Decoupling device for wave-activated generator having rotor equipped with permanent magnets

Abstract

The invention relates to a decoupling device for a wave-activated generator having a rotor equipped with permanent magnets. The aim of the invention is to provide a simple decoupling device which allows a rotor equipped with permanent magnets to be decoupled from a drive shaft of a ship in the event of damage in a very short period of time and which securely and continuously fixes the rotor. According to the invention, the rotor (4) is fastened to the drive shaft (11) by means of an adapter ring (8) by means of fastening bolts (10). For each stator end side, at least three radially distributed cantilevers (12) are fastened to the stator housing (1). For each cantilever (12), at least one gasket element (15) is arranged between the cantilever (12) and the inner circumferential surface (17) of the rotor (4). At least one pressing opening (16) is provided in each cantilever (12). The cantilever (12) is connected to the stator end side of the stator housing (1) by means of a threaded connection. The cantilevers (12) hold the rotor (4) on the inner peripheral surface (17) of the rotor body (5). A special gasket element (15) makes it possible to form a form fit between the individual cantilevers (12) and the rotor body (5). A plurality of pressing openings (16) provided with internal threads are formed in the cantilevers. By means of the pushing threads in the cantilever (12), the gasket element (15) can be easily installed and removed by means of suitable screws through a few operations.

Description

Technical Field

[0001] The present invention relates to a decoupling device for a bearingless wave generator having a rotor equipped with permanent magnets (permanent magnet rotor). The rotor consists of a rotor body with permanent magnets screwed onto it. The rotor body is directly connected to the drive shaft of a ship. Background Art

[0002] The use of wave generators with rotors equipped with permanent magnets (PMMs) to supply power to onboard electrical systems in ships is known in various applications and is growing. In these cases, the PMM rotor is typically mounted directly on the main drive train. In the event of damage to the stator and / or the electrical distribution circuit and / or the rotor itself, the wave generator must be shut down quickly because continued rotation of the PMM rotor induces a voltage in the stator. This significant voltage can cause serious damage, particularly stator overheating and even fire. Therefore, it is essential to stop the drive shaft as quickly as possible. This stoppage should only last a short time, as a ship cannot maneuver without a rotating drive shaft and will drift uncontrollably in the water. It is known to decouple such permanent magnet rotors from the main drive shaft and reliably prevent further rotation by securing the rotor. Only when the rotor is secured and its connection to the main drive shaft is released can the main drive shaft be restarted and continue to be driven. Since these are usually structurally large electrical wave generators, securing the rotor can take a long time. Therefore, the downtime of the drive shaft must be minimized as much as possible.

[0003] WO 2016 / 162595 or EP 3 127 224 B1 describe an electric motor with a rotor equipped with permanent magnets. The rotor has two successive, mutually separated rotor sections, on which permanent magnets are arranged that generate a magnetic field with a defined pole pitch. This two-part rotor has a coupling system for each rotor section, for connecting it to the rotor shaft or for connecting the two rotor sections. One rotor section is arranged to be rotatable and fixed relative to the other rotor section by a certain angle that corresponds exactly to the pole pitch, so that the two rotor sections can still be separated from each other. The current chain is essentially zero. As a result, even if the rotor continues to rotate due to damage to the stator winding, the permanent magnets will hardly induce any voltage in the stator winding itself.

[0004] EP 3 681 019 A1 describes another device for separating a rotor equipped with permanent magnets from the shaft of a permanent magnet-excited electric motor. A special drive system can selectively connect the shaft of an electric motor comprising a stator and a rotor to the rotor when necessary, or disconnect the shaft from the rotor when necessary in the event of damage. This mechanical disconnect system is arranged between the rotor and the shaft so that the rotor can move axially relative to the shaft within a defined range. The mechanical disconnect system is configured to mechanically connect the rotor to the shaft in a first state and to mechanically disconnect the rotor from the shaft in a second state so that the rotor does not drive the shaft or cannot be set in rotation by the shaft.

[0005] EP 3 624 309 A1 describes a single, specially shaped permanent magnet module for a rotor equipped with permanent magnets. Each permanent magnet module comprises a base plate and a permanent magnet element fixed to the base plate. The base plate comprises a lower section and an upper section, the upper section being arranged between the lower section and the permanent magnet element. The permanent magnet modules are arranged so that they form special subgroups, the permanent magnet modules of different subgroups being distinguished from each other by the position of the upper section of their base plate relative to the lower section of the base plate. When the lower sections of the permanent magnet modules are oriented axially, successively and circumferentially staggered, a module is formed which can be moved axially, successively and circumferentially when necessary. As a result, the permanent magnet elements of the permanent magnet modules can be arranged on the surface of the rotor and moved, for example, in tilted rows.

[0006] The publication "The Switch Assembly Instructions DA0229PMM 1000F00," produced by the company "THE SWITCH," describes in detail the assembly process of an intermediate shaft into a small-sized generator with a permanently excited rotor. It also explains the installation of a generator with a separate intermediate shaft in a ship. Finally, the separation of the permanently excited rotor from the ship's shaft is described. Here, the entire rotor is radially secured in the housing using axially arranged bolts. The connection between the shaft and the rotor equipped with permanent magnets, established via a specially designed cone clutch, is then released.

[0007] A video produced by the company "THE SWITCH," titled "Permanent Magnet Shaft Generator Commissioning," available online at the following address: "theswitch.com / download-center / videos," shows a stylized / artistic assembly process for a wave generator. The video depicts a section of a ship's shaft being inserted into the generator's stator and assembled with a rotor excited by permanent magnets fixed to the stator. The video also shows the connection of a portion of the ship's shaft to the rotor and the release of the rotor's mounting. Finally, the installation and orientation of the wave generator within the ship relative to the drive shaft can be seen. Summary of the Invention

[0008] The object of the present invention is to provide a structurally simple decoupling device for large wave generators having a rotor with permanent magnets without its own bearings, which rotor allows, in the event of damage, the rotor with permanent magnets to be decoupled from, for example, the drive shaft of a ship in a shorter time than previously possible and which mechanically secures the rotor reliably and permanently so that the wave generator can be switched to a deenergized state.

[0009] According to the invention, this object is achieved by the features of the preamble and characterizing clause of claim 1. Further advantageous embodiments are described in the dependent claims.

[0010] According to the present invention, in a decoupling device for a wave generator having a rotor 4 equipped with permanent magnets and a solid stator housing 1, the rotor 4 equipped with permanent magnets is secured to a drive shaft 11, for example, of a vessel, using an adapter ring 8 with the aid of appropriately dimensioned securing bolts 10. At least three radially distributed arms 12 are secured to the stator housing 1 at each stator end. At least one specially dimensioned spacer element 15 is disposed between each arm 12 and the inner circumference 17 of the rotor 4, allowing for easy removal. If necessary, multiple separate spacer elements 15 may be provided for structural reasons. At least one push-on opening 16 is provided in each arm 12. Multiple push-on openings 16 may also be provided for structural reasons. The arms 12 are connected to the stator end of the stator housing 1 via a threaded connection or a similarly detachable connection. The arms 12 hold the rotor 4 on the inner circumference 17 of the rotor body 5. Special spacer elements 15 enable a positive fit between each cantilever arm 12 and the rotor body 5. A push-in opening 16 is formed in the cantilever arm and is preferably provided with an internal thread. This push-in thread in the cantilever arm 12 allows the spacer elements 15 to be easily installed and removed in a few steps and within a short time using suitable screws.

[0011] Advantageously, in the decoupling device for a wave generator having a rotor equipped with permanent magnets, the adapter ring 8 is designed as a single piece, two parts, or multiple parts and is also designed so that it can be used as an assembly template. In this case, the adapter ring can be used in particular as a hole template for a drive shaft 11 of a ship, for example.

[0012] In the simplest case, in the decoupling device for a wave generator having a rotor 4 equipped with permanent magnets, threads are introduced into each of the push openings 16, and push screws 18 can be respectively arranged in the push openings, that is, they can usually be screwed into the push openings, so that the rotor can be easily and simply moved and fixed first in the radial direction and then in the axial direction by rotating the push screws 18. However, it is also possible to provide multiple push openings 16 with threads, in which case multiple smaller push screws 18 can be used.

[0013] In the case of a decoupling device for a wave generator having a rotor 4 equipped with permanent magnets, additional recesses 21 can also be provided in or on the adapter ring 8 , for letting separately supplied cooling air flow through.

[0014] As a result, the rotor is precisely fixed in the center of the stator using the novel decoupling device. Another advantageous function of the decoupling device is that the rotor equipped with permanent magnets (usually with screw-on permanent magnets) can be held securely and centered relative to the stator lamination stack even during transport and later during assembly. Another significant advantage is that, if necessary, the novel adapter ring 8 can already be used in a simple manner as an assembly template for the drive shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be described in detail below in one embodiment with reference to the accompanying drawings.

[0016] Figure 1 The device according to the invention for fixing a rotor is shown.

[0017] Figure 2 One possible embodiment of an adapter ring 8 is shown. DETAILED DESCRIPTION

[0018] In a preferred embodiment, eight L-shaped arms 12 are provided and fixed in the decoupling device. Here, four arms are radially distributed at 90-degree angles on each stator end face 3. These eight arms 12 are designed to be mechanically stable, reliably supporting the entire mass of the rotor 4 and the always-maximum magnetic forces generated by the permanent magnets 7. The arms 12 are connected to the stator end faces of the stator housing 1 via one or more suitable screw connections or similar removable connections. The arms 12 hold the rotor 4 on the inner circumference 17 of the rotor body 5. Special spacer elements 15 enable a positive fit between each arm 12 and the rotor body 5. Internally threaded push-in openings 16 are formed in the arms. These push-in threads in the arms 12 allow the spacer elements 15 to be easily installed and removed with a few simple operations using suitable push-in screws 18. The spacer elements 15 are removed during operation of the wave generator.

[0019] If damage occurs to the wave generator or the electrical equipment behind it while the ship is in operation, the rotating rotor 4 must be braked and stopped as quickly as possible. This is achieved by shutting down the relevant drive shaft 11. This shutdown can only last for a short time because the ship is unmaneuverable without a drive. During this time, the so-called protective cover (not shown) on the end side of the stator housing 1 that covers the interior space of the motor must be immediately removed. With the help of the rotation device 9 of the drive shaft 11, by slightly rotating the drive shaft 11, the holes in the cantilever 12 are aligned with the holes in the rotor body. Next, the spacer elements 15 are placed between each cantilever 12 and the inner circumference 17 of the rotor body 5. Then, using the spacer elements 15, the cantilever 12 and the rotor body 5 are screwed together. Now, remove the fixing screws 10 between the adapter ring 8 and the drive shaft 11, and move the entire stator, including the rotor 4 screwed securely to the stator housing 1, axially along the shaft axis until the adapter ring 8 is no longer located within the centering edge of the drive shaft 11, with sufficient clearance, and any contact between the drive shaft 11 and the split adapter ring 8 during the next rotation of the drive shaft is reliably prevented. The axial movement of the entire wave generator relative to the drive shaft 11 can advantageously be accomplished simply with the aid of additional push screws. Thereafter, the drive shaft 11 can be restarted. The adapter ring 8 is designed as a split device and simultaneously serves as a hole template for the fixing holes in the drive shaft 11.

[0020] exist Figure 2FIGURE 8 shows a split adapter ring 8 according to the present invention, but without the partitions. In this embodiment, eight holes 19 for guiding the fastening bolts 10 connecting the adapter ring 8 to the drive shaft 11 are evenly distributed internally on the first pitch circle. These holes also serve as a hole template during assembly, as the drive shaft and the wave generator are often manufactured and supplied by different manufacturers. This reliably avoids potential errors, as incorrect alignment of the holes 19 for fastening to the drive shaft 11 can result in significant financial losses and time delays during assembly until such errors are corrected. Externally, two rows of holes for fastening bolts 20 connecting the adapter ring 8 to the rotor body 5 are arranged radially and arranged on two partial circles. An additional rotor inner ring is located inside the rotor body 5, preferably welded to it. The adapter ring 8 is mounted on this inner ring. The fastening bolts 20 for fastening the split adapter ring 8 are smaller than the fastening bolts for connecting the rotor shaft 11. In order to effectively cool the rotor body 5, in this embodiment, in this decoupling device for a wave generator having a rotor equipped with permanent magnets, additional recesses 21 are provided on the outside on the circumference of the adapter ring 8 for letting separately supplied cooling air flow through, thereby preventing an excessive heating of the rotor body 5 and thus of the permanent magnets that are sensitive to temperature increases.

[0021] The invention can be used as a reliable and quickly operational decoupling device in the event of a fault for a wave generator having a rotor 4 equipped with permanent magnets, in particular on a drive shaft 11 of a ship.

[0022] Reference Signs List

[0023] 1 stator housing

[0024] 2 stator lamination stack

[0025] 3 Stator end side

[0026] 4 rotors

[0027] 5 rotor body

[0028] 6 Rotor fixing hole

[0029] 7 permanent magnets

[0030] 8 Adapter ring

[0031] 9 Rotating device

[0032] 10 fixing bolts

[0033] 11 Drive shaft

[0034] 12 Cantilever (L-shaped)

[0035] 13 Cantilever hole

[0036] 14 Cantilever bolts

[0037] 15 Gasket element

[0038] 16 Push port

[0039] 17 Inner Surface

[0040] 18 Push screw

[0041] 19 Holes for fixing bolts to the drive shaft

[0042] 20 Holes for fixing bolts to the rotor body

[0043] 21 notch.

Claims

1. A decoupling device for a wave generator having a rotor (4) equipped with permanent magnets, the wave generator also having a solid stator housing (1), the rotor (4) equipped with permanent magnets being fastened to a drive shaft (11) of a vessel by means of an adapter ring (8) by means of fastening screws (10), characterized in that At least three radially distributed cantilevers (12) are fixed to the stator housing (1) at each stator end side, at least one spacer element (15) is respectively arranged between the cantilever (12) and the inner circumference (17) of the rotor (4), and at least one push opening (16) is arranged in each cantilever (12).

2. A decoupling device for a wave generator having a rotor (4) equipped with permanent magnets according to claim 1, characterized in that The adapter ring (8) is constructed as a one-piece or multi-part assembly template.

3. A decoupling device for a wave generator having a rotor (4) equipped with permanent magnets according to claim 1, characterized in that A thread is introduced into each of the push openings (16), and a push screw (18) can be arranged in the push opening.

4. A decoupling device for a wave generator having a rotor (4) equipped with permanent magnets according to claim 1, characterized in that Recesses (21) are provided in or on the adapter ring (8) for letting the supplied cooling air flow through.

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