JP2008223673A - Turbocharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turbocharger which suppresses turbulence of compressed air flowing in a diffuser part, and pressure loss, while improving supercharging performance, and further improves disassembling workability of a seal plate on the side of a compressor impeller from a bearing housing in maintenance, while enhancing the cooling capacity of the compressor impeller. <P>SOLUTION: The seal plate 20 on the side of the compressor impeller, which is positioned on the back surface of the compressor impeller 8 and formed larger than the outside diameter of the compressor impeller, is attached to the bearing housing 3 with a bolt 21 and cooled. A diffuser member 33 formed by arranging a blade member 32 on an annular member 31 is attached to the peripheral part of the seal plate for covering the head part of the bolt 21. The diffuser part 27 for the compressed air is formed between the diffuser member 33 and a compressor housing 2. A protruding piece 38 for disassembly, protruding toward the side of the compressor impeller 8, is protruded from the inner peripheral part of the annular member 31. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a turbocharger.

  In general, a turbocharger is configured such that a turbine and a compressor are connected on the same rotation shaft, and the compressor is driven by the turbine, and is widely used for improving the performance of an internal combustion engine.

  As an example of a conventional turbocharger, there is, for example, Patent Document 1, and the one disclosed in Patent Document 1 includes a turbine housing 1 and a compressor housing 2 as shown in FIGS. A bearing housing 3 is provided between the bearing 6 and the thrust bearing 7 so that the rotor shaft 5 of the turbine rotor 4 disposed in the turbine housing 1 extends through the bearing housing 3 toward the compressor housing 2. A compressor impeller 8 is fitted on the end of the rotor shaft 5 on the side opposite to the turbine rotor 4 so as to be disposed in the compressor housing 2.

  Inside the bearing housing 3 is an upper cooling space 9 that is located on the turbine housing 1 side in the bearing housing 3 and is concentrically disposed on the upper outer peripheral side of the rotor shaft 5, and the bearing housing 3 is located near the rotor shaft through hole 10 on the turbine housing 1 side and communicates with the upper cooling space 9. The turbine side seal space 11 is located in the lower part of the bearing housing 3 and the upper cooling space 9. And a lower oil discharge space 12 communicating with the turbine-side seal space 11 is formed. The lower oil discharge space 12 extends from the upper side to the lower side in a direction perpendicular to the axis of the rotor shaft 5 and is supplied with cooling lubricant C. An oil supply port 13, an oil supply hole 14 formed so as to intersect the oil supply port 13, and a hole formed so as to communicate with the oil supply hole 14 and for the upper cooling. And the jet holes 15 for injecting cooling lubricant C toward while 9 is formed.

  Further, a compressor impeller side seal plate 20 ′ located on the back surface of the compressor impeller 8 and formed substantially equal to the outer diameter of the compressor impeller 8 is attached to the bearing housing 3 with bolts 21 as fastening members, The compressor impeller side seal plate 20 ′ is formed with a donut-shaped compressor impeller side cooling space 22 ′ concentric with the rotor shaft 5 so as to communicate with the lower oil discharge space 12 at a lower portion thereof. A jet hole 24 that is formed so as to communicate with the oil supply hole 23 branched from the port 13 and injects the cooling lubricant C toward the upper portion of the compressor impeller side cooling space 22 ′ is formed. An oil drain 26 having a seal ring 25 loaded on the outer peripheral portion is fitted to the rotor shaft 5 passing through the compressor impeller side seal plate 20 '.

  On the other hand, on the outer periphery of the compressor impeller 8 in the compressor housing 2, a diffuser member 33 ′ in which a plurality of blade members 32 ′ for rectifying compressed air is arranged on an annular member 31 ′ is provided with a countersunk screw 34. The diffuser portion 27 for compressed air is formed between the diffuser member 33 ′ and the bearing housing 3.

  During operation of the turbocharger, exhaust gas of an internal combustion engine (not shown) is introduced into the turbine housing 1, and the turbine rotor 4 is rotated by the pressure of the exhaust gas, and the rotation of the turbine rotor 4 is transmitted via the rotor shaft 5. By being transmitted to the compressor impeller 8, the compressor impeller 8 is driven to rotate, and the air supplied to the internal combustion engine is compressed (supercharged).

  At this time, the lubricating oil C is supplied to the oil supply port 13 of the bearing housing 3, and the cooling lubricating oil C is injected from the jet hole 15 into the upper cooling space 9 through the oil supply hole 14. Then, it collides with the wall surface on the turbine housing 1 side in the upper cooling space 9 to cool the wall surface, and is discharged from the turbine side seal space 11 through the lower oil discharge space 12 to the outside.

  At the same time, the cooling lubricating oil C branches from the oil supply port 13 of the bearing housing 3 to the oil supply hole 23 and is injected from the jet hole 24 communicating with the oil supply hole 23 toward the upper portion of the compressor impeller side cooling space 22 ′. The compressor impeller side cooling space 22 ′ collides with the wall surface on the compressor impeller 8 side to cool the wall surface, and is discharged to the outside through the lower oil discharge space 12, whereby the compressor impeller 8 and the compressor impeller side seal are discharged. The high temperature air in the gap with the plate 20 ′ is cooled, and the temperature rise of the compressor impeller 8 is indirectly suppressed.

  The cooling lubricating oil C is also supplied to the bearing 6 and the thrust bearing 7, and cools the bearing 6 and the thrust bearing 7 while lubricating them.

Further, leakage of the cooling lubricating oil C supplied to the thrust bearing 7 to the compressor impeller 8 side is prevented by an oil drain 26 in which the seal ring 25 is loaded on the outer peripheral portion.
Japanese Patent No. 3606293

  However, in the case of a turbocharger as disclosed in Patent Document 1, the compressor impeller side cooling space 22 ′ is narrow, so that the entire back surface of the compressor impeller 8 cannot be sufficiently cooled.

  For this reason, the present inventors have formed the compressor impeller side seal plate 20 ′ larger than the outer diameter of the compressor impeller and expanded the compressor impeller side cooling space 22 ′, so that the entire rear surface of the compressor impeller 8 can be sufficiently provided. A turbocharger that can be cooled down is proposed.

  However, as described above, when the compressor impeller side seal plate 20 ′ is formed larger than the outer diameter of the compressor impeller, the bolt 21 for attaching the compressor impeller side seal plate 20 ′ to the bearing housing 3 is attached to the compressed air diffuser portion 27. Therefore, the flow of compressed air is disturbed, the pressure loss increases, and there is a possibility that an unfavorable situation may occur in terms of supercharging performance.

  On the other hand, in a small turbocharger for vehicles, the bearing 6 and the thrust bearing 7 are rarely replaced. However, in the case of a large marine turbocharger, the bearing 6 is regularly maintained once a year. In addition, since it is necessary to replace the thrust bearing 7, it is very important to consider workability when the compressor impeller side seal plate 20 ′ is disassembled from the bearing housing 3.

  In view of such circumstances, the present invention can suppress the turbulence of compressed air flowing through the diffuser section and pressure loss while improving the cooling capacity of the compressor impeller, and can improve the supercharging performance. An object of the present invention is to provide a turbocharger capable of improving the disassembly workability of the compressor impeller side seal plate from the bearing housing.

According to the present invention, a compressor impeller side seal plate, which is positioned behind the compressor impeller and formed larger than the outer diameter of the compressor impeller, is attached to a bearing housing in which the rotor shaft is rotatably supported by a fastening member. The impeller side seal plate can be cooled,
A diffuser member for rectifying compressed air is attached to the annular member on the outer peripheral portion of the compressor impeller side seal plate so as to cover the protruding portion of the fastening member, and the compressed air is interposed between the diffuser member and the compressor housing. The present invention relates to a turbocharger characterized in that a diffuser portion is formed.

  According to the above means, the following operation can be obtained.

  If comprised as mentioned above, it becomes possible to fully cool the whole back surface of a compressor impeller by forming the compressor impeller side seal plate larger than the outer diameter of a compressor impeller.

  In addition, since the compressor impeller side seal plate is formed larger than the outer diameter of the compressor impeller, a fastening member for attaching the compressor impeller side seal plate to the bearing housing must be disposed in the diffuser portion of the compressed air. The projecting portion of the fastening member is covered by the annular member of the diffuser member, so that the compressed air flowing through the diffuser portion is not disturbed, the pressure loss does not increase, and the supercharging performance is deteriorated. Nor.

  In the turbocharger, an annular concave groove into which the annular member of the diffuser member is fitted is formed on the outer peripheral portion of the compressor impeller side seal plate, and the fastening is performed at a required position in the circumferential direction in the concave groove. A hole for accommodating the protrusion of the member is formed, and a gap is formed between the inner peripheral edge of the annular member fitted into the groove and extending to the compressor impeller side and the surface of the compressor impeller side seal plate. The disassembling projecting piece can be projected. In this case, when performing maintenance, the compressor housing is removed from the bearing housing, the compressor impeller is removed from the rotor shaft, and then the disassembling projecting piece and the compressor are removed. In the gap formed between the surface of the impeller side seal plate, a minus driver or a dedicated work By inserting the tip of the screw, the annular member of the diffuser member is removed from the groove, the exposed fastening member is loosened, the compressor impeller side seal plate is removed from the bearing housing, and the bearing or thrust bearing can be replaced. It becomes possible to improve workability when disassembling the compressor impeller side seal plate from the bearing housing. The gap is formed to insert the tip of the tool. However, a smaller one does not affect the supercharging performance, and is preferably about 0.5 to 5 [mm].

  Further, in the turbocharger, projecting the disassembling projecting piece over the entire inner peripheral edge of the annular member minimizes the gap with respect to the outer peripheral end of the compressor impeller. This is preferable in improving the supercharging performance.

  According to the turbocharger of the present invention, while improving the cooling capacity of the compressor impeller, it is possible to suppress the turbulence and pressure loss of the compressed air flowing through the diffuser portion, and to improve the supercharging performance. Further, the bearing at the time of maintenance It is possible to achieve an excellent effect that the disassembly workability of the compressor impeller side seal plate from the housing can be improved.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 and 2 show an example of an embodiment of the present invention. In the figure, the same reference numerals as those in FIGS. 3 and 4 denote the same components, and the basic configuration is shown in FIGS. 4 is the same as the conventional one shown in FIG. 4, but the feature of this example is that, as shown in FIGS. 1 and 2, a compressor impeller 8 is mounted on a bearing housing 3 on which a rotor shaft 5 is rotatably supported. A compressor impeller side seal plate 20 positioned on the back surface of the compressor impeller 8 and formed larger than the outer diameter of the compressor impeller 8 is attached with bolts 21 as fastening members, so that the compressor impeller side seal plate 20 can be cooled, and the compressor impeller A diffuser member 33 formed by disposing a plurality of blade members 32 for rectifying compressed air on an annular member 31 is provided on the outer periphery of the side seal plate 20. Attached by countersunk screws 34 to cover the head of the bolt 21 as the projecting portion of the member, it lies in the formation of the diffuser portion 27 of the compressed air between the diffuser member 33 and the compressor housing 2.

  In the case of this illustrated example, an annular groove 36 into which the annular member 31 of the diffuser member 33 is fitted is formed on the outer periphery of the compressor impeller side seal plate 20, and the circumferential direction in the groove 36 is formed. A hole 37 for receiving the head of the bolt 21 as a protruding portion of the fastening member is formed at a required position, and is projected to the compressor impeller 8 side on the inner peripheral edge of the annular member 31 fitted into the groove 36. A disassembling projecting piece 38 is formed so as to form a gap S between the compressor impeller side seal plate 20 and the surface thereof.

  Here, the disassembling protrusion 38 protrudes over the entire inner peripheral edge of the annular member 31, thereby minimizing the gap t with respect to the outer peripheral end of the compressor impeller 8 over the entire periphery. Although it is preferable to improve the supercharging performance, the disassembling projecting piece 38 may be provided at one or a plurality of locations in the circumferential direction on the inner peripheral edge of the annular member 31. Of course.

  On the other hand, the bearing housing 3 is divided into a bearing housing main body 3a and a bush 3b incorporated in the central portion of the bearing housing main body 3a and rotatably supporting the rotor shaft 5 via a bearing 6. The bush 3b is assembled to the bearing housing body 3a from the opening on the compressor impeller 8 side and fastened by a bolt 19, and the opening on the compressor impeller 8 side of the bearing housing body 3a is connected with the compressor impeller side seal plate 20. The structure is such that it is covered like a lid. The bearing housing body 3a includes an upper cooling space 9 positioned on the turbine housing 1 side in the bearing housing body 3a and surrounding the upper outer periphery of the bush 3b, and a turbine in the bearing housing body 3a. Located in the vicinity of the rotor shaft through hole 10 on the housing 1 side, and located below the bush 3b in the bearing housing body 3a, and a turbine side seal space 11 defined from the upper cooling space 9 by the bush 3b. In addition, a lower oil discharge space 12 communicating with the upper cooling space 9 and the turbine side seal space 11 is formed.

  The bearing housing 3 is provided with a supply means 28 for spraying the cooling lubricant C onto the compressor impeller side seal plate 20, and the supply means 28 for the cooling lubricant C is provided in the bearing housing body. 3a, an oil supply port 13 formed so as to extend from above to below in a direction perpendicular to the axis of the rotor shaft 5, and the bush communicating with the oil supply port 13 and extending in a direction parallel to the axis of the rotor shaft 5 An oil supply hole 14 formed in 3b and a jet hole 24 that communicates with the oil supply hole 14 and injects the cooling lubricant C toward the upper part of the compressor impeller side seal plate 20 are configured. The bush 3 b is formed so as to intersect the oil supply hole 14 with a jet hole 15 that communicates with the oil supply hole 14 and injects the cooling lubricant C into the upper cooling space 9. An oil supply hole 17 that is provided and capable of supplying a cooling lubricant C to the bearing 6 is also formed, and a plug 18 is screwed into a place overlapping the upper cooling space 9 of the oil supply hole 17, thereby providing the oil supply hole 17. The cooling lubricant C does not flow out from the upper cooling space 9 from 17. Also, the cooling lubricant C is supplied to the thrust bearing 7 from the end of the oil supply hole 14.

  Further, the compressor impeller side seal plate 20 is provided with partition means 29 for preventing the cooling lubricant C sprayed by the supply means 28 from directly reaching the rotor shaft 5 penetrating portion of the compressor impeller side seal plate 20. The partition means 29 of the compressor impeller side seal plate 20 that is formed is formed of a cylindrical body that is concentric with the rotor shaft 5 and surrounds the outer periphery of the through portion of the rotor shaft 5. And a compressor impeller side cooling space 22 disposed on the outer periphery of the compressor impeller side seal space 35 is constituted by a partition member 29a, and the end of the partition member 29a is brought into close contact with the outer periphery of the thrust bearing 7. As a result, the thrust bearing 7 is supported to be pressed against the bush 3b. It is. The lower part of the compressor impeller side seal space 35 communicates with the compressor impeller side cooling space 22 through a notch 29b formed in the lower part of the partition member 29a.

  Next, the operation of the illustrated example will be described.

  When configured as described above, the compressor impeller side seal plate 20 is formed larger than the outer diameter of the compressor impeller 8, so that the entire back surface of the compressor impeller 8 can be sufficiently cooled.

  Moreover, since the compressor impeller side seal plate 20 is formed larger than the outer diameter of the compressor impeller 8, the bolt 21 as a fastening member for attaching the compressor impeller side seal plate 20 to the bearing housing 3 is used as a diffuser portion for compressed air. 27, but the head portion of the bolt 21 as the protruding portion of the fastening member is covered by the annular member 31 of the diffuser member 33 so as to be accommodated in the hole portion 37. The flowing compressed air is not disturbed, the pressure loss does not increase, and there is no fear that the supercharging performance is lowered.

  On the other hand, at the inner peripheral edge of the annular member 31 inserted into the concave groove 36, a gap S is formed between the surface of the compressor impeller side seal plate 20 and the compressor impeller 8 side. When the maintenance is performed, the compressor housing 2 is removed from the bearing housing 3, the compressor impeller 8 is removed from the rotor shaft 5, and then the disassembling projecting piece 38 and the compressor impeller side seal are provided. Inserting a tip of a minus driver or a dedicated tool into the gap S formed between the surface of the plate 20 causes the annular member 31 of the diffuser member 33 to be detached from the concave groove 36 and exposed fastening. Loosen bolt 21 as a member and remove compressor impeller side seal plate 20 from bearing housing 3 May be replaced with bearings 6 and the thrust bearing 7, it is possible to improve the workability in disassembling the compressor wheel side sealing plate 20 from the bearing housing 3. The gap S is formed to insert the tip of the tool. However, a smaller one does not affect the supercharging performance, and is preferably about 0.5 to 5 [mm].

  Thus, while improving the cooling capacity of the compressor impeller 8, the turbulence and pressure loss of the compressed air flowing through the diffuser portion 27 can be suppressed, the supercharging performance can be improved, and the compressor from the bearing housing 3 during maintenance can be improved. The disassembly workability of the impeller side seal plate 20 can be improved.

  It should be noted that the turbocharger of the present invention is not limited to the illustrated example described above, and it is needless to say that various changes can be made without departing from the scope of the present invention.

1 is an overall schematic cross-sectional view showing an example of an embodiment for carrying out the present invention. It is a principal part expanded sectional view of FIG. It is a whole schematic sectional drawing which shows an example of the conventional turbocharger. It is a principal part expanded sectional view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Turbine housing 2 Compressor housing 3 Bearing housing 3a Bearing housing main body 3b Bush 4 Turbine rotor 5 Rotor shaft 6 Bearing 8 Compressor impeller 13 Oil supply port 14 Oil supply hole 17 Oil supply hole 20 Compressor impeller side seal plate 21 Bolt (fastening member)
22 Compressor impeller side cooling space 24 Jet hole 27 Diffuser part 31 Ring member 32 Wing member 33 Diffuser member 36 Concave groove 37 Hole part 38 Protrusion piece for disassembly C Cooling oil S Gap t Gap

Claims (3)

A compressor impeller side seal plate, which is positioned behind the compressor impeller and formed larger than the outer diameter of the compressor impeller, is attached to a bearing housing in which the rotor shaft is rotatably supported by a fastening member, and the compressor impeller side seal plate Can be cooled,
A diffuser member for rectifying compressed air is attached to the annular member on the outer peripheral portion of the compressor impeller side seal plate so as to cover the protruding portion of the fastening member, and the compressed air is interposed between the diffuser member and the compressor housing. A turbocharger characterized by forming a diffuser part.   An annular concave groove into which the annular member of the diffuser member is fitted is formed on the outer peripheral portion of the compressor impeller side seal plate, and the protruding portion of the fastening member is accommodated in a required position in the circumferential direction in the concave groove. A disassembling projecting piece is formed in which a hole is formed, and a gap is formed on the inner peripheral edge of the annular member fitted into the concave groove to the compressor impeller side and between the surface of the compressor impeller side seal plate. The turbocharger of Claim 1 which protruded. The turbocharger according to claim 2, wherein the disassembling protrusion piece is provided so as to protrude over the entire inner peripheral edge of the annular member.

Images