JP6447724B2 - Rotating machine - Google Patents

Description

  The present disclosure relates to a rotating machine in which a rotating shaft is supported by a bearing.

  As such a technique, as described in Patent Document 1, an electric supercharger is known in which a compressor wheel is attached to a rotating shaft and a motor rotor fixed to the rotating shaft is rotated by a motor. In this electric supercharger, a ring portion that surrounds the rotating shaft, a damper provided inside the ring portion, and a rolling bearing are provided. The rolling bearing is attached to the end of the rotating shaft. The rolling bearing is a grease-filled bearing in which grease is sealed.

JP 2012-102700 A

  The bearing may be attached to the rotating shaft by press fitting. When the bearing is press-fitted into the rotating shaft, it is difficult to remove the bearing from the rotating shaft when replacing the bearing. For example, even if an external force is directly applied to the bearing fixed to the rotating shaft, the bearing cannot be easily removed. An object of this indication is to provide the rotating machine which can remove a bearing from a rotating shaft easily.

A rotary machine according to an aspect of the present disclosure is a rotary machine including a rotary shaft that is rotatably supported in a housing, the impeller attached to one end of the rotary shaft, and the housing that is press-fitted into the rotary shaft. A bearing that rotatably supports the rotating shaft and is a grease lubricated ball bearing, and a flange member that is attached to the rotating shaft and is adjacent to the bearing in the axial direction of the rotating shaft, The bearing is attached to the back side of the impeller and is disposed between the impeller and the collar member. The collar member penetrates the rotating shaft and is connected to the boss portion adjacent to the bearing and the rotating shaft. And a flange portion extending in the radial direction.

  According to one aspect of the present disclosure, the bearing can be easily detached from the rotating shaft.

FIG. 1 is a cross-sectional view of a rotating machine according to a first embodiment of the present disclosure. FIG. 2 is an enlarged cross-sectional view of a portion A in FIG. 3, (a) is a cross-sectional view showing the collar member in FIG. 2, and (b) is a cross-sectional view showing the collar member in FIG. In FIG. 4, (a) and (b) are sectional views for explaining a bearing removing step. FIG. 5 is an enlarged cross-sectional view illustrating a bearing portion of a rotary machine according to the second embodiment of the present disclosure, and corresponds to FIG. It is sectional drawing which expands and shows the bearing part of the rotary machine which concerns on a comparative example.

  A rotary machine according to an aspect of the present disclosure is a rotary machine including a rotary shaft that is rotatably supported in a housing, and is a bearing that is press-fitted into the rotary shaft and rotatably supports the rotary shaft with respect to the housing. And a flange member attached to the rotary shaft and adjacent to the bearing in the axial direction of the rotary shaft, the collar member being connected to the boss portion and the boss portion passing through the rotary shaft and adjacent to the bearing. And a flange portion extending in the radial direction of the rotation shaft.

  According to this rotating machine, the collar member attached to the rotating shaft is adjacent to the bearing in the axial direction. The boss portion of the collar member is adjacent to the bearing, and the collar portion extends in the radial direction. Therefore, by applying an axial external force to the collar-like portion, the boss portion is pressed against the bearing, and the bearing press-fitted into the rotating shaft can be easily removed.

  In some embodiments, the bearing is a grease-lubricated ball bearing, and a cylindrical portion surrounding the bearing from the outer peripheral side is held inside the housing, and the collar portion of the collar member is Arranged inside. In this case, since the collar portion is arranged inside the cylindrical portion, the clearance between the collar portion and the inner periphery of the cylindrical portion can be reduced. Therefore, the flow of fluid such as air that can pass through the ball bearing is effectively prevented. As a result, grease removal is suppressed, and the life of the bearing is extended and the durability is improved.

  In some embodiments, the rotating shaft is provided with a rotating body that protrudes outward in the radial direction from the collar portion, and a gap is provided in the axial direction between the collar portion and the rotating body. It has been. When a rotating body that projects radially outward is provided on the rotating shaft, the rotating body may become an obstacle when an external force is applied to the collar-shaped portion. According to said structure, a jig | tool etc. can be arrange | positioned in the space | interval provided between the collar-shaped part and the rotary body, and it becomes easy to apply an axial external force to a bearing via this jig | tool etc. . Therefore, even when the rotating body that projects radially outward is provided on the rotating shaft, the bearing can be easily detached from the rotating shaft.

  In some embodiments, the bearing is a radial ball bearing including an inner ring press-fitted into a rotating shaft and an outer ring that is rotatable relative to the inner ring via a plurality of balls, and the boss portion is a collar-shaped portion. It protrudes further to the bearing side and abuts against the inner ring, and a gap is provided in the axial direction between the collar-shaped part and the outer ring. In this case, since the boss part is in contact with the inner ring of the bearing, it is easy to move the inner ring press-fitted into the rotating shaft relative to the rotating shaft by applying an axial external force to the collar-like part. Furthermore, since a gap is provided between the collar-shaped portion and the outer ring of the bearing, it is possible to prevent the collar-shaped portion from interfering with the outer ring even when the collar member rotates as the rotating shaft rotates.

  A rotating machine according to another aspect of the present disclosure is adjacent to a housing, a rotating shaft housed in the housing, a bearing that supports one side in the axial direction of the rotating shaft, and the other axial side of the bearing. A collar member, and the collar member includes a boss portion through which the rotating shaft passes and adjacent to the bearing, and a collar-shaped portion connected to the boss portion and extending in the radial direction of the rotating shaft.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant descriptions are omitted.

  With reference to FIG. 1, the electric supercharger (rotary machine) 1 of 1st Embodiment is demonstrated. As shown in FIG. 1, the electric supercharger 1 is applied to, for example, an internal combustion engine of a vehicle or a ship. The electric supercharger 1 includes a compressor 7. The electric supercharger 1 rotates the compressor impeller 8 by the interaction of the rotor part 13 and the stator part 14, compresses a fluid such as air, and generates compressed air.

  The electric supercharger 1 includes a rotating shaft 12 that is rotatably supported in the housing 2, and a compressor impeller 8 that is fixed to a distal end portion (one end portion) 12 a of the rotating shaft 12. The housing 2 includes a motor housing 3 that houses the rotor portion 13 and the stator portion 14, and an end wall 4 that closes an opening on the other end side (right side in the drawing) of the motor housing 3. A compressor housing 6 that houses the compressor impeller 8 is provided on one end side (the left side in the drawing) of the motor housing 3. The compressor housing 6 includes a suction port 9, a scroll portion 10, and a discharge port 11.

  The compressor impeller 8 is made of, for example, a resin or a carbon fiber reinforced resin (hereinafter referred to as “CFRP”; CFRP: Carbon Fiber Reinforced Plastic), thereby reducing the weight.

  The rotor portion 13 is fixed to the central portion of the rotating shaft 12 in the axial direction D1 and includes one or more permanent magnets (not shown) attached to the rotating shaft 12. The stator portion 14 is fixed to the inner surface of the motor housing 3 so as to surround the rotor portion 13, and includes a coil portion (not shown) formed by winding a conductive wire 14a. When an alternating current is passed through the coil portion of the stator portion 14 through the conducting wire 14a, the rotary shaft 12 and the compressor impeller 8 rotate as a unit by the interaction between the rotor portion 13 and the stator portion 14. When the compressor impeller 8 rotates, the compressor impeller 8 sucks external air through the suction port 9, compresses the air through the scroll unit 10, and discharges it from the discharge port 11. The compressed air discharged from the discharge port 11 is supplied to the internal combustion engine described above.

  The electric supercharger 1 includes two ball bearings (bearings) 20 that are press-fitted into the rotating shaft 12 and rotatably support the rotating shaft 12 with respect to the housing 2. The ball bearings 20 are provided in the vicinity of the distal end portion 12a and the proximal end portion 12b of the rotary shaft 12, respectively, and support the rotary shaft 12 by both ends. The ball bearing 20 is, for example, a grease lubricated radial ball bearing. More specifically, the ball bearing 20 may be a deep groove ball bearing or an angular ball bearing. As shown in FIG. 2, the ball bearing 20 includes an inner ring 20a press-fitted into the rotary shaft 12, and an outer ring 20b that can rotate relative to the inner ring 20a via a plurality of balls 20c.

  One ball bearing 20 is attached to the back side (right side in the figure) of the compressor impeller 8. A cylindrical bearing sleeve (cylindrical portion) 21 is attached to the outer peripheral side of one ball bearing 20. As shown in FIG. 1, the ball bearing 20 and the bearing sleeve 21 are fixed to the rotary shaft 12 by a shaft end nut 16 provided at the tip 12 a of the rotary shaft 12. A cylindrical bearing sleeve 21 is disposed on the outer peripheral side of the one ball bearing 20. The bearing sleeve 21 is press-fitted into a bearing surrounding portion 23 formed on one end side of the motor housing 3 in the axial direction D1.

  The other ball bearing 20 is attached between the rotary shaft 12 and the end wall 4. A cylindrical bearing sleeve (cylindrical portion) 22 is attached to the outer peripheral side of the other ball bearing 20. The bearing sleeve 22 is press-fitted into a cylindrical portion (inner peripheral surface) formed so as to protrude into the motor housing 3 at the center of the end wall 4. An annular spring receiver 26 is provided between the other ball bearing 20 and the end wall 4. The spring receiver 26 is urged toward one side in the axial direction D1 by a spring 27 disposed in a cylindrical portion at the center of the end wall 4.

  The motor housing 3 is made of, for example, aluminum. On the other hand, the inner ring 20a and the outer ring 20b of the ball bearing 20 are made of iron. Therefore, bearing sleeves 21 and 22 made of iron such as carbon steel and having the same degree of hardness as the ball bearing 20 are provided between the ball bearing 20 and the motor housing 3. The bearing sleeves 21 and 22 surround the ball bearing 20 from the outer peripheral side. As a result, the motor housing 3 made of a relatively soft material is protected from wear.

  The rotating shaft 12, the compressor impeller 8 fixed to the rotating shaft 12, the rotor portion 13, the ball bearing 20, and the spring receiver 26 constitute a rotating portion integrally in the housing 2, and the axial direction described above It is biased to one side of D1. The annular portion 23a of the bearing surrounding portion 23 is opposed to one end side of the ball bearing 20, whereby the rotating portion is positioned in the axial direction D1.

  Subsequently, the bearing structure of the electric supercharger 1 will be described in detail with reference to FIG. 2 and FIG. As shown in FIG. 2, the rotor portion 13 is a rotating body that protrudes outward in the radial direction D <b> 2 from the rotating shaft 12. The outer diameter of the rotor part 13 is larger than the outer diameter of the outer ring 20b of the ball bearing 20, for example. The outer diameter of the rotor portion 13 is, for example, larger than the inner diameter of the bearing sleeve 21 and smaller than the outer diameter of the bearing sleeve 21. The outer diameter of the rotor portion 13 may be larger than the outer diameter of the bearing sleeve 21. An annular step 12c having a diameter slightly larger than that of the rotating shaft 12 is formed at a position corresponding to one end face in the axial direction D1 of the rotor portion 13 of the rotating shaft 12. That is, the step portion 12 c of the rotating shaft 12 is disposed inside the one end surface of the rotor portion 13 in the axial direction D1.

  In the electric supercharger 1 of this embodiment, a spacer (collar member) 30 is interposed between the ball bearing 20 and the stepped portion 12c. The spacer 30 is fixed to the rotating shaft 12 and is adjacent to the ball bearing 20 in the axial direction D1. The spacer 30 is made of iron such as carbon steel.

  As shown in FIG. 3A, the spacer 30 includes a cylindrical boss portion 31 that comes into contact with the inner ring 20 a of the ball bearing 20 and a collar portion 32 that is connected to the boss portion 31. A through hole 30 a through which the rotary shaft 12 passes is provided at the center of the boss portion 31. The collar portion 32 extends in the radial direction D2 in an annular shape.

  The boss portion 31 includes an annular boss portion first end surface 31a on one end side in the axial direction D1, and an annular boss portion second end surface 31b on the other end side in the axial direction D1. The collar portion 32 includes an annular collar-shaped first end surface 32a on one end side in the axial direction D1, and an annular collar-shaped second end surface 32b on the other end side in the axial direction D1. The thickness of the boss part 31 in the axial direction D1, that is, the distance between the boss part first end face 31a and the boss part second end face 31b is the thickness of the collar part 32, that is, the collar part first end face 32a and the collar part. It is larger than the distance between the second end face 32b. In other words, the boss 31 protrudes further toward the ball bearing 20 than the collar 32. Furthermore, the boss part 31 protrudes to the step part 12 c side from the collar part 32. The thickness of the boss part 31 can be determined by, for example, the length (width) of the ball bearing 20 in the axial direction D1. The thickness of the collar portion 32 can be determined based on the strength required when a ball bearing 20 described later is removed.

  As shown in FIG. 2, the boss portion 31 of the spacer 30 is in contact with the inner ring 20 a of the ball bearing 20. Since the boss portion first end surface 31 a protrudes from the collar portion first end surface 32 a, a gap is provided between the collar portion first end surface 32 a and the outer ring 20 b of the ball bearing 20.

  The outer diameter of the collar portion 32 is smaller than the inner diameter of the bearing sleeve 21. The bearing sleeve 21 protrudes from the ball bearing 20 to the other side in the axial direction D1. A collar portion 32 is disposed inside the protruding portion of the bearing sleeve 21. A narrow annular gap g is provided between the inner peripheral surface of the bearing sleeve 21 and the outer peripheral surface of the collar portion 32. As described above, the spacer 30 is disposed in the bearing sleeve 21 and the clearance g, which is a slight clearance, is formed, so that air passage to the ball bearing 20 is suppressed.

  The rotor portion 13 described above projects outward in the radial direction D2 from the collar portion 32. By projecting the flange-shaped second end surface 32b of the collar-shaped second end surface 32b, a gap S is provided between the collar-shaped second end surface 32b and the rotor portion 13.

  A spacer 30 is similarly provided between the other ball bearing 20 and the rotor portion 13. Since the configuration of the other ball bearing 20, the bearing sleeve 22, and the spacer 30 is the same as described above, the description thereof is omitted.

  Next, with reference to FIG. 4, the extraction process of the ball bearing 20 from the rotating shaft 12 is demonstrated. As shown in FIG. 4A, a bearing removal tool 40 is prepared. The bearing removing tool 40 includes a cylindrical body 41 in which a semi-cylindrical housing divided into two parts is combined, and a jig 42 provided on an upper part of the cylindrical body 41 and in which semicircular plate portions are combined. The rotating shaft 12 is inserted into the upper portion of the cylindrical body 41 and the central portion of the jig 42 in a state where the ball bearing 20 and the spacer 30 are press-fitted into the rotating shaft 12. Here, the edge part of the opening provided in the center part of the jig | tool 42 is arrange | positioned at the space | interval S mentioned above. Thus, the jig 42 can be pressed against the collar portion 32 of the spacer 30 in the axial direction D1.

  When the front end 12a of the rotating shaft 12 is pushed downward in the state of FIG. 4A, as shown in FIG. 4B, the spacer 30 is interposed (more specifically, between the boss 31 and the inner ring 20a). The rotary shaft 12 is extracted from the ball bearing 20 by pressure welding. Thereby, the ball bearing 20 is easily removed. The other ball bearing 20 can also be removed by the same procedure as described above.

  According to the electric supercharger 1, the spacer 30 attached to the rotating shaft 12 is adjacent to the ball bearing 20 in the axial direction D1. The boss portion 31 of the spacer 30 is adjacent to the ball bearing 20 and the collar portion 32 extends in the radial direction D2. Therefore, by applying an external force in the axial direction D1 to the collar portion 32, the boss portion 31 is pressed against the ball bearing 20, and the ball bearing 20 press-fitted into the rotating shaft 12 can be easily removed.

  Alternatively, the flange portion 32 extends in the radial direction D <b> 2, so that the clearance is narrow, and the flow of air that can pass through the ball bearing 20 is hindered. As a secondary effect, the removal of grease contained in the ball bearing 20 is suppressed, and the life of the ball bearing 20 is extended. In the ball bearing 20 provided on the back side of the compressor impeller 8, this effect is remarkable.

  As shown in FIG. 6, in the configuration in which the bearing sleeve 50 that does not protrude from the ball bearing 20 is used and the spacer 30 is not provided, the air flow F is likely to occur as the compressor impeller 8 rotates. For this reason, the grease contained in the ball bearing 20 is easily carried away, which is a factor of reducing the durability of the ball bearing 20. According to the electric supercharger 1 including the spacer 30, the removal of grease contained in the ball bearing 20 is suppressed.

  According to the electric supercharger 1, since the collar portion 32 is disposed inside the bearing sleeve 21, the gap g between the collar portion 32 and the inner periphery of the bearing sleeve 21 is small. Therefore, the flow of air that can pass through the ball bearing 20 is hindered. As a result, the removal of grease contained in the ball bearing 20 is further suppressed.

  According to the electric supercharger 1, the jig 42 can be disposed at the interval S provided between the collar portion 32 and the rotor portion 13, and the ball bearing 20 is connected to the shaft via the jig 42. It becomes easier to apply external force in the direction. Therefore, the ball bearing 20 can be easily detached from the rotating shaft 12 even when the rotor portion 13 that projects outward in the radial direction D <b> 2 is provided on the rotating shaft 12.

  According to the electric supercharger 1, since the boss portion 31 is in contact with the inner ring 20a of the ball bearing 20, the inner ring 20a press-fitted into the rotary shaft 12 by applying an external force in the axial direction D1 to the collar portion 32. Is easily moved relative to the rotary shaft 12. Furthermore, since a gap is provided between the collar portion 32 and the outer ring 20b of the ball bearing 20, the collar portion 32 interferes with the outer ring 20b even when the spacer 30 rotates as the rotating shaft 12 rotates. It is prevented.

  With reference to FIG. 5 and FIG.3 (b), the electric supercharger 1 of 2nd Embodiment is demonstrated. In the electric supercharger 1, a spacer 30A having a flat other end surface in the axial direction D1 is used. For example, when a ball bearing 20A of a different type from the ball bearing 20 (for example, an angular bearing) is used, the shape of the spacer is changed because the ball bearing 20A has a size different from that of the ball bearing 20. It is. The boss part 31A and the collar part 32A of the spacer 30A are thinner in the axial direction D1 than the boss part 31 and the collar part 32 of the spacer 30. Note that the material of the spacer 30 </ b> A may be changed from the material of the spacer 30 from the viewpoint of securing strength. For example, the spacer 30A made of chromium molybdenum steel may be used. In the thin spacer 30A, the collar-shaped second end surface 32b and the collar-shaped second end surface 32b are flush with each other and form a flat surface. Even in this case, an interval S similar to the above is provided between the boss portion 31 </ b> A and the rotor portion 13.

  Even with such a structure using the spacer 30 </ b> A, the same operation and effect as those of the first embodiment can be obtained.

  As mentioned above, although embodiment of this indication was described, this invention is not restricted to said embodiment. For example, the arrangement relationship of the spacer 30 with respect to the bearing sleeve 21 is not limited to the above-described aspect. The spacer 30 may be disposed outside the bearing sleeve 21 without the spacer 30 being disposed in the bearing sleeve 21. The collar-shaped part 32 may be arrange | positioned so that the axial direction D1 of the bearing sleeve 21 may be adjoined.

  The bearing sleeve 21 is not provided, and the housing may include a portion having the same shape as the bearing sleeve. That is, as long as the difference in material between the housing and the bearing is solved, the housing and the bearing (the outer ring of the bearing) may be brought into contact without the bearing sleeve.

  The bearing is not limited to a grease lubricated ball bearing. For example, a ball bearing employing another lubrication method (oil lubrication or the like) may be used. The bearing is not limited to a radial bearing, and may be a thrust bearing.

  The structure of the present invention can be applied to any rotating machine in which a bearing is press-fitted into a rotating shaft. For example, the present invention can be applied to a type of electric supercharger that includes a turbine and assists rotation by a motor, and can also be applied to a general supercharger other than the electric supercharger. Further, the present invention is not limited to a rotary machine including a compressor, and the present invention can also be applied to a generator that generates power by a turbine.

  According to some aspects of the present disclosure, the bearing can be easily removed from the rotating shaft.

1 Electric supercharger (rotary machine)
2 Housing 7 Compressor 8 Compressor impeller (impeller)
12 Rotating shaft 13 Rotor (rotating body)
14 Stator 20 Ball Bearing (Bearing)
20A ball bearing (bearing)
20a Inner ring 20b Outer ring 20c Ball 21 Bearing sleeve (cylindrical part)
22 Bearing sleeve (cylindrical part)
23 bearing surrounding portion 23a annular portion 30 spacer (collar member)
30A Spacer (Tub member)
31 Boss part 31A Boss part 32 Collar part 32A Collar part D1 Axial direction D2 Radial direction S Interval

Claims (5)

A rotating machine comprising a rotating shaft rotatably supported in a housing,
An impeller attached to one end of the rotating shaft;
A bearing that is press-fitted into the rotating shaft and rotatably supports the rotating shaft with respect to the housing, and is a grease lubricated ball bearing ;
A collar member attached to the rotating shaft and adjacent to the bearing in the axial direction of the rotating shaft;
The bearing is attached to the back side of the impeller and is disposed between the impeller and the collar member,
The collar member is a rotating machine including a boss part that penetrates the rotating shaft and is adjacent to the bearing, and a collar part that is connected to the boss part and extends in a radial direction of the rotating shaft. Inside the front Symbol housing and the cylindrical portion is held to surround the outer peripheral side of the bearing,
The rotary machine according to claim 1, wherein the collar portion of the collar member is disposed inside the cylindrical portion. The rotating shaft is provided with a rotating body that protrudes outward in the radial direction from the collar-shaped portion,
The rotating machine according to claim 1 or 2, wherein a gap is provided in the axial direction between the collar portion and the rotating body. The bearing is a radial ball bearing including an inner ring press-fitted into the rotating shaft and an outer ring that is rotatable relative to the inner ring via a plurality of balls,
The boss portion protrudes more toward the bearing than the collar-shaped portion and is in contact with the inner ring,
The rotating machine according to any one of claims 1 to 3, wherein a gap is provided in the axial direction between the collar portion and the outer ring. A housing;
A rotating shaft housed in the housing;
An impeller attached to one end of the rotating shaft;
The bearing that is a bearing that supports one side in the axial direction of the rotating shaft and is a grease lubricated ball bearing ;
A flange member adjacent to the other axial side of the bearing,
The bearing is attached to the back side of the impeller and is disposed between the impeller and the collar member,
The collar member is
A boss that penetrates the rotating shaft and is adjacent to the bearing;
A collar portion connected to the boss portion and extending in the radial direction of the rotation shaft;
Including rotating machinery.

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