JP6194616B2 - Turbocharger - Google Patents

Description

  The present invention relates to a supercharger.

  A turbocharger used in an internal combustion engine has a structure in which a compressor impeller and a turbine impeller are coaxially connected. The turbine impeller is rotationally driven by exhaust gas from the internal combustion engine, and the compressor impeller compresses air by the rotational drive. The compressed air is supplied to the internal combustion engine. Some turbochargers include a tachometer in order to measure the rotation speed of the compressor impeller.

  As this tachometer, for example, in Patent Document 1 below, a nut for fixing a compressor impeller to a rotating shaft is made of a ferromagnetic material and magnetized, and a magnetic sensor for detecting the magnetic flux of the magnetized nut is provided in a compressor housing. (See FIG. 2 of Patent Document 1), and a rotary shaft of the compressor impeller provided with a groove, and an electromagnetic pickup attached to the bearing housing so as to face this groove (see Patent Document 1) (See FIG. 3).

Japanese Patent Laid-Open No. 62-194466

However, the prior art has the following problems.
In the form of measuring with a magnetic sensor attached to the compressor housing, the tip of the magnetic sensor may be exposed in the intake flow passage formed in the compressor housing, and the turbulence may occur in the gas flow sucked into the compressor impeller. .
In addition, in the configuration in which the electromagnetic pickup is attached to the bearing housing, the lubricating oil is supplied to the bearing at a predetermined pressure. Therefore, as a countermeasure against oil leakage, the position where the lubricating oil pressure is released (in the prior art, the bearing and bearing The tip of the electromagnetic pickup must be placed between However, in a supercharger that employs a water-cooled bearing housing, a cooling water flow path is usually formed at that position. Cooling water is supplied to the cooling water flow path at a high pressure so that the cooling water does not boil even when the temperature is 100 ° C. or higher. When an electromagnetic pickup is inserted at that position, cooling water leaks or leaked cooling water. There may be a problem of mixing the oil and the lubricating oil, which may affect the cooling structure of the bearing housing.

  The present invention has been made in view of the above problems, and measures the rotation speed of the compressor impeller without disturbing the flow of gas sucked into the compressor impeller and without affecting the cooling structure of the bearing housing. The purpose is to provide a turbocharger that can be used.

In order to solve the above problems, the present invention provides a turbocharger having a bearing housing that holds a bearing that rotatably supports a rotating shaft of a compressor impeller, and a tachometer that measures the rotation speed of the compressor impeller. The bearing housing is provided with a cooling water flow path through which cooling water flows, and the tachometer is inserted into the bearing housing while avoiding the cooling water flow path, and a tip of the tachometer is inserted into the compressor impeller. A configuration is adopted in which it is disposed between the back surface and the bearing.
By adopting this configuration, in the present invention, the tachometer is inserted into the bearing housing such that the tip of the tachometer is disposed between the back surface of the compressor impeller and the bearing, avoiding the cooling water flow path. Since the space between the back side of the compressor impeller and the bearing does not face the intake flow path of the gas sucked into the compressor impeller, the flow of the gas sucked into the compressor impeller is not disturbed by the tip of the tachometer. Further, since the tachometer is inserted into the bearing housing while avoiding the cooling water flow path, it is possible to solve the problem of cooling water leakage and mixing of the leaked cooling water and lubricating oil.

Further, in the present invention, a lubricating oil seal portion is provided between the bearing and the compressor impeller, and the tip of the tachometer is between the back surface of the compressor impeller and the lubricating oil seal portion. The structure of being arranged in is adopted.
By adopting this configuration, in the present invention, the tip of the tachometer is inserted into the bearing housing so as to be disposed between the back surface of the compressor impeller and the lubricating oil seal portion in front of the bearing. Since the space between the rear surface of the compressor impeller and the lubricating oil seal portion does not face the lubricating oil flow path, it is possible to solve the problem of the influence on the measurement due to the lubricating oil leakage or the lubricating oil.

Further, in the present invention, the bearing housing has a seal plate provided with the lubricating oil seal portion, and the seal plate has a hole portion through which the tachometer is inserted. Adopt the configuration.
By adopting this configuration, in the present invention, a hole is formed in the seal plate portion where the cooling water flow path is not formed, and a tachometer is inserted into the hole to avoid the cooling water flow path easily. A tachometer can be provided.

Moreover, in this invention, the structure that the groove part for measuring the said rotation speed is provided in the base part of the said compressor impeller is employ | adopted.
By adopting this configuration, in the present invention, a groove is provided at the root of the compressor impeller, and the tip of the tachometer is disposed so as to face this groove. At the root of the compressor impeller, the cooling water flow path and the lubricating oil flow path pass nearby, so that the influence on measurement due to heat can be reduced.

Moreover, in this invention, the said groove part employ | adopts the structure that it has a cross-sectional outline shape of a flat dome shape.
By adopting this configuration, in the present invention, the groove portion in the root portion of the compressor impeller has a flat dome-like cross-sectional contour shape, thereby reducing stress concentration due to tensile stress acting in the radial direction by centrifugal force. it can.

Moreover, in this invention, the structure that the groove part for measuring the said rotation speed is provided in the back surface of the said compressor impeller is employ | adopted.
By adopting this configuration, in the present invention, a groove is provided on the back surface of the compressor impeller, and the tip of the tachometer is disposed so as to face the groove. On the back surface of the compressor impeller, since the tensile stress acting in the radial direction by the centrifugal force is smaller than that at the root portion, the restriction on the shape of the groove portion is reduced.

Moreover, in this invention, the structure that the said groove part has a hemispherical cross-sectional outline shape is employ | adopted.
By adopting this configuration, in the present invention, the groove on the back surface of the compressor impeller has a hemispherical cross-sectional profile, thereby reducing the region where the groove is formed while avoiding stress concentration, thereby rotating the compressor impeller. The influence on the balance adjustment can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the supercharger which can measure the rotation speed of a compressor impeller is obtained, without disturbing the flow of the gas suck | inhaled by a compressor impeller, and without affecting the cooling structure of a bearing housing.

It is a whole block diagram of the supercharger in 1st Embodiment of this invention. It is a figure which shows the structure of the compressor impeller in 1st Embodiment of this invention. It is a figure which shows the principal part structure of the compressor impeller in 1st Embodiment of this invention. It is a figure which shows the structure of the compressor impeller in 2nd Embodiment of this invention. It is a figure which shows the principal part structure of the compressor impeller in 2nd Embodiment of this invention.

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

(First embodiment)
FIG. 1 is an overall configuration diagram of a supercharger 1 according to the first embodiment of the present invention.
The supercharger 1 receives a turbine 2 that receives exhaust gas exhausted from an internal combustion engine or the like, obtains rotational power, a shaft portion 3 that transmits rotational power obtained by the turbine 2, and a rotation transmitted from the shaft portion 3. And a compressor 4 that compresses air by power.

  The turbine 2 includes a turbine housing 2a and a turbine impeller 2b. The turbine housing 2a is a container that houses the turbine impeller 2b and includes exhaust gas passages (the scroll passage 2c and the exhaust passage 2d) that are connected to the accommodation space of the turbine impeller 2b. The turbine impeller 2b is a radial impeller that is driven to rotate by receiving the exhaust gas flowing from the scroll passage 2c to the exhaust passage 2d.

  The shaft portion 3 includes a bearing housing 3a, a bearing 3b, and a rotating shaft 3c. The bearing housing 3a is a container that accommodates the bearing 3b and the rotating shaft 3c, and is fixed to the turbine housing 2a. The bearing 3b is accommodated in the bearing housing 3a and supports the rotating shaft 3c to be rotatable. The rotary shaft 3 c has one end connected to the turbine impeller 2 b and the other end connected to a compressor impeller 4 b (described later) of the compressor 4.

  The compressor 4 includes a compressor housing 4a and a compressor impeller 4b. The compressor housing 4a is a container that accommodates the compressor impeller 4b and includes an air flow path (intake flow path 4c and scroll flow path 4d) connected to the accommodation space of the compressor impeller 4b. The compressor impeller 4b is a radial impeller that is rotationally driven by the rotational power transmitted through the rotary shaft 3c, compresses the air supplied from the intake passage 4c, and discharges the compressed air to the scroll passage 4d.

  In the supercharger 1 configured as described above, when exhaust gas is introduced from the internal combustion engine into the scroll flow path 2c, the exhaust gas is supplied to the turbine impeller 2b. By supplying the exhaust gas, the turbine impeller 2b, the rotating shaft 3c, and the compressor impeller 4b rotate together. Thereby, rotational power is obtained in the turbine 2, and this rotational power is transmitted to the compressor 4 via the shaft portion 3, and compressed air is generated in the compressor 4.

  Next, the configuration of the bearing housing 3a of the supercharger 1 will be described in detail.

  A journal bearing 3b1 and a thrust bearing 3b2 are assembled as bearings 3b in the bearing housing 3a. The journal bearings 3b1 are arranged in pairs at a predetermined interval so as to receive the radial load of the rotary shaft 3c. The thrust bearing 3b2 is disposed outside the journal bearing 3b1 (on the compressor impeller 4b side) and receives a load in the axial direction of the rotating shaft 3c.

  The bearing housing 3a is formed with a lubricating oil passage 3f through which lubricating oil flows and a cooling water passage 3g through which cooling water flows. The lubricating oil passage 3f is formed inside the bearing housing 3a so as to guide the lubricating oil to the journal bearing 3b1, the thrust bearing 3b2, and the rotating shaft 3c. The cooling water flow path 3g does not communicate with the lubricating oil flow path 3f, and is formed inside the bearing housing 3a so that the cooling water flows around the journal bearing 3b1 and the rotation shaft 3c. As described above, the bearing housing 3a includes an oil cooling type and a water cooling type cooling structure.

  The bearing housing 3a has a seal plate 3d on the compressor housing 4a side. The seal plate 3d is fastened and fixed to the main body of the bearing housing 3a by a bolt (not shown). The seal plate 3d has a lubricant seal portion 3d1. The lubricating oil seal portion 3d1 is disposed between the thrust bearing 3b2 and the compressor impeller 4b, and seals the lubricating oil supplied to the thrust bearing 3b2 so as not to leak to the back surface 4b1 side of the compressor impeller 4b. It has become.

  The bearing housing 3a is provided with a tachometer 10 for measuring the rotation speed of the compressor impeller 4b. The tachometer 10 is inserted into the bearing housing 3a while avoiding the cooling water flow path 3g, and the tip 11 thereof is disposed between the back surface 4b1 of the compressor impeller 4b and the bearing 3b (thrust bearing 3b2). In the present embodiment, the tip 11 of the tachometer 10 is arranged between the back surface of the compressor impeller 4b and the lubricant seal portion 3d1 before the bearing 3b.

  A hole 3d2 for inserting the tachometer 10 is formed in the seal plate 3d. The hole 3d2 extends in the radial direction and is formed through the seal plate 3d. The bearing housing 3a is also formed with a hole 3a1 through which the tachometer 10 is inserted. The hole 3a1 and the hole 3d2 communicate with each other in the radial direction so that the tachometer 10 can be inserted in the bearing housing 3a in an orthogonal direction orthogonal to the rotation shaft 3c. The tip 11 of the tachometer 10 faces the root portion 4b2 of the compressor impeller 4b with a gap.

FIG. 2 is a diagram illustrating a configuration of the compressor impeller 4b according to the first embodiment of the present invention. FIG. 3 is a diagram illustrating a main configuration of the compressor impeller 4b according to the first embodiment of the present invention. 3A shows the configuration of the compressor impeller 4b on the back surface 4b1 side, and FIG. 3B shows the configuration of the root portion 4b2 of the compressor impeller 4b.
As shown in FIG. 2, the root part 4b2 of the compressor impeller 4b is provided with a groove part 20 for measuring the rotational speed.

  The tachometer 10 is a gap sensor that measures the distance from the root portion 4b2 of the compressor impeller 4b. In the present embodiment, for example, an eddy current gap sensor having a sensor coil at the tip 11 can be employed as the tachometer 10. In other words, the tachometer 10 of the present embodiment is configured to measure the rotational speed of the compressor impeller 4b by detecting the groove 20 provided in the root portion 4b2 of the compressor impeller 4b by the action of eddy current. .

  The compressor impeller 4b of this embodiment has a screw hole 4b3 for screwing the rotary shaft 3c, and has a solid structure in which the hole does not penetrate in the axial direction. Here, the root portion 4b2 of the compressor impeller 4b is a portion corresponding to a neck portion (neck portion) of the compressor impeller 4b formed to protrude from the back surface 4b1 to form the screw hole 4b3. As shown in FIG. 2, the groove part 20 provided in the root part 4b2 of the compressor impeller 4b is formed linearly along the axial direction.

  Moreover, this groove part 20 is formed in one place of the surrounding surface of the root part 4b2, as shown to Fig.3 (a). As shown in FIG. 3B, the groove portion 20 of the present embodiment has a flat dome-like cross-sectional contour shape. More specifically, the groove 20 has a bottom surface 21 and two curved surfaces 22. The bottom surface 21 is a flat surface portion that continuously connects the two curved surfaces 22. The curved surface 22 is a side wall portion that rises from both sides of the bottom surface 21.

  Then, the effect | action of the attachment structure of the tachometer 10 of the supercharger 1 comprised as mentioned above is demonstrated.

  As shown in FIG. 1, the tachometer 10 is inserted into the bearing housing 3a while avoiding the cooling water passage 3g, and the tip 11 thereof is disposed between the back surface 4b1 of the compressor impeller 4b and the bearing 3b. The area from the back surface 4b1 side of the compressor impeller 4b to the bearing 3b is an area that does not face the intake passage 4c for the gas sucked into the compressor impeller 4b. For this reason, the flow of the gas sucked into the compressor impeller 4b by the tip 11 of the tachometer 10 is not disturbed.

  The tachometer 10 is inserted through a hole 3d2 that is provided in the seal plate 3d and extends in the radial direction. The seal plate 3d is not formed with the cooling water flow path 3g. By forming the hole 3d2 in the seal plate 3d, the tachometer 10 can be easily disposed avoiding the cooling water flow path 3g. . Thus, in this embodiment, since the tachometer 10 is inserted into the bearing housing 3a avoiding the cooling water flow path 3g, there is a problem of cooling water leakage or mixing of the leaked cooling water and lubricating oil. Can be resolved.

  In the present embodiment, a lubricant seal portion 3d1 is provided outside the bearing 3b, and the tip 11 of the tachometer 10 is located between the back surface 4b1 of the compressor impeller 4b and the lubricant seal portion 3d1. It is arranged. A region between the back surface 4b1 side of the compressor impeller 4b and the lubricating oil seal portion 3d1 is a region that does not face the lubricating oil flow path 3f. As described above, the tip 11 of the tachometer 10 is disposed between the back surface 4b1 of the compressor impeller 4b and the lubricant seal portion 3d1 in front of the bearing 3b, so that the lubricating oil leakage from the hole 3d2 can be reduced. The problem of influence on measurement due to the presence of the lubricating oil between the tip 11 and the groove 20 can be solved.

  Moreover, in this embodiment, the groove part 20 for measuring rotation speed is provided in the root part 4b2 of the compressor impeller 4b. In the root part 4b2 of the compressor impeller 4b, since the cooling water flow path 3g and the lubricating oil flow path 3f pass nearby, the influence on measurement due to heat can be reduced. The entire compressor housing 4a generates heat, for example, at about 200 ° C. due to heat generated when the gas is compressed. Therefore, in the conventional structure in which the tachometer 10 is attached to the compressor housing 4a, it is necessary to select one having heat resistance. On the other hand, the bearing housing 3a is cooled to, for example, about 100 ° C. by water cooling and oil cooling. For this reason, in this embodiment, the restriction | limiting by heat resistance decreases, and the freedom degree of selection of the sensor used for the tachometer 10 can be raised.

  Moreover, in this embodiment, the groove part 20 has a cross-sectional outline shape of a flat dome shape, as shown in FIG.3 (b). When the compressor impeller 4b rotates, a stress is exerted so that the blade is pulled radially outward by centrifugal force. This tensile stress acts more toward the root of the blade portion of the compressor impeller 4b. The groove portion 20 is formed of a bottom surface 21 and two curved surfaces, and has a configuration in which the curvature is moderately taken as a whole. For this reason, it can be set as the structure which can reduce the stress concentration in the groove part 20 even if tensile stress acts in the root part 4b2 of the compressor impeller 4b.

  Thus, according to the above-described embodiment, the bearing housing 3a that holds the bearing 3b that rotatably supports the rotation shaft of the compressor impeller 4b, and the tachometer 10 that measures the rotation speed of the compressor impeller 4b are provided. The bearing housing 3a is provided with a cooling water passage 3g through which cooling water flows, and the tachometer 10 is inserted into the bearing housing 3a while avoiding the cooling water passage 3g. By adopting a configuration in which the tip 11 is disposed between the back surface 4b1 of the compressor impeller 4b and the bearing 3b, the flow of the gas sucked into the compressor impeller 4b is not disturbed, and the bearing housing 3a The rotation speed of the compressor impeller 4b is measured without affecting the cooling structure. It can turbocharger 1 is obtained.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

FIG. 4 is a diagram showing a configuration of the compressor impeller 4b in the second embodiment of the present invention. FIG. 5 is a diagram illustrating a main configuration of the compressor impeller 4b according to the second embodiment of the present invention. 5A shows the configuration on the back surface 4b1 side of the compressor impeller 4b, and FIG. 5B shows the configuration of the region A in FIG.
The second embodiment is different from the above-described embodiment in that a groove 20 for measuring the number of rotations is provided on the back surface 4b1 of the compressor impeller 4b.

  In the second embodiment, as shown in FIG. 4, a groove portion 20 is provided on the back surface 4b1 of the compressor impeller 4b, and the tachometer 10 is disposed obliquely so that the groove portion 20 and the tip 11 face each other. As shown in FIG. 5A, the groove portion 20 of the second embodiment is provided at a position about half the radius of the compressor impeller 4b in the radial direction. Moreover, the groove part 20 has a hemispherical cross-sectional outline shape, as shown in FIG.5 (b). The groove 20 has a curved surface 23. The curved surface 23 is formed with an R diameter equal to or smaller than the curved surface 22 of the above embodiment.

  According to the second embodiment having the above configuration, the tip of the tachometer 10 is disposed on the back surface 4b1 of the compressor impeller 4b. The back surface 4b1 of the compressor impeller 4b is a region that does not face the intake passage 4c for the gas sucked into the compressor impeller 4b. For this reason, the flow of the gas sucked into the compressor impeller 4b by the tip 11 of the tachometer 10 is not disturbed as in the above embodiment.

  In the back surface 4b1 of the compressor impeller 4b, since the tensile stress acting in the radial direction by the centrifugal force is small as compared with the root portion 4b2 of the above embodiment, the restriction on the shape of the groove portion 20 is reduced. Therefore, in 2nd Embodiment, the area | region which forms the groove part 20 is made small, avoiding stress concentration, by making the groove part 20 in the back surface 4b1 of the compressor impeller 4b into a hemispherical cross-sectional outline shape. Thus, in 2nd Embodiment, the groove part 20 can be made small and it becomes possible to reduce the influence which it has on the rotation balance adjustment of the compressor impeller 4b.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above-described embodiment, the configuration in which the tip of the tachometer is disposed between the back surface of the compressor impeller and the lubricant seal is described, but the present invention is not limited to this configuration, for example, The tip of the tachometer may be arranged on the inner side (bearing side) of the lubricant seal. Even within the lubricating oil flow path, if the pressure of the lubricating oil is released, sealing measures are easy, and the occurrence of lubricating oil leakage from the insertion hole of the tachometer can be prevented.

  Further, for example, in the above-described embodiment, the configuration in which the groove for measuring the number of rotations has a flat dome-like cross-sectional contour shape including a bottom surface and two curved surfaces has been described (see FIG. 3B). The bottom surface is not necessarily a flat surface, and may be a curved surface having a larger R diameter than the other two curved surfaces, for example.

  For example, in the above-described embodiment, the configuration in which the tachometer includes a gap sensor has been described. However, the present invention is not limited to this configuration. For example, a magnet is embedded in a compressor impeller and the magnetic flux is detected. Thus, a magnetic sensor for measuring the rotation speed of the compressor impeller may be employed.

  Further, for example, in the above-described embodiment, the compressor impeller has been described with respect to a configuration having a solid structure including a screw hole for screw fastening with the rotating shaft, but the present invention is not limited to this configuration, for example, The compressor impeller can also be applied to a structure having a through-hole that is provided with an insertion hole through which the rotation shaft is inserted and is nut-fastened at the tip of the compressor impeller. In this case, the structure which provides a groove part in the back surface of the compressor impeller of 2nd Embodiment can be applied suitably.

  DESCRIPTION OF SYMBOLS 1 ... Supercharger, 3a ... Bearing housing, 3b ... Bearing, 3c ... Rotating shaft, 3d ... Seal plate, 3d1 ... Lubricating oil seal part, 3d2 ... Hole, 3g ... Cooling water flow path, 4b ... Compressor impeller, 4b1 ... Back surface, 4b2 ... root portion, 10 ... tachometer, 11 ... tip, 20 ... groove portion

Claims (5)

A bearing housing that rotatably supports the rotating shaft of the compressor impeller is provided, a bearing housing provided with a cooling water passage through which cooling water flows, and a tip that is inserted into the bearing housing while avoiding the cooling water passage. A turbometer disposed between a back surface of the compressor impeller and the bearing, and a tachometer for measuring the rotation speed of the compressor impeller,
Supercharger, wherein the the base portion from the rear of the compressor impeller extending in the axial direction of the rotary shaft, the groove for measuring the rotational speed is provided, it. Between the bearing and the compressor impeller, a lubricant seal portion is provided,
The supercharger according to claim 1, wherein a tip of the tachometer is disposed between a back surface of the compressor impeller and the lubricating oil seal portion. The bearing housing has a seal plate provided with the lubricant seal portion,
The supercharger according to claim 2, wherein a hole for inserting the tachometer is formed in the seal plate.   The supercharger according to any one of claims 1 to 3, wherein the groove portion has a flat dome-like cross-sectional contour shape. A bearing housing including a bearing and formed with a cooling water channel;
The compressor impeller tachometer is inserted into the bearing housing while avoiding the cooling water channel, and the tip is disposed between the back surface of the compressor impeller and the bearing;
Have
Supercharger, wherein the the base portion extending in the axial direction of the rotary shaft, the groove facing the front end of the tachometer is provided, that from the rear of the compressor impeller.

Images