CN220106156U - Liquid-cooled exciting coil - Google Patents

Abstract

The utility model discloses a liquid-cooled exciting coil, which comprises a coil group and a plurality of middle joints, wherein the coil group comprises a plurality of coil units which are sequentially stacked along a first direction, each coil unit is sequentially provided with a plurality of annular coils along a second direction, a diversion channel is arranged in each annular coil, the diversion channels in the annular coils of each coil unit are sequentially communicated, and the annular coils are provided with a cooling liquid inlet communicated with the diversion channel and a cooling liquid outlet communicated with the diversion channel; the cooling liquid outlets of the two adjacent coil units are communicated through a single middle joint, the middle joint is provided with a liquid outlet, and the coiling directions of the annular coils of the two adjacent coil units are opposite. According to the utility model, the two adjacent coil units are communicated together by arranging the middle joint, and the liquid outlet is arranged on the middle joint, so that the cooling liquid flows out from the liquid outlet of the middle unit after passing through the two coil units, the flow path of the cooling liquid is shortened, and the cooling efficiency of the cooling liquid is improved.

Description

Liquid-cooled exciting coil

Technical Field

The utility model relates to a liquid-cooled exciting coil, and belongs to the technical field of electric vibrating tables.

Background

The vibrating table is also called a vibration exciter or a vibration generator. It is a device that uses electric, electro-hydraulic, piezoelectric or other principles to obtain mechanical vibrations. The principle is that an excitation signal is input to a coil placed in a magnetic field to drive a workbench connected with the coil. The electric vibration table is characterized in that a constant magnetic field in a working air gap and an alternating magnetic field of a driving coil are realized by introducing current into an exciting coil, the exciting coil generates certain heat due to the influence of resistance, the exciting coil is required to be cooled in order to ensure that the vibration table can work for a long time, the cooling modes comprise natural cooling, air cooling, liquid cooling and other cooling modes, and the liquid cooling can realize better forced cooling by using liquid such as oil or water as a cooling medium, so that the electric vibration table has high cooling efficiency and is widely applied to medium-large-sized electric vibration tables.

The single exciting coil of the traditional exciting device is formed by winding two layers continuously in a forward direction and a backward direction, and when cooling, cooling liquid flows out through the two layers of coils, so that the flow path of the cooling liquid is larger, and the cooling effect is lower; in addition, the traditional exciting coil needs to store a layer of exciting copper wires by a wire storage cylinder, the winding steps are complicated, and the waste materials are much.

Disclosure of Invention

In order to overcome the defects in the prior art, the utility model aims to provide a liquid-cooled exciting coil.

In order to achieve the purpose of the utility model, the technical scheme adopted by the utility model comprises the following steps:

the utility model provides a liquid-cooled exciting coil, which comprises a coil group and a plurality of intermediate joints, wherein the coil group comprises a plurality of coil units which are sequentially stacked along a first direction, each coil unit is provided with a plurality of annular coils which are sequentially arranged along a second direction, the inside of each annular coil is provided with a diversion channel which extends along the length direction of the annular coil, the diversion channels in the plurality of annular coils contained in each coil unit are sequentially communicated, at least one annular coil is provided with a cooling liquid inlet which is communicated with the diversion channel, and at least one annular coil is provided with a cooling liquid outlet which is communicated with the diversion channel; the cooling liquid outlets of two adjacent coil units are communicated through a single middle joint, the middle joint is provided with a liquid outlet, the liquid outlet is communicated with two cooling liquid outlets connected with the middle joint, and the coiling directions of the annular coils contained in the two adjacent coil units are opposite.

Compared with the prior art, the utility model has the advantages that:

according to the utility model, the two adjacent coil units are communicated together by arranging the middle joint, and the liquid outlet is arranged on the middle joint, so that the cooling liquid flows out from the liquid outlet of the middle unit after passing through the two coil units, the flow path of the cooling liquid is shortened, and the cooling efficiency of the cooling liquid is improved.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present utility model, and other drawings may be obtained according to the drawings without inventive effort to those skilled in the art.

FIG. 1 is a schematic diagram of a coil assembly according to an embodiment of the present utility model;

FIG. 2 is a schematic diagram of the embodiment of FIG. 1 from another perspective;

FIG. 3 is a schematic diagram of the coiled construction of two adjacent coil units in the embodiment of FIG. 1;

FIG. 4 is a schematic diagram of a coil unit in an embodiment of the utility model;

FIG. 5 is a schematic diagram of a stacked configuration of two coil units in one embodiment of the utility model;

FIG. 6 is a schematic view of the structure of the intermediate joint and the fixing plate in one embodiment of the utility model;

FIG. 7 is a schematic view of a liquid collecting pipe according to an embodiment of the present utility model;

fig. 8 is a schematic diagram of a coil assembly with a plastic package according to an embodiment of the present utility model.

Reference numerals illustrate:

100. a coil assembly; 110. a coil unit; 120. a hollow wire; 121. a cooling liquid inlet; 122. a cooling liquid outlet; 200. an intermediate joint; 210. a liquid outlet; 220. a T-shaped channel; 221. a first connection port; 222. a second connection port; 300. a fixing plate; 310. a through hole; 320. a quick connector; 400. a liquid collecting pipe; 410. a first liquid collecting pipe; 420. a second liquid collecting pipe; 430. a liquid injection port; 440. a liquid separating port; 441. a first main liquid separation port; 442. a first auxiliary liquid separating port; 443. a second main liquid separating port; 444. a second auxiliary liquid separating port; 500. a plastic package piece; 600. a rubber tube.

Detailed Description

In view of the shortcomings in the prior art, the inventor of the present utility model has long studied and practiced in a large number of ways to propose the technical scheme of the present utility model. The technical scheme, the implementation process, the principle and the like are further explained as follows.

The utility model provides a liquid-cooled exciting coil, which comprises a coil assembly 100 and a plurality of middle joints 200, wherein the coil assembly 100 comprises a plurality of coil units 110 which are sequentially stacked along a first direction, a plurality of annular coils which are sequentially arranged along a second direction are arranged in each coil unit 110, a diversion channel which extends along the length direction of the annular coils is arranged in each annular coil, the diversion channels in the plurality of annular coils contained in each coil unit 110 are sequentially communicated, at least one annular coil is provided with a cooling liquid inlet 121 communicated with the diversion channel, and at least one annular coil is provided with a cooling liquid outlet 122 communicated with the diversion channel; the coolant outlets 121 of the adjacent two coil units 110 are communicated through a single intermediate joint, the intermediate joint 200 is provided with a liquid outlet 210, the liquid outlet 210 is communicated with the two coolant outlets 122 connected with the intermediate joint 200, and the coiling directions of the annular coils contained in the adjacent two coil units 110 are opposite.

In one embodiment, as shown in fig. 1, 2, 4 and 5, the number of coil units 110 is even, when in use, a plurality of annular coils are first assembled into one coil unit 110 along the clockwise direction of the second direction, then the plurality of annular coils are assembled into one coil unit 110 along the anticlockwise direction of the second direction, and the remaining annular coils are assembled into the coil unit 110 in the manner of reversing the alternating coiling direction. With the first coil unit 110 being placed on the first layer again, the second coil unit 110 is stacked on the lower side of the first coil unit 110 to form the second layer, and then the remaining coil units 110 are sequentially stacked such that the coiling directions of the adjacent two coil units 110 are opposite.

The coil assembly 100 is formed by vertically overlapping a plurality of coil units 110, so that the coil assembly 100 is simple and convenient to manufacture, and the production efficiency is improved. In addition, the structure also avoids the mode that the traditional exciting coil stores one layer of exciting copper wires by the wire storage cylinder.

In addition, as shown in fig. 3 and 4, the annular coils are respectively formed with a cooling fluid inlet 121 and a cooling fluid outlet 122, wherein the cooling fluid outlet 122 of the first coil unit 110 and the cooling fluid outlet 122 of the adjacent second coil unit 110 are communicated through an intermediate joint 200, a fluid outlet 210 is provided on the intermediate joint 200, the fluid outlet 210 is mutually communicated with the cooling fluid outlet 122 of the first coil unit 110 and the cooling fluid outlet 122 of the second coil unit 110, when cooling is required, cooling fluid is injected from the cooling fluid inlet 121 of the coil unit 110, the cooling fluid respectively flows along the diversion channels inside the annular coils, wherein the cooling fluid respectively flows through the diversion channels of the adjacent two annular coils in opposite coiling directions, and then the cooling fluid of the first coil unit 110 and the cooling fluid in the second coil unit 110 flow out from the respective cooling fluid outlets 122 and are converged in the intermediate joint 200, and then the cooling fluid flows out of the coil assembly 100 from the fluid outlet 210 of the intermediate joint 200. In the above manner, the coolant outlets 122 of the remaining adjacent two coil units 110 whose coiling directions are opposite are communicated through the respective intermediate joints 200.

In the above structure, two adjacent annular coil units 110 are communicated through the middle joint 200, when cooling is needed, cooling liquid is injected from the cooling liquid inlets 121 of the coil units, the cooling liquid flows through the two adjacent coil units 110 along opposite flow paths, and then flows out of the liquid outlets 210 on the middle joint 200 together, so that a cooling liquid cooling mode of multiple in and multiple out is achieved, the cooling liquid injected from each cooling liquid inlet 121 only flows through one layer of the coil units 110, the flow path of the cooling liquid can be effectively reduced, the cooling effect of the cooling liquid is greatly improved, and in addition, the flow directions of the cooling liquid of the two mutually communicated coil units 110 are opposite, so that the cooling uniformity is improved, and the cooling efficiency is improved.

In particular, the cooling liquid may be selected from water or oil, and the like, as appropriate, and the existing cooling liquid may be selected as required by those skilled in the art.

Further, the first direction and the second direction are arranged to intersect. In one embodiment, the first direction is an axial direction of the coil assembly, the second direction is a radial direction of the coil assembly, and the first direction and the second direction are perpendicular to each other, so that the flow of the cooling liquid is more uniform, and the cooling efficiency is improved.

Further, the annular coil is made of a single hollow wire in a planar spiral winding mode, one end at the outer side of the hollow wire forms the cooling liquid outlet, and one end at the inner side of the hollow wire forms the cooling liquid inlet.

The coil assembly 100 is formed by stacking a plurality of coil units 110 up and down, wherein the coil units 110 are formed by spirally winding a single hollow wire 120 in a plane, and two ends of the hollow wire 120 are respectively formed with a cooling liquid inlet 121 and a cooling liquid outlet 122. In use, a first hollow wire 120 is wound into one coil unit 110 in a clockwise direction, then a second hollow wire 120 is wound into one coil unit 110 in a counter-clockwise direction, a third hollow wire 120 is wound into one coil unit 110 in a clockwise direction, and a fourth hollow wire 120 is wound into one coil unit 110 in a counter-clockwise direction, and the remaining hollow wires 120 are wound into one coil unit 110 in a manner opposite to the alternating winding direction described above. With the coil units 110 wound with the first hollow wire 120 being placed on the first layer, the coil units 110 wound with the second hollow wire 120 are stacked on the lower side of the first layer of the coil units 110 to form a second layer, and then the remaining coil units 110 are stacked in sequence, so that the winding directions of the adjacent two coil units 110 are opposite.

The coil unit 110 is formed by winding a single hollow wire 120, and the coil assembly 100 is simple and convenient to manufacture, thereby improving the production efficiency. In addition, the material is further saved.

In addition, as shown in fig. 3 and 4, both ends of the hollow wire 120 are respectively formed with a coolant inlet 121 and a coolant outlet 122, wherein the coolant outlet 122 of the first hollow wire 120 and the coolant outlet 122 of the adjacent second hollow wire 120 are communicated through an intermediate joint 200, a liquid outlet 210 is provided on the intermediate joint 200, and the liquid outlet 210 is communicated with the coolant outlet 122 of the first hollow wire 120 and the coolant outlet 122 of the second hollow wire 120.

Further, as shown in fig. 4, since the coil unit 110 is formed by spirally winding a single hollow wire 120 in a plane, both ends of the hollow wire 120 are formed at both inner and outer sides of the coil unit 110, respectively, since injection of a cooling liquid and collection of the cooling liquid are required to be completed in a cooling operation, and in addition, the cooling liquid outlet 122 is required to be communicated through the intermediate joint 200, one end of the outside of the coil unit 110 is set as the cooling liquid outlet 122 and one end of the inside of the coil unit 110 is set as the cooling liquid inlet 121 for convenience of operation.

Further, the intermediate joint is provided with a first connecting port, a second connecting port and a liquid outlet, the first connecting port and the second connecting port are respectively communicated with the cooling liquid outlet, and the liquid outlet is arranged between the first connecting port and the second connecting port.

Preferably, the intermediate joint is of T-or Y-configuration.

In the connection structure between the intermediate connector 200 and the coolant outlet 122, as shown in fig. 3, the intermediate connector 200 is provided with a T-shaped or Y-shaped channel 220 for communicating the coolant outlets 122 of two adjacent hollow wires 120, and in one embodiment, the coolant outlet 122 of the two hollow wires 120 communicated with the intermediate connector 200 opposite to the upper hollow wire 120 is communicated with a first connection port 221, the coolant outlet 122 of the opposite hollow wire 120 is communicated with a second connection port 222, and the coolant enters the T-shaped channel 220 from the first connection port 221 and the second connection port 222, respectively, and flows out from the liquid outlet 210 of the T-shaped channel 220.

In a specific embodiment, the intermediate joint 200 further includes a first mounting groove in communication with the first connection port 221, the coolant outlet 122 in mating connection with the first mounting groove, and a second mounting groove in communication with the second connection port 222, the second mounting groove in mating connection with the cold zone liquid outlet. In the above structure, the first mounting groove and the second mounting groove may be formed by respectively recessing two ends of the T-shaped channel 220 inward, and when mounting, one end of the hollow wire 120 with the coolant outlet 122 is respectively connected to the first mounting groove and the second mounting groove, and the connection manner may be threaded connection or plugging connection, and the outer diameter of the coolant outlet 122 is smaller than the inner diameter of the first mounting groove. Thereby facilitating the installation of the coolant outlet 122 and the intermediate joint 200 and improving the connection stability and the sealability at the interface.

Further, the fixing plate 300 is further included, and the plurality of intermediate connectors 200 are arranged on the fixing plate 300 in a vertically parallel manner in a length alignment manner, and the fixing plate 300 is provided with a through hole 310, and the through hole 310 is communicated with the liquid outlet 210.

As shown in fig. 6, the plurality of intermediate connectors 200 are connected together by the fixing plate 300, and firstly, the installation of the intermediate connectors 200 can be facilitated, because the plurality of intermediate connectors 200 are required to be connected with the hollow wires 120 respectively, the installation is relatively inconvenient, and all the intermediate connectors 200 are installed on the fixing plate 300 in a length aligned manner, so that the connection installation with the cold-zone liquid outlets in a plurality of opposite directions is facilitated. In addition, all the intermediate connectors 200 are connected through the fixing plate 300, so that the intermediate connectors 200 can be electrically connected in series, and the multi-layer coil units 110 are connected in series, thereby ensuring the integrity of a circuit.

Further, the device further comprises a plurality of quick connectors 320, wherein the quick connectors 320 are connected to the liquid outlet 210, the quick connectors 320 are communicated with the liquid outlet 210, and the quick connectors 320 extend outwards through the through holes 310.

In the above structure, as shown in fig. 6, the liquid outlet 210 on the middle joint 200 is connected with the quick connector 320, and then the device for collecting and utilizing the cooling liquid is directly connected with the quick connector 320, so that the operation is convenient, the collection and utilization of the cooling liquid are also convenient, and the quick connector 320 passes through the through hole 310 on the fixing plate 300 to extend outwards, thereby effectively avoiding the influence of interference of the fixing plate 300 when collecting the cooling liquid.

Further, the liquid collecting pipe 400 is further included, the liquid collecting pipe 400 comprises a liquid injecting port 430 and a plurality of liquid separating ports 440 which are communicated with each other, and the plurality of liquid separating ports 440 are respectively communicated with the plurality of cooling liquid inlets 121.

The coil assembly 100 is composed of a plurality of coil units 110, so that a plurality of cooling liquid inlets 121 are formed, when cooling is needed, the cooling liquid is respectively injected into the cooling liquid inlets 121, as shown in fig. 7, a liquid collecting pipe 400 is arranged, liquid distributing openings 440 of the liquid collecting pipe 400 are respectively communicated with the cooling liquid inlets 121, when the cooling liquid is needed to be injected, the cooling liquid is only needed to be injected from liquid injecting openings 430 of the liquid collecting pipe 400, the cooling liquid enters the liquid collecting pipe 400, and then respectively enters corresponding hollow wires 120 from the liquid distributing openings 440, so that the injection of the cooling liquid is greatly facilitated, and the working efficiency is improved.

More specifically, the liquid collecting tube 400 extends along the axial direction of the coil unit 110, the liquid collecting tube 400 includes a first end and a second end opposite to each other, the first end forms a liquid injecting port 430, the second end is provided with a plurality of liquid separating branch pipes arranged in a single row from bottom to top, the extending direction of the liquid separating branch pipes forms a certain angle with the extending direction of the liquid collecting tube 400, and the liquid separating branch pipes form liquid separating ports 440.

In the above structure, as shown in fig. 7, two ends of the extension direction of the liquid collecting tube 400 are provided as a first end and a second end, in one embodiment, the first end is an upper end, the end forms the liquid injection port 430, the second end extends outwards to form a plurality of liquid separating branches, and the liquid separating branches form the liquid separating port 440, wherein the positions and the distances of the liquid separating branches are set according to the orientation and the positions of the cooling liquid inlet 121, and particularly, the liquid separating branches are arranged in a way of being arranged in a single row from bottom to top, so as to be convenient to communicate with the cooling liquid inlet 121.

In particular, in one embodiment, the extension direction of the manifold is 90 degrees from the extension direction of the header 400.

Further, as shown in fig. 7, the two liquid collecting pipes 400 are a first liquid collecting pipe 410 and a second liquid collecting pipe 420, respectively, the cooling liquid inlet 121 of the uppermost coil unit 110 and the cooling liquid inlet 121 on the same side thereof are communicated with the liquid dividing port 440 of the first liquid collecting pipe 410, and the cooling liquid inlet 121 on the opposite side of the cooling liquid inlet 121 of the uppermost coil unit 110 and the liquid dividing port 440 of the second liquid collecting pipe 420 are communicated.

Since the winding directions of the adjacent two hollow wires 120 are opposite, the directions of the cooling liquid inlets 121 of the adjacent two hollow wires 120 are also opposite, and thus, two liquid collecting pipes 400 are provided, the cooling liquid inlets 121 are respectively communicated with one liquid collecting pipe 400 toward the same hollow wire 120, and in one embodiment, the cooling liquid inlet 121 of the uppermost hollow wire 120 and the cooling liquid inlet 121 of the hollow wire 120 having the same winding direction are communicated with the liquid dividing port 440 of the first liquid collecting pipe 410, and the cooling liquid inlet 121 of the hollow wire 120 of the second layer and the cooling liquid inlet 121 of the hollow wire 120 having the same winding direction are connected with the second liquid collecting pipe 420. On one hand, the convenience of injecting the cooling liquid can be effectively improved; on the other hand, the same side of the cooling liquid inlet 121 is communicated with one liquid collecting pipe 400, so that the flow division of the cooling liquid in different directions is further reduced, and the flow efficiency of the cooling liquid is improved.

Specifically, the liquid separating opening 440 of the first liquid collecting tube 410 includes a first main liquid separating opening 441 and a plurality of first auxiliary liquid separating openings 442, the first main liquid separating opening 441 is electrically connected in series with the cooling liquid inlet 121 of the uppermost coil unit 110, the liquid separating opening 440 of the second liquid collecting tube 420 includes a second main liquid separating opening 443 and a plurality of second auxiliary liquid separating openings 444, and the second main liquid separating opening 443 is electrically connected in series with the cooling liquid inlet 121 of the lowermost coil unit 110.

In the above structure, the first liquid collecting pipe 410 and the second liquid collecting pipe 420 are respectively provided with the first main liquid separating opening 441 and the second main liquid separating opening 443, the first main liquid separating opening 441 is electrically connected in series with the cooling liquid inlet 121 of the uppermost coil unit 110, and the second main liquid separating opening 443 is electrically connected in series with the cooling liquid inlet 121 of the lowermost coil unit 110, so that the coil assembly 100 forms a complete series circuit.

In an embodiment in which the first main liquid dividing port 441 and the second main liquid dividing port 443 are electrically connected in series with the cooling liquid inlet 121, the first main liquid dividing port 441 and the second main liquid dividing port 443 are welded to the cooling liquid inlet 121, and the first sub liquid dividing port 442 and the second sub liquid dividing port 444 are communicated with the cooling liquid inlet 121 via the rubber tube 600.

Further, as shown in fig. 8, the coil assembly 100 further includes a molding member 500, and the coil assembly 100 is integrally encapsulated in the molding member 500, and the cooling liquid inlet 121 and the cooling liquid outlet 122 are exposed out of the molding member 500.

In the above structure, the coil assembly 100 is integrally packaged in the plastic package 500, so that the structural stability and impact resistance of the coil assembly 100 can be effectively ensured, the plastic package 500 is exposed from the cooling liquid inlet 121 and the cooling liquid outlet 122, the stable connection of cooling liquid and electricity can be realized, and the working stability of the coil is ensured. In one embodiment, the molding compound 500 is an epoxy material.

It should be understood that the above embodiments are merely for illustrating the technical concept and features of the present utility model, and are intended to enable those skilled in the art to understand the present utility model and implement the same according to the present utility model without limiting the scope of the present utility model. All equivalent changes or modifications made in accordance with the spirit of the present utility model should be construed to be included in the scope of the present utility model.

Claims (10)

1. A liquid-cooled field coil, comprising:

the coil assembly comprises a plurality of coil units which are sequentially stacked along a first direction, a plurality of annular coils which are sequentially arranged along a second direction are arranged in each coil unit, a diversion channel which extends along the length direction of the annular coils is arranged in each annular coil, the diversion channels in the annular coils which are contained in each coil unit are sequentially communicated, at least one annular coil is provided with a cooling liquid inlet which is communicated with the diversion channel, and at least one annular coil is provided with a cooling liquid outlet which is communicated with the diversion channel;

the cooling liquid outlets of the adjacent two coil units are communicated through a single middle joint, the middle joint is provided with a liquid outlet, the liquid outlet is communicated with the two cooling liquid outlets connected with the middle joint, and the coiling directions of the annular coils contained in the adjacent two coil units are opposite.

2. A liquid-cooled field coil as set forth in claim 1, wherein: the first direction and the second direction are arranged in a crossing manner.

3. A liquid-cooled field coil as set forth in claim 1, wherein: the annular coil is made by spirally winding a single hollow wire plane, one end at the outer side of the hollow wire forms the cooling liquid outlet, and one end at the inner side forms the cooling liquid inlet.

4. A liquid-cooled field coil as set forth in claim 3 wherein: the intermediate joint is provided with a first connecting port, a second connecting port and a liquid outlet, the first connecting port and the second connecting port are respectively communicated with the cooling liquid outlet, and the liquid outlet is arranged between the first connecting port and the second connecting port;

and/or, the middle joint is of a T-shaped or Y-shaped structure.

5. A liquid-cooled field coil as set forth in claim 4 wherein: the fixing device is characterized by further comprising a fixing plate, wherein a plurality of middle joints are aligned in length and are arranged on the fixing plate in an up-down parallel mode, the fixing plate is provided with through holes, and the through holes are communicated with the liquid outlet.

6. A liquid-cooled field coil as set forth in claim 3 wherein: the liquid collecting pipe comprises a liquid injecting port and a plurality of liquid separating ports which are communicated with each other, and the liquid separating ports are respectively communicated with the cooling liquid inlets.

7. A liquid-cooled field coil as set forth in claim 6, wherein: the liquid collecting pipe extends along the axial direction of the coil unit, the liquid collecting pipe comprises a first end and a second end which are opposite to each other, the first end forms the liquid injection port, the second end is provided with a plurality of liquid separating branch pipes which are arranged in a single row from bottom to top, the extending direction of the liquid separating branch pipes forms a certain angle with the extending direction of the liquid collecting pipe, and the liquid separating branch pipes form the liquid separating port.

8. A liquid-cooled field coil as set forth in claim 7 wherein: the liquid collecting pipes comprise a first liquid collecting pipe and a second liquid collecting pipe, the cooling liquid inlet of the coil unit at the topmost layer and the cooling liquid inlet at the same side of the cooling liquid inlet are communicated with the liquid distributing opening of the first liquid collecting pipe, and the cooling liquid inlet at the opposite side of the cooling liquid inlet of the coil unit at the topmost layer and the liquid distributing opening of the second liquid collecting pipe are communicated.

9. A liquid-cooled field coil as set forth in claim 8 wherein: the liquid distribution port of the first liquid collecting pipe comprises a first main liquid distribution port and a plurality of first auxiliary liquid distribution ports, the first main liquid distribution port is electrically connected with the cooling liquid inlet of the coil unit at the uppermost layer in series, the liquid distribution port of the second liquid collecting pipe comprises a second main liquid distribution port and a plurality of second auxiliary liquid distribution ports, and the second main liquid distribution port is electrically connected with the cooling liquid inlet of the coil unit at the lowermost layer in series.

10. A liquid-cooled field coil as set forth in claim 1, wherein: the coil assembly is integrally packaged in the plastic package, and the cooling liquid inlet and the cooling liquid outlet are exposed out of the plastic package.