JP5012730B2 - Impeller mounting structure and turbocharger - Google Patents

Description

  The present invention relates to an impeller mounting structure for mounting a compressor impeller on a rotor shaft in a supercharger.

  In recent years, superchargers such as a marine supercharger and a vehicular supercharger have become widespread, and the supercharger rotates the turbine impeller by the energy of exhaust gas from the engine to rotate the compressor impeller to the rotor. The air supplied to the engine is supercharged by being driven to rotate in conjunction with the shaft (turbine shaft). Here, the turbine impeller is integrally connected to one end of the rotor shaft. And the general impeller attachment structure for attaching a compressor impeller to the one end part of a rotor axis | shaft becomes as follows (refer patent document 1).

  That is, an attachment shaft is formed with a reduced diameter on one end side of the rotor shaft, and this attachment shaft constitutes a part of the rotor shaft. The mounting shaft can be inserted into a through hole formed in the central portion of the compressor impeller, and has a male screw portion on the tip side. Furthermore, a tightening nut that presses the compressor impeller to the stepped portion on the proximal end side of the mounting shaft is screwed onto the male thread portion of the mounting shaft.

Therefore, the mounting shaft is inserted into the through hole of the compressor impeller. And a clamping nut is tightened and a compressor impeller is pressed to the level | step-difference part of the base end side of a mounting shaft. Thereby, the compressor impeller can be attached to the rotor shaft.
JP 2000-044452 A

  By the way, in a supercharger such as a marine supercharger, water washing or the like may be performed on a compressor impeller during maintenance. On the other hand, water is removed from the tip of the mounting shaft to the clearance between the outer peripheral surface of the mounting shaft and the inner peripheral surface of the through hole of the compressor impeller (in other words, the fitting portion between the mounting shaft and the compressor impeller) by washing the compressor impeller with water. If the intrusion occurs, rust is generated in the fitting portion between the mounting shaft and the compressor impeller, which causes deterioration of the mounting shaft and the compressor impeller, which makes it difficult to increase the durability of the turbocharger.

  Therefore, an object of the present invention is to provide an impeller mounting structure and a supercharger having a novel configuration that can solve the above-described problems.

A first feature of the present invention is an impeller mounting structure for mounting a compressor impeller on a rotor shaft in a supercharger, wherein the compressor impeller is formed with a reduced diameter on one end side of the rotor shaft, and is formed at a central portion of the compressor impeller. The compressor impeller can be inserted into the through-hole, has a male screw portion on the tip side, and is screwed into the mounting shaft constituting a part of the rotor shaft and the male screw portion of the mounting shaft. A clamping nut that presses against the stepped portion on the proximal end side of the mounting shaft, and a tip end portion of the mounting shaft that protrudes from the clamping nut in a watertight manner, so that the mounting shaft extends from the distal end portion of the mounting shaft. And a seal cap that prevents water from entering the gap between the outer peripheral surface of the compressor impeller and the inner peripheral surface of the through hole of the compressor impeller .

  According to a feature of the invention, the mounting shaft is inserted into the through hole of the compressor impeller. And the said fastening nut is fastened and the said compressor impeller is pressed to the said level | step-difference part of the base end side of the said attachment shaft. The tip end portion of the mounting shaft protruding from the tightening nut is covered by the seal cap. Thereby, the compressor impeller can be attached to the rotor shaft.

  According to a second aspect of the present invention, in the supercharger that supercharges the air supplied to the engine using the energy of the exhaust gas from the engine, the impeller mounting structure according to the first aspect is provided. Is the gist.

  According to the 2nd characteristic, there exists an effect | action similar to the effect | action by a 1st characteristic.

  According to the present invention, the compressor impeller is attached to the rotor shaft while the tip end portion of the attachment shaft protruding from the clamping nut is covered by the seal cap. Even when performing the above, the gap between the tip end portion of the mounting shaft and the outer peripheral surface of the mounting shaft and the inner peripheral surface of the through hole of the compressor impeller (in other words, the fitting portion between the mounting shaft and the compressor impeller) ) Can be prevented from entering water. Therefore, deterioration of the mounting shaft and the compressor impeller can be suppressed, and the durability of the supercharger can be sufficiently increased.

(First embodiment)
A first embodiment will be described with reference to FIGS. 1 and 2.

  Here, FIG. 1 is a side sectional view of the marine turbocharger according to the first embodiment, and FIG. 2 is an enlarged side sectional view of a main part of the marine turbocharger according to the first embodiment. In the drawings, “F” indicates the forward direction, and “R” indicates the backward direction.

  As shown in FIG. 1, the marine supercharger 1 according to the first embodiment supercharges the air supplied to the engine using the energy of the exhaust gas from the engine (not shown). . The specific configuration of the marine supercharger 1 is as follows.

  The marine turbocharger 1 includes a bearing housing 3, and a plurality of bearings 5 are provided in the bearing housing 3, and the plurality of bearings 5 have a rotor shaft ( (Turbine shaft) 7 is rotatably provided. In other words, the bearing housing 3 is provided with the rotor shaft 7 via the bearing 5 so as to be rotatable.

  A compressor housing 9 is provided on the front side (one side) of the bearing housing 3. A compressor impeller 11 is provided in the compressor housing 9, and the compressor impeller 11 is integrally connected to a front end portion (one end portion) of the rotor shaft 7. Here, the compressor impeller 11 includes a compressor hub 13 integrally connected to the front end portion of the rotor shaft 7, and a plurality of compressor blades 15 provided at equal intervals on the outer peripheral surface of the compressor hub 13. Yes.

  An air intake port 17 for taking in air is formed on the front side of the compressor housing 9 (in other words, the inlet side of the compressor impeller 11), and this air intake port 17 can be connected to a silencer (not shown). is there. An annular diffuser passage 19 for boosting the compressed air is formed on the outlet side of the compressor impeller 11 between the bearing housing 3 and the compressor housing 9, and the diffuser passage 19 is an air intake port. 17 communicates. Further, a compressor scroll passage 21 is formed inside the compressor housing 9 so as to surround the compressor impeller 11, and the compressor scroll passage 21 communicates with the diffuser passage 19. An air discharge port (not shown) for discharging the compressed air is formed at an appropriate position of the compressor housing 9, and this air discharge port communicates with the compressor scroll passage 21, and Can be connected to other cylinders.

  A turbine housing 23 is provided on the rear side (other side) of the bearing housing 3. A turbine impeller 25 is provided in the turbine housing 23, and the turbine impeller 25 is integrally connected to the rear end portion (the other end portion) of the rotor shaft 7. Here, the turbine impeller 25 includes a turbine hub 27 integrally connected to the rear end portion of the rotor shaft 7, and a plurality of turbine blades 29 provided at equal intervals on the outer peripheral surface of the turbine hub 27. ing.

  A gas intake (not shown) for taking in exhaust gas is formed at an appropriate position of the turbine housing 23, and this gas intake can be connected to an engine cylinder (not shown). A turbine scroll passage 31 is formed inside the turbine housing 23 so as to surround the turbine impeller 25, and the turbine scroll passage 31 communicates with the gas inlet. Further, a gas discharge port 33 for discharging exhaust gas is formed on the rear side of the turbine housing 23 (in other words, on the outlet side of the turbine impeller 25). The gas discharge port 33 is formed in the turbine scroll passage 31. And can be connected to an exhaust gas purification device (not shown).

  The marine turbocharger 1 according to the first embodiment includes an impeller attachment structure 35, and the impeller attachment structure 35 is a structure for attaching the compressor impeller 11 to the front end portion (one end portion) of the rotor shaft 7. is there. And the specific structure of the impeller attachment structure 35 which is the principal part of embodiment of this invention is as follows.

  That is, as shown in FIGS. 2 and 1, a mounting shaft 37 is formed on the front end side (one end side) of the rotor shaft 7 with a reduced diameter. This mounting shaft 37 is a part of the rotor shaft 7. It constitutes. The mounting shaft 37 can be fitted into a through hole 13h formed in the central portion of the compressor hub 13 (in other words, the central portion of the compressor impeller 11), and has a male screw portion 37s on the distal end side. Yes. Note that the stepped portion B is formed on the base end side of the mounting shaft 37 by forming the mounting shaft 37 with a reduced diameter on the front end side of the rotor shaft 7.

  A fastening nut 39 that presses the compressor hub 13 (in other words, the compressor impeller 11) toward the stepped portion B side of the base end of the mounting shaft 37 is screwed into the male screw portion 37 s of the mounting shaft 37. . In the embodiment of the present invention, one tightening nut 39 is used, but a plurality of tightening nuts 39 may be used.

  A seal cap 41 is screwed into the male thread portion 37 s of the mounting shaft 37, and the seal cap 41 covers the tip end portion of the mounting shaft 37 protruding from the tightening nut 39 in a watertight manner. . Further, the head portion of the seal cap 41 has a curved surface shape that becomes gradually narrower in the distal direction, and the thickness of the head portion of the seal cap 41 is larger than the thickness of the peripheral wall portion of the seal cap 41. It is thick.

  Gaskets (not shown) are provided between the front end surface of the compressor hub 13 and the rear side surface of the tightening nut 39 and between the front side surface of the tightening nut 39 and the rear side surface of the seal cap 41. It doesn't matter.

  Then, the effect | action and effect of 1st Embodiment are demonstrated.

  When the exhaust gas taken into the turbine housing 23 from the gas inlet is supplied to the turbine impeller 25 side via the turbine scroll passage 31, the turbine impeller 25 can be driven to rotate by the energy of the exhaust gas, and the compressor The impeller 11 can be driven to rotate in conjunction with the rotor shaft 7. Thereby, the air taken in from the air intake port 17 to the compressor impeller 11 side can be compressed and discharged from the air discharge port via the diffuser flow path 19 and the compressor scroll flow path 21 and supplied to the engine cylinder. Can be supercharged. (General operation of the marine turbocharger 1 according to the first embodiment)

  In addition to the general operation of the marine supercharger 1 according to the first embodiment, the attachment shaft 37 is fitted into the through hole 13 h of the compressor hub 13. Then, the tightening nut 39 is tightened to press the compressor hub 13 to the stepped portion B on the proximal end side of the mounting shaft 37. Further, the seal cap 41 is tightened so that the rear side surface of the seal cap 41 is brought into pressure contact with the front side surface of the tightening nut 39. Thereby, the compressor impeller 11 can be attached to the rotor shaft 7 in a state where the tip end portion of the attachment shaft 37 protruding from the tightening nut 39 is watertightly covered by the seal cap 41 (the impeller attachment according to the first embodiment). Action of structure 35 (1)).

  In addition, since the head of the seal cap 41 has a curved shape that gradually narrows toward the tip, the flow of air taken from the air intake port 17 toward the compressor impeller 11 can be stabilized (first). Action (2) of the impeller mounting structure 35 according to the embodiment.

  Therefore, according to the first embodiment, the compressor impeller 11 can be attached to the rotor shaft 7 in a state where the tip end portion of the mounting shaft 37 protruding from the tightening nut 39 by the seal cap 41 is watertightly covered. Even when the compressor impeller 11 is washed with water or the like, the clearance between the outer peripheral surface of the mounting shaft 37 and the inner peripheral surface of the through hole 13h of the compressor hub 13 (in other words, the mounting shaft 37). It is possible to prevent water from entering the fitting portion of the compressor hub 13. Therefore, deterioration of the attachment shaft 37 and the compressor impeller 11 can be suppressed, and the durability of the marine supercharger 1 can be sufficiently increased.

  Moreover, since the flow of the air taken in from the air intake port 17 to the compressor impeller 11 side can be stabilized, energy loss can be suppressed and the compression efficiency of the marine supercharger 1 can be increased.

(Second Embodiment)
A second embodiment will be described with reference to FIG.

  Here, FIG. 3 is an enlarged side cross-sectional view of a main part of the marine turbocharger according to the second embodiment. In the drawings, “F” indicates the forward direction, and “R” indicates the backward direction.

  As shown in FIG. 3, the marine turbocharger 43 according to the second embodiment has substantially the same configuration as the marine supercharger 1 according to the first embodiment, and the marine vessel according to the second embodiment. Of the specific configuration of the turbocharger 43, only parts different from the specific configuration of the marine supercharger 1 according to the first embodiment will be described. In addition, about the component corresponding to the component in the marine supercharger 1 which concerns on 1st Embodiment among the some components in the marine turbocharger 43 which concerns on 2nd Embodiment, the same number is shown in a figure. A description thereof will be omitted.

  That is, the marine turbocharger 43 according to the second embodiment includes an impeller attachment structure 45 for attaching the compressor impeller 11 to the front end portion (one end portion) of the rotor shaft 7. A seal cap 47 is integrally provided on the front side surface of the tightening nut 39 in the impeller mounting structure 45, and the seal cap 47 watertightly attaches the tip end portion of the mounting shaft 37 protruding from the tightening nut 39. It is something to cover. Further, the head portion of the seal cap 47 has a curved surface shape that becomes gradually narrower toward the distal end direction, and the thickness of the head portion of the seal cap 47 is larger than the thickness of the peripheral wall portion of the seal cap 47. It is thick.

  A gasket (not shown) may be provided between the front end surface of the compressor hub 13 and the rear side surface of the tightening nut 39.

  Next, the operation and the like of the second embodiment will be briefly described.

  The mounting shaft 37 is inserted into the through hole 13 h of the compressor hub 13. Then, the tightening nut 39 is tightened to press the compressor hub 13 to the stepped portion B on the proximal end side of the mounting shaft 37. Thereby, the compressor impeller 11 can be attached to the rotor shaft 7 in a state where the tip end portion of the mounting shaft 37 protruding from the tightening nut 39 is watertightly covered by the seal cap 47.

  Further, since the head of the seal cap 47 has a curved surface shape that becomes gradually narrower in the distal direction, the flow of air taken from the air intake port 17 to the compressor impeller 11 side can be stabilized.

  Therefore, also in 2nd Embodiment, there can exist an effect similar to 1st Embodiment.

(Third embodiment)
A third embodiment will be described with reference to FIG.

  Here, FIG. 4 is an enlarged side sectional view of a main part of the marine turbocharger according to the third embodiment. In the drawings, “F” indicates the forward direction, and “R” indicates the backward direction.

  As shown in FIG. 4, the marine turbocharger 49 according to the third embodiment has substantially the same configuration as the marine supercharger 1 according to the first embodiment, and relates to the third embodiment. Of the specific configuration of the marine supercharger 49, only the parts different from the specific configuration of the marine supercharger 1 according to the first embodiment will be described. In addition, about the component corresponding to the component in the marine supercharger 1 which concerns on 1st Embodiment among the some components in the marine turbocharger 49 which concerns on 3rd Embodiment, the same number is shown in a figure. A description thereof will be omitted.

  That is, the marine turbocharger 49 according to the third embodiment includes an impeller attachment structure 51 for attaching the compressor impeller 11 to the front end portion (one end portion) of the rotor shaft 7. A seal cap 53 is screwed onto the male thread portion 37 s of the mounting shaft 37 in the impeller mounting structure 51, and the seal cap 53 is formed by attaching the tip end portion of the mounting shaft 37 protruding from the tightening nut 39. It covers watertightly. Further, a cylindrical guard 53g that covers the tightening nut 39 in a watertight manner is formed on the periphery of the seal cap 53. Further, the head portion of the seal cap 53 has a curved surface shape that becomes gradually narrower in the distal direction, and the thickness of the head portion of the seal cap 53 is larger than the thickness of the peripheral wall portion of the seal cap 53. It is thick.

  A gasket (not shown) may be provided between the front end surface of the compressor hub 13 and the rear side surface of the tightening nut 39.

  Then, the effect | action etc. of 3rd Embodiment are demonstrated easily.

  The mounting shaft 37 is inserted into the through hole 13 h of the compressor hub 13. Then, the tightening nut 39 is tightened to press the compressor hub 13 to the stepped portion B on the proximal end side of the mounting shaft 37. Further, the seal cap 53 is tightened so that the rear end surface of the guard 53 g of the seal cap 53 is pressed against the front end surface of the compressor hub 13. Thereby, the compressor impeller 11 can be attached to the rotor shaft 7 in a state where the tip end portion of the mounting shaft 37 protruding from the tightening nut 39 and the tightening nut 39 are watertightly covered by the seal cap 53.

  In addition, since the head of the seal cap 53 has a curved surface shape that gradually decreases in the distal direction, the flow of air taken in from the air intake port 17 to the compressor impeller 11 side can be stabilized.

  Therefore, also in 3rd Embodiment, there can exist an effect similar to 1st Embodiment.

  In addition, this invention is not restricted to description of the above-mentioned embodiment, In addition, it can implement in a various aspect. Further, the scope of rights encompassed by the present invention is not limited to these embodiments.

It is a sectional side view of the supercharger for ships concerning a 1st embodiment. It is an expanded sectional side view of the principal part of the supercharger for ships which concerns on 1st Embodiment. It is an expanded sectional side view of the principal part of the supercharger for ships which concerns on 2nd Embodiment. It is an expanded sectional side view of the principal part of the supercharger for ships which concerns on 3rd Embodiment.

Explanation of symbols

B Stepped portion 1 Marine turbocharger 7 Rotor shaft 11 Compressor impeller 13 Compressor hub 13h Through hole 15 Compressor blade 35 Impeller mounting structure 37 Mounting shaft 37s Male thread 39 Tightening nut 41 Seal cap 43 Marine turbocharger 45 Impeller mounting Structure 47 Seal cap 49 Marine supercharger 51 Impeller mounting structure 53 Seal cap 53g Guard

Claims (6)

In the impeller mounting structure for mounting the compressor impeller on the rotor shaft in the turbocharger,
The rotor shaft is formed with a reduced diameter on one end side, and can be inserted into a through hole formed in the central portion of the compressor impeller, and has a male screw portion on the tip side, and constitutes a part of the rotor shaft Mounting shaft to
A tightening nut that is screwed into the male threaded portion of the mounting shaft and presses the compressor impeller to a stepped portion on the proximal end side of the mounting shaft;
By covering the tip end portion of the mounting shaft protruding from the clamping nut in a watertight manner, the clearance between the tip end portion of the mounting shaft and the outer peripheral surface of the mounting shaft and the inner peripheral surface of the through hole of the compressor impeller A seal cap that prevents water from entering ,
An impeller mounting structure characterized by comprising:   The impeller mounting structure according to claim 1, wherein the head portion of the seal cap has a curved surface shape that gradually decreases in a distal direction.   The impeller mounting structure according to claim 1 or 2, wherein the seal cap is screwed into the male screw portion of the mounting shaft.   The impeller mounting structure according to claim 1, wherein the seal cap is provided integrally with the tightening nut. The impeller mounting structure according to claim 3, wherein a cylindrical guard that covers the tightening nut is formed on a peripheral edge of the seal cap . In the supercharger that supercharges the air supplied to the engine using the energy of the exhaust gas from the engine,
A supercharger comprising the impeller mounting structure according to any one of claims 1 to 5.

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