JP5974582B2 - Bearing support structure - Google Patents

Description

  The present invention relates to a bearing support structure for reducing vibration of a rotating shaft in a rotating device such as a motor or a generator.

  Conventionally, a bearing support structure that constitutes a squeeze film damper is known as a means for reducing vibration of a rotating shaft incorporated in a rotating device.

  This is configured so that a slight gap is formed between the outer peripheral surface of the bearing that supports the rotating shaft and the inner peripheral surface of the housing, and oil is held inside the gap. It is possible to obtain a damping effect by suppressing the relative displacement between them by the viscous resistance of the oil.

  Generally, for ease of manufacture, an annular bearing case is manufactured separately from the bearing, and is fixed to the outer ring side of the bearing inside the bearing case. In many cases, a squeeze film damper portion is formed between the two (see, for example, Patent Document 1).

  Also, various types of squeeze film dampers have been proposed, a type that completely seals the oil in the gap, a type that has oil holes provided to compensate for the leakage from the gap to the outside, and a deteriorated oil In order to be able to supply new oil by discharging the oil, it is roughly divided into three types in which an oil drain hole is provided in addition to the oil supply hole. Furthermore, even if it is a type that has an oil supply hole and an oil drain hole, these oil supply holes and oil drain holes are always open and used while slightly flowing oil, and it is necessary to supply and discharge oil. Some are used only when they are open.

  These types are suitable for selection in consideration of the usage environment, usage conditions, or manufacturing cost, but rotations used under severe usage conditions such as equipment that requires high-speed rotation or high output, or equipment that generates heat. As a device that requires continuous use over a long period of time, it is preferable to use a device that is provided with oil supply holes and oil discharge holes and that constantly supplies and discharges oil through them. .

Japanese Patent Laid-Open No. 2005-321535

  As described above, oil supply holes and oil discharge holes are provided in the gaps that make up the squeeze film damper part, and if it is assumed to be used with a slight flow of oil, oil is supplied to the squeeze film damper part. It is necessary to provide an oil supply valve in the oil supply path and adjust the amount of oil supply according to the opening of the oil supply valve.

  At this time, if the position and balance of the oil supply hole and the oil discharge hole with respect to the squeeze film damper are not appropriate, the oil-filled space will be substantially blocked, and a fine adjustment of the opening of the oil supply valve will occur. As a result, the hydraulic pressure of the squeeze film damper portion changes greatly, and the damping coefficient changes greatly. For this reason, the damper characteristic for suppressing the vibration is not stable, and the target vibration reduction effect of the rotating device may not be obtained. Even when oil is supplied directly from the oil pump without providing an oil valve, similar problems may occur due to various disturbances upstream of the oil supply path, such as pulsation of the oil pump and clogging of piping. is there.

  Further, depending on the positional relationship between the oil supply hole and the oil discharge hole with respect to the squeeze film damper portion, the bearing case may be eccentric in the housing due to the flow of oil. Due to the occurrence of such eccentricity, the size of the gap becomes non-uniform in the circumferential direction, so that there is a possibility that the damping characteristics are different in the circumferential direction and a stable vibration reducing effect cannot be obtained.

  An object of the present invention is to effectively solve such problems. Specifically, the present invention obtains a stable damping characteristic without depending on conditions on the upstream side of the oil supply path, such as the opening of the oil supply valve. An object of the present invention is to provide a bearing support structure that can stabilize the damping characteristics by suppressing the eccentricity of the bearing case and can effectively reduce the vibration of the rotating device.

  In order to achieve this object, the present invention takes the following measures.

That is, the bearing support structure of the first invention includes a bearing that rotatably supports the rotating shaft, a cylindrical bearing case that supports the bearing from the outer peripheral side, and a bearing housing that is disposed on the outer peripheral side of the bearing case. Comprising a squeeze film damper portion by supplying oil between an outer peripheral surface of the bearing case and the bearing housing, wherein the bearing housing includes:
An oil supply port, an oil supply path communicating from the oil supply port toward the bearing case, and an oil discharge port for discharging oil accumulated in the interior are provided. And is elastically supported on the inner surface of the bearing housing via the O-ring, and is formed in an annular oil supply groove formed in the axial center and supplied with oil through the oil supply path, the oil supply groove and the oil supply groove a large-diameter portion corresponding to the squeeze film damper portion is formed between the O-ring, and an annular oil discharge groove is respectively formed between the O-ring with these large-diameter portion, the oil discharge groove and the An oil drain opening that communicates the inner side in the axial direction and the outer side in the axial direction with the O-ring interposed between the O-ring is provided at a portion that contacts the inner periphery of the O-ring by opening the O-ring toward the inner peripheral surface side. Features.

  With this configuration, oil is supplied to the squeeze film damper portion through the oil supply groove and oil can be discharged through the oil discharge groove and the oil discharge port, so that the oil is not blocked by the O-ring. Pressure change due to the opening of the valve is less likely to occur. Further, since the bubbles do not accumulate inside due to the flow of oil, the attenuation coefficient can be kept substantially constant. Furthermore, since the oil supply side and the oil discharge side are each formed as an annular groove with respect to the squeeze film damper part, the flow resistance at the entrance and exit of the squeeze film damper part becomes uniform over the entire circumference, and the damping coefficient is further increased. In addition, it is possible to further stabilize the damping characteristic by suppressing the eccentricity caused by the hydraulic pressure that occurs with oil supply or drainage.

  In addition, it is possible to make the flow path resistance on the oil drain side more uniform in the circumferential direction, and in order to further increase the effect of making the damping coefficient constant, the oil drain port is arranged in the circumferential direction. It is preferable that a plurality of them are provided in a uniform manner.

  Further, in order to use the oil flowing out from the oil discharge port also for the lubrication of the bearing to further simplify the configuration and reduce the manufacturing cost, at least one of the oil discharge ports is connected to the shaft of the rotary shaft. It is preferable to arrange it vertically above the center.

  Further, in order to properly supply the oil discharged from the oil discharge port to the inner bearing through the inner surface of the bearing case, the inner diameter toward the center in the axial direction is provided on the inner peripheral side in the vicinity of both end faces of the bearing case. It is preferable to configure so that a tapered portion is formed.

  The bearing support structure of the second invention includes a bearing that rotatably supports the rotating shaft, a cylindrical bearing case that supports the bearing from the outer peripheral side, and a bearing housing that is disposed on the outer peripheral side of the bearing case. Comprising a squeeze film damper portion by supplying oil between an outer peripheral surface of the bearing case and the bearing housing, wherein the bearing housing is connected to the bearing case from the oil supply port and the oil supply port. An oil supply passage that communicates with the oil supply passage and an oil discharge port for discharging the oil accumulated inside, and the bearing case is an annular oil supply groove that is supplied with oil through the oil supply passage in the axial center. The O-rings are arranged on both sides of the oil supply groove, and are elastically supported on the inner surface of the bearing housing via the O-rings. A large-diameter portion corresponding to the squeeze film damper portion is formed on the outer side in the axial direction, and the outer side in the axial direction of the large-diameter portion is opened as an oil drainage portion. It is characterized in that at least a plurality of recesses are provided for communicating the inner side in the axial direction and the outer side in the axial direction with the O-ring interposed therebetween.

  Even in this case, as in the first invention, the squeeze film damper portion is supplied with oil through the recess from the oil supply groove, and oil can be discharged through the oil discharge portion. As a result, the oil is not closed, and the pressure change due to the opening of the oil supply valve hardly occurs. Further, since the bubbles do not accumulate inside due to the flow of oil, the attenuation coefficient can be kept substantially constant. Furthermore, since the oil supply side is formed as an annular groove with respect to the squeeze film damper part and the oil discharge side is opened as the oil discharge part, the flow resistance at the entrance and exit of the squeeze film damper part is uniform over the entire circumference. Thus, the damping coefficient can be further stabilized, and the eccentricity is not caused by the hydraulic pressure generated by the oil supply or oil discharge.

  Further, in order to suppress the tilt of the bearing and stabilize the vibration damping effect, it is preferable that the bearing is supported at the substantially axial center of the bearing case.

  According to the present invention described above, a stable damping characteristic is obtained without depending on the upstream side condition of the oil supply path such as the opening of the oil supply valve, and the damping characteristic is further stabilized by suppressing the eccentricity of the bearing case. Therefore, it is possible to provide a bearing support structure capable of effectively reducing vibration of the rotating device.

Sectional drawing which shows the principal part of the motor provided with the bearing support structure which concerns on 1st Embodiment of this invention. Sectional drawing explaining the flow of the oil in the bearing support structure. The perspective view of the bearing case used for the bearing support structure. Sectional drawing which expands and shows the principal part of the bearing support structure. Sectional drawing which expands and shows the principal part at the time of cut | disconnecting in a different position in the circumferential direction from FIG. Sectional drawing which expands and shows the principal part of the bearing support structure which concerns on 2nd Embodiment of this invention. The perspective view of the bearing case used for the bearing support structure which concerns on 3rd Embodiment of this invention. Sectional drawing which expands and shows the principal part of the bearing support structure. Sectional drawing which expands and shows the principal part at the time of cut | disconnecting in a position different from FIG. 8 in the circumferential direction.

Embodiments of the present invention will be described below with reference to the drawings.
<First Embodiment>

  FIG. 1 shows a motor 1 as a rotating device incorporating a bearing support structure B1 according to the first embodiment.

  The motor 1 is configured as a three-phase induction motor, and is configured to rotatably support a rotor 13 that is a rotor inside a stator 12 that is a stator. Then, by applying a three-phase alternating voltage to the coil provided in the stator 12, an induction magnetic field is generated inside, and a driving force is generated in the rotor 13 to cause rotation.

  The stator 12 is fixed to the inner peripheral surface 11a of the casing 11 formed in a cylindrical shape. Further, the rotor 13 is fitted into the outer peripheral surface 63 of the rotating shaft 6 and is fixed by being restricted in position in the axial direction using the fixed collar 14. The rotary shaft 6 has a hollow hole 64 formed in the shaft center to reduce weight.

  The rotating shaft 6 to which the rotor 13 is attached as described above is rotatably supported using the bearing support structure B1 described in detail below, while being position-regulated with respect to the casing 11 to which the stator 12 is attached. It has become. In FIG. 1, only the vicinity of one end for supporting the rotating shaft 6 is illustrated for the sake of simplicity, but actually the other end is configured in the same manner. However, it is not necessary that the one end 61 and the other end shown in the figure have the same shape, and the shaft 1 and gears may be appropriately changed to connect to an external device using the motor 1 as a drive source. May be.

  The bearing support structure B <b> 1 elastically supports the bearing 5 for supporting the rotating shaft 6, the bearing case 4 for supporting the bearing 5, and the pair of O-rings 33 and 33. It is comprised from the cover member 2 as a bearing housing.

  First, the inner peripheral side of the bearing 5 is fitted and fixed to a bearing mounting portion 62 that is a part of the outer peripheral surface 63 of the rotating shaft 6. And the outer peripheral side of the bearing 5 is being fixed inside the bearing case 4 formed as a cylindrical bush. Specifically, as shown in an enlarged view in FIG. 4, a ball bearing including an inner ring 5 a, an outer ring 5 b, and a rolling ball 5 c is used as the bearing 5, and the inner ring 5 a has a bearing mounting portion 62 of the rotating shaft 6. By being press-fitted, the rotation shaft 6 is fixed. Similarly, the outer ring 5b is also fixed to the inner peripheral surface 4b of the bearing case. Therefore, the rotating shaft 6 can be relatively rotated while maintaining a concentric position without causing play between the rotating shaft 6 and the bearing case 4. For fixing the inner ring 5a and the outer ring 5b of the bearing 5, various means such as fastening using shrinkage or a collar can be used in addition to press-fitting.

  Returning to FIG. 1, the lid member 2 has a shape including a cylindrical portion 22 for housing the bearing case 4 therein, and a disk-shaped flange portion 21 having a diameter larger than that of the cylindrical portion 22. The flange portion 21 is fixed in a state where the flange portion 21 is in contact with the end surface 11 b of the casing 11. The flange portion 21 is formed with a fitting portion 21 a as a convex portion concentric with the cylindrical portion 22. By fitting the fitting portion 21 a into the inner peripheral surface 11 a of the casing 11, The cylindrical portion 22 can be positioned so as to be concentric. By doing so, the rotary shaft 6 whose position is regulated by the bearing case 4 housed in the cylindrical portion 22 and the housing 11 to be housed are configured concentrically, and as a result, the stator 12 and the rotor 13 are slightly clearanceed. It is possible to hold in a positional relationship with

  Further, an oil supply port 24 for supplying oil is provided on the upper side of the lid member 2, and drill holes 26 a, 26 b, and 26 c are sequentially provided to the oil supply port 24, and unnecessary openings in the middle are provided. By sealing the portion with a plug member 26x such as a set screw, it is configured as an oil supply path 26 from the oil supply port 24 to the oil supply hole (drill hole) 26c. From the oil supply hole 26c, oil can be supplied to the oil supply groove 41 of the bearing case 4 as described later.

  In addition, consideration is given to the lid member 2 so that oil does not flow out to unnecessary portions. Small diameter portions 23, 23 are formed inside the cylindrical portion 22 that houses the bearing case 4 in the lid member 2, and adjacent to the bearing case 4 in the axial end direction of the rotary shaft 6. By approaching the outer periphery of 6, oil does not leak to the outside along the end of the rotating shaft 6. Further, the small diameter portion 23 is provided with a through hole 27 only at a lower position so that oil can be moved in the axial direction through the through hole 27.

  Further, the flange portion 21 of the lid member 2 is formed with a step portion 21b as a circular concave portion in the axial direction, an O-ring groove 21c is formed near the outer diameter, and an O-ring 32 is formed therein. Is provided. Further, an annular plate 31 is provided inside the stepped portion 21b while being in contact with the O-ring 32. By sealing with the O-ring 32, the gap between the annular plate 31 and the stepped portion 21b is drained. It functions as an oil passage. And the through-hole 28 is provided in the part located in the position which continues to this level | step-difference part 21b, and the perpendicular | vertical lower side. In addition, an oil drain port 25 is provided at a position that is located vertically below the through hole 28 and is close to the fitting portion 21a. The oil supplied from the oil supply port 24 is collected downward by the action of gravity in the casing 11, and the accumulated oil is discharged to the outside through the oil discharge port 25.

  In addition, the motor 1 has a function of supplying cooling oil to the outer periphery of the stator 12 and a coil end included in the stator 12 through another supply port (not shown) and is directed to the bearing case 4 as described above. Part of the oil supplied in this way also acts as such cooling oil. Thus, the oil used for cooling the stator including the coil end is also gathered downward in the casing 11 and discharged through the oil discharge port 25. That is, the oil discharge port 25 is configured to jointly discharge oil mainly required to form the squeeze film damper and oil supplied to cool the stator 12.

  Next, the shape of the bearing case 4 which can be said to be a main part in the present invention will be described. As shown in FIG. 3, the bearing case 4 has a substantially cylindrical shape, and both end faces 4c, 4c are formed perpendicular to the axial direction. Further, many steps are formed on the outer peripheral surface 4a as portions having different outer diameters, and are arranged symmetrically with the axial center position as a boundary. Further, taper portions 4c and 4c having an inner diameter that decreases toward the center in the axial direction are formed in the vicinity of both ends of the inner peripheral surface 4b.

  FIG. 4 is an enlarged view of the main part in FIG. 1 cut along a vertical plane. Of the outer peripheral surface 4 a of the bearing case 4, the central portion in the axial direction is greatly cut close to the inner diameter, and is formed as an annular first oil supply groove 41. Further, a second oil supply groove 42 is formed adjacent to the outside in the axial direction, and a large-diameter portion 43 corresponding to the squeeze film damper portion and an oil discharge groove 44 are sequentially formed outside the second oil supply groove 42. Further, an O-ring groove 45 is formed at an intermediate position of the oil discharge groove 44, and the oil discharge groove 44 is divided between the end circumferential surface 46 with the O-ring groove 45 interposed therebetween.

  Here, the term “groove” used in the present application simply refers to a recessed portion, and does not refer only to a concave shape with a recessed center. For this reason, those having a concave cross section such as the first oil supply groove 41 and those having an L shape cross section such as the second oil supply groove 42 and oil discharge groove 44 are commonly expressed as “grooves”, The same applies to the description.

  At both ends of the bearing case 4, oil drain ports 47 to 47 are provided at three positions in the circumferential direction at positions extending from the oil drain groove 44 to the end circumferential surface 46 as shown in FIG. 3. Yes. Each oil discharge port 47 opens a part of the oil discharge groove 44 to the inner peripheral surface 4b side, and has a shape cut out as a part of an ellipse when viewed from the outer diameter side. Returning to FIG. 4, one of the three oil discharge ports 47 to 47 is incorporated so as to be positioned on the same vertical upper side as the oil supply path 26. Therefore, in the case of FIG. 5 showing the cutting position slightly inclined in the circumferential direction from FIG. 4, the oil supply passage 26 is not seen, the oil discharge port 47 does not exist, and the oil discharge groove 44 is an O-ring. 33 is sealed against the outside in the axial direction.

  Returning to FIG. 4, the O-rings 33 and 33 are fitted into the O-ring grooves 45 and 45, and the bearing case 4 is elastically supported by the inner peripheral surface 22 a of the cylindrical portion 22 in the lid member 2. It has become so. Thus, the large-diameter portion 43 forms a slight parallel gap of about 0.1 mm with the inner peripheral surface 22a, and oil is supplied into the squeeze film damper portion.

  The oil is supplied to the first oil supply groove 41 through the oil supply path 26 and further sent to the large diameter portions 43 and 43 through the second oil supply grooves 42 and 42. In the first oil supply groove 41, a large gap is formed between the first oil supply groove 41 and the inner peripheral surface 22 a, and thus functions as an oil reservoir for storing the supplied oil inside. Moreover, since the 1st supply groove | channel 41 is the state continuous in the circumferential direction, even if the oil supply path | route 26 is provided only in the upper side, it is easy to distribute oil to the whole circumferential direction, and from the upper direction accompanying oil supply. It is possible to suppress the eccentricity of the bearing case 4 with respect to the lid member 2. Also, disturbances such as fluctuations in the amount of oil supplied on the upstream side of the oil supply path 26 are weakened by the first supply groove 41, so that the influence on the damper characteristics can be reduced.

  Further, the second supply groove 42 is set so that the oil accumulated in the first supply groove 41 can be continuously and smoothly supplied to the large diameter portion 43 constituting the film damper portion. For this purpose, the second supply groove 42 has dimensions such as a gap and a length with respect to the inner peripheral surface 22a so that the flow resistance of the oil in the squeeze film damper portion is about 1/10. Is preferably set.

  Further, the oil that has passed through the large diameter portion 43 reaches the oil drain groove 44 on the outer side in the axial direction. Except for a part where the oil drain port 47 is formed as shown in FIG. 4, the oil drain groove 44 is sealed outward in the axial direction by the O-ring 33 as shown in FIG. Since it is continuous as an annular groove with respect to the circumferential direction, it is possible to appropriately generate a flow. It is preferable that the oil flow resistance from the oil drain groove 44 to the oil outlet 47 is also about 1/10 of the squeeze film damper portion. By doing so, it is possible to reduce the pressure difference in the circumferential direction, so that it is possible to obtain an appropriate vibration damping effect without making the damper characteristic different depending on the position in the circumferential direction.

  In this way, the oil supply side and the oil discharge side can be formed as continuous grooves in the circumferential direction with respect to the squeeze film damper portion, and the oil can be smoothly moved to the respective sides. Furthermore, when the oil moves to the oil supply side, the first oil supply groove 41 suppresses the pressure fluctuation in order to reduce the influence. Even when the oil moves to the oil discharge side, the oil discharge port 47 is opened, so that the pressure fluctuation can be kept small.

  In general, by adopting the above configuration, the oil is not blocked on the oil supply side and oil discharge side of the squeeze film damper section, and so-called infinite width theory is established as the theoretical boundary condition. By doing so, the attenuation coefficient is stabilized at a substantially constant value. Therefore, an almost constant damper characteristic can be obtained without being affected by the opening of the oil supply valve or the pulsation of the pump for oil supply, and the vibration damping effect can be obtained more stably.

  On the other hand, in the state where the oil is blocked by the squeeze film damper part, the so-called infinite boundary theory (infinite width theory) is established as a theoretical boundary condition. In addition, the pressure changes greatly with the disturbance on the upstream side, and the damping coefficient becomes unstable.

  Furthermore, as described above, the bearing case 4 is formed in a symmetric shape with the axial center position as a boundary, and supports the bearing 5 at the axial center position. Therefore, it is possible to prevent the rotating shaft 6 from tilting while supporting the bearing 5 in a well-balanced state, regardless of whether it is a static state or a rotating state, and the oil flow can also be applied substantially equally in the axial direction. It does not cause resistance by generating an excessive thrust force and does not cause uneven pressure distribution. Therefore, it is possible to further stabilize the attenuation coefficient.

  Further, as shown in FIG. 4, the oil that has passed through the large-diameter portion 43 passes through the oil discharge ports 47 to 47 and is discharged. At this time, since part of the oil discharge ports 47 to 47 is arranged vertically upward, the oil discharged through this is supplied to the rotating shaft 6 from directly above and supplied to the bearing 5. It has come to be. By doing so, the oil supplied to obtain the effect as the squeeze film damper acts at the same time as the lubricating oil of the bearing 5.

  By supplying oil from the outside to the bearing support structure B1 configured as described above, a desired damper effect can be obtained. Hereinafter, description will be added again along the flow of oil.

  First, oil is supplied from the oil supply port 24 as shown by the arrow in FIG. The oil is supplied into the first oil supply groove 41 of the bearing case 4 shown in FIG. And it supplies to the large diameter part 43 which is a squeeze film damper part via the 2nd supply groove | channel 42. FIG. The oil flows into the discharge groove 44 from the outside in the axial direction of the large diameter portion 43, and is discharged from the gap between the bearing case 4 and the lid member 2 through the discharge port 47.

  At this time, the first oil supply groove 41 functions as an oil reservoir and absorbs the disturbance on the upstream side, and is formed as an annular groove continuous in the circumferential direction, so that the pressure in the circumferential direction is made uniform. Eccentricity associated with refueling can be suppressed. In addition, the second supply groove 42 and the discharge groove 44 are also formed as annular grooves that are continuous in the circumferential direction, and the flow resistance is sufficiently smaller than that of the squeeze film damper portion. It is difficult to cause the accompanying pressure change, and more stable damper characteristics can be obtained. Furthermore, on the oil drain groove 44 side, since the continuous discharge ports 47 are provided in the circumferential direction so as to be evenly distributed, the pressure non-uniformity in the circumferential direction is further eliminated and stable. Damper characteristics can be obtained.

  Further, the oil discharged from the discharge port 47 located on the upper side is collected along the taper portion 47 in the axial direction, supplied to the bearing 5 and can also act as lubricating oil. .

  Returning to FIG. 2, of the oil discharged from the gap between the bearing case 4 and the lid member 3, the oil that has moved to the inner side in the axial direction (left side in the drawing) than the bearing 5 follows the gravity according to the lid member 2. And passes between the tip of the cylindrical portion 22 and the stator 12 and is collected downward. At this time, the oil touches the surface of the stator 12 and the coil end to cool them. Of the oil discharged from the gap between the bearing case 4 and the lid member 2, the oil that has moved to the axially outer side (right side in the drawing) from the bearing 5 passes through the through hole 27 provided in the small diameter portion 23. Passing further, moving downward through the gap between the annular plate 31 and the stepped portion 21b, and passing through the through hole 28, moving from a position that is axially inward of the bearing 5 as described above. The oil collected together with the collected oil and collected inside is discharged from the oil discharge port 25 while acting as cooling oil for the stator 12.

  In this way, an oil flow is always generated from the oil supply port 24 to the oil discharge port 25. Therefore, new oil is always supplied, the characteristics are more stable without causing deterioration, air does not stay inside, and it is possible to suppress a decrease in the damper effect due to air accumulation. It is possible.

  As described above, the bearing support structure B <b> 1 in the present embodiment includes the bearing 5 that rotatably supports the rotating shaft 6, the cylindrical bearing case 4 that supports the bearing 5 from the outer peripheral side, and the bearing case 4. In a bearing support structure B1 that includes a bearing housing (lid member) 2 disposed on the outer peripheral side and supplies oil between the outer peripheral surface 4a of the bearing case 4 and the bearing housing 2 to form a squeeze film damper portion. The bearing housing 2 includes an oil supply port 24, an oil supply path 26 communicating from the oil supply port 24 toward the bearing case 4, and an oil discharge port 25 for discharging the oil accumulated inside, The bearing case 4 is provided with O-rings 33, 33 in the vicinity of both ends in the axial direction, and is elastically supported by the inner surface 22a of the bearing housing 2 via the O-rings 33, 33. An annular oil supply groove 41 formed in the center in the axial direction and supplied with oil through the oil supply passage 26, and a large diameter formed between the oil supply groove 41 and the O-rings 33 and 33 and corresponding to the squeeze film damper portion. Portions 43, 43, annular oil drain grooves 44, 44 formed between the large diameter portions 43, 43 and the O-rings 33, 33, and the oil drain grooves 44, 44 on the inner peripheral surface. The oil outlets 47 to 47 open to the side are provided.

  Since it is configured in this manner, oil is supplied to the squeeze film damper portion through the oil supply groove 41, and oil can be discharged through the oil discharge grooves 44 and 44 and the oil discharge ports 47 to 47. , 33 does not block the oil, and the pressure change due to the opening of the oil supply valve is less likely to occur. Further, since the bubbles do not accumulate inside due to the flow of oil, the attenuation coefficient can be kept substantially constant. Furthermore, since the oil supply side and the oil discharge side are each formed as an annular groove with respect to the squeeze film damper part, the flow resistance at the entrance and exit of the squeeze film damper part becomes uniform over the entire circumference, and the damping coefficient is further increased. Can be stabilized, and eccentricity does not occur due to the hydraulic pressure generated with oil supply or drainage.

  Further, since the plurality of oil discharge ports 47 to 47 are provided in the circumferential direction, the flow path resistance on the oil discharge side can be made more uniform in the circumferential direction, and the damping coefficient can be increased. It is possible to further increase the effect of making it constant.

  Further, since at least one of the oil discharge ports 47 to 47 is arranged vertically above the axis of the rotary shaft 6, a part of the oil flowing out from the oil discharge ports 47 to 47 is transferred to the bearing 5. It can be applied, and it can be used as a lubricating oil for the bearing 5 to simplify the apparatus and reduce the manufacturing cost.

  Further, since tapered portions 48 and 48 whose inner diameter decreases toward the center in the axial direction are formed on the inner peripheral side in the vicinity of both end faces of the bearing case 4, the oil discharged from the oil discharge ports 47 to 47 is discharged. It becomes easy to be supplied to the inner bearing 5 along the inner surface of the bearing case 4, and can be used more effectively as the lubricating oil of the bearing 5.

Furthermore, since the bearing 5 is configured to be supported substantially at the center in the axial direction of the bearing case 4, it is possible to effectively obtain a damping characteristic while suppressing the inclination of the bearing 5. .
Second Embodiment

  Next, as a second embodiment, a case where a bearing support structure B2 is configured as shown in FIG. 6 will be described.

  The bearing support structure B2 in the second embodiment is only different in the shape of the bearing case 4 from the bearing support structure B1 in the first embodiment shown in FIGS. Therefore, the description of the entire configuration corresponding to FIGS. 1 and 2 is omitted, and the same portions as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

  Hereinafter, description will be made with reference to FIG. 6 while comparing with FIG. 4 in the first embodiment.

  The bearing case 104 in the second embodiment is formed in a cylindrical shape having substantially the same size as the bearing case 4 in the first embodiment, and the inner peripheral surface 104b and both end surfaces 104c, 104c are inner peripheral surfaces in the bearing case 4. 4b and both end surfaces 4c, 4c are the same shape, and only the outer peripheral surface 104a is different from the outer peripheral surface 4a of the bearing case 4.

  Similar to the bearing case 4, an annular first oil supply groove 41 is formed in the axial center of the outer peripheral surface 104 a. A large-diameter portion 143 corresponding to the squeeze film damper portion and an oil drain groove 144 are sequentially formed adjacent to the outside in the axial direction. Further, an O-ring groove 45 is formed in the vicinity of the end of the oil drain groove 144, and the oil drain groove 144 is divided between the end circumferential surface 46 with the O-ring groove 45 interposed therebetween. . Further, at both ends of the bearing case 104, oil drain ports 47 to 47 are provided at three positions in the circumferential direction at positions extending from the oil drain groove 144 to the end circumferential surface 46 as in the case of the first embodiment. Each is provided.

  In the bearing support structure B2 including the bearing case 104 formed in this way, the oil supplied to the first oil supply groove 41 through the oil supply path 26 is squeezed film damper via the first oil supply grooves 41, 41. To the large diameter portions 143 and 143 corresponding to the portions. Further, the oil that has passed through the large-diameter portion 43 reaches the oil drain grooves 144 and 144 on the outer side in the axial direction, and is discharged to the outside through the oil drain ports 47 to 47. In this way, it is possible to smoothly generate the oil flow and obtain a stable damping effect as in the case of the first embodiment.

  Here, the bearing case 104 used in the present embodiment does not have a portion corresponding to the second oil supply groove 42 in the bearing case 4 in the second embodiment, and the large-diameter portion 143 is closer to the axial central portion by that amount. Is formed. Further, the oil drain groove 144 is elongated in the axial direction by the amount that the large diameter portion 143 is disposed closer to the center.

  As described above, the second supply groove 42 formed in the bearing case 4 in the first embodiment continues the oil accumulated in the first supply groove 41 to the large-diameter portion 43 constituting the film damper portion. Thus, it can be supplied smoothly. That is, even when the second supply groove 42 is eliminated as in the second embodiment, there is no problem in the function as a damper as long as oil can be smoothly supplied from the first supply groove 41 to the film damper portion. On the other hand, compared to the first embodiment, the two large-diameter portions 143 and 143 are close to the center in the axial direction, so that it is possible to suppress the change in the damper characteristics due to the influence of the inclination of the bearing case 4, which is preferable. It is.

  Further, since the large diameter portions 143 and 143 are closer to the center, it is possible to shorten the overall length of the bearing case 104. However, if this is done, the positions of the O-ring grooves 45 near the both ends will be close to each other, and the bearing case 4 supported by the O-rings 33 33 will easily tilt. Therefore, in the present embodiment, the axial length of the bearing case 104 and the interval between the O-ring grooves 45 and 45 are also suppressed in the same manner as the bearing case 4 of the first embodiment. By doing so, it is possible to stabilize the performance.

  The oil drain groove 144 is longer in the axial direction than the bearing case 4, but the flow of oil from the oil drain groove 144 to the oil outlet 47 can be adjusted by adjusting the outer dimensions. If the road resistance is about 1/10 of the squeeze film damper portion, a damper effect that is the same as that of the first embodiment can be obtained.

As described above, even when configured as in the present embodiment, it is possible to produce the same excellent effects as in the case of the first embodiment.
<Third Embodiment>

  Next, a case where the bearing support structure B3 is configured using the bearing case 204 shown in FIG. 7 will be described as a third embodiment.

  The bearing support structure B3 according to the third embodiment is different from the bearing support structure B1 according to the first embodiment shown in FIGS. 1 to 5 and the bearing support structure B2 according to the second embodiment shown in FIG. Only the shape of 4 (104) is different. Therefore, description of the overall configuration corresponding to FIGS. 1 and 2 is omitted. The oil path from the oil supply port 24 to the oil discharge port is substantially the same except for the vicinity of the bearing case 4 (104). Further, the same portions as those in the first embodiment and the second embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 7, the bearing case 204 has a substantially cylindrical shape, and both end surfaces 204 c and 204 c are perpendicular to the axial direction. In addition, many steps are formed on the outer peripheral surface 204a as portions having different outer diameters, and are arranged symmetrically with the axial center position as a boundary. Tapered portions 204c and 204c having an inner diameter that decreases toward the center in the axial direction are formed near both ends of the inner peripheral surface 204b. On the outer peripheral surface 204a, two circular recesses 246, 246 are formed as a set and arranged at three locations in the circumferential direction.

  FIG. 8 is an enlarged view of the main part in FIG. 1, with the bearing case 204 attached in place of the bearing case 4 and cut by a vertical surface.

  Of the outer peripheral surface 204 a of the bearing case 204, the central portion in the axial direction is greatly cut close to the inner diameter and formed as an annular first oil supply groove 241. Further, a second oil supply groove 242 is formed adjacent to the outside in the axial direction, and a large-diameter portion 243 corresponding to the squeeze film damper portion and an oil discharge portion 244 are sequentially formed outside the second oil supply groove 242. Further, O-ring grooves 245 and 245 are formed at intermediate positions of the second oil supply grooves 242 and 242, respectively, and the second oil supply grooves 242 and 242 are respectively divided in the axial direction across the O-ring grooves 245 and 245. Has been. The bearing case 204 is elastically supported by the inner peripheral surface 22a of the cylindrical portion 22 of the lid member 2 through the O-rings 33 and 33 fitted in the O-ring grooves 245 and 245. .

  Further, the bearing case 204 is formed with the concave portion 246 that is not penetrated to the inner peripheral surface 204b at a position that spans both of the second oil supply grooves 242 divided into two around the O-ring groove 245. Has been. By doing so, the oil supplied from the first oil supply groove 241 side passes through the lower part of the O-ring 33 through the recess 246 without being closed by the O-ring 33, and moves to the opposite side. It can be supplied to the unit 243. Moreover, the recessed part 246 is equally distributed at three places of the circumferential direction, and does not produce a big pressure distribution in the circumferential direction.

  The large diameter portion 243 forms a slight gap with the inner peripheral surface 22a to form a squeeze film damper portion. The outer side in the axial direction from the large diameter portion 243 is formed as an oil drain portion 244 having an outer diameter substantially equal to that of the second oil supply groove 242 and is opened toward the end portion.

  The oil is supplied to the first oil supply groove 241 through the oil supply passage 26 and reaches the second oil supply grooves 242 and 242 as in the first embodiment and the second embodiment. In the first oil supply groove 241, a large gap is formed between the inner peripheral surface 22a and the oil supplied through the oil supply path 26 functions as an oil reservoir part, as in the first embodiment. Further, since the first supply groove 241 is continuous in the circumferential direction, even if the oil supply passage 26 is provided only on the upper side, it is easy to distribute the oil in the entire circumferential direction, and the pressure due to the oil supply is reduced. By dispersing, it is possible to suppress the eccentricity of the bearing case 204 with respect to the lid member 2.

  Further, the O-rings 33 and 33 are disposed in the second oil supply grooves 242 and 242, respectively, but the portions that contact the inner periphery of the O-rings 33 and 33 are opened downward by the recesses 246 to 246, Since it is in a communication state between the axially inner side and the axially outer side, it does not block, and oil is easily supplied to the large diameter portions 243 and 243 through these portions. Since the recesses 246 to 246 exist only at three positions in the circumferential direction, when cut at other positions, the recesses 246 to 246 are as shown in FIG. That is, at a position where the recesses 246 to 246 do not exist, the O-rings 33 and 33 located in the middle of the second oil supply grooves 242 and 242 are closed in the axial direction. However, since the second oil supply grooves 242 and 242 are formed as annular grooves that are continuous in the circumferential direction, it is possible to cause a smooth flow in the circumferential direction.

  Further, the channel resistance in the recesses 246 and 246 is set to be about 1/10 as compared with the squeeze film damper portion. Therefore, the oil inside the first oil supply groove 241 can be easily moved to the large diameter portions 243 and 243 and the pressure difference in the circumferential direction can be suppressed.

  Further, the oil that has passed through the large diameter portion 243 reaches the oil drain portion 244 on the outer side in the axial direction. The flow path resistance in the oil drainage part 244 is also configured to be sufficiently smaller than that of the large diameter part 243.

  In this way, the oil supply side and the oil discharge side are formed as continuous grooves or circumferential surfaces in the circumferential direction with respect to the squeeze film damper portion, and the oil is smoothly moved to the respective sides. Can do. Furthermore, when the oil moves to the oil supply side, the first oil supply groove 241 reduces pressure fluctuations to reduce the influence. Even when the oil moves to the oil drain side, the pressure fluctuation can be kept small because the oil drain portion 244 is opened.

  Therefore, also in this embodiment, as in the case of the first embodiment, the oil is not blocked on the oil supply side and the oil discharge side of the squeeze film damper portion, and the attenuation coefficient is stabilized at a substantially constant value. It becomes possible.

  The oil discharged from the discharge portion 244 is collected along the taper portion 248 in the axial direction and supplied to the bearing 5 so that it can also act as a lubricating oil. .

  As described above, the bearing support structure B3 in the present embodiment includes the bearing 5 that rotatably supports the rotating shaft 6, the cylindrical bearing case 204 that supports the bearing 5 from the outer peripheral side, and the bearing case 204. In a bearing support structure B3, which includes a bearing housing (lid member) 2 disposed on the outer peripheral side and supplies oil between the outer peripheral surface 204a of the bearing case 204 and the bearing housing 2 to form a squeeze film damper portion. The bearing housing 2 includes an oil supply port 24, an oil supply path 26 communicating from the oil supply port 24 toward the bearing case 204, and an oil discharge port 25 for discharging the oil accumulated inside, The bearing case 204 is formed with an annular oil supply groove 241 in which oil is supplied through the oil supply passage 26 at the center in the axial direction, and the oil supply groove 241 is sandwiched between the oil supply grooves 241. O-rings 33, 33 are arranged on the side, and are elastically supported on the inner surface of the bearing housing 2 through the O-rings 33, 33, and squeeze film dampers are axially outward from these O-rings 33, 33. Large-diameter portions 243 and 243 corresponding to the portions are formed, the axially outer sides of the large-diameter portions 243 and 243 are opened as oil drain portions 244 and 244, and further, on the inner periphery of the O-rings 33 and 33 At least a plurality of recesses 246 and 246 for communicating the inner side in the axial direction and the outer side in the axial direction with the O-rings 33 and 33 interposed therebetween are provided at the abutting portions.

  Even in this case, as in the case of the first embodiment, the squeeze film damper is supplied with oil through the recesses 246 and 246 from the oil supply groove 241 and through the oil discharge parts 244 and 244. By allowing the oil to drain, the oil is not blocked by the O-rings 33 and 33, and the pressure change due to the opening of the oil supply valve is less likely to occur. Further, since the bubbles do not accumulate inside due to the flow of oil, the attenuation coefficient can be kept substantially constant. Furthermore, since the oil supply side is formed as an annular groove 241 with respect to the squeeze film damper part and the oil discharge side is opened as oil discharge parts 244 and 244, the flow resistance at the entrance and exit of the squeeze film damper part is It becomes uniform over the entire circumference, and the damping coefficient can be further stabilized, and eccentricity does not occur due to the hydraulic pressure generated by oil supply or oil discharge.

  The specific configuration of each unit is not limited to the above-described embodiment.

  For example, in the above-described embodiment, the bearing case 4 (104, 204) is regulated in the radial direction by the inner peripheral surface 22a of the cylindrical portion 22 via the O-rings 33, 33, but is not positioned in the axial direction. Although the configuration is not restricted, it is also possible to provide a configuration in which an axial positioning member is appropriately provided to regulate the position. For example, in FIG. 1, another ring-shaped member is fixed from the inner side in the axial direction to the axial front end portion of the cylindrical portion 22, and the bearing case 4 (104, 204) is connected between the ring-shaped member and the small diameter portion 23. ) Position restriction may be performed. By doing so, it is possible not only to obtain a damping effect in the radial direction, but also to perform positioning with high accuracy while preventing the axial direction from coming off. Furthermore, a pin is inserted and engaged with the first oil supply groove 41 (141, 241) from the outer peripheral side of the cylindrical portion 22 toward the inner peripheral side at a position different from the phase of the oil supply hole 26c. Also in the configuration, it is possible to prevent the shaft from being detached and positioned in the axial direction as described above. In this case, when the tip of the pin comes into contact with the outer peripheral surface (4a, 104a, 204a) of the bearing case 4 (104, 204), the function as a damper is hindered. It is preferable to abut only on the side wall, and it is preferable to provide a plurality of such pins in the circumferential direction so as to suppress the inclination of the bearing case 4 (104, 204). . In addition, it can be said that care should be taken not to obstruct the oil flow inside the first oil supply groove 41 (141, 241) even when the pin is inserted.

  Further, in the first embodiment described above, the oil discharge port 47 has a shape in which a part below the O-ring 33 is cut out, but between the oil discharge groove 44 and the inner peripheral surface 4b of the bearing case 4 or As long as it can be communicated in the direction of the end face 4c, it may have a different shape as appropriate, and can be made into a narrow hole shape by processing using a drill or the like. Even in this case, it is necessary to set the oil flow resistance to about 1/10 of the squeeze film damper portion. For this purpose, the oil flow resistance may be appropriately adjusted depending on the diameter and the number of holes. It is also preferable to supply oil directly to the bearing 5 and to use it as lubricating oil by directing the opening direction of the hole toward the bearing 5.

  Other configurations can be variously modified without departing from the spirit of the present invention.

2 ... Lid member
DESCRIPTION OF SYMBOLS 4 ... Bearing case 5 ... Bearing 6 ... Rotating shaft 22 ... Cylindrical part 22a ... (Cylindrical part) Inner peripheral surface (squeeze film damper part)
24 ... Oil supply port 25 ... Oil discharge port 26 ... Oil supply path 33 ... O-ring 41 ... First oil supply groove 42 ... Second oil supply groove 43 ... Large diameter part (squeeze film damper part)
44 ... Oil drain groove 47 ... Oil drain port 48 ... Tapered part B1, B2, B3 ... Bearing support structure

Claims (6)

A bearing that rotatably supports the rotating shaft, a cylindrical bearing case that supports the bearing from the outer peripheral side, and a bearing housing that is disposed on the outer peripheral side of the bearing case, the outer peripheral surface of the bearing case and the bearing In the bearing support structure that configures the squeeze film damper part by supplying oil between the housing,
The bearing housing includes an oil supply port, an oil supply path communicating from the oil supply port toward the bearing case, and an oil discharge port for discharging oil accumulated inside;
The bearing case is provided with an O-ring in the vicinity of both axial ends, and is elastically supported on the inner surface of the bearing housing via the O-ring.
An annular oil supply groove formed in the center in the axial direction and supplied with oil through the oil supply path, a large diameter part formed between the oil supply groove and the O-ring and corresponding to the squeeze film damper part, An annular oil drain groove formed between the diameter portion and the O-ring, and each oil drain groove and the O-ring are opened to the inner peripheral surface side to be in contact with the inner periphery of the O-ring. A bearing support structure comprising an oil drain port that communicates between an axially inner side and an axially outer side across the O-ring .   The bearing support structure according to claim 1, wherein a plurality of the oil discharge ports are equally arranged in a circumferential direction.   The bearing support structure according to claim 2, wherein at least one of the oil discharge ports is arranged vertically above the axis of the rotating shaft. The bearing support structure according to any one of claims 1 to 3, wherein a tapered portion having an inner diameter that decreases toward an axial center is formed on an inner peripheral side in the vicinity of both end faces of the bearing case. A bearing that rotatably supports the rotating shaft, a cylindrical bearing case that supports the bearing from the outer peripheral side, and a bearing housing that is disposed on the outer peripheral side of the bearing case, the outer peripheral surface of the bearing case and the bearing In the bearing support structure that configures the squeeze film damper part by supplying oil between the housing,
The bearing housing includes an oil supply port, an oil supply path communicating from the oil supply port toward the bearing case, and an oil discharge port for discharging oil accumulated inside;
The bearing case is formed with an annular oil supply groove that is supplied with oil through the oil supply path at the center in the axial direction, O-rings are arranged on both sides of the oil supply groove, and the bearing housing While being elastically supported on the inner surface,
A large-diameter portion corresponding to the squeeze film damper portion is formed on the axially outer side from these O-rings, and the axially outer side of the large-diameter portion is opened as an oil drainage portion,
The bearing support structure is characterized in that at least a plurality of recesses for communicating the inner side in the axial direction and the outer side in the axial direction with the O-ring interposed therebetween are provided in a portion that contacts the inner periphery of the O-ring.   The bearing support structure according to claim 1, wherein the bearing is supported at substantially the center in the axial direction of the bearing case.

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