the second yoke magnetic contact area 8 comprises a second contact area 10. According to a preferred embodiment, the second yoke magnetic contact area 8 is arranged on the opposite side of the first yoke magnetic contact area 7.

[0030] The electromagnetic drive unit 2 further includes at least a first coil 24 that is at least partially wound around an area on the yoke 4. According to a preferred embodiment, the electromagnetic drive unit 2 further includes a second coil 25 that is at least partially wound around an area on the yoke 4. In this preferred embodiment, the first yoke magnetic contact area 7 and the second yoke magnetic contact area 8 are arranged in the area between the first coil 24 and the second coil 25.

[0031] The electromagnetic drive unit 2 further comprises at least a first permanent magnet 19, which is arranged between the two parts of the magnetic yoke 4. In particular, the first permanent magnet 19 is arranged between the first magnetic yoke magnetic contact area 7 and the second magnetic yoke magnetic contact area 8. According to a preferred embodiment, the electromagnetic drive unit 2 further comprises a second permanent magnet 24, which is also arranged between the two parts of the magnetic yoke 4.

[0032] According to a preferred embodiment, Figure 3 、 Figure 5 、 Figure 6 and Figure 7 As shown, the arrangement including the yoke 4 , the first and second coils 24 , 25 , and the first and second permanent magnets 19 , 20 is substantially symmetrical.

[0033] The armature 3 is pivotally mounted about a predetermined axis of rotation 6. The armature 3 includes at least a first arm 42, wherein the first arm 42 is implemented as a first armature magnetic contact area 5 for contacting a first yoke magnetic contact area 7 and a second yoke magnetic contact area 8 of the yoke 4. The first magnetic contact area 5 preferably includes both sides of the first arm. In the first stage of the electromagnetic drive unit 2, the first armature magnetic contact area 5 is in contact with the first contact area 9. In the second stage of the electromagnetic drive unit 2, the first armature magnetic contact area 5 is in contact with the second contact area 10. As described above, the electromagnetic drive unit 2 is mechanically connected to the switching arrangement of the relay 1. The relay 1 has two different switching states: on and off. In the on state of the relay 1, the electromagnetic drive unit 2 is in the first state. In the off state of the relay 1, the electromagnetic drive unit 2 is in the second state.

[0034] According to a preferred embodiment, the yoke 4 comprises further magnetic contact areas on opposite sides of the first yoke magnetic contact area 7 and the second yoke magnetic contact area 8. The further magnetic contact areas comprise a third yoke magnetic contact area 26 with a third contact area 28 and a fourth yoke magnetic contact area 27 with a fourth contact area 29.

[0035] According to Figure 3 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 and Figure 11 In the preferred embodiment shown, the armature 3 includes a second arm 43, wherein the second arm 43 is implemented as the second armature magnetic contact area 30. The armature 3 is preferably implemented with point symmetry. Another word for point symmetry is center symmetry. In the first state of the electromagnetic drive unit 2, the second armature magnetic contact area 30 is in contact with the third yoke magnetic contact area 26. In the second state of the electromagnetic drive unit 2, the second armature magnetic contact area 30 is in contact with the fourth yoke magnetic contact area 27.

[0036] According to the present invention, the first yoke magnetic contact region 7 and the second yoke magnetic contact region 8 are formed and / or arranged such that the magnetic retaining torque in the first state is higher than the magnetic retaining torque in the second state.

[0037] In the further description, the invention is described with respect to the first yoke magnetic contact region 7 and the second yoke magnetic contact region 8 and the first armature magnetic contact region 5. All described features and / or details are also part of the preferred embodiment comprising the third yoke magnetic contact region 26 and the fourth yoke magnetic contact region 27 and the second armature magnetic contact region 30.

[0038] According to the first embodiment of the electromagnetic drive unit 2 , different magnetic holding torques are achieved by different designs of the two contact regions 9 , 10 .

[0039] The center of the contact area is independent of the geometry of the contact area. Preferably, a first perpendicular distance from the rotation axis 6 to the first center 11 or first center of mass of the first contact area 9 is greater than a second perpendicular distance from the rotation axis 6 to the second center 12 or second center of mass of the second contact area 10. The first center 11 and the second center 12 are Figure 4 Therefore, even if the resultant magnetic force of the first magnetic force 44 and the second magnetic force 45 is the same, the magnetic holding torque at the first yoke magnetic contact area 7 will be higher than the magnetic holding torque at the second yoke magnetic contact area 8.

[0040] According to a preferred embodiment, the surface of the first contact region 9 is smaller than the surface of the second contact region 10. In a preferred embodiment, the surface area of the first contact region 9 is 55%-80%, in particular 60%-75%, and especially about 70% of the surface area of the second contact region 10. Therefore, the first magnetic force 44 in the smaller first contact region 9 is higher than the second magnetic force 45 in the larger second contact region 10. Figure 8 and Figure 9 The different first magnetic forces 44 and second magnetic forces 45 are shown in the switched-on state and the switched-off state.

[0041] The first contact area 9 and the second contact area 10 can have different forms. According to another preferred embodiment, each of the first contact area 9 and the second contact area 10 has a flat rectangular form. This is advantageous from a manufacturing perspective. Preferably, the rectangle of the first contact area 9 and the rectangle of the second contact area 10 have substantially the same width. The first length of the first contact area 9 is shorter than the second length of the second contact area 10. This provides a practical and simple implementation of different surfaces for the first contact area 9 and the second contact area 10.

[0042] Preferably, the first contact area 9 and the second contact area 10 are flat areas. The shape of the flat area can be circular, rectangular, elliptical, or any other geometric shape. Due to manufacturing irregularities, the geometric shape of the first contact area 9 and / or the second contact area 10 can also include a combination of flat areas and lines and / or dots.

[0043] Besides features related to the surface of the contact areas 9 , 10 , the position of these contact areas also has an influence on the magnetic holding torque, since the torque is the resultant force multiplied by the perpendicular distance.

[0044] According to a further development of the contact areas 9, 10, the first outer end 13 of the first contact area 9 and the second outer end 14 of the second contact area 10 are at the same distance from the axis of rotation 6. Figure 4 Therefore, the first vertical distance will definitely be greater than the second vertical distance.

[0045] According to the second embodiment of the electromagnetic drive unit 2, the magnetic holding torque can be influenced by the design of the inner part of the yoke magnetic contact area 7, 8. Different magnetic holding torques can be obtained by different designs of the inner part of the yoke magnetic contact area 7, 8.

[0046] According to this second embodiment, the first yoke magnetic contact region 7 includes a first transition edge, which is arranged adjacent to the first inner end 31 of the first contact region 9. The second yoke magnetic contact region 8 includes a second transition edge, which is arranged adjacent to the second inner end 32 of the second contact region 10. The inner portion is closer to the axis of rotation 6 than the contact region. The first and second transition edges are preferably embodied as rounded edges, flat areas, a combination of short flat areas, a combination of short rounded edges, or a combination of rounded edges and flat areas. The first transition edge is larger than the second transition edge.

[0047] According to a preferred embodiment, the first transition edge is implemented as a first rounded edge 15 having a first radius 16, and the second transition edge is implemented as a second rounded edge 17 having a second radius 18. The first rounded edge 15 is arranged adjacent to the first inner end 31 of the first contact region 9. The second rounded edge 17 is arranged adjacent to the second inner end 32 of the second contact region 10. In other words, the contact regions 9 and 10 end at the points where the rounded edges 15 and 17, respectively, begin. The first radius 16 is larger than the second radius 18. The larger first radius 16 contributes to the magnetic flux in the first yoke magnetic contact region 7. The magnetic field is concentrated in the first contact region 9, and the magnetic flux density and the first magnetic force 44 increase.

[0048] Preferably, the second radius 18 is 30%-55%, in particular about 40%-45%, and especially 43% of the first radius 16, or the first radius 16 is 2.2-2.9 times, in particular about 2.5 times, the size of the second radius 18. For example, the first radius 16 may be between 0.8 mm and 0.9 mm, and the second radius 18 may be between 0.32 mm and 0.36 mm.

[0049] Figure 10 and Figure 11 Another preferred embodiment is shown. In this embodiment, the first transition edge is implemented as a first chamfer 51. Furthermore, in the third yoke magnetic contact region 26, the transition edge is implemented as a second chamfer 52.

[0050] According to a third embodiment of the electromagnetic drive unit 2 , features, in particular all features, of the first embodiment of the electromagnetic drive unit 2 are combined with features, in particular all features, of the second embodiment of the electromagnetic drive unit 2 . Figures 3 to 6 An electromagnetic drive unit 2 according to a third embodiment is shown.

[0051] Figure 1 、 Figure 2 and Figure 7A relay having an electromagnetic drive unit 2 according to the present invention is shown. The relay 1 further comprises at least a fixed first electrical contact 21 and a movable contact arm 22 having at least a second electrical contact 23. The fixed first electrical contact 21 is arranged on a first contact piece 35 of the relay 1, which comprises at least one opening for external connection.

[0052] According to a preferred embodiment, relay 1 is point-inverted and includes a fixed third electrical contact 33. Furthermore, contact arm 22 is point-symmetrical and includes a movable fourth electrical contact 34. Fixed third electrical contact 33 is arranged on a second contact piece 36 of relay 1, which includes at least one opening or soldering tab for external connection.

[0053] The movable contact arm 22 is mechanically connected to the rotatable armature 3 via a leaf spring 37, and the first electrical contact 21 contacts the second electrical contact 23 in the first state of the electromagnetic drive unit 2. Details of the leaf spring 37 are described in the applicant's WO 2021 / 008991A1.

[0054] According to another preferred embodiment, relay 1 includes an auxiliary electrical path from first auxiliary contact piece 38 to second auxiliary contact piece 39. Relay 1, in particular, includes at least one auxiliary spring 40, 41, which also serves as an electrical contact element. Auxiliary springs 40, 41 bias contact arm 22 toward fixed first electrical contact 21 in the second state. In this second state, second electrical contact 23 is spaced apart from fixed first electrical contact 21. According to a preferred embodiment, relay 1 includes first auxiliary spring 40 and second auxiliary spring 41. Auxiliary springs 40, 41 also support electromagnetic drive unit 2 in moving contact arm 22 from the second state to the first state.

[0055] As already partially described, the actual relay 1 is configured to have two different stable states. The first stable state is defined as the on state. In this state, the electrical contacts 21, 23, 33, 34 are closed, in particular, in contact, and current can flow through the relay 1. The second stable state is defined as the off state. In this state, the electrical contacts 21, 23, 33, 34 are open, in particular, separated, and current flow through the relay 1 is prohibited.

[0056] Although the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention as defined by the appended claims. The exemplary embodiments should be considered in an illustrative manner only and not for purposes of limitation. Accordingly, the scope of the present invention is defined not by the detailed description but by the appended claims.

[0057] The following are principles for understanding and interpreting actual disclosures.

[0058] Features are generally introduced with the indefinite article "a, an, an." Thus, unless the context indicates otherwise, "a, an, an" should not be understood as referring to a quantity.

[0059] Unless the context requires otherwise, the conjunction "or" must be interpreted as inclusive rather than exclusive. "A or B" also includes "A and B", where "A" and "B" represent random features.

[0060] Unless otherwise defined in the disclosure of the present invention, in some embodiments, ordinal numbers (such as "first," "second," or "third") are used to distinguish feature X or object Y. In particular, the presence of an ordinal number for a feature X or object Y in a claim does not mean that the embodiment of the present invention covered by the claim must have additional feature X or another object Y.

[0061] Unless the context dictates otherwise, "substantially" appearing in connection with a numerical value includes a tolerance of ±10% around the given numerical value.

[0062] For ranges of values, the endpoints are included unless the context dictates otherwise.

Claims

1. An electromagnetic drive unit (2), in particular for a relay (1), comprising an armature (3), a yoke (4), a first permanent magnet (19) and a first coil (24), The armature (3) is pivotally mounted about a predetermined rotation axis (6), the armature (3) comprising a first armature magnetic contact region (5), the yoke (4) comprising a first yoke magnetic contact region (7) and a second yoke magnetic contact region (8), the first yoke magnetic contact region (7) comprising a first contact region (9), and the second yoke magnetic contact region (8) comprising a second contact region (10), In a first state of the electromagnetic drive unit (2), the first armature magnetic contact area (5) is in contact with the first contact area (9), and in a second state of the electromagnetic drive unit (2), the first armature magnetic contact area (5) is in contact with the second contact area (10), It is characterized by: The first yoke magnetic contact region (7) and the second yoke magnetic contact region (8) are formed so that a first magnetic retaining torque in the first state is higher than a second magnetic retaining torque in the second state.

2. The electromagnetic drive unit (2) according to claim 1, characterized in that The second yoke magnetic contact region (8) is arranged on an opposite side of the first yoke magnetic contact region (7).

3. The electromagnetic drive unit (2) according to claim 1 or 2, characterized in that: A first perpendicular distance from the rotation axis (6) to a first center (11) of the first contact area (9) is greater than a second perpendicular distance from the rotation axis (6) to a second center (12) of the second contact area (10).

4. The electromagnetic drive unit (2) according to any one of claims 1 to 3, characterized in that: The surface area of the first contact region (9) is smaller than the surface area of the second contact region (10).

5. The electromagnetic drive unit (2) according to claim 4, characterized in that The surface area of the first contact region (9) is 55%-80%, in particular 60%-75%, especially about 70% of the surface area of the second contact region (10).

6. The electromagnetic drive unit (2) according to any one of claims 1 to 5, characterized in that: The first contact area (9) and the second contact area (10) have a rectangular form, the first contact area (9) and the second contact area (10) have substantially the same width, and a first length of the first contact area (9) is shorter than a second length of the second contact area (10).

7. The electromagnetic drive unit (2) according to claim 6, characterized in that The first outer end (13) of the first contact area (9) and the second outer end (14) of the second contact area (10) are at the same distance from the rotation axis (6).

8. The electromagnetic drive unit (2) according to any one of claims 1 to 7, characterized in that: The first yoke magnetic contact area (7) includes a first transition edge, and the second yoke magnetic contact area (8) includes a second transition edge, the first transition edge is arranged adjacent to the first inner end (31) of the first contact area (9), the second transition edge is arranged adjacent to the second inner end (32) of the second contact area (10), and the first transition edge is larger than the second transition edge.

9. The electromagnetic drive unit (2) according to claim 8, characterized in that The first transition edge is implemented as a first rounded edge (15) having a first radius (16), the second transition edge is implemented as a second rounded edge (17) having a second radius (18), and the first radius (16) is greater than the second radius (18).

10. The electromagnetic drive unit (2) according to claim 9, characterized in that The second radius (18) is 30%-55%, in particular approximately 40%-45%, and especially 43% of the first radius (16).

11. The electromagnetic drive unit (2) according to claim 8, characterized in that The first transition edge is implemented as a first chamfer (51).

12. The electromagnetic drive unit (2) according to any one of claims 1 to 11, characterized in that The first permanent magnet (19) is arranged between the first yoke magnetic contact area (7) and the second yoke magnetic contact area (8).

13. A relay (1) comprising an electromagnetic drive unit (2) according to any one of claims 1 to 12, the relay (1) comprising at least a fixed first electrical contact (21) and a movable contact arm (22) having at least a second electrical contact (23), the movable contact arm (22) being mechanically connected to a rotatable armature (3) via a leaf spring (37), the first electrical contact (21) contacting the second electrical contact (23) in a first state of the electromagnetic drive unit (2).

14. A hybrid circuit breaker comprising at least a semiconductor switch unit and a bypass relay, wherein: The bypass relay is arranged in parallel with the semiconductor switching unit, and is characterized in that the bypass relay is implemented as a relay (1) according to claim 13.

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