Relay

Abstract

A relay (1) comprises an electromagnetic drive unit (2) having a rotatable armature (3) and a yoke (4), wherein the armature (3) comprises a first magnetic contact area (5), the yoke (4) comprises a second magnetic contact area (6), the first magnetic contact area (5) contacts the second magnetic contact area (6) in a first state of the relay (1), the relay (1) further comprises at least a non-movable first electrical contact (7) and a movable contact arm (8) having at least a second electrical contact (9), wherein the first electrical contact (7) contacts the second electrical contact (9) in the first state, wherein the armature (3) and the contact arm (8) are arranged together on a shaft (10) and are implemented as a torsion element (11) together with the shaft (10).

Description

Technical Field

[0001] The invention relates to a relay. Background Art

[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 low resistance and low dissipated energy.

[0003] Electromagnetic relays are part of so-called hybrid switchgear, in particular hybrid circuit breakers (HCBs). Hybrid switchgear contains a semiconductor switching unit that is shunted by a relay. Such a relay is usually called a bypass relay. In normal operation, the contacts of the bypass relay are closed and the semiconductor switching unit is usually in non-conducting mode. The semiconductor switching unit can also be in conducting or semi-conducting mode. The current through the switchgear flows through the low-resistance bypass relay.

[0004] In terms of short-circuit switch-off operation, the bypass relays must open their contacts as quickly as possible. The faster the contact opening operation, the faster the current commutates to the semiconductor switching unit. Fast-opening bypass relays enable the semiconductor switching unit to cut off rising currents at a lower level than slow-opening contacts. If the semiconductor switching unit does not need the ability to cut off large currents, the complete semiconductor switching unit can be implemented with semiconductor elements with a lower maximum current capability. Such semiconductors are physically smaller than high-current semiconductors. They have lower resistance and heat dissipation, and they result in a lower loop inductance of the semiconductor switching unit, resulting in lower current commutation times.

[0005] The bypass relay contact opening time or speed is the central point of the hybrid circuit breaker design. This time or speed limits the miniaturization of the entire switchgear. The actual contact opening time of the bypass relay has a direct impact on most other components, especially the required power rating of the semiconductors. Slow bypass relays require semiconductor switching units with high power ratings. Due to the large size of high power rated semiconductors, the bypass relay contact opening time is the largest factor affecting the overall size of the hybrid switchgear.

[0006] The contact opening time is partly affected by the power of the electromagnetic drive system. The power of the electromagnetic drive system in a practical system is limited by many factors, especially the power of the power supply, and again the total available volume of the device.

[0007] A disadvantage of known or available relays is that their contact opening times are too long to build compact hybrid circuit breakers. Another disadvantage is that the opening time increases with several switching cycles. Summary of the invention

[0008] An object of the present invention is to overcome the disadvantages of the prior art by providing a relay having a very low or short contact opening time or fast opening contacts.Another object of the present invention is to provide a relay with low resistance and low power requirements for fast switching operations.

[0009] According to the invention, this object is solved by the following features.

[0010] A relay comprises an electromagnetic drive unit having a rotatable armature and a yoke, wherein the armature comprises a first magnetic contact area, the yoke comprises a second magnetic contact area, the first magnetic contact area contacts the second magnetic contact area in a first state of the relay, the relay further comprises at least a non-movable first electrical contact and a movable contact arm having at least a second electrical contact, the first electrical contact contacts the second electrical contact in the first state, characterized in that the armature and the contact arm are arranged together on a shaft, and the shaft is implemented as a torsion element.

[0011] The relay according to the invention thus has a high contact pressure resulting in a low resistance. The relay has no air gap between the yoke and the armature, resulting in a low power demand on the coil of the electromagnetic drive unit when switching. The torsion element can provide a high contact pressure as well as the missing air gap in many switching operations, thereby compensating for physical inaccuracies and physical variations in the electrical contact system and the magnetic system. Since such compensation in one direction of rotation is sufficient, the torsion element or the shaft can also be designed to be rigid or to support movement in a time-dependent direction of rotation in order to open the contacts.

[0012] The arrangement of the armature and the contact arm on the same axis provides a system with low inertial mass and low moment of inertia. Therefore, the armature and the contact arm can be accelerated very quickly. The acceleration of the armature and the contact arm requires low energy.

[0013] Therefore, the relay according to the present invention can cut off the low voltage current within 500 μs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The invention is described with reference to the accompanying drawings, which show preferred embodiments only.

[0015] Figure 1 shows the open front side of the relay according to the invention in a second state;

[0016] Figure 2 Shows Figure 1 The open rear side of the middle relay;

[0017] Figure 3 Shown in the first state Figure 1 The open front side of the relay in;

[0018] Figure 4 Shows Figure 3 The open rear side of the middle relay;

[0019] Figure 5 shows the Figure 3 A cross-sectional view taken from the AA cutting plane;

[0020] Figure 6 Shows Figure 1 The armature, shaft and contact arm of the relay, wherein the cross section of the contact arm is open;

[0021] Figure 7 Shows Figure 6 The armature in; and

[0022] Figure 8 Shows Figure 6 The axis in. DETAILED DESCRIPTION

[0023] Figure 1 Figure 5 shows a relay 1, which includes an electromagnetic drive unit 2 having a rotatable armature 3 and a yoke 4, the armature 3 including a first magnetic contact area 5, the yoke 4 including a second magnetic contact area 6, the first magnetic contact area 5 is in contact with the second magnetic contact area 6 in a first state of the relay 1, the relay 1 also includes at least a non-movable first electrical contact 7 and a movable contact arm 8 having at least a second electrical contact 9, in the first state, the first electrical contact 7 is in contact with the second electrical contact 9, wherein the armature 3 and the contact arm 8 are arranged together on a shaft 10 and are implemented as a torsion element 11 together with the shaft 10.

[0024] The relay 1 according to the invention thus has a high contact pressure resulting in a low resistance. The relay 1 has no air gap between the yoke 4 and the armature 3, resulting in a low power demand for the coils 21, 22 of the electromagnetic drive unit 2 during switching. The torsion element 11 can provide a high contact pressure as well as a missing air gap in many switching operations, which compensates for physical inaccuracies and physical variations in the electrical contact system and the electromagnetic system. Since it is sufficient to perform this compensation in one direction of rotation, the torsion element 11 or the shaft 10 can also be designed to be rigid or to support movement in a time-dependent direction of rotation to disconnect the electrical contacts 7, 9, 14, 15.

[0025] The arrangement of the armature 3 and the contact arm 8 on the same shaft 10 provides a system with low inertial mass and low moment of inertia. Therefore, the armature 3 and the contact arm 8 can be accelerated very quickly. The acceleration of the armature 3 and the contact arm 8 requires low energy.

[0026] Therefore, the relay 1 according to the present invention can cut off the low voltage current in 500 μs or less.

[0027] The actual relay 1 is preferably a relay 1 for low voltage applications.

[0028] The relay 1 is particularly suitable for use as a bypass relay in a hybrid circuit breaker comprising at least a semiconductor switching unit and a bypass relay, wherein the bypass relay is arranged in parallel with the semiconductor switching unit. The applicant describes a hybrid circuit breaker according to this concept in WO2015 / 028634. Preferably, the bypass relay is implemented as the relay 1 according to the present invention.

[0029] The relay 1 comprises an electromagnetic drive unit 2 and an electrical switching device.

[0030] The electromagnetic drive unit 2 comprises a rotatable armature 3 and a yoke 4. The electromagnetic drive unit 2 further comprises at least a first coil 21 which is at least partially wound around the area of ​​the yoke 4. According to a preferred embodiment, the electromagnetic drive unit 2 further comprises a second coil 22 which is at least partially wound around the area of ​​the yoke 4.

[0031] The electromagnetic drive unit 2 also comprises in particular at least a first permanent magnet 23, which is arranged between the two parts of the yoke 4. According to a preferred embodiment, the electromagnetic drive unit 2) also comprises a second permanent magnet 24, which is also arranged between the two parts of the yoke 4.

[0032] According to a preferred embodiment, Figure 1 As shown in FIG. 5 , the arrangement including the yoke 4 , the first and second coils 21 , 22 and the first and second permanent magnets 23 , 24 is substantially symmetrical.

[0033] The actual relay 1 can be in two different stable states. The first state is defined as the on state. In this state, the electrical contacts 7, 9, 14, 15 are closed or in contact, and current is allowed to flow through the relay 1. The second state is defined as the off state. In this state, the electrical contacts 7, 9, 14, 15 are open or separated, and current is prohibited from flowing through the relay 1.

[0034] The relay 1 according to the actual invention is a bistable relay.

[0035] The armature 3 is rotatably mounted. The armature 3 comprises at least a first arm having a first magnetic contact area 5 in contact with a second magnetic contact area 6 of the yoke 4. In the first state, the first magnetic contact area 5 is in contact with the second magnetic contact area 6. The first magnetic contact area 5 preferably comprises both sides of the first arm.

[0036] According to a preferred embodiment, the yoke 4 comprises a further magnetic contact zone on the opposite side of the second magnetic contact zone 6, which is in fact called fifth magnetic contact zone 27. The armature 3 is specifically designed so that the first magnetic contact zone 5 contacts the fifth magnetic contact zone 27 in the second state of the relay.

[0037] according to Figure 1In the preferred embodiment shown in FIG. 5 , the armature 3 comprises a second arm, which is implemented as a third magnetic contact zone 16. Preferably, the armature 3 is substantially symmetrically constructed. According to this embodiment, the yoke 4 also comprises a fourth magnetic contact zone 17 and a sixth magnetic contact zone 28. In the first state, the third magnetic contact zone 16 is in contact with the fourth magnetic contact zone 17. In the second state, the third magnetic contact zone 16 is in contact with the sixth magnetic contact zone 28.

[0038] The electrical contact mechanism comprises at least a non-movable first electrical contact 7, which is arranged on a first contact piece 25, which comprises at least one opening or solder for external connection. The electrical contact mechanism also comprises at least one movable contact arm 8. On the contact arm 8 at least a second electrical contact 9 is arranged.

[0039] In the first state, the first electrical contact 7 contacts the second electrical contact 9 .

[0040] According to a preferred embodiment, Figure 1 5, the contact arm 8 is substantially symmetrical and comprises a third electrical contact 14 for contacting a non-movable fourth electrical contact 15 of the relay 1. The non-movable fourth electrical contact 15 is arranged on a second contact piece 26 comprising at least one opening or solder for external connection.

[0041] The contact arm 8 according to the preferred embodiment provides a double contact point for making or breaking and is also referred to as a contact bridge.

[0042] All electrical contacts are implemented as switch contacts. They are not implemented as any type of sliding contacts or blade contacts.

[0043] The contact arm 8 is coupled to the armature 3 via a shaft 10. The armature 3 and the contact arm 8 are arranged together on the same shaft 10. The shaft 10 is designed as a torsion element 11.

[0044] The shaft 10 can be formed according to any material or form or include any cross-section, as long as it has sufficient flexibility or elasticity to compensate for the physical differences of the electromagnetic drive unit 2 and the electrical contact system, so that the magnetic contact areas 5, 6, 16, 17, 27, 28 can be contacted without air gaps, and the electrical contact areas 7, 9, 14, 15 are connected with sufficient contact pressure. The torsion element 11 must also have sufficient flexibility to compensate for the predefined degree of position and / or size changes of the magnetic contact areas 5, 6, 16, 17, 27, 28 and / or the electrical contacts 7, 9, 14, 15.

[0045] According to a preferred embodiment, the shaft 10 is implemented as a torsion spring 12. This is a simple embodiment of a torsion element 11. Other terms for the torsion spring 12 are torsion spring or torsion bar or torque bar.

[0046] In particular, the torsion spring 12 is implemented as a leaf spring 13. It is therefore easy to connect the armature to the contact arm 8, ie this connection is rigid in the direction of rotation intended to open the electrical contacts 7, 9, 14, 15.

[0047] Figure 8 A preferred embodiment of the shaft 10 is shown as a flat torsion spring 12 , 13 . Figure 8 The torsion of the leaf spring 13 is shown.

[0048] According to a particularly preferred embodiment, the torsion spring 12 is also arranged and embodied to accelerate the contact arm 8 at the beginning of the separation movement of the electrical contacts 7, 9. This acceleration at the beginning of the movement supports the armature 3 by opening the contacts 7, 9, 14, 15 and additionally shortens the contact opening time. This further acceleration can be provided by torsion of the leaf spring 13, such as Figure 8 As shown. The torsion spring 12 will be tightened during the on-operation and transmit the torque of the electromagnetic drive unit 2 to the electrical contacts as contact pressure. At the beginning of the off-operation, the torsion spring 12 first accelerates the armature 3 and then the contact arm 8. The acceleration period lasts as long as the contact arm 8 or at least the second electrical contact 9 is in contact with at least the immovable first electrical contact 7.

[0049] Figure 7 The armature 3 and an opening or recess 33 in the armature 3 for arranging the shaft 10 are shown. This recess 33 contains two contact surfaces 34 for supporting the shaft 10 in the form of a leaf spring 13. The contact surfaces 34 of the recess 33 are preferably arranged on the same side as the electrical contacts 9, 14 at the contact arm 8. Figure 6 and Figure 7 From the perspective of FIG. 3 , the contact surface 34 on the right side is on the top area of ​​the groove 33 . The corresponding third electrical contact 14 on the right side of the contact arm 8 is arranged on the upper side of the contact arm 8 .

[0050] The relay 1 comprises a relay housing 18, which is only shown in FIG5 . The relay housing 18 comprises two bushings for supporting the shaft 10. The shaft 10 is floatingly mounted in the relay housing 18 with a certain movement tolerance in a direction perpendicular to the axis of the shaft 10. This enables the shaft 10 to compensate for further variations in the geometry of the electromagnetic drive unit 2 and / or the electrical contact system.

[0051] According to another preferred embodiment, the relay 1 comprises an auxiliary electrical path from the first auxiliary contact 31 to the second auxiliary contact 32. The relay 1 or the auxiliary electrical path comprises at least one auxiliary spring 19, 20, which is also an electrical contact element. In the second state, the auxiliary spring 19, 20 biases the contact arm 8 in the direction toward the first electrical contact 7, in which second state the second electrical contact 9 is spaced apart from the first electrical contact 7. According to a preferred embodiment with an additional second auxiliary spring 20, the auxiliary electrical path is closed in the second state. The auxiliary springs 19, 20 further support the electromagnetic drive unit 2 for bringing the contact arm 8 from the second state to the first state.

Claims

1. A relay (1), comprising an electromagnetic drive unit (2) having a rotatable armature (3) and a yoke (4), wherein the rotatable armature (3) comprises a first magnetic contact area (5), the yoke (4) comprises a second magnetic contact area (6), the first magnetic contact area (5) contacts the second magnetic contact area (6) in a first state of the relay (1), the relay (1) further comprising at least a first non-movable electrical contact (7) and a movable contact arm (8) having at least a second electrical contact (9), the first electrical contact (7) contacts the second electrical contact (9) in the first state, wherein: The rotatable armature (3) is connected to the movable contact arm (8) via a shaft (10), wherein the shaft (10) is implemented as a torsion element (11), thereby allowing the rotatable armature (3) to rotate relative to the movable contact arm (8) through the torsion of the shaft (10).

2. The relay (1) according to claim 1, characterized in that: The shaft (10) is designed as a torsion spring (12).

3. The relay (1) according to claim 2, characterized in that: The torsion spring (12) is designed as a leaf spring (13).

4. The relay (1) according to claim 2 or 3, characterized in that: The torsion spring (12) is arranged and implemented to accelerate the movable contact arm (8) at the beginning of the separation movement of the first electrical contact (7) and the second electrical contact (9).

5. The relay (1) according to claim 1, characterized in that: The movable contact arm (8) is symmetrical and includes a third electrical contact (14) to contact a non-movable fourth electrical contact (15) of the relay (1) in the first state, and the rotatable armature (3) is symmetrical and includes a third magnetic contact area (16) to contact a fourth magnetic contact area (17) of the electromagnetic drive unit (2).

6. The relay (1) according to claim 1, characterized in that The relay (1) comprises a relay housing (18), and the shaft (10) is floatingly mounted in the relay housing (18) with a certain movement tolerance in a direction perpendicular to an axis of the shaft (10).

7. The relay (1) according to claim 1, characterized in that The relay (1) comprises at least one auxiliary spring (19, 20), wherein in a second state, the auxiliary spring (19, 20) biases the movable contact arm (8) in a direction toward the first electrical contact (7), and in the second state, the second electrical contact (9) is spaced apart from the first electrical contact (7).

8. 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 switch unit, characterized in that: The bypass relay is embodied as a relay (1) according to any one of claims 1 to 7.

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