WO2025110216A1 - 軸受 - Google Patents

軸受 Download PDF

Info

Publication number
WO2025110216A1
WO2025110216A1 PCT/JP2024/041336 JP2024041336W WO2025110216A1 WO 2025110216 A1 WO2025110216 A1 WO 2025110216A1 JP 2024041336 W JP2024041336 W JP 2024041336W WO 2025110216 A1 WO2025110216 A1 WO 2025110216A1
Authority
WO
WIPO (PCT)
Prior art keywords
seal body
sealing member
seal
ring
bearing according
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.)
Pending
Application number
PCT/JP2024/041336
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
優 山▲崎▼
匠悟 加藤
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MinebeaMitsumi Inc
Original Assignee
MinebeaMitsumi Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by MinebeaMitsumi Inc filed Critical MinebeaMitsumi Inc
Priority to JP2025520194A priority Critical patent/JP7799905B2/ja
Publication of WO2025110216A1 publication Critical patent/WO2025110216A1/ja
Priority to JP2025284130A priority patent/JP2026040756A/ja
Anticipated expiration legal-status Critical
Pending legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
    • A61C1/00—Dental machines for boring or cutting ; General features of dental machines or apparatus, e.g. hand-piece design
    • A61C1/02—Dental machines for boring or cutting ; General features of dental machines or apparatus, e.g. hand-piece design characterised by the drive of the dental tools
    • A61C1/05—Dental machines for boring or cutting ; General features of dental machines or apparatus, e.g. hand-piece design characterised by the drive of the dental tools with turbine drive
    • 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
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/72—Sealings
    • F16C33/76—Sealings of ball or roller bearings

Definitions

  • the present invention relates to a bearing, and in particular to a bearing used in a dental handpiece driven by an air turbine.
  • a dental handpiece has a head with a rotation mechanism and a tool that is detachably attached to the head.
  • the rotation mechanism both ends of a shaft member are supported by bearings, and turbine blades are attached to the shaft member.
  • the bearings use ball bearings that have an inner ring, an outer ring, and a cage that holds multiple rolling elements (balls) between the inner ring and the outer ring.
  • Compressed air can be supplied to the turbine blades from a supply passage, and the compressed air is blown against the turbine blades of the rotation mechanism, causing the turbine blades to rotate, the shaft member to rotate, and the tool to rotate.
  • Some bearings used in conventional dental handpieces have a braking function, as disclosed in Patent Document 1, for example.
  • an annular seal ring is fixed to the outer ring of the bearing, and the inner end of the seal ring is capable of contacting the inner ring of the bearing.
  • the inner end of the seal ring comes into contact with the inner ring of the bearing, applying a braking force to the inner ring and stopping the rotation of the inner ring.
  • the present invention was made in consideration of the above-mentioned problems, and its purpose is to provide a bearing that enables higher speed rotation.
  • the bearing according to the present invention is a bearing that supports a shaft member provided with turbine blades that rotate by receiving compressed air, and includes an inner ring, an outer ring installed on the outer peripheral side of the inner ring, a plurality of rolling elements interposed between the inner ring and the outer ring, a cage that holds the rolling elements at intervals in the circumferential direction, and an annular sealing member disposed between the inner ring and the outer ring around the axis x so as to be capable of closing the space between the inner ring and the outer ring, the sealing member has a support ring that is an annular member for supporting the sealing member on the outer peripheral side, and a seal facing groove having a seal contact surface, a recess, and a protrusion is formed on the outer peripheral surface of the inner ring that faces the outer peripheral side, the seal contact surface is contactable from the outside with the inner peripheral end of the sealing member in the axial direction, and the recess extends in the axial direction at least in the region
  • the bearings of the present invention allow for higher speed rotation.
  • FIG. 1 is an external view of an example of a dental handpiece including a bearing according to the present invention.
  • 2 is a cross-sectional view showing an example of a head portion of the dental handpiece shown in FIG. 1.
  • FIG. 3 is a cross-sectional view showing a schematic configuration of an example of a bearing according to the present invention used in the head portion shown in FIG. 2 .
  • FIG. 4 is a partial enlarged view of the bearing shown in FIG. 3 .
  • FIG. 4 is a partial enlarged view of the bearing shown in FIG. 3 .
  • 3 is a partially enlarged cross-sectional view showing a schematic configuration of another example of a bearing according to the present invention used in the head portion shown in FIG. 2.
  • FIG. 1 is an external view of a dental handpiece 1 as an example of a dental handpiece equipped with a bearing according to the present invention
  • FIG. 2 is a cross-sectional view showing a head part 2 as an example of a head part of the dental handpiece 1
  • FIG. 3 is a cross-sectional view showing a schematic configuration of a ball bearing 5 as an example of a bearing according to the present invention used in the head part 2.
  • FIGS. 4 and 5 are partial enlarged views of the ball bearing 5 shown in FIG. 3. Note that FIG. 4 shows the ball bearing 5 in the dental handpiece 1 in a stopped state, and FIG.
  • the stopped state is a state in which compressed air is not acting on the sealing member and the sealing member is not deformed by the action of compressed air, as described later.
  • the driven state is a state in which compressed air is acting on the sealing member and the sealing member is deformed.
  • the dental handpiece 1 has a head portion 2 with a rotation mechanism 4, and a tool 3 that is removably attached to the head portion 2.
  • the tool 3 is rotated at high speed (e.g., 400,000 revolutions per minute or more) to cut teeth, etc.
  • the ball bearing 5 is a bearing that supports a shaft member 7 provided with turbine blades 8 that rotate when compressed air is supplied from an air supply port 9.
  • the ball bearing 5 includes an inner ring 10, an outer ring 20 installed on the outer periphery of the inner ring 10, a plurality of rolling elements 30 interposed between the inner ring 10 and the outer ring 20, and a retainer 31 that holds the rolling elements 30 at intervals in the circumferential direction.
  • the ball bearing 5 also includes an annular sealing member 40 disposed between the inner ring 10 and the outer ring 20 around the axis x so as to be able to close the space between the inner ring 10 and the outer ring 20.
  • the sealing member 40 has a support ring 42, which is an annular member for supporting the sealing member 40 on the outer periphery.
  • a seal facing groove 11 is formed on the outer periphery 10b of the inner ring 10 that faces the outer periphery.
  • the seal facing groove 11 includes a seal contact surface 13, a recess 14, and a protrusion 12.
  • the seal contact surface 13 is configured so that the inner peripheral end 41a, which is the end on the inner peripheral side of the sealing member 40, can come into contact from the outside in the direction of the axis x.
  • the recess 14 extends radially in the direction of the axis x at least in the area facing the support ring 42.
  • the outer side is one side in the direction of the axis x
  • the inner side is the other side in the direction of the axis x.
  • the inner side of the ball bearing 5 is the side close to the turbine blade 8 in the direction of the axis x
  • the outer side of the ball bearing 5 is the side away from the turbine blade 8 in the direction of the axis x.
  • the radial direction is the direction perpendicular to the axis x.
  • the inner side is the inner side in the radial direction and is the side approaching the axis x in the radial direction
  • the outer side is the opposite end of the inner side, the outer side in the radial direction, and is the side away from the axis x in the radial direction.
  • the ball bearing 5 includes an inner ring 10 having a raceway groove 10c on the outer peripheral surface 10b that forms an inner ring raceway, an outer ring 20 having a raceway groove 20c on the inner peripheral surface 20a that forms an outer ring raceway, a plurality of rolling elements (balls) 30 interposed between the inner ring raceway and the outer ring raceway, and an annular cage 31 that rotatably holds the rolling elements 30 at intervals in the circumferential direction.
  • the ball bearing 5 also includes a sealing member 40.
  • the sealing member 40 is provided to prevent lubricant from leaking from inside the ball bearing 5 and foreign matter from entering inside the ball bearing 5.
  • the sealing member 40 is also provided as a brake mechanism for the rotating mechanism 4. As described above, the sealing member 40 is provided between the inner ring 10 and the outer ring 20 so as to be able to block the space between the inner ring 10 and the outer ring 20.
  • the inner peripheral surface of the retainer 31 faces the outer peripheral surface 10b of the inner ring 10, and the outer peripheral surface of the retainer 31 faces the inner peripheral surface 20a of the outer ring 20.
  • the retainer 31 has a plurality of pockets (not shown) at regular or approximately regular intervals in the circumferential direction for holding the rolling elements 30 in a freely rolling manner, and holds the rolling elements 30.
  • the outer peripheral surface 20b of the outer ring 20 is fitted into the housing 6, and the shaft member 7 is fitted into the inner peripheral surface 10a of the inner ring 10.
  • a pair of ball bearings 5 supports the shaft member 7 with the turbine blades 8 between them.
  • the inner ring 10 and the outer ring 20 are relatively rotatable around the axis x. That is, when the dental handpiece 1 is driven, that is, when compressed air is supplied to the turbine blades 8, the inner ring 10 rotates at high speed relative to the outer ring 20.
  • the sealing member 40 is provided in the opening between the inner ring 10 and the outer ring 20 on the side where the compressed air that has passed through the ball bearing 5 is discharged. That is, in each of a pair of ball bearings 5 that face each other across the turbine blades 8, the sealing member 40 is provided in the outer opening between the inner ring 10 and the outer ring 20.
  • the sealing member 40 includes a seal body 41, a support ring 42, and a snap ring 43.
  • the sealing member 40 is also fixed to the end 21 of the outer ring 20.
  • the end 21 is the outer end in the direction of the axis x.
  • the seal body 41 is an elastic, elastically deformable member, and is a plate-shaped member having an annular shape around the axis x.
  • the support ring 42 is, for example, a plate-shaped member having an annular shape around the axis x and a predetermined rigidity.
  • the inner diameter D2 of the support ring 42 is larger than the inner diameter D1 of the seal body 41.
  • the snap ring 43 is, for example, an elastic member having an annular or approximately annular shape around the axis x.
  • the snap ring 43 is a member for fixing the sealing member 40 to the outer ring 20 via the support ring 42.
  • the snap ring 43 is, for example, a C-ring.
  • the seal body 41, the support ring 42, and the snap ring 43 are stacked from the outside in the direction of the axis x in the order of the snap ring 43, the support ring 42, and the seal body 41, and are fixed to the end 21 of the outer ring 20.
  • the seal body 41 and the support ring 42 are sandwiched between the end 21 of the outer ring 20 and the snap ring 43, and are fixed to the end 21 of the outer ring 20 by the snap ring 43.
  • the turbine blades 8 and shaft member 7 continue to rotate for a while due to inertia, and during this time the inside of the ball bearing 5 is in a negative pressure state where the air pressure is lower than the outside of the ball bearing 5. For this reason, air containing foreign matter may be sucked into the inside of the ball bearing 5 or the inside of the housing 6 from around the dental handpiece 1.
  • This sucking of air into the inside of the housing 6 when the dental handpiece 1 is stopped is called the suck-back phenomenon.
  • the sealing member 40 is pressed against the inner ring 10 by the air flow during the suck-back phenomenon, suppressing the sucking of air from the outside and preventing the inflow of foreign matter.
  • the sealing member 40 also acts as a brake for the rotating mechanism 4, applying a braking force to the inner ring 10 rotating due to inertia. For this reason, the sealing member 40 can shorten the time until the dental handpiece 1 stops.
  • the support ring 42 contacts the outer peripheral portion of the seal body 41 around the entire circumference around the axis x. This prevents or inhibits the seal body 41 from coming off the outer ring 20 when it is subjected to pressure from compressed air.
  • the support ring 42 also reinforces the contact between the inner peripheral end 41a of the seal body 41 and the seal contact surface 13 of the inner ring 10. This allows the support ring 42 to further strengthen the braking force of the brake function of the seal body 41.
  • the inner ring 10 and the outer ring 20 are made of, for example, stainless steel, and the rolling elements 30 are made of, for example, stainless steel or ceramics.
  • sealing member 40 and the structure formed by the sealing member 40, the inner ring 10, and the outer ring 20 will now be described in more detail.
  • the sealing member 40 is fixed to the seal groove 22 of the outer ring 20.
  • the seal groove 22 is a groove recessed toward the outer peripheral surface 20b of the outer ring 20 and extends in an annular shape around the axis x.
  • the seal groove 22 has an inclined surface 23, an annular surface 24, and a bottom surface 25.
  • the inclined surface 23 is a cylindrical surface around the axis x and is located on the outside of the seal groove 22 in the axis x direction.
  • the inclined surface 23 expands in diameter from the outside to the inside in the axis x direction, and in cross section, it is inclined radially outward as it moves from the outside to the inside in the axis x direction.
  • the annular surface 24 is an annular surface extending along a plane perpendicular to the axis x and faces outward in the axis x direction.
  • the bottom surface 25 is an annular surface facing radially inward and extends between the inclined surface 23 and the annular surface 24.
  • the seal groove 22 has a cylindrical surface 26 and a toric surface 27 that form a step adjacent to the toric surface 24.
  • the cylindrical surface 26 is a cylindrical surface about the axis x that spreads inward in the direction of the axis x from the inner peripheral end of the toric surface 24.
  • the cylindrical surface 26 is, for example, a cylindrical surface.
  • the toric surface 27 is an annular surface that extends along a plane perpendicular to the axis x, and faces outward in the direction of the axis x. The toric surface 27 extends from the inner end of the cylindrical surface 26.
  • the outer peripheral end (outer peripheral end 41b) of the seal body 41 is accommodated in the step formed by the cylindrical surface 26 and the annular surface 27, and is supported in contact with the cylindrical surface 26 and the annular surface 27.
  • the snap ring 43 is in contact with the inclined surface 23, and sandwiches the seal body 41 between the outer ring 20 via the support ring 42, and fixes the seal body 41 and the support ring 42 to the seal groove 22.
  • the seal body 41 is a circular sheet-shaped member.
  • the seal body 41 contains at least one resin selected from fluororesin, fluororubber, nitrile rubber, hydrogenated nitrile rubber, acrylic rubber, ethylene propylene diene rubber, etc. as a base resin.
  • the base resin may be a resin in which a porous resin (such as a three-dimensional mesh structure) is impregnated with an elastomer.
  • the fluororesin include polytetrafluoroethylene and perfluoroelastomer.
  • the fluororesin may be a composite of polytetrafluoroethylene and perfluoroelastomer so as to have sliding properties and elasticity.
  • the composite of polytetrafluoroethylene and perfluoroelastomer may be, for example, a porous (such as a three-dimensional mesh structure) polytetrafluoroethylene impregnated with liquid perfluoroelastomer and hardened.
  • the fluororubber include vinylidene fluoride, tetrafluoroethylene-propylene, and tetrafluoroethylene-purovinyl ether.
  • the hardness of the seal body 41 is, for example, Shore A60-90 (in accordance with JIS K6253:2012), or Shore A70-90 (in accordance with JIS K6253:2012).
  • the thickness T1 of the seal body 41 is, for example, 0.5 mm or less, or 0.2 mm or less, or 0.1 mm or less.
  • the radial length W0 of the contact area between the seal body 41 and the support ring 42 is, for example, 1/2 to 3/4, or 2/3 to 3/4 of the radial width W1 of the seal body 41.
  • Such hardness and dimensions make it easier for the seal body 41 to deform appropriately when the air turbine that supplies compressed air is operating (when compressed air passes through the inside of the ball bearing 5).
  • the tear strength of the seal body 41 in accordance with JIS K6252:2007 is not particularly limited, but is, for example, 50 N/mm or more, 65 N/mm or more, or 80 N/mm or more. Furthermore, the tensile strength of the seal body 41 in accordance with JIS K6251:2010 is, for example, 30 MPa or more. By having such tear strength and tensile strength, the durability of the seal body 41 is further improved when the air turbine is repeatedly operated and stopped.
  • the support ring 42 is an annular member made of metal or resin.
  • the support ring 42 has a higher hardness than the seal body 41.
  • the snap ring 43 is a member made of metal or resin.
  • the snap ring 43 has a structure that generates a biasing force in the radial outward direction. This biasing force acts on the inclined surface 23 of the seal groove 22, biasing the snap ring 43 inward in the direction of the axis x.
  • the snap ring 43 presses the seal body 41 and the support ring 42 against the annular surface 27 of the outer ring 20.
  • the inner diameter D2 of the support ring 42 is larger than the inner diameter D1 of the seal body 41
  • the inner diameter D3 of the snap ring 43 is larger than the inner diameter D2 of the support ring 42.
  • the inner ring 10 has an outer peripheral surface 10b on which a raceway groove 10c along which the rolling elements 30 move is formed, and a seal facing groove 11 that faces the sealing member 40.
  • the seal facing groove 11 is a groove that is recessed toward the inner peripheral surface 10a of the inner ring 10, and extends annularly around the axis x.
  • the seal opposing groove 11 has a seal contact surface 13, a recess 14, and a protrusion 12.
  • the seal contact surface 13 is an annular surface around the axis x and faces outward in the direction of the axis x.
  • the seal contact surface 13 is connected to the outer peripheral surface 10b at its inner end.
  • the inner peripheral end 41a of the seal body 41 contacts the seal contact surface 13 when the air turbine is stopped (when no pressure from the compressed air is acting), that is, when the dental handpiece 1 is at rest. In this way, when the dental handpiece 1 is at rest, the seal body 41, which has not been deformed by the action of the compressed air, contacts the seal contact surface 13 of the inner ring 10 from the outside at its inner peripheral end 41a.
  • the inner peripheral end 41a of the seal body 41 may be biased toward the seal contact surface 13 of the inner ring 10, or may not be biased toward the seal contact surface 13 of the inner ring 10.
  • the seal body 41 may be deformed and the inner peripheral end 41a may be pressed against the seal contact surface 13, or the seal body 41 may not be deformed and the inner peripheral end 41a may be in contact with the seal contact surface 13 without generating a reaction force.
  • the recess 14 extends outward from the seal contact surface 13 in the direction of the axis x, and forms an annular groove recessed radially inward between the seal contact surface 13 and the protrusion 12.
  • the recess 14 extends in the direction of the axis x in a region facing at least the inner end (inner end 42a) of the support ring 42, and when viewed in the radial direction, the recess 14 faces at least the inner end 42a of the support ring 42. It is preferable that at least a portion of the recess 14 has a cylindrical surface 14a extending in the direction of the axis x.
  • the cylindrical surface 14a is a cylindrical surface or an approximately cylindrical surface with the axis x as its central axis or approximately central axis.
  • the recess 14 has a cylindrical surface 14a between the end (inner end 14b) connected to the seal contact surface 13 and the protrusion 12, and the cylindrical surface 14a faces the inner peripheral end 42a of the support ring 42 and the inner peripheral end (inner peripheral end 43a) of the snap ring 43 in the radial direction.
  • the cylindrical surface 14a extends outward from the snap ring 43 in the axial x direction.
  • the recess 14 extends in the axial x direction in the region radially facing the sealing member 40, so that the flow of the exhausted compressed air is less likely to be impeded. This improves the exhaust efficiency of the supplied compressed air, and the flow rate of the compressed air supplied to the turbine blade 8 can be increased, allowing the ball bearing 5 to rotate at a higher speed. This allows the tool 3 to rotate at a higher speed.
  • the protrusion 12 is a flange-shaped portion that connects to the outer end of the recess 14 in the axial x direction.
  • the protrusion 12 is located further outward in the axial x direction than the snap ring 43.
  • the outer diameter D4 of the protrusion 12 is smaller than the inner diameter D1 of the seal body 41.
  • a curved surface is formed on the inner edge (edge 12a) of the protrusion 12 in the axial x direction.
  • the edge 12a of the protrusion 12 draws a convex curve on the outer periphery and inward. This makes it less likely that the flow of the discharged compressed air will be impeded.
  • the time from when the supply of compressed air is stopped until the seal body 41 comes into contact with the seal contact surface 13 can be shortened, and the time until the tool 3 stops can be shortened. In this way, the brake performance can be improved.
  • the outer end (outer end 14c) of the recess 14 in the axial x direction is preferably located outward of the inner end 41a of the deformed seal body 41 in the axial x direction when the dental handpiece 1 is in operation (when compressed air pressure is applied).
  • the minimum distance L1 between the deformed seal body 41 and the recess 14 or the protrusion 12 is preferably equal to or greater than the thickness T1 of the seal body 41. Note that, in the embodiment of the present invention shown in FIG. 5, the minimum distance L1 is the radial distance between the deformed seal body 41 and the recess 14, but the minimum distance L1 is not limited to this. For example, the minimum distance L1 may be the distance in the axial x direction.
  • this minimum distance L1 is 1.2 times or more the thickness of the seal body 41. It is even more preferable that the size of the gap between the deformed seal body 41 and the seal contact surface 13, the recess 14, and the protrusion 12 gradually increases toward the minimum distance L1. In this way, the recess 14 extends sufficiently long in the direction of the axis x, and the gap between the seal body 41 and the recess 14 or the protrusion 12 is sufficiently large, making it less likely that the flow of the discharged compressed air will be impeded.
  • the seal body 41 is made of a material that makes it easier to deform.
  • the hardness and dimensions of the seal body 41 are also values that make it easier to deform. For this reason, the seal body 41 is easier to deform than conventional seal bodies.
  • the seal body 41 deforms more greatly, making it less likely to impede the flow of compressed air that passes through the ball bearings 5 and is discharged to the outside of the head portion 2.
  • the ball bearing 5 makes it less likely that the flow of compressed air passing through the ball bearing 5 and being discharged to the outside of the head portion 2 will be impeded, and the rotation speed of the rotation mechanism 4 of the dental handpiece 1 in the driven state can be increased.
  • the seal body 41 is more easily deformed than conventional seal bodies. Therefore, when the dental handpiece 1 is stopped and the turbine blades 8 and shaft member 7 continue to rotate by inertia, when the inside of the ball bearing 5 becomes negative pressure, this negative pressure can press the seal body 41 more strongly against the seal contact surface 13. Therefore, even if the seal body 41 wears over time, the deterioration of the braking performance of the seal body 41 can be suppressed. In this way, the ball bearing 5 can improve the durability of the brake mechanism, thereby lengthening the period during which the desired braking performance is exhibited. In addition, the braking performance of the seal body 41 can be improved.
  • the operating range of the inner peripheral end 41a of the seal body 41 when compressed air acts on it can be changed.
  • the inner peripheral end 41a of the seal body 41 can be deformed more greatly, and the flow rate of compressed air discharged to the outside of the head part 2 through the ball bearing 5 can be increased.
  • the rotation speed of the rotating mechanism 4 of the dental handpiece 1 can be reduced, and the braking performance of the seal body 41 can be improved.
  • the ball bearing 5 according to the embodiment of the present invention can enable higher speed rotation.
  • ball bearing 5A as another example of a bearing according to the present invention.
  • ball bearing 5A has a seal-facing groove 11A that is different from seal-facing groove 11.
  • components that have the same or similar functions as the configuration of the above-mentioned ball bearing 5 will be given the same reference numerals and their explanation will be omitted, and components that differ from the above-mentioned ball bearing 5 will be explained.
  • Figure 6 is a partially enlarged cross-sectional view showing the schematic configuration of a ball bearing 5A as another example of a bearing according to the present invention used in the head portion 2.
  • Figure 6 shows the ball bearing 5A in the dental handpiece 1 in a stopped state.
  • no compressed air acts on the seal body 41 of the ball bearing 5A shown in Figure 6, and the seal body 41 is not deformed.
  • the inner ring 10 of the ball bearing 5A has a seal opposing groove 11A that is different from the seal opposing groove 11 of the ball bearing 5 described above.
  • the width W of the gap G is set so that when the dental handpiece 1 is stopped and the turbine blades 8 and shaft member 7 are rotating by inertia, and the inside of the ball bearing 5 becomes negative pressure, the seal body 41 is sucked by this negative pressure, and the inner end portion 41a of the seal body 41 is pressed against the seal contact surface 13.
  • the width W of the gap G is the width of the gap G in the direction of the axis x.
  • the width W of the gap G is less than the thickness T1 of the seal body 41.
  • the seal body 41 comes into contact with the seal contact surface 13 only when the dental handpiece 1 is stopped and the turbine blades 8 and shaft member 7 are rotating by inertia and the inside of the ball bearing 5 is under negative pressure. This shortens the time that the seal body 41 comes into contact with the seal contact surface 13 of the rotating inner ring 10, reducing wear of the seal body 41 between the seal contact surface 13. This reduces wear between the seal body 41 and the seal contact surface 13 even if the inner diameter D2 of the support ring 42 is reduced to make the inner end 41a of the seal body 41 less likely to deform. This therefore improves the durability of the seal body 41 while improving the braking ability of the seal body 41.
  • the ball bearing 5A can achieve the same effect as the ball bearing 5 described above, and can achieve the same effect as the ball bearing 5 described above.
  • the above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. Furthermore, the above-described embodiments do not limit the use of the present invention, and the present invention may include anything as its use.
  • the components of the above-described embodiments, as well as their arrangement, materials, conditions, shape, size, etc., are not limited to those exemplified, and may be modified as appropriate.
  • the present invention includes differences that arise in implementation due to manufacturing tolerances, etc.
  • the components shown in different embodiments may be partially substituted or combined to the extent that there is no technical contradiction.
  • the configurations may be selectively combined as appropriate to achieve at least some of the above-described problems and effects.

Landscapes

  • Health & Medical Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Engineering & Computer Science (AREA)
  • Epidemiology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Dentistry (AREA)
  • Oral & Maxillofacial Surgery (AREA)
  • Mechanical Engineering (AREA)
  • Dental Tools And Instruments Or Auxiliary Dental Instruments (AREA)
  • Rolling Contact Bearings (AREA)
PCT/JP2024/041336 2023-11-24 2024-11-21 軸受 Pending WO2025110216A1 (ja)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2025520194A JP7799905B2 (ja) 2023-11-24 2024-11-21 軸受
JP2025284130A JP2026040756A (ja) 2023-11-24 2025-12-26 軸受

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US202363602484P 2023-11-24 2023-11-24
US63/602,484 2023-11-24

Publications (1)

Publication Number Publication Date
WO2025110216A1 true WO2025110216A1 (ja) 2025-05-30

Family

ID=95826616

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2024/041336 Pending WO2025110216A1 (ja) 2023-11-24 2024-11-21 軸受

Country Status (3)

Country Link
JP (2) JP7799905B2 (https=)
TW (1) TW202521860A (https=)
WO (1) WO2025110216A1 (https=)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007046767A (ja) * 2005-05-13 2007-02-22 Nsk Ltd クリーナモータ用軸受
DE102012000757A1 (de) * 2012-01-18 2013-07-18 Minebea Co., Ltd. Wälzlager mit Dichtungssystem
JP2017211076A (ja) * 2016-05-19 2017-11-30 日本精工株式会社 転がり軸受及びエアタービン用軸受ユニット

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007046767A (ja) * 2005-05-13 2007-02-22 Nsk Ltd クリーナモータ用軸受
DE102012000757A1 (de) * 2012-01-18 2013-07-18 Minebea Co., Ltd. Wälzlager mit Dichtungssystem
JP2017211076A (ja) * 2016-05-19 2017-11-30 日本精工株式会社 転がり軸受及びエアタービン用軸受ユニット

Also Published As

Publication number Publication date
TW202521860A (zh) 2025-06-01
JP7799905B2 (ja) 2026-01-15
JPWO2025110216A1 (https=) 2025-05-30
JP2026040756A (ja) 2026-03-09

Similar Documents

Publication Publication Date Title
CN111503161B (zh) 滚动轴承和空气涡轮机用轴承单元以及牙科空气涡轮机手持件
JP6686738B2 (ja) 転がり軸受及びエアタービン用軸受ユニット
JP7799905B2 (ja) 軸受
JP6651912B2 (ja) 転がり軸受及びエアタービン用軸受ユニット
JP6125412B2 (ja) 軸シール装置、回転機械、及び軸シール装置の製造方法
CN114901960B (zh) 空气涡轮用滚动轴承
CN114867948B (zh) 空气涡轮用滚动轴承
JP7367321B2 (ja) 転がり軸受
CN115280029B (zh) 滚动轴承
JP7645206B2 (ja) 医療器具又は美容器具のための転がり軸受
EP4233776B1 (en) Dental handpiece
JP2020174901A (ja) 医療用切削器械用シール部材、及び、この医療用切削器械用シールを備えた医療用切削器械
JPWO2025110216A5 (https=)
JP4506262B2 (ja) 転がり軸受ユニットの密封手段転がり軸受ユニット
JP2006132328A (ja) 軸シール機構および回転機械
JP2006194201A (ja) ポンプ
JP2017211064A (ja) 密封部材、及び、転がり軸受装置

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref document number: 2025520194

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 2025520194

Country of ref document: JP

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 24894207

Country of ref document: EP

Kind code of ref document: A1