KR100923190B1 - Supercharger with electric motor - Google Patents

Abstract

In the supercharger 10 with an electric motor of the present invention, the electric motor 20 is disposed at a position adjacent to the compressor impeller 6 and the center housing 14 surrounds the electric motor 20 and is also provided at the diffuser portion 25. It has a cooling liquid flow path 34 formed so that it may adjoin. In the cooling liquid flow path 34, the 1st cooling structure part 38 is formed in the site | part of the electric motor 20 side, and the 2nd cooling structure part 39 is formed in the site | part of the diffuser part 25, The 1st cooling structure part 38 ) To cool the electric motor 20 and to cool the diffuser portion 25 by the second cooling structure 39.

Description

Supercharger with electric motor {SUPERCHARGER WITH ELECTRIC MOTOR}

1 is a view for explaining the prior art.

2 is a view for explaining another conventional technology.

3 is a cross-sectional view showing an embodiment of the present invention.

4 is a partially enlarged view of FIG. 3.

[Patent Document 1] Japanese Unexamined Patent Publication No. 2003-293785

[Patent Document 2] Japanese Unexamined Patent Publication No. 2004-44451

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supercharger driven by the exhaust gas of an internal combustion engine, to compressed and intakes intake air, and more particularly to a supercharger with an electric motor provided with an electric motor for assisting the rotational drive of a compressor.

In order to improve the performance of the internal combustion engine, a supercharger (also called a turbocharger), which is driven by the exhaust gas of the internal combustion engine and compresses the intake air, is widely used. In addition, a supercharger with an electric motor which improves acceleration response and the like by inserting an electric motor coaxially with the shaft of the supercharger and accelerating rotational drive of the compressor is also used.

Patent Document 1 discloses a prior art relating to a supercharger with an electric motor. 1: is sectional drawing which shows the structure of the supercharger 50 with an electric motor disclosed by patent document 1. As shown in FIG. On the exhaust passage side of the supercharger 50, a turbine impeller 52 and a turbine housing 51A surrounding the turbocharger 50 are arranged. The turbine housing 51A has a scroll chamber 63 formed around the turbine impeller 52, and the scroll chamber 63 communicates with the turbine impeller 52 through the annular gas flow path 64. In the turbine housing 51A, an exhaust port 65 concentric with the turbine impeller 52 is formed at the center thereof.

The compressor impeller 53 and the compressor housing 51B which surrounds the compressor impeller 53 are arrange | positioned at the intake passage side of the supercharger 50 with an electric motor. The compressor housing 51B has a scroll chamber 66 formed around the compressor impeller 53, and the scroll chamber 66 communicates with the compressor impeller 53 via the diffuser portion 67 formed in an annular shape. It is. In the compressor housing 51B, a compressor impeller 53 and a concentric intake port 68 are formed in the center thereof.

The turbine impeller 52 and the compressor impeller 53 are connected by the shaft 54. The shaft 54 is rotatably supported by a bearing 55 embedded in the center housing 51C. The center housing 51C also includes a motor 58 having a rotor 56 coaxially connected with the shaft 54 and a stator 57 disposed around the rotor 56.

In the supercharger 50 with the electric motor configured as described above, when the exhaust gas discharged from the internal combustion engine (engine) is introduced into the scroll chamber 63, the exhaust gas flows to the exhaust port 65 through the annular gas flow path 64 and the turbine impeller 52. In the process of passing through) rotates the turbine impeller (52). Then, the compressor impeller 53 connected to the turbine impeller 52 is rotated via the shaft 54, and this rotational drive is assisted by the electric motor 58, and the air sucked in from the inlet port by the compressor impeller 53. To accelerate. The accelerated air is decelerated and pressurized in the course of passing through the diffuser portion 67, introduced into the scroll chamber 66, discharged from the discharge portion not shown, and supplied to the internal combustion engine.

In such a supercharger with an electric motor, the motor 58 rotates at high speed while the supercharger is in operation, and generates heat by wind loss or Eddy-Current loss. In addition, since high-temperature exhaust gas flows through the turbine, the electric motor 58 becomes hot by heat conduction from the turbine impeller 52 to the shaft 54 and from the shaft 54 to the rotor 56. When the motor 58 is at a high temperature, there is a problem that the magnetic flux of the permanent magnet therein is reduced or the efficiency of the motor 58 is lowered. In the supercharger of Patent Document 1, as shown in FIG. 1, the coolant flow path 60 is formed to surround the electric motor 58 inside the housing 51, and the coolant 61 flows through the coolant flow path 60. The electric motor 58 is configured to cool.

Regardless of whether or not the electric motor 58 is mounted, in some automobiles equipped with a supercharger, the exhaust gas may be refluxed to combustion air to remove nitrogen oxides in the exhaust gas. In addition, a blow-by gas (gas including a mixed gas leaked from the combustion chamber to the crank chamber through the piston and the cylinder) is discharged from the engine, and the blow-by gas is reduced in order to reduce the mixed gas discharged to the outside air as much as possible. May be refluxed with combustion air and burned again. Therefore, part of the combustion air sucked into the supercharger contains exhaust gas, blow-by gas and the like. Since the oil mist of the engine oil is mixed in the exhaust gas, the oil mist is attached to both sidewalls constituting the flow path in the process of passing through the diffuser portion 67 using the above-described supercharger 50 with an electric motor. . At this time, since the combustion air passing through the diffuser portion 67 is compressed and heated up, the oil mist attached to the wall portion is carbonized and solidified by the heat of the compressed air. For this reason, the solidified carbonized layer narrows the flow path of the diffuser portion 67 to increase the flow resistance, and as a result, there is a problem that the compression efficiency of the supercharger is lowered and further, the reliability is lowered. In addition, the carbonized layer is peeled off due to the difference in thermal expansion between the compressor housing and the carbonized layer, the vibration of the engine, and the like, which may be intaken into the engine.

In order to solve this problem, Patent Document 2 is disclosed as a prior art document relating to a supercharger without an electric motor. 2 is a cross-sectional view showing the configuration of the supercharger 70 disclosed in Patent Document 2. As shown in FIG. As shown in FIG. 2, this supercharger 70 is comprised by the diffuser flow path 67a, the seal plate adjoining part 67b and the housing adjoining part 67c which oppose each other through this. The cooling path 72 which distributes a cooling water at least in the seal plate adjacent part 67b is provided. Since the seal plate adjacent part 67b is cooled by the cooling water flowing through the cooling furnace 72 by this structure, even if an oil mist adheres to the seal plate adjacent part 67b, it is comprised so that carbonization may not be carried out. In Fig. 2, parts corresponding to the components of the motor-supercharger 50 shown in Fig. 1 are given the same reference numerals as in Fig. 1.

As described above, a technique for preventing the accumulation of oil mist in the diffuser portion has been proposed for the supercharger without the electric motor, but the same technique has not been proposed for the supercharger with an electric motor. Therefore, in the supercharger with an electric motor, oil mist accumulates in the diffuser portion, and the solidified carbonized layer narrows the flow path of the diffuser portion 67 to increase the flow resistance, and thus there remains a problem of lowering the compression efficiency of the supercharger.

In addition, in the supercharger with an electric motor, although the cooling structure (cooling furnace 72) similar to patent document 2 mentioned above is provided, it is conceivable to prevent the solidification of oil mist in the diffuser part 67, However, patent document 1 When providing the cooling furnace 72 like patent document 2 in the supercharger 50 with an electric motor of 2, it is necessary to provide the cooling liquid flow path 60 and a cooling furnace separately. Therefore, there is a problem of increasing the weight of the vehicle as a result of the complexity of the structure, the increase of the weight, the increase in the size of the device, the increase in cost, and the effect on the mountability of the vehicle.

SUMMARY OF THE INVENTION In view of the above-described problems, the present invention can suppress or prevent the accumulation of oil mist in the diffuser portion, thereby improving the compression efficiency and reliability of the supercharger by preventing an increase in flow resistance as the flow path of the diffuser portion is narrowed. It is also an object of the present invention to provide a supercharger with an electric motor that can suppress the weight increase, the size of the device, and the cost increase by simplifying the structure by not requiring separate cooling systems for cooling the motor and the diffuser part.

In order to achieve the above object, the first invention relates to a turbine impeller driven by an exhaust gas of an internal combustion engine, a turbine housing surrounding the turbine impeller, and a turbine impeller connected to the shaft to rotate and compress intake air. A compressor impeller, a compressor housing surrounding the compressor impeller, an electric motor located between the turbine impeller and the compressor impeller, a center capable of rotationally driving the shaft, and a center rotatably supporting the shaft and incorporating the motor. A scroll chamber having a housing and being annularly formed in the compressor housing to discharge compressed air, and a diffuser extending radially outward from the compressor impeller outlet and communicating the outlet of the compressor impeller with the scroll chamber. In supercharger with electric motor having department The center housing is characterized by having the first cooling structure portion cooling the electric motor by the cooling liquid, a second cooling structure portion cooling the diffuser portion by the common cooling fluid with the cooling liquid of the first cooling structure portion.

According to a second aspect of the present invention, in the first invention, the electric motor is disposed at a position adjacent to the compressor impeller, and the center housing is formed to surround the electric motor and to be adjacent to the diffuser, and the coolant is disposed therein. It has a cooling liquid flow path to circulate, The said 1st cooling structure part is formed in the said motor side part of the said cooling liquid flow path, The said 2nd cooling structure part is formed in the diffuser part side part, It is characterized by the above-mentioned.

According to the first invention, since the electric motor is cooled in the first cooling structure and the diffuser is cooled in the second cooling structure, the solidification of oil mist in the diffuser can be suppressed or prevented. In addition, since the motor and the diffuser are cooled by the common cooling liquid in the first cooling structure and the second cooling structure, it is not necessary to independently supply the cooling liquid to the respective cooling structures. Therefore, even if a cooling structure for cooling both the electric motor and the diffuser is provided, the cooling system can be simplified.

According to the second invention, since the motor is disposed at a position adjacent to the compressor impeller and a cooling liquid flow path having a first cooling structure portion and a second cooling structure portion is formed around the cooling system, the cooling of the electric motor and the cooling of the diffuser portion are performed in one cooling system. Can be realized. Therefore, it is not necessary to separately provide the first cooling structure for cooling the motor and the second cooling structure for cooling the diffuser, that is, it is not necessary to provide a separate cooling system, so that the cooling system is simplified to increase the weight, the device. The size and cost can be suppressed. In addition, since the influence on the mountability to a vehicle can be suppressed to a minimum, it can greatly contribute to weight reduction of a vehicle.

That is, according to the present invention, the compression efficiency and reliability of the supercharger can be improved by suppressing or preventing the solidification of oil mist in the diffuser portion and preventing an increase in the flow resistance as the flow path of the diffuser portion is narrowed. Since individual cooling systems are not required to cool the motors and diffusers, the simplified structure provides an excellent effect of reducing weight, increasing device size and increasing costs.

[Description of Preferred Embodiment]

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described in detail based on an accompanying drawing. In addition, the same code | symbol is attached | subjected to the part common in each drawing, and the overlapping description is abbreviate | omitted.

3 is a cross-sectional view of a supercharger with an electric motor according to an embodiment of the present invention. As shown in FIG. 3, the turbocharger 10 with the electric motor includes a turbine impeller 2, a turbine housing 4, a shaft 12, a compressor impeller 6, a compressor housing 8, an electric motor 20, and a center. The housing 14 or the like.

On the side of the exhaust passage, a turbine impeller 2 which is rotationally driven by the exhaust gas G of the internal combustion engine, and a turbine housing 4 surrounding the turbine impeller 2 are arranged. The turbine housing 4 has a scroll chamber 9 formed around the turbine impeller 2, and the scroll chamber 13 communicates with the turbine impeller 2 via the annular gas flow passage 11. Moreover, the turbine housing 4 is provided with the exhaust port 17 concentric with the turbine impeller 2 in the center part.

In the intake side passage, a compressor impeller 6 for compressing the intake air and a compressor housing 8 surrounding the compressor impeller 6 are arranged. The compressor housing 8 has a scroll chamber 21 formed annularly around the compressor impeller 6 to discharge compressed air A. An annular diffuser portion 25 is formed between the outlet of the compressor impeller 6 and the scroll chamber 21 extending radially outward from the outlet of the compressor impeller 6 so as to communicate therebetween. The air A accelerated by the compressor impeller 6 is decelerated and pressurized to guide the scroll chamber 21. In the compressor housing 8, a compressor impeller 6 and a concentric intake port 27 are formed in the center thereof.

The turbine impeller 2 and the compressor impeller 6 are connected by a shaft 12, and the shaft 12 is rotatably supported by a bearing 19 embedded in the center housing 14. The turbine housing 4 and the center housing 14 are connected by a coupling 3, and the compressor housing 8 and the center housing are connected by bolts 5.

The motor 20 is a rotor which is built in the center housing 14 and is disposed at a position adjacent to the compressor impeller 6 and is made of a permanent magnet which is coaxial with the shaft 12 and rotates with the shaft 12. 20A (rotor) and stator 20B (stator) composed of coils arranged around the rotor 20A.

The center housing 14 discharges the oil supply passage 22 for supplying the lubricating oil 42 to the bearing 16, and the lubricating oil 42 lubricating and cooling the bearing 19 through the inside of the bearing 16. An oil discharge path 24 is formed therein. The oil supply passage 22 is configured to supply, for example, lubricant oil 42 at around 80 ° C by a lubricant pump (not shown) provided outside.

The turbine impeller 2 side of the center housing 14 is interposed with the turbine side seal ring 26 for preventing the lubricating oil 42 from leaking from the clearance between the center housing 14 and the shaft 12.

4 is a partially enlarged view of FIG. 3. As shown in FIG. 4, between the turbine-side seal plate 28 and the shaft 12 provided at the position between the electric motor 20 and the bearing part inside the center housing 14, the lubricant is prevented from leaking from the gap. The compressor side seal ring 30 is interposed.

A disk-shaped seal plate 29 is interposed between the center housing 14 and the compressor housing 8, and the diffuser portion 25 of the present embodiment includes a seal plate 29 and a seal plate of the compressor housing 8. It is defined by the part 8a which opposes 29, and the flow path 25a between them.

The center housing 14 further includes a first cooling structure 38 for cooling the electric motor 20 with a cooling liquid and a second cooling for cooling the diffuser portion 25 with a cooling liquid common to the first cooling structure 38. It has a structural part 39. The first cooling structure 38 and the second cooling structure 39 will be described in more detail below.

As shown in FIG. 4, the center housing 14 includes a housing main body 15 and a flow path forming member 16, and a cooling liquid flow path 34 is disposed between the housing main body 15 and the flow path forming member 16. Is formed. The coolant flow path 34 surrounds the electric motor 20 and is formed to be adjacent to the unfolder 25. The flow path forming member 16 has a flow path recess 16a for circulating the coolant and is formed in a ring shape as a whole, and the portion of the compressor impeller outlet side of the flow path forming member 16 is formed with a protrusion projecting outward in the radial direction. . The protrusion is sandwiched between the center housing 14 and the compressor housing 8 so that the flow path forming member 16 is fixed to the center housing 14 and the compressor housing 8. And the cooling liquid flow path 34 which distribute | circulates a cooling liquid by the flow path recessed part 16a of the housing main body 15 and the flow path formation member 16 is prescribed | regulated. The O-ring 31 is interposed between the housing main body 15 and the flow path forming member 16, and the space between them is kept tight.

The coolant flow path 34 extends in the center housing 14 in the circumferential direction and is formed in an annular shape, and is configured to distribute a coolant for cooling the electric motor 20 and the diffuser portion 25 therein. The cooling liquid flow path 34 may be formed so that the outer periphery of the electric motor 20 may be completely rounded, and may be formed in a C shape when seen from the axial direction of the shaft 12. The coolant is supplied to the coolant flow path 34 by a coolant pump (not shown) provided outside through a coolant supply port (not shown), and discharged to the outside from the coolant discharge port (not shown). As this cooling liquid, water can be applied, for example. In addition, you may use oil (lubricating oil 42 etc.) as a cooling liquid.

As shown in FIG. 4, the above-mentioned 1st cooling structure part 38 is formed in the site | part of the motor 20 side of the coolant flow path 34, and the above-mentioned agent is formed in the diffuser part 25 side part of the coolant flow path 34. As shown in FIG. 2 cooling structures 39 are formed. In addition, the fin cooling parts 38a and 39a are formed in the 1st cooling structure part 38 and the 2nd cooling structure part 39, respectively, and are comprised so that a heat transfer area may be enlarged and a heat conduction efficiency may be improved. In addition, the thickness of the member of the site | part which comprises the 2nd cooling structure part 39 is set so that heat exchange of a cooling liquid and the diffuser part 25 may be fully performed. Thus, the structure is configured to conduct heat exchange between the cooling liquid flowing through the cooling liquid flow path 34 and the electric motor 20 and between the cooling liquid and the diffuser portion 25. That is, it is comprised so that the electric motor 20 and the diffuser part 25 may be cooled by transmitting the heat of the electric motor 20 and the diffuser part 25 to the cooling liquid of the cooling liquid flow path 34. FIG.

In addition, in this embodiment, although the flow path formation member 16 and the seal plate 29 are comprised separately, the member which comprised these integrally may be sufficient.

Next, the operation and action of the supercharger 10 with the electric motor configured as described above will be described with reference to FIGS. 3 and 4.

In the supercharger 10 with the electric motor, when the exhaust gas G discharged from the internal combustion engine (engine) is introduced into the scroll chamber 9, the exhaust gas G flows through the annular gas flow passage 11 to the exhaust port 17 and the turbine impeller 2 Rotate the turbine impeller (2) in the course of passing through). Then, the compressor impeller 6 connected to the turbine impeller 2 is rotated via the shaft 12, and the rotational driving thereof is assisted by the electric motor 20, and the compressor impeller 6 is driven from the inlet port 27. Accelerate inhaled air A. The accelerated air A is decelerated and pressurized in the course of passing through the diffuser portion 25, introduced into the scroll chamber 21, discharged from the discharge portion not shown, and supplied to the internal combustion engine. The air intake | inspired by the compressor impeller 6 is 20 degreeC and normal pressure, for example, this is heated up and raised to 180 degreeC and 1.5 atmospheric pressure at the exit of the compressor impeller 6, for example, and the diffuser part ( At the outlet of 25), it is elevated to, for example, 180 ° C., to 2.0 atmospheres.

In addition, a coolant is supplied to the coolant flow path 34, and the first cooling structure 38 cools the electric motor 20 from the periphery thereof, and the second cooling structure part of the diffuser portion 25 is the second cooling structure 39. The part adjacent to (39) (hereinafter referred to as 'seal plate adjacency') is cooled. As a result, temperature rise is suppressed to 120 degrees C or less of a seal plate adjacent part. It has been confirmed that the engine oil has fluidity without being carbonized at about 120 ° C. Therefore, in the process of passing the intake air including the oil mist of the engine oil through the diffuser portion 25, even if the oil mist is attached to the adjacent portion of the seal plate, it is not solidified and deposited on the attached portion, It blows into the scroll chamber 21 by this.

Moreover, since the compressed air passing through the diffuser part 25 is cooled by cooling the seal plate adjacent part, the part 8a adjacent to the flow path 25a of the compressor housing 8 is also cooled through compressed air. Therefore, even when oil mist is attached to this part 8a, it does not accumulate in the attachment part and blows off to the scroll chamber 21 by air flow.

On the other hand, the oil mist adheres to this part by forming an oil repellent film in the material adjacent to the seal plate and the part 8a of the compressor housing 8 and having no affinity with the engine oil and repelling the oil mist. It may be prevented. As a material of an oil repellent film, the fluororesin (polytetrafluoroethylene) excellent in heat resistance and corrosion resistance is preferable, for example.

As described above, according to the turbocharger 10 of the present invention described above, since the electric motor 20 is cooled by the first cooling structure 38 and the diffuser portion 25 is cooled by the second cooling structure 39, the diffuser It is possible to suppress or prevent the solidification of oil mist in the section 25. In addition, since the electric motor 20 and the diffuser part 25 are cooled by the common cooling liquid in the 1st cooling structure part 38 and the 2nd cooling structure part 39, it is not necessary to supply a cooling liquid independently to each cooling structure part. Therefore, even if the cooling structure part for cooling both the electric motor 20 and the diffuser part 25 is provided, a cooling system can be simplified.

In addition, according to the turbocharger 10 of the present invention, the electric motor 20 is disposed at a position adjacent to the compressor impeller 6, and the first cooling structure 38 and the second cooling structure 39 are disposed around the motor 20. Since the branch has a coolant flow path 34, the cooling of the electric motor 20 and the cooling of the diffuser portion 25 can be realized in one cooling system. Therefore, it is not necessary to separately provide the first cooling structure 38 for cooling the electric motor 20 and the second cooling structure 39 for cooling the diffuser 25, that is, provide a separate cooling system. Since there is no need, the cooling system can be simplified to suppress weight increase, device enlargement and cost increase. In addition, since the influence on the mountability with respect to a vehicle can be suppressed to the minimum, it can greatly contribute to weight reduction of a vehicle.

Therefore, according to the present invention, the compression efficiency and reliability of the supercharger can be improved by suppressing or preventing the solidification of oil mist in the diffuser part and preventing the increase in the flow path resistance as the flow path of the diffuser part is narrowed. Since no separate cooling system is required to cool the motor and diffuser, the structure can be simplified, resulting in an excellent effect of suppressing weight increase, device enlargement and cost increase.

In addition, this invention is not limited to embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.

According to the present invention, the compression efficiency and reliability of the supercharger can be improved by preventing or increasing the accumulation of oil mist in the diffuser portion, thereby preventing the increase in flow resistance as the flow path of the diffuser portion is narrowed. Since a separate cooling system is not required for cooling, a simple structure makes it possible to obtain a supercharger with an electric motor that can suppress weight increase, device enlargement and cost increase.

Claims (2)

A turbine impeller driven by exhaust gas of the internal combustion engine, a turbine housing surrounding the turbine impeller, a compressor impeller connected to the turbine impeller and a shaft to rotate and compress intake air, and a compressor housing surrounding the compressor impeller And a motor located between the turbine impeller and the compressor impeller and capable of rotationally driving the shaft, and a center housing rotatably supporting the shaft and incorporating the motor. A supercharger with an electric motor having a scroll chamber formed in an annular shape and discharging compressed air, and a diffuser portion extending radially outward from the compressor impeller outlet and communicating the outlet of the compressor impeller with the scroll chamber. The electric motor is disposed at a position adjacent to the compressor impeller, The center housing includes a housing main body and a flow path forming member, and is formed between the housing main body and the flow path forming member so as to be adjacent to the diffuser portion while surrounding the electric motor, and has a coolant flow path through which the coolant flows. The cooling liquid flow path is a cooling liquid in common with the cooling liquid of the first cooling structure portion cooling the electric motor by a cooling liquid to the motor side portion of the flow path forming member, and the diffuser portion side portion of the flow passage forming member. A second cooling structure for cooling the diffuser by The flow path forming member has a protrusion that projects radially outward from a portion of the compressor impeller outlet side, and the flow path forming member is fitted into the center housing and the compressor housing so that the flow path forming member is formed in the center housing and the compressor housing. Supercharger with an electric motor, characterized in that fixed to. The method of claim 1, And a plurality of fins are formed in the first cooling structure and the second cooling structure, respectively.

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