EP3367398B1

EP3367398B1 - Traction tansformer for installation on a vehicle

Info

Publication number: EP3367398B1
Application number: EP16857191.7A
Authority: EP
Inventors: Akihiro Nagase
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2015-10-21
Filing date: 2016-09-02
Publication date: 2021-01-20
Anticipated expiration: 2036-09-02
Also published as: JP6359202B2; CN108140469B; WO2017068873A1; JPWO2017068873A1; CN108140469A; EP3367398A4; EP3367398A1

Description

Technical Field

The present invention relates to a traction transformer, and more particularly, to a traction transformer configured to cool a refrigerant oil through utilization of traveling wind caused by traveling of a vehicle.

Background Art

Devices such as an air-conditioning device, a power converter, a controller, and a transformer which are mounted to a vehicle generate a large amount of heat during operation. As cooling systems for those devices, there have been known a forced air-cooled system using an electric fan and a natural running air cooling system utilizing traveling wind caused by traveling of the vehicle.
The natural running air cooling system has become more popular in recent years in view of the fact that the natural running air cooling system saves more energy and causes less noise than the forced air-cooled system. The natural running air cooling system has generally been adopted as a cooling method for a device such as a traction transformer installed under a floor (see, for example, Patent Literature 1).
This is because, when the natural running air cooling system is applied to, for example, the traction transformer installed under the floor, the traction transformer can efficiently be cooled from the following reasons. That is, between an underfloor surface of the vehicle and a railway track surface, in addition to an inflow of the traveling wind from a side surface of the vehicle, the traveling wind which has been reflected on the railway track surface flows toward the traction transformer installed on the underfloor surface.
As a result, even when a large number of peripheral devices are arranged around the traction transformer, the traveling wind having a high flow rate flows in the surroundings of a cooler for the traction transformer, thereby being capable of achieving an effective cooling.
Meanwhile, for example, a low-floor vehicle which is popular in Europe has a narrow installation space under the floor, and hence large-scale peripheral devices such as the air-conditioning device, the power converter, and the controller are installed on a rooftop of the vehicle together with the traction transformer. In order to cool such a traction transformer installed on the rooftop of the vehicle, the forced air-cooled system using the electric fan has hitherto been adopted.

Citation List

Patent Literature

[PTL 1] JP 2004-363253 A

Summary of the Invention

Technical Problem

However, when a natural running air cooling system is adopted so as to cool a traction transformer, in a case in which the peripheral devices are installed in front of the traction transformer in a traveling direction of a vehicle, the peripheral devices cause the traveling wind to separate upward during traveling of the vehicle, with the result that a stagnation region in which wind having a low flow rate flows is generated in rear of the peripheral devices in the traveling direction of the vehicle. Thus, there has been the following problem.
That is, when a position to which the traction transformer takes in the traveling wind is located in the stagnation region, depending on the arrangement of the peripheral devices and the traction transformer, traveling wind having a sufficient flow rate cannot be sufficiently taken in to the surroundings of the cooler for the traction transformer, with the result that a sufficient cooling performance cannot be obtained with the traveling wind.
The present invention has been made in order to solve the above-mentioned problem, and has an object to provide a traction transformer, which prevents a position to which traveling wind is taken in from overlapping with a stagnation region located in rear of peripheral devices in a traveling direction of a vehicle, and which is effectively cooled by the traveling wind.

Solution to the Problem

According to the present invention, there is provided a traction transformer according to present claim 1.

Advantageous Effects of the Invention

In the traction transformer according to the present invention, the position to which the traction transformer takes in the traveling wind is prevented from overlapping with the stagnation region located in rear of the peripheral devices in the traveling direction of the vehicle, and the traction transformer can effectively be cooled by the traveling wind.

Brief Description of the Drawings

FIG. 1: is a top view for illustrating a rolling stock to which a traction transformer according to a first embodiment of the present invention is installed.
FIG. 2: is a side view for illustrating the rolling stock to which the traction transformer according to the first embodiment of the present invention is installed.
FIG. 3: is a top view for illustrating a structure of the traction transformer according to the first embodiment of the present invention.
FIG. 4: is a side view for illustrating the structure of the traction transformer according to the first embodiment of the present invention.
FIG. 5: is a schematic sectional view taken along the line A-A of FIG. 4, for illustrating an installation state of the traction transformer according to the first embodiment of the present invention on a rooftop.
FIG. 6: is a perspective view for illustrating an outer appearance of a cooler for the traction transformer according to the first embodiment of the present invention.
FIG. 7: is a perspective view for illustrating a detailed shape of a duct of the traction transformer according to the first embodiment of the present invention.
FIG. 8: is an explanatory view for illustrating a flow of traveling wind in the rear of a peripheral device.
FIG. 9: is a side view for illustrating a state in which the traction transformer according to the first embodiment of the present invention is arranged on a rooftop of a vehicle.
FIG. 10: is a top view of the vehicle, for illustrating a flow field when the vehicle travels.
FIG. 11: is a top view for illustrating a structure of a traction transformer according to a second embodiment of the present invention.
FIG. 12: is a side view for illustrating a state in which the traction transformer according to the second embodiment of the present invention is arranged on the rooftop of the vehicle.
FIG. 13: is a top view for illustrating a structure of a modification example of the traction transformer according to the second embodiment of the present invention.
FIG. 14: is a perspective view for illustrating a duct in a case of the modification example of the traction transformer according to the second embodiment of the present invention.
FIG. 15: is a side view for illustrating a state in which the modification example of the traction transformer according to the second embodiment of the present invention is arranged on the rooftop of the vehicle.

Description of Embodiments

In embodiments of the present invention, description is made by exemplifying a rolling stock as a vehicle. However, it is needless to say that the present invention is also applicable to vehicles other than a rolling stock, such as a tram or a bus.

First Embodiment

FIG. 1 is a top view for illustrating an example of a rolling stock which includes a traction transformer 10a according to a first embodiment of the present invention installed on a rooftop. FIG. 2 is a side view of the rolling stock illustrated in FIG. 1.
In the following description, description is made with the following definitions. That is, a vehicle length direction being a direction in which the vehicle moves corresponds to an X direction. A vehicle width direction corresponds to a Y direction. A vehicle height direction corresponds to a Z direction.
Further, description is made with the following definitions. That is, a vehicle traveling direction corresponds to a - (minus) X direction. A direction from left to right when facing in the vehicle traveling direction corresponds to a + (plus) Y direction. A direction from a floor to a roof corresponds to a + (plus) Z direction.
As illustrated in FIG. 1 and FIG. 2, the traction transformer 10a and a plurality of peripheral devices 3 are provided on a rooftop 2 of a vehicle 1. Two peripheral devices 3 are installed in front of the traction transformer in the traveling direction, and one peripheral device 3 is installed in rear of the traction transformer 10a in the traveling direction.
In this case, the terms "in front of the traction transformer in the traveling direction" indicate a position in the - (minus) X direction, and the terms "in rear of the traction transformer 10a in the traveling direction" indicate a position in the + (plus) X direction. Examples of the peripheral devices 3 include a power converter, a controller, and an air-conditioning device.
Description is made with the following definition. That is, the rooftop 2 corresponds to an entire upper surface of the vehicle 1 or a part of the upper surface of the vehicle 1. It is needless to say that the structure, the number, and the arrangement of the peripheral devices installed on the rooftop 2 are not limited to those described above.
FIG. 3 is a top view for illustrating a structure of the traction transformer 10a according to the first embodiment. In FIG. 3, the same or corresponding parts are denoted by the same reference symbols, and the detailed description thereof is omitted.
As illustrated in FIG. 3, the traction transformer 10a includes a transformer main body 12 having a casing. Inside the transformer main body 12, a winding 9 serving as a main heat source is provided. A pipe 11 is connected to the transformer main body 12 to form a circulation path for a refrigerant oil.
In the halfway of the pipe 11, an oil pump 13 which is configured to forcibly circulate the refrigerant oil is installed at a position in the - (minus) X direction with respect to the transformer main body 12. Further, a conservator 15 which is configured to absorb a thermal expansion amount of the refrigerant oil is installed at a position in the + (plus) X direction with respect to the transformer main body 12.
On both sides of the transformer main body 12 in the Y direction, there are provided coolers 14a which are configured to cool the refrigerant oil through heat exchange with traveling wind. At the position in the - (minus) X direction with respect to the transformer main body 12 and the coolers 14a, a duct 16a is provided. Further, at the position in the + (plus) X direction with respect to the transformer main body 12 and the coolers 14a, a duct 16b is provided.
The duct 16a is configured to prevent the traveling wind from flowing into the transformer main body 12 from the position in the - (minus) X direction with respect to the duct 16a. The duct 16b takes in the traveling wind generated by the traveling of the vehicle and changes an air-blowing direction thereinside, to thereby blow the traveling wind thus taken in to the coolers 14a.
An insulation oil is used as the refrigerant oil, and in particular, a silicone oil having a flame resisting, an ester oil having a small load on environment during disposal, or other types of oils are used for the vehicle. The casing of the transformer main body 12 is manufactured with a metal, for example, an iron steel or an aluminum. Further, a surface of the casing is coated with a metal for corrosion prevention.
An insulating member such as an insulating bush is installed on a portion of the transformer main body 12, which is connected to an electric wire. The conservator 15 is configured to absorb a thermal expansion when a temperature of the refrigerant oil changes. The capacity of the conservator 15 is set so as to sufficiently absorb the thermal expansion.
FIG. 4 is a side view for illustrating a structure of the traction transformer 10a according to the first embodiment of the present invention. In FIG. 4, the same or corresponding parts are denoted by the same reference symbols, and the detailed description thereof is omitted. As illustrated in FIG. 4, the duct 16a serving as a second duct is provided at the position in the - (minus) X direction with respect to the transformer main body 12.
Further, the duct 16b serving as a first duct is installed at the position in the + (plus) X direction with respect to the transformer main body 12. Further, the duct 16a and the duct 16b are provided so as to face each other in the X direction while sandwiching the transformer main body 12 therebetween.
FIG. 5 is a schematic sectional view taken along the line A-A of FIG. 4, for illustrating an installation state of the traction transformer 10a according to the first embodiment of the present invention on the rooftop 2. In order to facilitate the understanding of the cross-sectional position, the cross-sectional position is indicated using FIG. 4 which is a view for illustrating the traction transformer 10a.
That is, FIG. 5 is a sectional view taken along the line A-A including the vehicle 1 in addition to the traction transformer 10a. In FIG. 5, the same or corresponding parts are denoted by the same reference symbols, and the detailed description thereof is omitted.
An inlet port 30 which is configured to take in the traveling wind is formed in the duct 16b. Further, the dotted line indicates a rolling stock gauge 17. The rolling stock gauge 17 refers to a limit range of a size of the cross section of a vehicle body of the rolling stock, and is a limit value of the vehicle in the Y direction and the Z direction at which the rolling stock can safely travel on a railway track.
An upper space of the rooftop 2 within the rolling stock gauge 17 is formed so that a width of the upper space in the Y direction becomes narrower toward the + (plus) Z direction in consideration of a structural body on a railway track such as a tunnel. The height of the transformer main body 12 in the + (plus) Z direction is set lower than that of the duct 16b. Thus, the inlet port 30 is opened toward the + (plus) Z direction with respect to the transformer main body 12.
FIG. 6 is a perspective view for illustrating an outer appearance of the cooler 14a of the traction transformer 10a according to the first embodiment of the present invention. The cooler 14a includes a plurality of cooling pipes 19a and a plurality of cooling pipes 19b having different sizes and being formed into an inverted U-shape. In this case, the plurality of cooling pipes 19a and the plurality of cooling pipes 19b having different sizes are provided on the same plane.
The cooling pipes 19a are provided at the outermost portion of the cooler 14a. The cooler 14a is constructed by arraying the plurality of cooling pipes 19a and the plurality of cooling pipes 19b which are provided on the same plane in the X direction. Both end portions of each of the cooling pipes 19a and each of the cooling pipes 19b are connected to an inlet header 18a and an outlet header 18b, respectively.
With reference to FIG. 3, FIG. 4, and FIG. 6, description is made of a connection between the pipe 11 and the traction transformer 10a. The pipe 11 is connected from an outlet of the transformer main body 12 to an intake port of the oil pump 13, and extends from a discharge port of the oil pump 13 to branch in the + (plus) Y direction and a - (minus) Y direction. The branched portions of the pipe 11 each extend in the + (plus) X direction to be connected to each of the inlet headers 18a of the coolers 14a, and go out of each of the outlet headers 18b of the coolers 14a to extend in the + (plus) X direction.
Then, the branched portions of the pipe 11 extend in the - (minus) Y direction and the + (plus) Y direction to branch with the conservator 15, and the pipe 11 is connected to an inlet of the transformer main body 12. In FIG. 3, FIG. 4, and FIG. 6, the same or corresponding parts are denoted by the same reference symbols, and the detailed description thereof is omitted.
The cooling pipes 19a which are provided on the outermost side of the cooler 14a are formed so that a side is inclined in conformity to a shape of the rolling stock gauge 17. Further, an outermost surface 20 of the cooler 14a which is illustrated in FIG. 6 is a surface formed of outer portions of the plurality of cooling pipes 19a. The outermost surface 20 of the cooler 14a is formed along the rolling stock gauge 17.
The cooling pipes 19a and cooling pipes 19b are illustrated in FIG. 6 as a plurality of cylindrical tubes. However, the cooling pipes 19a and cooling pipes 19b are not limited thereto, and may be, for example, a flat tube or a rectangular tube.
The cooling pipes are arranged on both the sides of the transformer main body in the Y direction. In this manner, the traction transformer with a good weight balance can be obtained. In addition, it is possible to effectively take in outside air into the coolers from the sides in the Y direction when the vehicle is stopped, and hence natural convection is promoted in the transformer main body. As a result, a heat exchange performance when the vehicle is stopped is enhanced.
FIG. 7 is a perspective view for illustrating a detailed shape of the duct 16b of the traction transformer 10a according to the first embodiment of the present invention. In FIG. 7, the same or corresponding parts are denoted by the same reference symbols, and the detailed description thereof is omitted.
The duct 16b includes the inlet ports 30 for taking in traveling wind 33, and air blowing ports 31 for discharging the traveling wind 33 which is taken in to the coolers 14a as the cooling air 34. Further, a recess 32 is formed at a lower portion of the duct 16b. The vehicle 1 travels toward the - (minus) X direction, and hence the traveling wind 33 flows in the + (plus) X direction.
The inlet ports 30 and the air blowing ports 31 are formed so that the openings are oriented in the - (minus) X direction. The inlet ports 30 and the air blowing ports 31 are smoothly connected to each other by a connection portion 35a formed inside the duct 16b. An air-blowing direction of the traveling wind 33 is changed by the connection portion 35a. That is, the traveling wind 33 flowing in the + (plus) X direction is taken in through the inlet ports 30, and passes through the connection portion 35a.
In this manner, the traveling wind 33 flows in an outward direction of the vehicle and is guided in -the Z direction, and then the air-blowing direction is changed to an opposite direction. As a result, the traveling wind 33 is blown out through the air blowing ports 31 as the cooling air 34 toward the - (minus) X direction.
The recess 32 is formed at a center lower portion of the duct 16b in the Y direction. The pipe 11 can communicate between the recess 32 formed in the duct 16b and the rooftop 2 of the vehicle. Thus, when the pipe 11 is arranged between the transformer main body 12 and the oil pump 13, and between the conservator 15 and the transformer main body 12, the pipe 11 does not need to circumvent the duct 16b. As a result, a total length of the pipe 11 can be reduced.
Further, the air blowing ports 31 are each formed at a position apart from each of the inlet ports 30 in the + (plus) Y direction or in the - (minus) Y direction. Further, the air blowing ports 31 are each formed at a position apart from each of the inlet ports 30 in the - (minus) Z direction. That is, the inlet ports 30 and the air blowing ports 31 are formed at positions apart from each other in the Y direction and the Z direction. As a result, it is possible to prevent the cooling air 34 which is heated in the coolers 14a and the traveling wind 33 from being mixed at the inlet ports 30.
The two air blowing ports 31 which are formed in the duct 16b face the coolers 14a. Each of those air blowing ports 31 is formed at a position in the + (plus) X direction with respect to the cooler 14a, and each of the air blowing ports 31 faces the cooler 14a. The traveling wind 33 which is taken in through the inlet ports 30 is guided by the connection portion 35a so that the air-blowing direction of the traveling wind 33 becomes opposite. As a result, the cooling air 34 is blown through the air blowing ports 31 toward the coolers 14a which face the air blowing ports 31.
In FIG. 7, the air-blowing direction of the traveling wind 33 and the air-blowing direction of the cooling air 34 are opposite to each other. The traveling wind 33 taken in from a position in the + (plus) X direction of the duct 16b can be blown to the coolers 14a which are provided at positions in the - (minus) X direction of the duct 16b as the cooling air 34.
The structure of the duct 16b is described, and the duct 16a also has the same structure and only the arrangement is different. Thus, the description of the duct 16a is omitted. It is needless to say that the duct 16a and the duct 16b may have different structures from each other. In this case, the shape of the duct can be changed in accordance with the structure of the peripheral devices 3 of the vehicle, and the cooling performance can further be improved.
FIG. 8 is an explanatory view for illustrating a flow of the traveling wind 33 at a position in the + (plus) X direction of the peripheral device 3. In FIG. 8, the same or corresponding parts are denoted by the same reference symbols, and the detailed description thereof is omitted.
When the vehicle 1 travels in the - (minus) X direction, the traveling wind 33, which has flowed over an upper surface of the peripheral device 3 and been separated therefrom, gradually approaches the rooftop 2 and adheres to the rooftop 2 in the end.
In general, a stagnation region is formed at the position in the + (plus) X direction of the peripheral device 3 in accordance with a height of the peripheral device 3. In the stagnation region, a wind flow having a high flow rate does not occur. In this case, when the traction transformer 10a is arranged in the stagnation region, the traction transformer 10a cannot take in sufficient traveling wind, with the result that the cooling performance is largely reduced.
In general turbulence, when it is assumed that the height of the peripheral device 3 is defined as h, an entrance length x, which is a length required to reach a reattachment point at which the wind having been separated by the peripheral device 3 reattaches, is about 7h in rear of the peripheral device 3 in the traveling direction.
The height h of the peripheral device 3 which is arranged on the rooftop 2 of the vehicle changes in accordance with the structure of the vehicle 1, and the maximum value of the height h is 1 m due to a restriction of the rolling stock gauge 17. In this case, in rear of the peripheral device 3, the entrance length x of about 7 m is required at maximum. However, in many cases, a large number of peripheral devices 3 are arranged on the rooftop 2 for efficient use of a limited area. Thus, it is difficult to arrange the traction transformer 10a while securing a distance with respect to the peripheral device 3 in the + (plus) X direction.
FIG. 9 is a side view for illustrating a state in which the traction transformer 10a according to the first embodiment of the present invention is arranged on the rooftop 2 of the vehicle. In FIG. 9, the same or corresponding parts are denoted by the same reference symbols, and the detailed description thereof is omitted.
The traveling wind 33 which has flowed over the peripheral device 3 positioned in the - (minus) X direction of the traction transformer 10a passes over the duct 16a arranged at the position in the - (minus) X direction of the transformer main body 12, and then separates from the traction transformer 10a.
For example, a length of the transformer main body 12 in the X direction is 2.5 m, and a height difference between an upper surface of the duct 16b illustrated in FIG. 5, which is restricted by the rolling stock gauge 17, and an upper surface of the transformer main body 12 is about 0.30 m.
In this case, the separated traveling wind 33 reattaches to the duct 16b at a rear position by about 2 m in the traveling direction. Thus, the transformer main body 12 can take in the traveling wind 33 having a sufficient flow rate through the inlet ports 30 at the rear position by about 2 m in the traveling direction.
FIG. 10 is a top view of the vehicle 1, for illustrating a flow field when the vehicle travels. In FIG. 10, the same or corresponding parts are denoted by the same reference symbols, and the detailed description thereof is omitted. Cooling air 36 is obtained in such a manner that the cooling air 34 is blown to the coolers and is heated through heat exchange with the refrigerant oil. The peripheral devices 3 are arranged on the rooftop 2 of the vehicle 1 so as to sandwich the traction transformer 10a in the X direction.
The traveling wind 33 which has been separated by the peripheral device 3 approaches the vehicle 1 as the traveling wind 33 further flows in the + (plus) X direction. However, due to the duct 16a provided at the position in the - (minus) X direction of the transformer main body 12, the traveling wind 33 does not flow into a region in a - (minus) X direction of the coolers 14a.
As the traveling wind 33, which has passed over the upper surface of the duct 16a, further flows in the + (plus) X direction, the traveling wind 33 gradually approaches the transformer main body 12, and reattaches to the upper surface of the transformer main body 12. The high-speed traveling wind 33 flows over the upper surface of the transformer main body 12, and hence heat radiation efficiency from the surface of the transformer main body 12 is improved.
Further, the traveling wind 33 which flows over the surface of the transformer main body 12 is taken in to the duct 16b having an opening at a position in the + (plus) X direction of the transformer main body 12. Inside the duct 16b, the inlet ports 30 and the air blowing ports 31 communicate with each other by the connection portion 35a. The traveling wind which has been taken in through the inlet ports 30 is sent through the air blowing ports 31 which are formed on both sides of the transformer main body 12 in the Y direction as the cooling air 34.
The cooling air 34 which is discharged from the duct 16b exchanges heat with the refrigerant oil in the coolers 14a. As illustrated in FIG. 6, the cooler 14a has a shape in which the cylindrical cooling pipes 19a and 19b are arranged in a plurality of lines along the X direction.
Thus, as the cooling air 34 having entered the coolers 14a further flows in the coolers 14a in the + (plus) X direction, the cooling air 34 is gradually diffused through clearances between the cooling pipes 19a and 19b to an outside of the coolers 14a.
As illustrated in FIG. 10, the cooling air 36 which has been diffused to the outside of the coolers 14a after completion of the heat exchange with the refrigerant oil merges with the traveling wind 33 which flows around the coolers 14a in the + (plus) X direction, and flows in the + (plus) X direction.
The inlet ports 30 of the duct 16b are not formed at a position in the + (plus) X direction of the coolers 14a. Thus, the cooling air 36 which has been diffused and exhausted from the coolers 14a is not taken in to the duct 16b again, and the cooling air 34 having a low temperature is always sent to the coolers 14a.
An opening direction of the inlet ports 30 of the duct 16a and an opening direction of the inlet ports 30 of the duct 16b are opposed to each other in the X direction. Similarly, an opening direction of the air blowing ports 31 of the duct 16a and an opening direction of the air blowing ports 31 of the duct 16b are opposed to each other in the X direction.
The duct 16a and the duct 16b are arranged so as to face each other in the X direction while sandwiching the transformer main body 12 therebetween. Thus, even when the traveling direction of the vehicle is changed, it is possible to supply the cooling air 34 to the coolers 14a similarly to the case before the traveling direction is changed.
Further, there is no shielding member at positions in the + (plus) Z direction of the transformer main body 12 and the coolers 14a, and hence the natural convection occurs also when the vehicle is stopped. Thus, sufficient heat radiation property can be secured.
In the present invention, description is made by exemplifying the case in which the coolers are arranged on both the sides of the transformer main body in the Y direction, but the present invention is not limited thereto.
For example, in a case of a traction transformer with a winding having a small heat generating amount, it is needless to say that the cooler may be arranged on only one side surface of the transformer main body in the vehicle width direction.
In the first embodiment, two ducts are provided, but it is needless to say that only one duct 16b may be provided at the position in the + (plus) X direction of the transformer main body 12. In this case, the inlet ports 30 of the duct 16b only need to be formed, in the traveling direction of the vehicle 1, in rear of a position at which the traveling wind separated by the peripheral device 3 provided in the front portion of the vehicle 1 in the traveling direction reattaches to the surface of the transformer main body 12.
That is, the duct 16b only needs to be provided in the rear portion of the vehicle 1 in the traveling direction with respect to the transformer main body 12 and the cooler 14a. In this case, it is possible to take in the traveling wind 33 outside the stagnation region through the inlet ports 30, thereby being capable of effectively cooling the transformer main body 12.

Second Embodiment

FIG. 11 is a top view for illustrating a structure of a traction transformer 10b according to a second embodiment of the present invention. The structure of the traction transformer 10b is different from that of the traction transformer 10a according to the first embodiment which is illustrated in FIG. 3 in that auxiliary devices such as the oil pump 13 and the conservator 15 are arranged between the duct 16a and the transformer main body 12 and between the duct 16b and the transformer main body 12.
Coolers 14b have a shape elongated in the X direction as compared to the coolers 14a according to the first embodiment. This is because a cover 37a for covering the oil pump 13 and a cover 37b for covering the conservator 15 are provided between the duct 16a and the transformer main body 12 and between the duct 16b and the transformer main body 12, respectively.
In the following description, the same parts as or corresponding parts to the traction transformer 10a according to the first embodiment are denoted by the same reference symbols, and the detailed description thereof is omitted.
FIG. 12 is a side view for illustrating a state in which the traction transformer 10b according to the second embodiment of the present invention is arranged on the rooftop 2 of the vehicle 1. The cover 37a and the cover 37b are provided so that respective upper surfaces have the same height as that of the upper surface of the transformer main body 12. Further, it is desired that the transformer main body 12 be provided to be close to the cover 37a and the cover 37b in the X direction.
In this case, the traveling wind 33 is prevented from flowing into a region between the cover 37a and the transformer main body 12 and a region between the cover 37b and the transformer main body 12. As a result, a sufficient amount of the traveling wind 33 can be taken in through the inlet ports 30. The auxiliary devices are arranged between the duct 16a and the transformer main body 12 and between the duct 16b and the transformer main body 12.
Thus, it is possible to increase a length of a flat portion which is formed of the surface of the transformer main body 12 and the surfaces of the cover 37a and the cover 37b covering the auxiliary devices by a length of the auxiliary devices in the X direction. That is, the entrance length for the reattaching of the traveling wind 33 can be increased, thereby being capable of taking in a larger amount of traveling wind 33 in the limited region.
One cause of an increase in distance for the reattaching of the separated traveling wind 33 is a vertical vortex generated between the traveling wind 33 and the devices. As a distance between the duct 16a and the duct 16b which are arranged so as to be opposed to each other in the X direction while sandwiching the transformer main body 12 therebetween increases, reattaching of the separated traveling wind 33 is promoted. However, when the oil pump 13 and the conservator 15 which are different in height are arranged in the halfway, an unnecessary vortex is generated on the surfaces.
Thus, the traveling wind 33 cannot be taken in effectively through the inlet ports 30. The cover 37a and the cover 37b are provided so that the respective upper surfaces have the same height as that of the upper surface of the transformer main body 12, and hence such a vortex can be prevented from being generated.
FIG. 13 is a top view for illustrating a structure in a case of a modification example of the traction transformer according to the second embodiment of the present invention. Further, FIG. 14 is a perspective view for illustrating a duct 16d of a traction transformer 10c according to the second embodiment of the present invention.
In FIG. 13 and FIG. 14, the same or corresponding parts are denoted by the same reference symbols, and the detailed description thereof is omitted. In FIG. 14, a connection portion 35b for connecting the inlet ports 30 and the air blowing ports 31 of the duct 16d is provided. As illustrated in FIG. 13 and FIG. 14, the length of the duct 16d in the - (minus) X direction is longer than that of the duct 16b according to the first embodiment.
In this case, in the duct 16d, portions of the connection portion 35b which are connected to the air blowing ports 31 are extended in the - (minus) X direction. The duct 16c has the same structure as the duct 16d and only arrangement is different, and hence the description thereof is omitted.
It is needless to say that the duct 16c and the duct 16d may have different structures from each other. In this case, the shape of the duct can be changed in accordance with the structure of the peripheral devices 3 of the vehicle 1, and the cooling performance can further be improved.
When the auxiliary devices are arranged between the transformer main body 12 and the duct 16c and between the transformer main body 12 and the duct 16d, the traction transformer 10b includes the coolers 14b extending in the X direction by a length of the auxiliary devices. Meanwhile, in the traction transformer 10c, the portions of the connection portion 35b which are connected to the air blowing ports 31 are extended.
Instead of extending the coolers 14a, the portions of the connection portion 35b which are connected to the air blowing ports 31 of each of the duct 16c and the duct 16d are extended, and hence a weight of the traction transformer 10c can be reduced.
FIG. 15 is a side view for illustrating a state in which the modification example of the traction transformer according to the second embodiment of the present invention is arranged on the rooftop 2 of the vehicle 1. As illustrated in FIG. 15, a cover 37c and a cover 37d having different shapes are provided instead of the cover 37a and the cover 37b. The cover 37c is formed so that an upper surface gradually lowers from the transformer main body 12 side to the duct 16c side.
Similarly, the cover 37d is formed so that an upper surface gradually lowers from the transformer main body 12 side to the duct 16d side. Thus, in the traction transformer 10c, the inlet ports 30 of each of the duct 16c and the duct 16d can be formed larger, and hence it is possible to take in a larger amount of traveling wind 33.
Further, the cover may be formed of a plate material having a small opening ratio, for example, a punched metal. In this case, with the punched metal having a small opening ratio, the influence on the introduced wind of the traveling wind 33 to the duct 16 can be suppressed, and the air heated in the cover can be released to an outside of the cover. As a result, the heat radiation property of the cover can be enhanced.
In the second embodiment, the structure in which the two ducts are provided is adopted, but it is needless to say that a structure in which only one duct is provided at the position in the + (plus) X direction of the transformer main body may be adopted.
In this case, the duct 16d only needs to be provided, in the traveling direction of the vehicle, in rear of the position at which the traveling wind which is separated by the peripheral device 3 provided in the front portion of the vehicle in the traveling direction reattaches to the surface of the transformer main body 12. In this case, it is possible to take in the traveling wind through the inlet ports outside the stagnation region, and hence the transformer main body can effectively be cooled.
In the second embodiment, the ducts having the same structure are provided to the transformer main body so that the respective inlet ports 30 and the respective air blowing ports 31 face each other in the X direction. With this structure, even when the traveling direction of the vehicle is changed, the cooling performance of the traction transformer which is the same as that before the traveling direction is changed can be obtained. With this, the second embodiment of the present invention has been described.

List of Reference Signs

1: vehicle
2: rooftop
9: winding
10a, 10b, 10c: traction transformer
11: pipe
12: transformer main body
13: oil pump
14a, 14b: cooler
15: conservator
16a, 16b, 16c, 16d: duct
19a: cooling pipe
20: outermost surface
30: inlet port
31: air blowing port
32: recess
35a, 35b: connection portion
37a, 37b, 37c, 37d: cover

Claims

A traction transformer (10a, 10b, 10c) for installation on a vehicle, comprising:
- a transformer main body (12), which has a winding (9), and is connectable to a pipe (11) through which a refrigerant oil circulates;

- an oil pump (13), which is configured to circulate the refrigerant oil through the pipe (11);

- a cooler (14a, 14b), which is connectable to the pipe (11), and is configured to cool the refrigerant oil;
characterised in that the traction transformer further comprises:
- a first duct (16b, 16d), which is provided in rear of the transformer main body (12) and the cooler (14a, 14b) in the traveling direction of the vehicle, when the traction transformer is installed on the vehicle, and includes:
- a first inlet port (30), which is configured to take in traveling wind (33) caused by traveling of the vehicle;

- a first air blowing port (31), which is configured to blow the traveling wind (33) to the cooler (14a, 14b) as cooling air (34); and

- a first connection portion (35a, 35b), which is configured to connect the first inlet port (30) and the first air blowing port (31) to each other, and is configured to guide the traveling wind (33) so that an air-blowing direction of the travelling wind is changed from a direction opposite to the traveling direction of the vehicle at the first inlet port to an opposite air-blowing direction at the first air blowing port, and to cause the guided traveling wind (33) to be discharged as the cooling air (34) through the first air blowing port (31).
A traction transformer according to claim 1,
wherein the transformer main body (12), the oil pump (13), and the cooler (14a, 14b) are providable on a rooftop of the vehicle.
A traction transformer according to claim 1 or 2,
wherein the first inlet port (30) and the first air blowing port (31) are formed at positions apart from each other in at least one of a vehicle width direction or a vehicle height direction.
A traction transformer according to any one of claims 1 to 3,
wherein the first duct (16b) is arranged so that an upper surface of the transformer main body (12) and a lower surface of the first inlet port (30) have the same height, and that a recess (32) which enables the pipe (11) to pass through the first duct (16b) is formed in a lower surface of the first duct (16b).
A traction transformer according to any one of claims 1 to 4 further comprising
- a second duct (16a, 16c), which is provided in front of the transformer main body (12) and the cooler (14a, 14b) in the traveling direction of the vehicle, and includes:
- a second inlet port (30) formed so as to face the first inlet port (30);

- a second air blowing port (31) formed so as to face the first air blowing port (31); and

- a second connection portion (35a, 35b) configured to connect the second inlet port (30) and the second air blowing port (31),

wherein the second connection portion (35a, 35b) is configured to guide wind which is taken in through the second inlet port (30) so that an air-blowing direction of the wind thus taken in is opposite, and to cause the wind to be discharged to the cooler (14a, 14b) through the second air blowing port (31).
A traction transformer according to claim 5,
wherein the second inlet port (30) and the second air blowing port (31) are formed at positions apart from each other in the at least one of the vehicle width direction or the vehicle height direction.
A traction transformer according to claim 5 or 6,
wherein the second duct (16a) is arranged so that the upper surface of the transformer main body (12) and a lower surface of the second inlet port (30) have the same height, and that a recess (32) which enables the pipe to pass through the second duct (16a) is formed in a lower surface of the second duct (16a).
A traction transformer according to any one of claims 1 to 7,
wherein the cooler (14a, 14b) comprises a plurality of coolers (14a, 14b), and wherein the plurality of coolers (14a, 14b) are provided on both sides of the transformer main body (12) in the vehicle width direction.
A traction transformer according to any one of claims 1 to 8,
wherein the cooler (14a, 14b) includes a plurality of cooling pipes (19a, 19b) which have an inverted U-shape, and
wherein an outermost surface (20) which is a surface of outer portions of the plurality of cooling pipes (19a, 19b) is formed along a rolling stock gauge (17).
A traction transformer according to any one of claims 5 to 7,
further comprising:
- a conservator (15) configured to absorb a thermal expansion amount of the refrigerant oil which circulates through the pipe (11); and

- covers (37a, 37b, 37c, 37d) which are configured to cover the oil pump (13) and the conservator (15),

- wherein upper surfaces of the covers (37a, 37b, 37c, 37d) and an upper surface of the transformer main body (12) are arranged at the same position in a vehicle height direction, and

- wherein the conservator (15) and the oil pump (13) are provided at sides closer to the transformer main body (12) with respect to the first duct (16b, 16d) and the second duct (16a, 16c).
A traction transformer according to claim 10,
wherein parts of the upper surfaces of the covers (37c, 37d) which are closer to the first duct (16d) and the second duct (16c) are formed so as to be lower than parts of the upper surfaces of the covers (37c, 37d) which are closer to the transformer main body (12).
A traction transformer according to claim 10 or 11,
wherein the covers (37a, 37b, 37c, 37d) are each formed of a punched metal.