US20200040903A1 - Bearing structure and electric compressor - Google Patents
Bearing structure and electric compressor Download PDFInfo
- Publication number
- US20200040903A1 US20200040903A1 US16/492,375 US201816492375A US2020040903A1 US 20200040903 A1 US20200040903 A1 US 20200040903A1 US 201816492375 A US201816492375 A US 201816492375A US 2020040903 A1 US2020040903 A1 US 2020040903A1
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- United States
- Prior art keywords
- housing
- bearing
- ring
- rotation shaft
- peripheral surface
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/05—Shafts or bearings, or assemblies thereof, specially adapted for elastic fluid pumps
- F04D29/056—Bearings
- F04D29/059—Roller bearings
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/05—Shafts or bearings, or assemblies thereof, specially adapted for elastic fluid pumps
- F04D29/056—Bearings
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D25/00—Pumping installations or systems
- F04D25/02—Units comprising pumps and their driving means
- F04D25/06—Units comprising pumps and their driving means the pump being electrically driven
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
- F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
- F04D29/668—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps damping or preventing mechanical vibrations
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C27/00—Elastic or yielding bearings or bearing supports, for exclusively rotary movement
- F16C27/06—Elastic or yielding bearings or bearing supports, for exclusively rotary movement by means of parts of rubber or like materials
- F16C27/066—Ball or roller bearings
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C35/00—Rigid support of bearing units; Housings, e.g. caps, covers
- F16C35/04—Rigid support of bearing units; Housings, e.g. caps, covers in the case of ball or roller bearings
- F16C35/06—Mounting or dismounting of ball or roller bearings; Fixing them onto shaft or in housing
- F16C35/07—Fixing them on the shaft or housing with interposition of an element
- F16C35/077—Fixing them on the shaft or housing with interposition of an element between housing and outer race ring
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B39/00—Component parts, details, or accessories relating to, driven charging or scavenging pumps, not provided for in groups F02B33/00 - F02B37/00
Definitions
- the present disclosure relates to a bearing structure and an electric compressor.
- the bearing structure described in Patent Document 1 includes a bearing which supports a shaft of a fan motor.
- An O-ring is attached to a groove of an outer race of the bearing.
- the O-ring is in contact with a housing.
- a viscous fluid is filled between two O-rings.
- the bearing structure described in Patent Document 2 includes a bearing which supports a drive shaft.
- An O-ring is attached to a groove of an outer race of the bearing. Highly viscous oil is applied to an outer diameter surface of the outer race.
- Patent Document 1 Japanese Unexamined Patent Publication No. 2000-120669
- Patent Document 2 Japanese Unexamined Patent Publication No. 2007-211865
- a collapse margin of the O-ring is set so that an insertion force of the bearing at the time of incorporating the bearing attached with the O-ring into the housing decreases.
- the insertion force is defined by a frictional coefficient and a radial force generated by the collapse margin of the O-ring. That is, the insertion force deceases when the radial force is decreased. As a result, it is possible to improve workability when incorporating the bearing.
- the bearing structure described in Patent Document 2 since a frictional coefficient between the inner diameter surface of the housing and the outer diameter surface of the outer race decreases, it is possible to prevent creeping in which the outer race rolls along the inner diameter surface of the housing.
- the present disclosure will describe a bearing structure capable of reliably preventing a vibration from being transmitted to a housing through a bearing.
- An aspect of the present disclosure provides a bearing structure for supporting a rotation shaft of a rotation body accommodated in a housing with respect to the housing, including: the rotation shaft; a bearing that is attached in the housing to support the rotation shaft with respect to the housing and includes an inner race through which the rotation shaft is inserted and an outer race which includes an annular groove portion formed on an outer peripheral surface facing an inner wall surface of the housing; and an O-ring which is disposed on the groove portion of the outer race of the bearing, protrudes outward in a radial direction in relation to the outer peripheral surface, and comes into contact with the inner wall surface of the housing, in which a clearance is formed between the inner wall surface of the housing and the outer peripheral surface of the bearing and the clearance is larger than a radial displacement amount of the O-ring.
- FIG. 1 is a cross-sectional view illustrating an electric compressor according to an embodiment of the present disclosure.
- FIG. 2 is a partially enlarged cross-sectional view illustrating a bearing structure of FIG. 1 .
- FIG. 3A is a diagram showing a relationship between a collapse margin of an O-ring and a reaction force of the O-ring and
- FIG. 3B is a diagram showing a relationship between a clearance and the collapse margin of the O-ring.
- FIG. 4A is a diagram showing a relationship between a clearance and a reaction force of the O-ring and FIG. 4B is a diagram showing a relationship between the clearance and a spring constant of the O-ring.
- FIG. 5 is a diagram showing a relationship between a clearance and a load displacement amount.
- FIG. 6A is a diagram showing a range of a clearance allowing the O-ring to prevent the rotation of the outer race
- FIG. 6B is a diagram showing a range of a clearance capable of reliably preventing the transmission of the vibration.
- FIG. 7 is a diagram in which FIGS. 6A and 6B overlap each other and is a diagram showing a range of a clearance preventing both of the transmission of the vibration and the rotation of the outer race.
- An aspect of the present disclosure is a bearing structure for supporting a rotation shaft of a rotation body accommodated in a housing with respect to the housing, including: the rotation shaft; a bearing that is attached in the housing to support the rotation shaft with respect to the housing and includes an inner race through which the rotation shaft is inserted and an outer race which includes an annular groove portion formed on an outer peripheral surface facing an inner wall surface of the housing; and an O-ring which is disposed on the groove portion of the outer race of the bearing, protrudes outward in a radial direction in relation to the outer peripheral surface; and comes into contact with the inner wall surface of the housing, in which a clearance is formed between the inner wall surface of the housing and the outer peripheral surface of the bearing and the clearance is larger than a radial displacement amount of the O-ring.
- the rotation shaft of the rotation body is supported by the bearing structure.
- the O-ring provided between the outer race of the bearing and the inner wall surface of the housing exhibits the same function as that of a spring.
- the radial displacement amount is defined on the basis of the mass of the rotation body and the spring constant of the O-ring. Since the clearance formed between the inner wall surface of the housing and the outer peripheral surface of the bearing is larger than the radial displacement amount of the O-ring, the contact of the outer race of the bearing with respect to the housing is prevented. According to the bearing structure, it is possible to reliably prevent the transmission of the vibration to the housing through the bearing.
- the inner wall surface of the housing, the bearing, and the O-ring are configured such that a frictional force between the inner wall surface of the housing and the O-ring becomes larger than a rotational force of the rotation body. In this case, it is possible to suppress the rotation of the outer race of the bearing when the rotation body rotates.
- An electric compressor includes a housing, a compressor impeller which is attached to an end portion of the rotation shaft and constitutes a part of the rotation body; and the bearing structure according to claim 1 or 2 for supporting the rotation shaft with respect to the housing.
- the electric compressor it is possible to prevent the outer race of the bearing from contacting the housing when the rotation body including the compressor impeller rotates.
- it is possible to reliably prevent the transmission of the vibration to the housing through the bearing it is possible to suppress an occurrence of a vibration or noise in the electric compressor.
- a rotation shaft 12 is set as a reference in the case of the “axial direction” or the “radial direction”.
- An electric compressor 1 is applied to, for example, an internal combustion engine of a vehicle or a ship.
- the electric compressor 1 includes a compressor 7 .
- the electric compressor 1 rotates a compressor impeller 8 by an interaction of a rotor portion 13 and a stator portion 14 and compresses a fluid such as air to generate compressed air.
- the electric compressor 1 may be connected to, for example, a turbocharger (not illustrated) applied to an internal combustion engine of a vehicle or a ship. In that case, the electric compressor 1 sends a compressed fluid such as compressed air to a compressor of the turbocharger. By the combination of the electric compressor 1 and the turbocharger, the electric compressor 1 assists the startup of the turbocharger.
- a turbocharger not illustrated
- the electric compressor 1 sends a compressed fluid such as compressed air to a compressor of the turbocharger.
- the electric compressor 1 includes the rotation shaft 12 which is rotatably supported inside a housing 2 and the compressor impeller 8 which is fastened to a front end portion 12 a of the rotation shaft 12 .
- the housing 2 includes a motor housing 3 which accommodates the rotor portion 13 and the stator portion 14 and an end wall 3 a which closes an opening at a second end side (which is the right side of the drawing and is the side opposite to the compressor impeller 8 ) of the motor housing 3 .
- a compressor housing 6 which accommodates the compressor impeller 8 is provided at a first end side (which is the left side of the drawing and is the side of the compressor impeller 8 ) of the motor housing 3 .
- the compressor housing 6 includes a suction port 9 , a scroll portion 10 , and a discharge port 11 .
- an inverter 19 for supplying a current to the stator portion 14 may be provided at the outside of the end wall 3 a.
- the rotor portion 13 is attached to a center portion of the rotation shaft 12 in the axial direction and includes one or plural permanent magnets (not illustrated) attached to the rotation shaft 12 .
- the stator portion 14 is attached to an inner surface of the motor housing 3 to surround the rotor portion 13 and includes a coil portion (not illustrated).
- the rotation shaft 12 and the compressor impeller 8 rotate together about a rotation axis A by the interaction of the rotor portion 13 and the stator portion 14 .
- the compressor impeller 8 rotates, the compressor 7 sucks external air through the suction port 9 , compresses air through the scroll portion 10 , and sends compressed air from the discharge port 11 .
- the compressed air discharged from the discharge port 11 is supplied to the above-described internal combustion engine.
- the electric compressor 1 includes two bearings 20 which rotatably support the rotation shaft 12 with respect to the housing 2 .
- the bearing 20 is attached in the motor housing 3 of the housing 2 .
- the bearing 20 supports the rotation shaft 12 to the motor housing 3 at both ends thereof.
- the first bearing 20 is provided in a sleeve portion 17 formed at the side of the compressor impeller 8 of the motor housing 3 .
- the second bearing 20 is provided in a sleeve portion 18 protruding from the end wall 3 a in the axial direction (toward the compressor impeller 8 ).
- the compressor impeller 8 is attached to the rotation shaft 12 by a shaft end nut 16 provided in the front end portion 12 a of the rotation shaft 12 .
- the rotation shaft 12 , the compressor impeller 8 fixed to the rotation shaft 12 , the rotor portion 13 , and the bearing 20 are integrated with one another inside the housing 2 to constitute a rotation body C.
- Each of the rotation shaft 12 , the compressor impeller 8 , the rotor portion 13 , and the bearing 20 constitutes a part of the rotation body C.
- the rotation body C is biased to one side in the axial direction while being accommodated in the motor housing 3 .
- An annular wall surface 17 b (see FIG. 2 ) of the sleeve portion 17 faces and contacts an end surface of the bearing 20 in the axial direction, so that the rotation body C is positioned in the axial direction.
- the vibration caused by the rotation of the rotation body C is suppressed. More specifically, the transmission of the vibration of the rotation body C to the housing 2 is prevented, so that the vibration of the electric compressor 1 is suppressed.
- the electric compressor 1 has a bearing structure including the bearing 20 .
- the bearing structures provided at two positions of the rotation shaft 12 in the axial direction have the same configuration. Each bearing structure supports the rotation shaft 12 of the rotation body C to the motor housing 3 .
- first bearing 20 and the bearing structure provided at the first end side will be described.
- a description of the second bearing 20 and the bearing structure provided at the second end side will be omitted.
- the arrangement of the second bearing 20 with respect to the sleeve portion 18 may be the same as the arrangement of the first bearing 20 with respect to the sleeve portion 17 .
- the bearing 20 is, for example, a ball bearing. More specifically, the bearing 20 is, for example, a grease lubricating type radial bearing. The bearing 20 may be a deep groove bearing or an angular bearing.
- the bearing 20 includes an inner race 21 through which the rotation shaft 12 is inserted and an outer race 22 which is relatively rotatable with respect to the inner race 21 through a plurality of balls 23 .
- the inner race 21 is press-fitted to, for example, the rotation shaft 12 .
- An inner peripheral surface 21 a of the inner race 21 is in contact with an outer peripheral surface 12 b of the rotation shaft 12 .
- An end surface at the side of the compressor impeller 8 of the inner race 21 may be in contact with an end surface perpendicular to the rotation axis A of a boss portion 8 a of the compressor impeller 8 .
- the sleeve portion 17 of the motor housing 3 includes a cylindrical inner peripheral surface (inner wall surface) 17 a which faces inwardly in the radial direction.
- the sleeve portion 17 supports the outer race 22 .
- the outer race 22 includes an outer peripheral surface 22 a which faces the inner peripheral surface 17 a of the sleeve portion 17 and two annular groove portions 22 c which are formed in the outer peripheral surface 22 a.
- the diameter of the outer peripheral surface 22 a of the outer race 22 is smaller than that of the inner peripheral surface 17 a of the sleeve portion 17 .
- a cylindrical clearance B is formed between the inner peripheral surface 17 a of the sleeve portion 17 and the outer peripheral surface 22 a of the outer race 22 .
- the end surface at the side of the compressor impeller 8 of the outer race 22 may be in contact with the wall surface 17 b perpendicular to the rotation axis A in the annular portion disposed at the outer peripheral side of the boss portion 8 a of the compressor impeller 8 . Additionally, the shape of the clearance B can be changed in response to the displacement of the rotation body C during the operation of the electric compressor 1 .
- Two groove portions 22 c are formed to be separated from each other in the axial direction. Each groove portion 22 c is continuous to the outer peripheral surface 22 a and opens outwardly in the radial direction.
- An annular O-ring 30 is disposed in each groove portion 22 c.
- the O-ring 30 is directly fitted to the outer race 22 .
- the O-ring 30 is formed of an elastic material.
- the O-ring 30 is formed of, for example, rubber.
- the inner peripheral surface of the O-ring 30 fitted to the groove portion 22 c is in contact with the bottom surface of the groove portion 22 c. A part of the outer peripheral side of the O-ring 30 protrudes outwardly in the radial direction in relation to the outer peripheral surface 22 a.
- An annular outer peripheral end surface which is most distant from the rotation axis A in the O-ring 30 is in contact with the inner peripheral surface 17 a of the sleeve portion 17 .
- the O-ring 30 has, for example, a circular cross-section in a natural state (a state not receiving any external force) before the O-ring is disposed between the hearing 20 and the sleeve portion 17 .
- the O-ring 30 which is fitted between the groove portion 22 c of the bearing 20 and the inner peripheral surface 17 a of the sleeve portion 17 is compressed (collapsed).
- the compressed O-ring 30 has, for example, a non-circular cross-section.
- the size of the clearance B is set in consideration of the diameter (the wire diameter) of the cross-section of the O-ring 30 , the collapse margin of the O-ring 30 , and the spring characteristics of the collapsed O-ring 30 .
- the size of the clearance B is not limited to these components and may be set in consideration of, for example, the hardness of the O-ring 30 . Additionally, the term of the “collapse margin” is the same concept as the “collapse amount” or the “collapse rate”. The term of the “collapse” is the same concept as the “compression”.
- F indicates the reaction force of the O-ring 30
- x indicates the collapse margin of the O-ring 30
- a, b, and c indicate coefficients when the wire diameter of the O-ring 30 is 1 mm (here, the coefficient is different according to the material and/or hardness)
- D indicates the wire diameter of the O-ring 30
- d0 indicates the diameter of the O-ring 30
- k indicates a coefficient.
- the collapse margin x of the O-ring 30 is expressed by the following Equation (2) from the dimensional relationship shown in FIG. 2 .
- X indicates the diameter of the bottom surface of the groove portion 22 c and Y indicates the inner diameter of the sleeve portion 17 .
- the radial size ⁇ of the clearance B is also expressed by the following Equation (3) from the dimensional relationship shown in FIG. 2 .
- Z indicates the outer diameter of the outer race 22 (the diameter of the outer peripheral surface 22 a ).
- Equation (4) a relationship between the radial size ⁇ of the clearance B and the collapse margin x of the O-ring 30 is expressed by the following Equation (4).
- Equation (4) is expressed as shown in FIG. 3B .
- FIG. 2 illustrates the wire diameter D of the O-ring 30 in a compressed state in order to easily understand the structure with reference to the drawings, but this is not precisely accurate.
- the wire diameter D is a diameter of the wire portion of the O-ring 30 in a natural state.
- each of the dimensions X, Y, and Z is a diameter based on the rotation axis A.
- the collapse margin x of the O-ring 30 decreases when the radial size ⁇ of the clearance B increases.
- the spring force of the O-ring 30 decreases when the radial size ⁇ of the clearance B increases as shown in FIG. 4A on the basis of the relationship of FIG. 3A and the relationship of FIG. 3B .
- the frictional force Fr between the O-ring 30 and the inner peripheral surface 17 a of the sleeve portion 17 is the product of the frictional coefficient ⁇ of the O-ring 30 and the drag force of the spring force F of the O-ring 30 of the rotation shaft 12 .
- the frictional force Fr also decreases when the spring force F decreases.
- a value obtained by dividing the frictional torque T f in the rotation direction generated in the boundary portion between the outer race 22 and the inner race 21 of the bearing 20 in accordance with the rotation of the rotation shaft 12 by the radius R based on the rotation axis A of the outer peripheral surface 22 a of the outer race 22 is set as the rotational force Ft.
- the frictional torque T f can be changed in accordance with the viscosity v of the grease, the rolling contact friction of the rolling elements, and the like in addition to the rotation speed of the rotation shaft 12 .
- a condition that prevents the rotation of the outer race 22 (and the O-ring 30 ) is that the frictional force Fr is larger than the rotational force Ft. That is, the establishment of the following Equation (5) becomes a first condition.
- the inner peripheral surface 17 a of the sleeve portion 17 of the motor housing 3 , the bearing 20 , and the O-ring 30 are set such that the frictional force Fr between the inner peripheral surface 17 a and the O-ring 30 becomes larger than the rotational force Ft of the rotation body C.
- the rotation of the outer race 22 is prevented when the clearance is 1.0 or more.
- Equation (6) the following Equation (6) is established.
- the collapse margin x of the O-ring 30 decreases when the radial size ⁇ of the clearance B increases from the relationship (Equation (4)) of FIG. 3B .
- the spring constant K decreases when the collapse margin x of the O-ring 30 decreases according to Equation (6).
- the spring constant K decreases when the clearance B (size ⁇ ) increases.
- K indicates the spring constant of the O-ring 30
- Mg indicates a load applied to the bearing 20 (rotor mass load+eccentric load+vibration load received by the bearing 20 )
- g indicates gravity acceleration.
- Equation (8) is established.
- a condition that prevents the outer race 22 from contacting the sleeve portion 17 is that the radial size ⁇ of the clearance B is larger than the displacement amount r.
- the range of the clearance needs to be in the range indicated by the arrow of the drawing.
- the range of the clearance needs to be in the range indicated by the arrow of the drawing.
- the clearance B of the range indicated by the arrow of FIG. 7 is set in order to realize both of the first condition, that is, the condition of stopping the rotation of the outer race 22 and the second condition, that is, the condition of suppressing the vibration.
- the size ⁇ of the clearance B is set in the range of realizing both of the rotation stop and the vibration suppression in consideration of the rotation load and the load applied to the O-ring 30 in this way. The point of realizing both of these is the characteristic of the embodiment.
- the rotation shaft 12 of the rotation body C is supported by the bearing structure.
- the O-ring 30 provided between the outer race 22 of the bearing 20 and the inner peripheral surface 17 a of the motor housing 3 has the same function as that of the spring with respect to the radial load.
- the radial displacement amount is defined on the basis of the mass, the eccentric load, and the vibration of the rotation body C and the spring constant of the O-ring 30 .
- the clearance B formed between the inner peripheral surface 17 a of the housing 2 and the outer peripheral surface 22 a of the bearing 20 is larger than the radial displacement amount of the O-ring 30 , it is possible to prevent the outer race 22 of the bearing 20 from contacting the sleeve portion 17 .
- the bearing structure it is possible to reliably prevent the transmission of the vibration to the housing 2 through the hearing 20 . No impact load is applied to the sleeve portion 17 and a damped load is applied thereto.
- the electric compressor 1 it is possible to prevent the outer race 22 of the bearing 20 from contacting the housing 2 when the rotation body C including the compressor impeller 8 rotates. Thus, since it is possible to reliably prevent the transmission of the vibration to the housing 2 through the bearing 20 , it is possible to suppress an occurrence of a vibration or noise in the electric compressor 1 .
- two bearings 20 may be provided and one of them may not be provided with the bearing structure.
- One of two bearings 20 may be omitted.
- the bearing structure When the bearing structure is provided only at one position, the bearing structure may be provided only at the first end side of the rotation shaft 12 or the second end side of the rotation shaft 12 .
- a relationship between the frictional force between the inner peripheral surface 17 a and the O-ring 30 and the rotational force of the rotation body C may not satisfy a relationship shown in the above-described embodiment. That is, the bearing structure which satisfies the second condition but does not satisfy the first condition may be employed. Also in this case, it is possible to obtain an effect that the transmission of the vibration to the housing 2 is reliably prevented.
- the cross-sectional shape of the O-ring 30 is not limited to the circular shape.
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Support Of The Bearing (AREA)
- Supercharger (AREA)
- Mounting Of Bearings Or Others (AREA)
- Rolling Contact Bearings (AREA)
Abstract
Description
- The present disclosure relates to a bearing structure and an electric compressor.
- Conventionally, a bearing structure described in
Patent Documents 1 and 2 is known. The bearing structure described in Patent Document 1 includes a bearing which supports a shaft of a fan motor. An O-ring is attached to a groove of an outer race of the bearing. The O-ring is in contact with a housing. A viscous fluid is filled between two O-rings. The bearing structure described inPatent Document 2 includes a bearing which supports a drive shaft. An O-ring is attached to a groove of an outer race of the bearing. Highly viscous oil is applied to an outer diameter surface of the outer race. - Patent Document 1: Japanese Unexamined Patent Publication No. 2000-120669
- Patent Document 2: Japanese Unexamined Patent Publication No. 2007-211865
- In the bearing structure described in Patent Document 1, a collapse margin of the O-ring is set so that an insertion force of the bearing at the time of incorporating the bearing attached with the O-ring into the housing decreases. The insertion force is defined by a frictional coefficient and a radial force generated by the collapse margin of the O-ring. That is, the insertion force deceases when the radial force is decreased. As a result, it is possible to improve workability when incorporating the bearing. In the bearing structure described in
Patent Document 2, since a frictional coefficient between the inner diameter surface of the housing and the outer diameter surface of the outer race decreases, it is possible to prevent creeping in which the outer race rolls along the inner diameter surface of the housing. - In the above-described related art, there is concern that the transmission of the vibration of the rotation body to the housing through the bearing cannot be reliably prevented. For example, when the outer race of the bearing comes into contact with the housing due to a vibration, the vibration will be transmitted much more. The present disclosure will describe a bearing structure capable of reliably preventing a vibration from being transmitted to a housing through a bearing.
- An aspect of the present disclosure provides a bearing structure for supporting a rotation shaft of a rotation body accommodated in a housing with respect to the housing, including: the rotation shaft; a bearing that is attached in the housing to support the rotation shaft with respect to the housing and includes an inner race through which the rotation shaft is inserted and an outer race which includes an annular groove portion formed on an outer peripheral surface facing an inner wall surface of the housing; and an O-ring which is disposed on the groove portion of the outer race of the bearing, protrudes outward in a radial direction in relation to the outer peripheral surface, and comes into contact with the inner wall surface of the housing, in which a clearance is formed between the inner wall surface of the housing and the outer peripheral surface of the bearing and the clearance is larger than a radial displacement amount of the O-ring.
- According to an aspect of the present disclosure, it is possible to reliably prevent a vibration from being transmitted to a housing through a bearing.
-
FIG. 1 is a cross-sectional view illustrating an electric compressor according to an embodiment of the present disclosure. -
FIG. 2 is a partially enlarged cross-sectional view illustrating a bearing structure ofFIG. 1 . -
FIG. 3A is a diagram showing a relationship between a collapse margin of an O-ring and a reaction force of the O-ring andFIG. 3B is a diagram showing a relationship between a clearance and the collapse margin of the O-ring. -
FIG. 4A is a diagram showing a relationship between a clearance and a reaction force of the O-ring andFIG. 4B is a diagram showing a relationship between the clearance and a spring constant of the O-ring. -
FIG. 5 is a diagram showing a relationship between a clearance and a load displacement amount. -
FIG. 6A is a diagram showing a range of a clearance allowing the O-ring to prevent the rotation of the outer race andFIG. 6B is a diagram showing a range of a clearance capable of reliably preventing the transmission of the vibration. -
FIG. 7 is a diagram in whichFIGS. 6A and 6B overlap each other and is a diagram showing a range of a clearance preventing both of the transmission of the vibration and the rotation of the outer race. - An aspect of the present disclosure is a bearing structure for supporting a rotation shaft of a rotation body accommodated in a housing with respect to the housing, including: the rotation shaft; a bearing that is attached in the housing to support the rotation shaft with respect to the housing and includes an inner race through which the rotation shaft is inserted and an outer race which includes an annular groove portion formed on an outer peripheral surface facing an inner wall surface of the housing; and an O-ring which is disposed on the groove portion of the outer race of the bearing, protrudes outward in a radial direction in relation to the outer peripheral surface; and comes into contact with the inner wall surface of the housing, in which a clearance is formed between the inner wall surface of the housing and the outer peripheral surface of the bearing and the clearance is larger than a radial displacement amount of the O-ring.
- According to the bearing structure, the rotation shaft of the rotation body is supported by the bearing structure. The O-ring provided between the outer race of the bearing and the inner wall surface of the housing exhibits the same function as that of a spring. When the rotation body rotates, the radial displacement amount is defined on the basis of the mass of the rotation body and the spring constant of the O-ring. Since the clearance formed between the inner wall surface of the housing and the outer peripheral surface of the bearing is larger than the radial displacement amount of the O-ring, the contact of the outer race of the bearing with respect to the housing is prevented. According to the bearing structure, it is possible to reliably prevent the transmission of the vibration to the housing through the bearing.
- In some aspects, the inner wall surface of the housing, the bearing, and the O-ring are configured such that a frictional force between the inner wall surface of the housing and the O-ring becomes larger than a rotational force of the rotation body. In this case, it is possible to suppress the rotation of the outer race of the bearing when the rotation body rotates.
- An electric compressor according to another aspect of the present disclosure includes a housing, a compressor impeller which is attached to an end portion of the rotation shaft and constitutes a part of the rotation body; and the bearing structure according to
claim 1 or 2 for supporting the rotation shaft with respect to the housing. According to the electric compressor, it is possible to prevent the outer race of the bearing from contacting the housing when the rotation body including the compressor impeller rotates. Thus, since it is possible to reliably prevent the transmission of the vibration to the housing through the bearing, it is possible to suppress an occurrence of a vibration or noise in the electric compressor. - Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Additionally, in the description of the drawings, the same reference numerals will be given to the same components and a repetitive description thereof will be omitted. In the description below, a
rotation shaft 12 is set as a reference in the case of the “axial direction” or the “radial direction”. - An electric compressor according to an embodiment will be described with reference to
FIG. 1 . An electric compressor 1 is applied to, for example, an internal combustion engine of a vehicle or a ship. The electric compressor 1 includes acompressor 7. The electric compressor 1 rotates acompressor impeller 8 by an interaction of arotor portion 13 and astator portion 14 and compresses a fluid such as air to generate compressed air. - The electric compressor 1 may be connected to, for example, a turbocharger (not illustrated) applied to an internal combustion engine of a vehicle or a ship. In that case, the electric compressor 1 sends a compressed fluid such as compressed air to a compressor of the turbocharger. By the combination of the electric compressor 1 and the turbocharger, the electric compressor 1 assists the startup of the turbocharger.
- The electric compressor 1 includes the
rotation shaft 12 which is rotatably supported inside ahousing 2 and thecompressor impeller 8 which is fastened to afront end portion 12 a of therotation shaft 12. Thehousing 2 includes amotor housing 3 which accommodates therotor portion 13 and thestator portion 14 and anend wall 3 a which closes an opening at a second end side (which is the right side of the drawing and is the side opposite to the compressor impeller 8) of themotor housing 3. Acompressor housing 6 which accommodates thecompressor impeller 8 is provided at a first end side (which is the left side of the drawing and is the side of the compressor impeller 8) of themotor housing 3. Thecompressor housing 6 includes a suction port 9, ascroll portion 10, and adischarge port 11. For example, aninverter 19 for supplying a current to thestator portion 14 may be provided at the outside of theend wall 3 a. - The
rotor portion 13 is attached to a center portion of therotation shaft 12 in the axial direction and includes one or plural permanent magnets (not illustrated) attached to therotation shaft 12. Thestator portion 14 is attached to an inner surface of themotor housing 3 to surround therotor portion 13 and includes a coil portion (not illustrated). When an AC current flows to the coil portion of thestator portion 14, therotation shaft 12 and thecompressor impeller 8 rotate together about a rotation axis A by the interaction of therotor portion 13 and thestator portion 14. When thecompressor impeller 8 rotates, thecompressor 7 sucks external air through the suction port 9, compresses air through thescroll portion 10, and sends compressed air from thedischarge port 11. The compressed air discharged from thedischarge port 11 is supplied to the above-described internal combustion engine. - The electric compressor 1 includes two
bearings 20 which rotatably support therotation shaft 12 with respect to thehousing 2. Thebearing 20 is attached in themotor housing 3 of thehousing 2. Thebearing 20 supports therotation shaft 12 to themotor housing 3 at both ends thereof. Thefirst bearing 20 is provided in asleeve portion 17 formed at the side of thecompressor impeller 8 of themotor housing 3. Thesecond bearing 20 is provided in asleeve portion 18 protruding from theend wall 3 a in the axial direction (toward the compressor impeller 8). For example, thecompressor impeller 8 is attached to therotation shaft 12 by ashaft end nut 16 provided in thefront end portion 12 a of therotation shaft 12. - The
rotation shaft 12, thecompressor impeller 8 fixed to therotation shaft 12, therotor portion 13, and thebearing 20 are integrated with one another inside thehousing 2 to constitute a rotation body C. Each of therotation shaft 12, thecompressor impeller 8, therotor portion 13, and thebearing 20 constitutes a part of the rotation body C. The rotation body C is biased to one side in the axial direction while being accommodated in themotor housing 3. An annular wall surface 17 b (seeFIG. 2 ) of thesleeve portion 17 faces and contacts an end surface of the bearing 20 in the axial direction, so that the rotation body C is positioned in the axial direction. - In the electric compressor 1 of the embodiment, the vibration caused by the rotation of the rotation body C is suppressed. More specifically, the transmission of the vibration of the rotation body C to the
housing 2 is prevented, so that the vibration of the electric compressor 1 is suppressed. In order to prevent the transmission of the vibration, the electric compressor 1 has a bearing structure including thebearing 20. The bearing structures provided at two positions of therotation shaft 12 in the axial direction have the same configuration. Each bearing structure supports therotation shaft 12 of the rotation body C to themotor housing 3. - Hereinafter, the
first bearing 20 and the bearing structure provided at the first end side will be described. A description of thesecond bearing 20 and the bearing structure provided at the second end side will be omitted. The arrangement of thesecond bearing 20 with respect to thesleeve portion 18 may be the same as the arrangement of thefirst bearing 20 with respect to thesleeve portion 17. - The
bearing 20 is, for example, a ball bearing. More specifically, thebearing 20 is, for example, a grease lubricating type radial bearing. Thebearing 20 may be a deep groove bearing or an angular bearing. - As illustrated in
FIG. 2 , thebearing 20 includes aninner race 21 through which therotation shaft 12 is inserted and anouter race 22 which is relatively rotatable with respect to theinner race 21 through a plurality ofballs 23. Theinner race 21 is press-fitted to, for example, therotation shaft 12. An innerperipheral surface 21 a of theinner race 21 is in contact with an outerperipheral surface 12 b of therotation shaft 12. An end surface at the side of thecompressor impeller 8 of theinner race 21 may be in contact with an end surface perpendicular to the rotation axis A of aboss portion 8 a of thecompressor impeller 8. - The
sleeve portion 17 of themotor housing 3 includes a cylindrical inner peripheral surface (inner wall surface) 17 a which faces inwardly in the radial direction. Thesleeve portion 17 supports theouter race 22. Theouter race 22 includes an outer peripheral surface 22 a which faces the innerperipheral surface 17 a of thesleeve portion 17 and twoannular groove portions 22 c which are formed in the outer peripheral surface 22 a. The diameter of the outer peripheral surface 22 a of theouter race 22 is smaller than that of the innerperipheral surface 17 a of thesleeve portion 17. For example, a cylindrical clearance B is formed between the innerperipheral surface 17 a of thesleeve portion 17 and the outer peripheral surface 22 a of theouter race 22. The end surface at the side of thecompressor impeller 8 of theouter race 22 may be in contact with the wall surface 17 b perpendicular to the rotation axis A in the annular portion disposed at the outer peripheral side of theboss portion 8 a of thecompressor impeller 8. Additionally, the shape of the clearance B can be changed in response to the displacement of the rotation body C during the operation of the electric compressor 1. - Two
groove portions 22 c are formed to be separated from each other in the axial direction. Eachgroove portion 22 c is continuous to the outer peripheral surface 22 a and opens outwardly in the radial direction. An annular O-ring 30 is disposed in eachgroove portion 22 c. The O-ring 30 is directly fitted to theouter race 22. The O-ring 30 is formed of an elastic material. The O-ring 30 is formed of, for example, rubber. The inner peripheral surface of the O-ring 30 fitted to thegroove portion 22 c is in contact with the bottom surface of thegroove portion 22 c. A part of the outer peripheral side of the O-ring 30 protrudes outwardly in the radial direction in relation to the outer peripheral surface 22 a. An annular outer peripheral end surface which is most distant from the rotation axis A in the O-ring 30 is in contact with the innerperipheral surface 17 a of thesleeve portion 17. - The O-
ring 30 has, for example, a circular cross-section in a natural state (a state not receiving any external force) before the O-ring is disposed between thehearing 20 and thesleeve portion 17. The O-ring 30 which is fitted between thegroove portion 22 c of thebearing 20 and the innerperipheral surface 17 a of thesleeve portion 17 is compressed (collapsed). The compressed O-ring 30 has, for example, a non-circular cross-section. The size of the clearance B is set in consideration of the diameter (the wire diameter) of the cross-section of the O-ring 30, the collapse margin of the O-ring 30, and the spring characteristics of the collapsed O-ring 30. The size of the clearance B is not limited to these components and may be set in consideration of, for example, the hardness of the O-ring 30. Additionally, the term of the “collapse margin” is the same concept as the “collapse amount” or the “collapse rate”. The term of the “collapse” is the same concept as the “compression”. - Referring to
FIGS. 3 to 7 , a concept of the size of the clearance B will be described. First, when the O-ring 30 has three kinds of wire diameters as shown inFIG. 3A , a reaction force becomes different in accordance with the wire diameter, the inner diameter, and the hardness even in the same collapse margin. The inclination of the tangent line L of each curve shown inFIG. 3A indicates the spring constant of the O-ring 30. - This relationship is expressed by the following Equation (1).
-
[Equation 1] -
F=λ*κ/D*d0*(ax 2 +bx+c) (1) - Here, F indicates the reaction force of the O-
ring 30, x indicates the collapse margin of the O-ring 30, a, b, and c indicate coefficients when the wire diameter of the O-ring 30 is 1 mm (here, the coefficient is different according to the material and/or hardness), D indicates the wire diameter of the O-ring 30, d0 indicates the diameter of the O-ring 30, and k indicates a coefficient. - Here, the collapse margin x of the O-
ring 30 is expressed by the following Equation (2) from the dimensional relationship shown inFIG. 2 . -
- Here, X indicates the diameter of the bottom surface of the
groove portion 22 c and Y indicates the inner diameter of thesleeve portion 17. - The radial size δ of the clearance B is also expressed by the following Equation (3) from the dimensional relationship shown in
FIG. 2 . -
- Here, Z indicates the outer diameter of the outer race 22 (the diameter of the outer peripheral surface 22 a).
- From Equations (2) and (3), a relationship between the radial size δ of the clearance B and the collapse margin x of the O-
ring 30 is expressed by the following Equation (4). -
[Equation 4] -
x=D−(Y−X)/2=D−(2*δ+Z−X)/2 (4) - Here, when the diameter X of the seat surface of the
groove portion 22 c, the wire diameter D of the O-ring 30, and the outer diameter Z of theouter race 22 are given values, Equation (4) is expressed as shown inFIG. 3B . Additionally,FIG. 2 illustrates the wire diameter D of the O-ring 30 in a compressed state in order to easily understand the structure with reference to the drawings, but this is not precisely accurate. The wire diameter D is a diameter of the wire portion of the O-ring 30 in a natural state. Further, each of the dimensions X, Y, and Z is a diameter based on the rotation axis A. - As shown in
FIG. 3B , the collapse margin x of the O-ring 30 decreases when the radial size δ of the clearance B increases. Further, the spring force of the O-ring 30 decreases when the radial size δ of the clearance B increases as shown inFIG. 4A on the basis of the relationship ofFIG. 3A and the relationship ofFIG. 3B . Furthermore, the frictional force Fr between the O-ring 30 and the innerperipheral surface 17 a of thesleeve portion 17 is the product of the frictional coefficient μ of the O-ring 30 and the drag force of the spring force F of the O-ring 30 of therotation shaft 12. Thus, the frictional force Fr also decreases when the spring force F decreases. - Meanwhile, a value obtained by dividing the frictional torque Tf in the rotation direction generated in the boundary portion between the
outer race 22 and theinner race 21 of the bearing 20 in accordance with the rotation of therotation shaft 12 by the radius R based on the rotation axis A of the outer peripheral surface 22 a of theouter race 22 is set as the rotational force Ft. The frictional torque Tf can be changed in accordance with the viscosity v of the grease, the rolling contact friction of the rolling elements, and the like in addition to the rotation speed of therotation shaft 12. - Here, a condition that prevents the rotation of the outer race 22 (and the O-ring 30) is that the frictional force Fr is larger than the rotational force Ft. That is, the establishment of the following Equation (5) becomes a first condition.
-
[Equation 5] -
Fr/Ft>1 (5) - The inner
peripheral surface 17 a of thesleeve portion 17 of themotor housing 3, thebearing 20, and the O-ring 30 are set such that the frictional force Fr between the innerperipheral surface 17 a and the O-ring 30 becomes larger than the rotational force Ft of the rotation body C. InFIG. 6A , the rotation of theouter race 22 is prevented when the clearance is 1.0 or more. - Meanwhile, since the spring constant K is the inclination of Equation (1) (that is, the differentiation of Equation (1)), the following Equation (6) is established.
-
[Equation 6] -
K=π*κ/D*d0*(2ax+b) (6) - Here, the collapse margin x of the O-
ring 30 decreases when the radial size δ of the clearance B increases from the relationship (Equation (4)) ofFIG. 3B . Further, the spring constant K decreases when the collapse margin x of the O-ring 30 decreases according to Equation (6). Thus, as shown inFIG. 4B , the spring constant K decreases when the clearance B (size δ) increases. - The displacement amount r is expressed by the following Equation (7) from the relationship of M*g*r=½*K*r2.
-
- Here, K indicates the spring constant of the O-
ring 30, Mg indicates a load applied to the bearing 20 (rotor mass load+eccentric load+vibration load received by the bearing 20), and g indicates gravity acceleration. - By applying Equations (2) and (6) to Equation (7), the following Equation (8) is established.
-
- A condition that prevents the
outer race 22 from contacting thesleeve portion 17 is that the radial size δ of the clearance B is larger than the displacement amount r. Thus, the establishment of the following Equation (9) from Equations (3) and (8) becomes a second condition. -
- The following equation needs to be established according to
- Equation (9).
-
- This corresponds to a range indicated by the arrow in
FIG. 6B . - As shown in
FIG. 4A , when the clearance B increases even in the case of the same load, the spring force decreases and hence the load displacement amount increases. As shown inFIG. 5 , in a case in which the displacement amount r (the load displacement amount) becomes larger than the size δ of the clearance B, the outer peripheral surface 22 a of theouter race 22 of thebearing 20 comes into contact with the innerperipheral surface 17 a of thesleeve portion 17 when the load displacement occurs. This may cause a vibration or noise. - Here, when the relationship (the second condition) shown in Equation (10) is established, the outer peripheral surface 22 a of the
outer race 22 does not come into contact with the innerperipheral surface 17 a of thesleeve portion 17. - Then, as shown in
FIG. 6A , in order to cause the O-ring 30 to stop the rotation of theouter race 22 from the first condition, the range of the clearance needs to be in the range indicated by the arrow of the drawing. Further, as shown in.FIG. 6B , in order to effectively suppress the vibration from the second condition, the range of the clearance needs to be in the range indicated by the arrow of the drawing. - From
FIGS. 6A and 6B , the clearance B of the range indicated by the arrow ofFIG. 7 is set in order to realize both of the first condition, that is, the condition of stopping the rotation of theouter race 22 and the second condition, that is, the condition of suppressing the vibration. In the embodiment, the size δ of the clearance B is set in the range of realizing both of the rotation stop and the vibration suppression in consideration of the rotation load and the load applied to the O-ring 30 in this way. The point of realizing both of these is the characteristic of the embodiment. - According to the embodiment, the
rotation shaft 12 of the rotation body C is supported by the bearing structure. The O-ring 30 provided between theouter race 22 of thebearing 20 and the innerperipheral surface 17 a of themotor housing 3 has the same function as that of the spring with respect to the radial load. When the rotation body C rotates, the radial displacement amount is defined on the basis of the mass, the eccentric load, and the vibration of the rotation body C and the spring constant of the O-ring 30. Since the clearance B formed between the innerperipheral surface 17 a of thehousing 2 and the outer peripheral surface 22 a of thebearing 20 is larger than the radial displacement amount of the O-ring 30, it is possible to prevent theouter race 22 of the bearing 20 from contacting thesleeve portion 17. According to the bearing structure, it is possible to reliably prevent the transmission of the vibration to thehousing 2 through thehearing 20. No impact load is applied to thesleeve portion 17 and a damped load is applied thereto. - In the above-described patent document, there is a document in which the spring force and the rotational friction force of the O-ring are considered. However, regarding the vibration suppression, there is no disclosure on the point of setting the collapse margin of the O-ring by focusing on the relationship between the load displacement amount and the clearance. In the embodiment, since the collision margin of the O-
ring 30 is set by focusing on these two points, there is an advantageous effect of compatibility between the vibration reduction and the rotation stop function. - Since the frictional force between the inner
peripheral surface 17 a of thehousing 2 and the O-ring 30 is larger than the rotational force of the rotation body C, it is possible to suppress the rotation of theouter race 22 of thebearing 20 when the rotation body C rotates. Particularly, in the electric compressor 1 of which the rotation speed can be abruptly increased, it is important to stop the rotation of theouter race 22. - According to the electric compressor 1, it is possible to prevent the
outer race 22 of the bearing 20 from contacting thehousing 2 when the rotation body C including thecompressor impeller 8 rotates. Thus, since it is possible to reliably prevent the transmission of the vibration to thehousing 2 through thebearing 20, it is possible to suppress an occurrence of a vibration or noise in the electric compressor 1. - Although the embodiment of the present disclosure has been described above, the invention is not limited to the above-described embodiment. For example, two
bearings 20 may be provided and one of them may not be provided with the bearing structure. One of twobearings 20 may be omitted. When the bearing structure is provided only at one position, the bearing structure may be provided only at the first end side of therotation shaft 12 or the second end side of therotation shaft 12. - A relationship between the frictional force between the inner
peripheral surface 17 a and the O-ring 30 and the rotational force of the rotation body C may not satisfy a relationship shown in the above-described embodiment. That is, the bearing structure which satisfies the second condition but does not satisfy the first condition may be employed. Also in this case, it is possible to obtain an effect that the transmission of the vibration to thehousing 2 is reliably prevented. - The cross-sectional shape of the O-
ring 30 is not limited to the circular shape. - According to some aspects of the present disclosure, it is possible to reliably prevent the transmission of the vibration to the housing through the bearing.
- 1: electric compressor, 2: housing, 3: motor housing, 6: compressor housing, 7: compressor, 8: compressor impeller, 12: rotation shaft, 13: rotor portion, 14: stator portion, 17 a: inner peripheral surface (inner wall surface), 20: bearing, 21: inner race, 21 a: inner peripheral surface, 22: outer race, 22 a: outer peripheral surface, 22 c: groove portion, 23: ball, 30: O-ring, A: rotation axis, B: clearance, C: rotation body.
Claims (5)
Applications Claiming Priority (3)
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JP2017071204 | 2017-03-31 | ||
JP2017-071204 | 2017-03-31 | ||
PCT/JP2018/012150 WO2018181186A1 (en) | 2017-03-31 | 2018-03-26 | Bearing structure and electric compressor |
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US20200040903A1 true US20200040903A1 (en) | 2020-02-06 |
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ID=63676107
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US16/492,375 Abandoned US20200040903A1 (en) | 2017-03-31 | 2018-03-26 | Bearing structure and electric compressor |
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US (1) | US20200040903A1 (en) |
JP (1) | JP6725064B2 (en) |
CN (1) | CN110073120A (en) |
DE (1) | DE112018001791T5 (en) |
WO (1) | WO2018181186A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11300130B2 (en) * | 2017-06-20 | 2022-04-12 | Dyson Technology Limited | Electric machine |
US20220145932A1 (en) * | 2019-03-15 | 2022-05-12 | Ntn Corporation | Rolling bearing |
US11976665B2 (en) | 2020-02-20 | 2024-05-07 | Mitsubishi Heavy Industries Engine & Turbocharger Ltd. | Compressor |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
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DE112019002201T5 (en) | 2018-04-27 | 2021-01-07 | Ihi Corporation | Bearings and turbochargers |
DE102020210331A1 (en) | 2019-12-11 | 2021-06-17 | Efficient Energy Gmbh | Bearing holder for receiving a bearing |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2545028B2 (en) * | 1993-02-12 | 1996-10-16 | 川崎重工業株式会社 | Bearing device |
JPH0989045A (en) * | 1995-09-27 | 1997-03-31 | Nec Eng Ltd | Shock absorbing support structure |
JP2000120669A (en) | 1998-10-07 | 2000-04-25 | Nsk Ltd | Rolling bearing |
JP4340145B2 (en) * | 2003-12-26 | 2009-10-07 | 株式会社日立製作所 | Anti-vibration tool holder |
JP2005321006A (en) * | 2004-05-07 | 2005-11-17 | Nsk Ltd | Rolling bearing device |
JP2006161876A (en) * | 2004-12-03 | 2006-06-22 | Nsk Ltd | Rolling bearing |
JP2006234097A (en) * | 2005-02-25 | 2006-09-07 | Nsk Ltd | Creep prevention device and rolling bearing |
JP2007211865A (en) | 2006-02-08 | 2007-08-23 | Ntn Corp | Creep preventive roller bearing |
CN101600890B (en) * | 2007-01-11 | 2011-08-10 | 日本精工株式会社 | Rolling bearing |
JP2009190141A (en) * | 2008-02-15 | 2009-08-27 | Mitsubishi Heavy Ind Ltd | Machine tool and machining method |
JP6035732B2 (en) * | 2011-12-16 | 2016-11-30 | 日本精工株式会社 | Rolling bearing |
JP6155573B2 (en) * | 2012-08-28 | 2017-07-05 | 株式会社Ihi | Centrifugal compressor |
JP2016148429A (en) * | 2015-02-13 | 2016-08-18 | 日本精工株式会社 | Friction roller type transmission |
-
2018
- 2018-03-26 WO PCT/JP2018/012150 patent/WO2018181186A1/en active Application Filing
- 2018-03-26 DE DE112018001791.5T patent/DE112018001791T5/en active Pending
- 2018-03-26 US US16/492,375 patent/US20200040903A1/en not_active Abandoned
- 2018-03-26 JP JP2019509808A patent/JP6725064B2/en active Active
- 2018-03-26 CN CN201880004998.9A patent/CN110073120A/en active Pending
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11300130B2 (en) * | 2017-06-20 | 2022-04-12 | Dyson Technology Limited | Electric machine |
US20220145932A1 (en) * | 2019-03-15 | 2022-05-12 | Ntn Corporation | Rolling bearing |
US11703081B2 (en) * | 2019-03-15 | 2023-07-18 | Ntn Corporation | Rolling bearing |
US11976665B2 (en) | 2020-02-20 | 2024-05-07 | Mitsubishi Heavy Industries Engine & Turbocharger Ltd. | Compressor |
Also Published As
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DE112018001791T5 (en) | 2019-12-12 |
JPWO2018181186A1 (en) | 2019-07-04 |
JP6725064B2 (en) | 2020-07-15 |
WO2018181186A1 (en) | 2018-10-04 |
CN110073120A (en) | 2019-07-30 |
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