Insulated through-tube

Abstract

The present invention relates to a device having a transmission, a through-tube (103) and a fixing device (101); wherein the through-tube (103) is fixed in the transmission by means of the fixing device (101). The fixing device (101) is implemented to be electrically insulated relative to the through-tube (103).

Description

Field of the Invention

[0001] The present invention relates to a device according to the preamble of claim 1. Background Art

[0002] There is a trend towards integrated drive trains in wind power plants. In an integrated drive train, the transmission and the generator form a structural unit. This gives rise to the problem of stray currents. Stray currents can occur in the form of high-frequency alternating current or low-frequency direct current or alternating current. There is a risk of damage to the teeth and rolling bearings due to voltage arcing.

[0003] In order to avoid collateral damage caused by stray currents, appropriate insulation measures must be taken. However, in a medium-speed drive train, the torque to be transmitted between the transmission and the generator is relatively high. At the same time, due to the integrated structural form of the drive train between the transmission and the generator, there is a lack of available structural space. This makes it difficult to adequately dimension the components that transmit torque. This particularly relates to the electrical insulation of the components that transmit torque.

[0004] In particular, the electrical insulation of so-called through-tubes is problematic because the length of the through-tube changes in the axial direction during temperature fluctuations. At the same time, the diameter of the through-tube changes. Due to the different coefficients of thermal expansion of the through-tube and the material considered as the electrical insulator, there is a risk that the through-tube "gets stuck" in the insulator. Summary of the Invention

[0005] The object of the present invention is to provide an improved solution compared to the transmissions known from the prior art. In particular, damage that may occur in an integrated drive train due to stray currents should be avoided.

[0006] This object is solved by the device according to claim 1. Preferred refinements are included in the dependent claims.

[0007] The transmission may in particular be a transmission for a wind power plant. The through-tube, also known as a pitch tube, is a tube for passing electrical or hydraulic supply lines through the transmission. It is characterized in that the through-tube passes through the transmission or the housing of the transmission and its openings are arranged outside the transmission or outside the housing of the transmission. The through-tube is preferably sealed relative to the housing of the transmission in a lubricant-impermeable manner.

[0008] The through-tube is fixed in the transmission by fixing means, i.e., in at least one component of the transmission. The through-tube is typically designed rotationally symmetric. Accordingly, the fixing means are preferably also rotationally symmetric.

[0009] The present invention is based on the recognition that, since the through-tube completely passes through the transmission device, the through-tube is the main transmitter of stray current. According to the present invention, the fixing device is thus implemented to be electrically insulated from the through-tube. Therefore, the fixing device electrically insulates the through-tube and the component of the transmission device that fixes the through-tube by means of the fixing device from each other. Thereby, the main cause of leakage current is eliminated. The present invention effectively prevents the leakage current from the generator from being introduced into the transmission device via the through-tube. The insulating part according to the present invention is particularly suitable for an integrated drive system because the insulating part occupies very little structural space.

[0010] Preferably, the through-tube is improved to be axially movable relative to the fixing device, that is, in the direction of the rotation axis, for example, in the direction of the rotation axis of the component in which the through-tube is fixed by means of the fixing device. Thereby, the length change of the through-tube caused by temperature fluctuations can be compensated.

[0011] In a preferred improvement, the component of the transmission device in which the through-tube is fixed by means of the fixing device is a shaft, especially a hollow shaft, or a planet carrier supported in a rotatable manner. According to the improvement, the fixing device electrically insulates the through-tube from the shaft or the planet carrier.

[0012] In a more preferred improvement, the fixing device has a through-hole. The hole is centered, that is, its central axis is oriented to coincide with the central axis of the through-tube. In particular, the through-tube and the hole can be rotationally symmetric. In this case, the symmetry axis of the through-tube and the symmetry axis of the hole coincide. The through-tube extends through the hole and engages with the fixing device there.

[0013] In a preferred improvement, the fixing device engages with the component of the transmission device in which the through-tube is fixed along its radial outer edge, or engages with the shaft or the planet carrier.

[0014] In a preferred improvement, the fixing device has a non-conductive body and a main body. The main body can be made of a conductive material. The non-conductive body is arranged between the through-tube and the main body, or according to the improvement, is arranged between the main body and the component of the transmission device in which the through-tube is fixed by means of the fixing structure, or is arranged between the main body and the shaft or the planet carrier.

[0015] Preferably, the main body is improved such that at least a part of the main body is radially arranged between the through-tube and the non-conductor. This part of the main body is preferably closed in the circumferential direction. In particular, this part of the main body can be formed as a hollow cylinder. It preferably completely fills the intermediate space extending between the through-tube and the non-conductor. More preferably, the main body and the through-tube, which have the same coefficient of thermal expansion as the material of the through-tube, are made of the same material.

[0016] This improved solution is advantageous when the non-conductor and the feedthrough tube have different coefficients of thermal expansion. There will then be a risk that different dimensional changes due to temperature fluctuations will impede the axial mobility of the feedthrough tube in the fixing device. The part of the fixing device according to the improved solution shields the dimensional changes of the feedthrough tube relative to the non-conductor. Thereby ensuring the axial mobility of the feedthrough tube.

[0017] The device is preferably improved using a generator which is connected to the transmission in a rotational action manner. This means that the output shaft of the transmission is non-rotatably connected to the input shaft of the generator. In particular, the transmission and the generator can form an integrated drive train.

[0018] In a more preferred improved solution, a coupling part is provided which non-rotatably connects the output shaft of the transmission to the input shaft of the generator. The coupling part serves as an electrical insulation. Thereby ensuring complete electrical insulation of the components endangered by voltage and the generator from the presence of the transmission.

[0019] What the present invention can achieve is to use a conductive feedthrough tube, such as a metal feedthrough tube. The concept on which the present invention is based can alternatively be achieved in such a way that instead of the fixing device providing electrical insulation, it is the feedthrough tube itself. This can be achieved by means of a feedthrough tube made of an insulator. Description of the Drawings

[0020] Embodiments of the present invention are shown in the drawings. Here, identical reference numerals denote identical or functionally identical features. In detail:

[0021] Figure 1 the fixing device in the inserted position is shown; and

[0022] Figure 2 the coupling part is shown. Detailed Description of the Invention

[0023] Figure 1 The fixing device 101 shown in the figure is used to fix the feedthrough tube 103 in the planet carrier 105 on the drive side. In particular, the radial positioning of the feedthrough tube 103 is determined by the fixing device 101. The fixing device 101 itself is rigidly fixed in the planet carrier 105, that is to say, the fixing between the fixing device 101 and the planet carrier 105 prohibits any relative movement between the fixing device 101 and the planet carrier 105.

[0024] The metal body 107 of the fixing device 101 is constructed in an L-shape in cross-section. The body 107 is screwed to the planet carrier 105. The corresponding screwing part is implemented in an electrically insulated manner.

[0025] The nose 109 screwed to the body 107 is inserted into the clearance 109 of the through pipe 103 so as to fix the through pipe 103 against relative rotation with respect to the planet carrier 105.

[0026] An insulating layer 113 is introduced into the gap extending between the body 107 and the planet carrier 105. The insulating layer is made of an electrical insulator such as polyamide. The insulating layer 113 electrically insulates the body 107 and thus the through pipe 103 from the planet carrier 105. Like the cross-section of the body 107, the cross-section of the insulating layer 113 is also L-shaped.

[0027] The axial side of the body 107 with an L-shaped cross-section extends between the insulating layer 113 and the through pipe 103 in the axial direction. In this way, the dimensional change of the insulating layer 113 caused by temperature fluctuations is prevented from affecting the through pipe 103. Therefore, the axial mobility of the through pipe 103 with respect to the planet carrier 105 is maintained even in the case of temperature fluctuations.

[0028] Figure 2 The coupling part 201 shown in FIG. connects the output-side sun shaft 203 to the input shaft 205 of the generator. The sun shaft 203 is configured with a first flange 207, and the input shaft 205 of the generator is configured with a second flange 209. The first flange 207 and the second flange 209 are screwed to each other. In this way, a connection against relative rotation between the first flange 207 and the second flange 209 is achieved.

[0029] A gasket 211 made of an electrical insulator is provided between the first flange 207 and the second flange 209. The screwed parts of the first flange 207 and the second flange 209 are also encapsulated with an electrical insulator. Therefore, the sun shaft 203 and the input shaft 205 of the generator are electrically insulated from each other. In combination with the insulated through pipe, complete insulation of the transmission with respect to the generator is achieved.

[0030] This combination method is particularly advantageous because the insulating part can be completely arranged in the structural space of the transmission. The external interface of the transmission is thus not affected.

[0031] List of reference numerals

[0032] 101 Fixing device

[0033] 103 Through pipe

[0034] 105 Planet carrier

[0035] 107 Body

[0036] 111 Clearance

[0037] 113 Insulating layer

[0038] 201 Coupling part

[0039] 203 Sun shaft

[0040] 205 Input shaft

[0041] 207 First flange

[0042] 209 Second flange

[0043] 211 Gasket

Claims

1. An apparatus having a gearing, a feedthrough tube (103) and a fixing device (101) for a wind power installation; wherein, the feedthrough tube (103) is fixed in the gearing by means of the fixing device (101); and the fixing device (101) is embodied to be electrically insulating relative to the feedthrough tube (103), characterized in that, the feedthrough tube (103) is fixed in the shaft of the gearing or in a rotatably supported planet carrier (105) by means of the fixing device (101); wherein, the fixing device (101) electrically insulates the feedthrough tube (103) relative to the shaft or the planet carrier (105), the fixing device (101) has a body (107) and a non-conductor (113), wherein, the non-conductor (113) is arranged between the body (107) and the shaft or the planet carrier (105).

2. The apparatus according to claim 1; characterized in that, the feedthrough tube (103) is axially movable relative to the fixing device (101).

3. The apparatus according to claim 1 or 2; characterized in that, the fixing device (101) has a central, through hole; wherein, the fixing device (101) engages with the feedthrough tube (103) in the hole.

4. The apparatus according to claim 1; characterized in that, the fixing device (101) engages with the shaft or with the planet carrier (105) along a radially outer edge of the fixing device.

5. The apparatus according to claim 1; characterized in that, at least a part of the body (107) is arranged radially between the feedthrough tube (103) and the non-conductor (113).

6. The apparatus according to claim 1 or 2; characterized in that it has a generator connected to the gearing in a rotationally operative manner.

7. The apparatus according to claim 6; characterized in that it has a coupling part (201) which connects the output shaft (203) of the gearing in a rotationally fixed manner to the input shaft (205) of the generator; wherein, the coupling part (201) is embodied to be electrically insulating.

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