Turbine rotor, machine core, and medical cutting instrument

Abstract

The invention provides a turbine rotor of a rotary cutting instrument and a rotary cutting instrument provided with the turbine rotor, which can reduce the rapid increase of the rotation speed of the turbine rotor and can inhibit the stall and the reduction of the cutting force when a cutting load is input during the rotation of the turbine rotor. A turbine rotor (42) is a turbine rotor (42) of a gas turbine handpiece (1), the turbine rotor (42) being formed of a metal having a density of 4.0 [g / cm3] or more.

Description

Technical Field

[0001] The present invention relates to a turbine rotor for a medical cutting instrument used in dental and surgical treatments, a movement that can be detachably attached to the medical cutting instrument, and a medical cutting instrument having the turbine rotor. Background Art

[0002] Conventionally, medical cutting instruments such as air turbine handpieces have been known. For example, in dental treatments, various medical cutting instruments such as air turbine handpieces and micro motor handpieces in which cutting tools such as diamond burs, cemented carbide burs, files, and drills are mounted in the handpiece are used. For example, an air turbine handpiece as a medical cutting instrument is described in Patent Document 1.

[0003] The air turbine handpiece described in Patent Document 1 houses a spindle and a turbine rotor in the head. The spindle has a substantially cylindrical shape with a hollow interior and is pivotally supported in the head via bearings. Further, the turbine rotor is fixed to the outer peripheral surface of the spindle, and the cutting tool is inserted into the hollow interior of the spindle.

[0004] In such an air turbine handpiece, the turbine rotor has conventionally been made of aluminum from the viewpoint of ease of machining during molding.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020 - 174901 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] However, while a turbine rotor made of aluminum can be easily molded into a complex shape, on the other hand, since the moment of inertia during rotation is small, the rotational speed is likely to rapidly increase. When the rotational speed of the turbine rotor rapidly increases, there is a problem that the load applied to the bearings that pivotally support the spindle becomes large. Further, since the moment of inertia of the turbine rotor made of aluminum during rotation is small, there is a problem that it is likely to stall and the cutting force is reduced when a cutting load is input during rotation.

[0010] The present invention provides a turbine rotor for a rotary cutting instrument, a movement having the turbine rotor, and a rotary cutting instrument having the turbine rotor, which can reduce the rapid increase in the rotational speed of the turbine rotor and can suppress stalling and a reduction in the cutting force when a cutting load is input during rotation of the turbine rotor.

[0011] Means for Solving the Problems

[0012] The first aspect of the present invention is a turbine rotor, which is a turbine rotor of a medical cutting instrument. Among them,

[0013] the turbine rotor is formed of a metal having a density of 4.0 [g / cm 3 or more.

[0014] The second aspect of the present invention is a turbine rotor, which is a turbine rotor of a medical cutting instrument. Among them,

[0015] the turbine rotor has: a rotating shaft portion having a substantially cylindrical shape; and a plurality of turbine blade portions that extend radially outward with respect to the axial direction of the rotating shaft portion and have a wing shape.

[0016] the rotating shaft portion is formed of a metal having a density of 4.0 [g / cm 3 or more.

[0017] The third aspect of the present invention is a turbine rotor, which is a turbine rotor of a medical cutting instrument. Among them,

[0018] a counterweight is installed on the turbine rotor.

[0019] the counterweight is formed of a material having a density higher than the density of the material of the turbine rotor.

[0020] The fourth aspect of the present invention is a movement, which is detachably installed on a medical cutting instrument. The movement includes:

[0021] any one of the above turbine rotors; and

[0022] a quick stop mechanism for braking the turbine rotor.

[0023] The fifth aspect of the present invention is a medical cutting instrument, which includes any one of the above turbine rotors. Among them,

[0024] the medical cutting instrument includes a quick stop mechanism for braking the turbine rotor.

[0025] Advantages of the Invention

[0026] According to the present invention, it is possible to reduce the rapid increase in the rotational speed of the turbine rotor and suppress the stall and the reduction of the cutting force when an input cutting load is applied during rotation. Description of the Drawings

[0027] Figure 1 It is a cross-sectional view of the head of an air turbine handpiece including the turbine rotor of the first embodiment of the present invention.

[0028] Figure 2 It is Figure 1 an enlarged view of the vicinity of the sealing member.

[0029] Figure 3 This is a cross-sectional view of the head of an air turbine handpiece equipped with a turbine rotor according to the second embodiment of the present invention.

[0030] Figure 4 This is a cross-sectional view of the head of an air turbine handpiece equipped with a turbine rotor according to the third embodiment of the present invention.

[0031] Figure 5 This is a cross-sectional view of the head of an air turbine handpiece equipped with a turbine rotor according to the fourth embodiment of the present invention. Detailed Embodiments

[0032] Hereinafter, based on the drawings, each embodiment of the turbine rotor, the movement mechanism, and the air turbine handpiece equipped with a turbine rotor, which is an example of the medical cutting instrument of the present invention, will be described. It should be noted that the drawings are viewed from the direction of the reference numerals.

[0033] [First Embodiment]

[0034] First, with reference to Figure 1 and Figure 2 the air turbine handpiece 1 according to the first embodiment of the present invention will be described.

[0035] As Figure 1 shown, the air turbine handpiece 1 of the present embodiment includes: a handpiece main body 10, which is the main body part of the air turbine handpiece 1; and a head 20 provided at the top end part of the handpiece main body 10. A cutting tool 30 is detachably mounted on the head 20. A plurality of cutting tools 30 may be mounted on the head 20 according to the cutting object to be cut using the air turbine handpiece 1 or the like.

[0036] At one end of the cutting tool 30 mounted on the head 20, a shaft portion 31 having a cylindrical shape is formed. By inserting the shaft portion 31 into the head 20, the cutting tool 30 is mounted on the head 20. One end of the cutting tool 30 (i.e., the top end portion of the shaft portion 31) is accommodated in the head 20, and the other end of the cutting tool 30 protrudes from the head 20 to the outside.

[0037] Here, in this specification and the like, for the sake of simplicity and clarity of description, for convenience, the axial direction of the shaft portion 31 of the cutting tool 30 in the air turbine handpiece 1 on which the cutting tool 30 is mounted on the head 20 is defined as the X direction. And, one end side of the cutting tool 30 (i.e., the top end portion side of the shaft portion 31) is defined as the X1 side, and the other end side of the cutting tool 30 is defined as the X2 side. In addition, unless otherwise specified, when referring to the axial direction, the circumferential direction, and the radial direction, it means the direction based on the axial direction of the shaft portion 31.

[0038] Therefore, the shaft portion 31 is formed at the X1-side end of the cutting tool 30. And, the X1-side end of the cutting tool 30 is accommodated in the head 20, and the X2-side end of the cutting tool 30 protrudes from the head 20 in the X2 direction.

[0039] The head 20 includes: a main housing 21 having a bottomed substantially cylindrical shape with an X1-side opening; and a head cover 22 that closes the opening portion of the main housing 21 on the X1 side. An internal accommodation space 200 surrounded by the main housing 21 and the head cover 22 is formed in the head 20.

[0040] The movement mechanism 40 is accommodated in the internal accommodation space 200 of the head 20. The movement mechanism 40 is modularized by the following components: a spindle 41 having a hollow substantially cylindrical shape extending in the X direction; a turbine rotor 42 fixed to the outer peripheral surface of the spindle 41; a chuck mechanism portion 44 supported on the inner peripheral surface of the spindle 41; a first bearing 451 and a second bearing 452; and a seal member 46. Moreover, the movement mechanism 40 includes a movement mechanism housing 400 that houses the spindle 41, the turbine rotor 42, the chuck mechanism portion 44, the first bearing 451, the second bearing 452, and the seal member 46. The movement mechanism housing 400 includes: a main movement mechanism housing 401 having a cylindrical shape with an X1-side opening; and a movement mechanism cover 402 provided at the opening portion of the main movement mechanism housing 401 on the X1 side. In the present embodiment, the movement mechanism 40 is detachable from the head 20. Therefore, by replacing the movement mechanism 40 mounted on the head 20, the spindle 41, the turbine rotor 42, the chuck mechanism portion 44, the first bearing 451, the second bearing 452, and the seal member 46 can be replaced. In addition, depending on the cutting object or the like for which the air turbine handpiece 1 is used for cutting, a plurality of movement mechanisms 40 can be mounted on the head 20.

[0041] A button 23 that can be displaced in the X direction with respect to the main housing 21 and the head cover 22 is provided on the X1 side of the head cover 22. The button 23 is connected to the chuck mechanism portion 44 of the movement mechanism 40. In addition, a coil spring 24 is mounted between the button 23 and the head cover 22, and the button 23 is biased toward the X1 side with respect to the head cover 22 by the coil spring 24.

[0042] The X1-side end of the spindle 41 is rotatably supported by the first bearing 451. The X2-side end of the spindle 41 is rotatably supported by the second bearing 452. The first bearing 451 is fixed to the movement mechanism cover 402 via an O-ring 491. The space between the first bearing 451 and the movement mechanism cover 402 is sealed by the O-ring 491. The second bearing 452 is fixed to the vicinity of the X2-side end of the main movement mechanism housing 401 via an O-ring 492. The space between the second bearing 452 and the main movement mechanism housing 401 is sealed by the O-ring 492.

[0043] The turbine rotor 42 has a rotating shaft portion 421 with a substantially cylindrical shape, which is fitted to the outer peripheral surface of the main shaft 41, and a plurality of turbine blade portions 422, which extend radially outward with respect to the axial direction of the rotating shaft portion 421 and have a wing shape. The rotating shaft portion 421 and the turbine blade portions 422 may be integrally formed of the same material, or may be formed of different materials and integrated by joining. In the present embodiment, the rotating shaft portion 421 and the turbine blade portions 422 are integrally formed of the same material. When the turbine rotor 42 rotates, the main shaft 41 also rotates integrally with the turbine rotor 42.

[0044] The chuck mechanism portion 44 includes a chuck portion 441 having a hollow substantially cylindrical shape, which is fitted to the inner peripheral surface of the main shaft 41 and supported, and a thruster 442 provided at the X1 side end of the main shaft 41 to operate the chuck portion 441. The cutting tool 30 is supported by the chuck portion 441 so as not to be displaced radially with respect to the main shaft 41.

[0045] The thruster 442 is fitted to the inner peripheral surface of the main shaft 41 and supported so as to be slidable in the X direction. The thruster 442 operates the chuck portion 441 to switch the X1 side end of the shaft portion 31 of the cutting tool 30 between a state of being held by the chuck portion 441 and a state of not being held by the chuck portion 441.

[0046] When the user presses the button 23 toward the X2 side, the thruster 442 connected to the button 23 slides toward the X2 side. The chuck portion 441 can be switched between an open state and a closed state, and is normally in the closed state. And, for the chuck mechanism portion 44, when the thruster 442 slides toward the X2 side by the user's pressing operation of the button 23 toward the X2 side, the chuck portion 441 becomes the open state.

[0047] When the cutting tool 30 is to be installed on the head 20, the user presses the button 23 toward the X2 side, whereby the thruster 442 slides toward the X2 side, the chuck portion 441 maintains the open state, and becomes a state where the cutting tool 30 can be inserted. Then, while maintaining the chuck portion 441 in the open state, the shaft portion 31 of the cutting tool 30 is inserted into the hollow interior of the main shaft 41 from the X2 side, and the tip of the shaft portion 31 of the cutting tool 30 is brought into contact with the chuck mechanism portion 44. Then, when the user releases the button 23 while the tip of the shaft portion 31 of the cutting tool 30 is in contact with the chuck mechanism portion 44, the thruster 442 slides toward the X1 side, and the chuck portion 441 becomes the closed state while holding the shaft portion 31 of the cutting tool 30. The cutting tool 30 maintains the state of being held by the chuck mechanism portion 44 and is installed on the head 20 via the movement mechanism 40. Thus, the cutting tool 30 can rotate integrally with the main shaft 41 and the turbine rotor 42.

[0048] In the case where the cutting tool 30 is to be removed from the head 20, the user presses the button 23 toward the X2 side while the cutting tool 30 is held by the chuck portion 441. As a result, the pusher 442 slides toward the X2 side, and the chuck portion 441 becomes an open state, and a state in which the cutting tool 30 can be removed is achieved. Then, the user pulls out the cutting tool 30 toward the X2 side while pressing the button 23 toward the X2 side, thereby pulling out the cutting tool 30 from the chuck mechanism portion 44 and removing it from the head 20.

[0049] The mobile phone main body 10 includes: a supply pipe (not shown) that supplies high-pressure air (compressed air), which is a working gas for the turbine rotor 42, to the head 20; and a discharge pipe (not shown) that discharges the high-pressure air supplied to the head 20 to the outside. It should be noted that the high-pressure air supplied to the head 20 is discharged to the outside not only from the discharge pipe but also from a gap generated between the contact piece 462 of the seal member 46 and the outer peripheral surface of the main shaft 41, which will be described later.

[0050] The high-pressure air supplied from the supply pipe is supplied to the inside of the movement housing 400 of the movement 40 and is ejected to the turbine blade portion 422 of the turbine rotor 42. The turbine blade portion 422 of the turbine rotor 42 receives the high-pressure air, and thereby the turbine rotor 42 rotates. As a result, the main shaft 41 and the cutting tool 30 rotate integrally with the turbine rotor 42.

[0051] The seal member 46 is fixed near the X2 side end of the main movement housing 401 having a substantially cylindrical shape.

[0052] As Figure 2 shown, the second bearing 452 has: an inner ring 452a and an outer ring 452b that face each other; and balls 452c that are located in the gap where the inner ring 452a and the outer ring 452b face each other.

[0053] An inner ring opening 452a1 is opened on the inner side of the inner ring 452a. The inner ring opening 452a1 is fixed to the outer peripheral surface of the main shaft 41. Therefore, the inner ring 452a rotates together with the main shaft 41.

[0054] The seal member 46 is a member that prevents foreign substances such as saliva and blood from entering the inside of the movement housing 400. The seal member 46 of the present embodiment prevents foreign substances from entering the turbine rotor 42 from the gap of the second bearing 452.

[0055] The sealing member 46 is formed of an elastic material. The sealing member 46 is formed of, for example, silicone rubber or fluororubber. It should be noted that the sealing member 46 may also be formed of an elastic material other than silicone rubber and fluororubber. The sealing member 46 has an annular shape that surrounds the outer peripheral surface of the main shaft 41 and has an opening at the central portion. The sealing member 46 includes an outer peripheral portion 461 with the thickest thickness and a contact piece 462 that extends from the inner edge portion of the outer peripheral portion 461 toward the center of the ring. The contact piece 462 is a portion with an elastic modulus lower than that of the outer peripheral portion 461 and is easily elastically deformed. In the sealing member 46, a ring opening 463 is formed at a portion closer to the center of the ring than the contact piece 462.

[0056] A seal holding member 47 is mounted on the X2 side of the outer ring 452b of the second bearing 452. The seal holding member 47 includes: a base member 471 fixed to the main core housing 401; and a clamping member 472 that clamps the outer peripheral portion 461 of the sealing member 46 together with the base member 471.

[0057] The base member 471 includes: a cylindrical portion 471a having a substantially hollow cylindrical shape; an outer flange portion 471b that extends radially outward from the X1 side end of the cylindrical portion 471a; and an inner flange portion 471c that extends radially inward from the X1 side end of the cylindrical portion 471a.

[0058] The cylindrical portion 471a is fitted and fixed to the main core housing 401 via an O-ring 493 provided on the outer peripheral surface of the cylindrical portion 471a.

[0059] The X1 side surface of the outer flange portion 471b abuts against the X2 side end surface of the outer ring 452b of the second bearing 452, and the X2 side surface of the outer flange portion 471b abuts against the main core housing 401. Further, the outer flange portion 471b is clamped in the X direction by the outer ring 452b of the second bearing 452 and the main core housing 401.

[0060] The base member 471 is arranged such that the outer peripheral portion 461 of the sealing member 46 faces the X2 side surface of the inner flange portion 471c.

[0061] The clamping member 472 is fixed to the base member 471 and abuts against the outer peripheral portion 461 of the sealing member 46 from the X2 side. Further, the seal holding member 47 clamps the outer peripheral portion 461 of the sealing member 46 by the inner flange portion 471c of the base member 471 and the clamping member 472.

[0062] Further, the contact piece 462 of the sealing member 46 is disposed in a space surrounded by the inner circumferential surface of the cylindrical portion 471a of the seal holding member 47 and the outer circumferential surface of the main shaft 41. Further, in a state where the turbine rotor 42 of the air turbine handpiece 1 is not operating, that is, in a state where high-pressure air is not supplied from the supply pipe of the handpiece main body 10 to the head 20, the contact piece 462 is in contact with the outer circumferential surface of the main shaft 41.

[0063] In addition, the diameter of the ring opening 463 of the sealing member 46 is configured to be smaller than the diameter of the outer circumferential surface of the main shaft 41. Therefore, in a state where the turbine rotor 42 of the air turbine handpiece 1 is not operating, that is, in a state where high-pressure air is not supplied from the supply pipe of the handpiece main body 10 to the head 20, the contact piece 462 of the sealing member 46 bends toward the X2 side and contacts the outer circumferential surface of the main shaft 41 by the contact pressure generated by the elastic force. It should be noted that the position where the contact piece 462 contacts the outer circumferential surface of the main shaft 41 is the opening edge of the ring opening 463.

[0064] In this way, when high-pressure air is not supplied from the supply pipe of the handpiece main body 10 to the head 20 and the turbine rotor 42 does not rotate, the contact piece 462 of the sealing member 46 abuts against the outer circumferential surface of the main shaft 41 and is in a state of blocking the gap between the main body housing 401 and the main shaft 41 (sealed state).

[0065] Thereby, foreign matters such as saliva and blood can be prevented from entering the inside of the movement 40.

[0066] When high-pressure air is supplied from the supply pipe of the handpiece main body 10 to the head 20, the air pressure inside the movement housing 400 becomes high. When the turbine rotor 42 rotates at a specified speed or more, air leaks from the movement housing 400 through the second bearing 452 into the space where the contact piece 462 of the sealing member 46 is disposed. Then, the contact piece 462 of the sealing member 46 is expanded radially outward of the main shaft 41 by the air leaking into the space where the contact piece 462 of the sealing member 46 is disposed, and the contact piece 462 of the sealing member 46 is separated from the outer circumferential surface of the main shaft 41, and a gap is generated between the contact piece 462 of the sealing member 46 and the outer circumferential surface of the main shaft 41.

[0067] As described above, when high-pressure air is supplied from the supply pipe of the handpiece main body 10 to the head 20, the turbine blade portion 422 of the turbine rotor 42 is subjected to high-pressure air, and thus the turbine rotor 42 rotates, and the main shaft 41 and the cutting tool 30 rotate integrally with the turbine rotor 42. And when high-pressure air is supplied from the supply pipe of the handpiece main body 10 to the head 20, a gap is generated between the contact piece 462 of the sealing member 46 and the outer circumferential surface of the main shaft 41. Therefore, the contact resistance between the main shaft 41 and the contact piece 462 of the sealing member 46 disappears, and it is in a state where it is easy to rotate.

[0068] On the other hand, when starting from the state where high-pressure air is supplied from the supply pipe of the handpiece main body 10 to the head 20 and the turbine rotor 42, the main shaft 41, and the cutting tool 30 rotate integrally, and the supply of high-pressure air from the supply pipe of the handpiece main body 10 to the head 20 is stopped, the rotational speeds of the turbine rotor 42, the main shaft 41, and the cutting tool 30 decelerate, and the air leaking into the space of the contact piece 462 where the seal member 46 is disposed decreases. When the rotational speed of the turbine rotor 42 becomes below a specified speed, the contact piece 462 of the seal member 46 that expands radially outward of the main shaft 41 returns to the state of contacting the outer peripheral surface of the main shaft 41. Then, by the contact resistance between the contact piece 462 of the seal member 46 and the outer peripheral surface of the main shaft 41, the rotations of the turbine rotor 42, the main shaft 41, and the cutting tool 30 are braked. In this way, the seal member 46 also functions as a quick stop mechanism that brakes the rotations of the turbine rotor 42, the main shaft 41, and the cutting tool 30 when the supply of high-pressure air from the supply pipe of the handpiece main body 10 to the head 20 is stopped. Thereby, the seal member 46 can stop the rotations of the turbine rotor 42, the main shaft 41, and the cutting tool 30 in a short time after the supply of high-pressure air from the supply pipe of the handpiece main body 10 to the head 20 is stopped.

[0069] The turbine rotor 42 is formed of a metal having a density of 4.0 [g / cm 3 or more. And when the turbine rotor 42 has eight blades with a diameter of 10 [mm] × an axial length of 3.2 [mm], the moment of inertia of the turbine rotor 42 is 10.8 [g·mm2] when formed of stainless steel. As a reference, when a turbine rotor of the same shape is formed of aluminum, the moment of inertia of the turbine rotor is 3.7 [g·mm2].

[0070] In this way, by forming the turbine rotor 42 of a metal having a density of 4.0 [g / cm 3 or more, the moment of inertia of the turbine rotor 42 can be increased. Thereby, when starting to supply high-pressure air from the supply pipe of the handpiece main body 10 to the head 20, the rapid increase in the rotational speed of the turbine rotor 42 can be reduced, and the load applied to the second bearing 452 can be reduced. In addition, when the turbine rotor 42 rotates and a cutting load is input to the turbine rotor 42 via the cutting tool 30, the stall of the turbine rotor 42 can be suppressed and the cutting force of the cutting tool 30 can be prevented from decreasing.

[0071] Moreover, in the air turbine handpiece 1, the center of gravity position can be made close to the head 20. Therefore, when high-pressure air is supplied from the supply pipe of the handpiece main body 10 to the head 20 and the turbine rotor 42 rotates, the natural vibration frequency of the turbine rotor 42 becomes higher. Thereby, when high-pressure air is supplied from the supply pipe of the handpiece main body 10 to the head 20 and the turbine rotor 42 rotates, the uncomfortable sound generated by the turbine rotor 42 can be reduced.

[0072] In the present embodiment, the turbine rotor 42 is formed of stainless steel. More specifically, in the present embodiment, the turbine rotor 42 is formed of SUS303 which is an austenitic stainless steel.

[0073] Thus, since the turbine rotor 42 is formed of stainless steel which is an easily machinable material, the turbine rotor 42 can be easily formed.

[0074] In addition, since the turbine rotor 42 is formed of an austenitic stainless steel which is a material that is not easily corroded even by hot water cleaning, its corrosion resistance is excellent. Therefore, there is no need to perform surface treatment such as coating with acid-resistant aluminum film to improve the corrosion resistance of the turbine rotor 42.

[0075] Moreover, the value of Young's modulus [GPa] / density [g / cm 3 of the turbine rotor 42 is 20 or more. Generally, when the same force acts on members having the same shape but different Young's moduli, the larger the Young's modulus, the smaller the deformation. And when the same rotation is given to members having the same shape but different densities, the greater the density, the greater the force acting on the object. Therefore, the larger the Young's modulus and the lower the density, the smaller the amount of deformation caused by rotation. In the present embodiment, since the value of Young's modulus [GPa] / density [g / cm 3 of the turbine rotor 42 is 20 or more, even if the turbine rotor 42 is rotated at high speed, the amount of deformation of the turbine rotor 42 can be small. Therefore, even if the turbine rotor 42 is rotated at high speed, it is possible to suppress the enlargement of the inner diameter of the rotating shaft portion 421 and prevent the fixing of the turbine rotor 42 to the main shaft 41 from becoming loose.

[0076] In addition, the air turbine handpiece 1 includes a sealing member 46 which also functions as a quick stop mechanism for braking the rotation of the turbine rotor 42, the main shaft 41, and the cutting tool 30 when the supply of high-pressure air from the supply pipe of the handpiece body 10 to the head 20 is stopped. Therefore, even when a material having a large moment of inertia is used for the turbine rotor 42, after the supply of high-pressure air from the supply pipe of the handpiece body 10 to the head 20 is stopped, the rotation of the turbine rotor 42, the main shaft 41, and the cutting tool 30 can be stopped in a short time.

[0077] In addition, since the sealing member 46 functions as a quick stop mechanism for braking the rotation of the turbine rotor 42, the main shaft 41, and the cutting tool 30, a quick stop mechanism can be provided without increasing the number of components.

[0078] At this time, the circumferential line roughness Rz of the outer circumferential surface of the main shaft 41 in contact with the sealing member 46 is 12.5 [μm] or less. Thus, by reducing the circumferential line roughness Rz of the outer circumferential surface of the main shaft 41, the contact resistance between the contact piece 462 of the sealing member 46 and the outer circumferential surface of the main shaft 41 can be sufficiently ensured when the supply of high-pressure air from the supply pipe of the handpiece main body 10 to the head 20 is stopped. Therefore, even when a material with a large moment of inertia is used for the turbine rotor 42, sufficient braking force for braking the rotation of the turbine rotor 42, the main shaft 41, and the cutting tool 30 can be ensured.

[0079] In addition, the air turbine handpiece 1 is used after injecting a lubricant into the head 20 before use. Therefore, the air turbine handpiece 1 is used in a state where the components inside the head 20 are coated with the lubricant. For example, first, the lubricant is sufficiently injected from the supply pipe of the handpiece main body 10 into the head 20 to remove the dirt adhering to the components inside the head 20 and make it a state where the components inside the head 20 are coated with the lubricant. Then, after removing the excess lubricant, the air turbine handpiece 1 is used.

[0080] Thereby, it is possible to prevent defects of the components inside the head 20 caused by the adhesion of dirt and to prevent wear of the first bearing 451 and the second bearing 452. In addition, when the air turbine handpiece 1 is used, the outer circumferential surface of the main shaft 41 and the sealing member 46 are also coated with the lubricant. Therefore, when the air turbine handpiece 1 is used and the supply of high-pressure air from the supply pipe of the handpiece main body 10 to the head 20 is stopped starting from the state where the turbine rotor 42, the main shaft 41, and the cutting tool 30 rotate integrally, and the rotation of the turbine rotor 42, the main shaft 41, and the cutting tool 30 is braked by the contact resistance between the contact piece 462 of the sealing member 46 and the outer circumferential surface of the main shaft 41, wear of the contact piece 462 of the sealing member 46 can be suppressed.

[0081] [Second Embodiment]

[0082] Next, Figure 3 The air turbine handpiece 1A as the second embodiment of the present invention will be described. It should be noted that in the following description, the same reference numerals are given to the same components as those of the air turbine handpiece 1 of the first embodiment, and the description is omitted or simplified. Hereinafter, the differences between the air turbine handpiece 1 of the first embodiment and the air turbine handpiece 1A of the second embodiment will be described in detail.

[0083] As Figure 3 shown, in the air turbine handpiece 1A of the present embodiment, the rotating shaft portion 421 and the turbine blade portion 422 of the turbine rotor 42 are formed of different materials.

[0084] In the present embodiment, the rotating shaft portion 421 has a density of 4.0 [g / cm3 For the above-described metal formation, the turbine blade portion 422 is formed of aluminum, resin, or the like. Specifically, the rotating shaft portion 421 is formed of stainless steel. More specifically, the rotating shaft portion 421 is formed of SUS303, which is an austenitic stainless steel.

[0085] Thus, since the rotating shaft portion 421 is formed of a metal with a density of 4.0 [g / cm 3 or more, the moment of inertia of the turbine rotor 42 can be increased. As a result, even when the turbine blade portion 422 has a complex shape, the turbine blade portion 422 can be easily formed, and when high-pressure air starts to be supplied from the supply pipe of the mobile phone body 10 to the head 20, the rapid increase in the rotational speed of the turbine rotor 42 can be reduced, and the load applied to the second bearing 452 can be reduced. In addition, when a cutting load is input to the turbine rotor 42 via the cutting tool 30 during the rotation of the turbine rotor 42, the stall of the turbine rotor 42 can be suppressed and the cutting force of the cutting tool 30 can be reduced.

[0086] In addition, the turbine blade portion 422 can be formed of aluminum, resin, or the like, which is a material that is easier to process. Therefore, even when the turbine blade portion 422 has a complex shape, the turbine blade portion 422 can be easily formed.

[0087] In addition, since the rotating shaft portion 421 has a substantially cylindrical shape, it can be easily formed even when formed of stainless steel.

[0088] In addition, the rotating shaft portion 421 is formed of an austenitic stainless steel, which is a material that is not easily corroded even by hot water cleaning, so it has excellent corrosion resistance. Therefore, there is no need to perform surface treatment such as coating with acid-resistant aluminum to improve the corrosion resistance of the rotating shaft portion 421.

[0089] Moreover, the value of the Young's modulus [GPa] / density [g / cm 3 of the rotating shaft portion 421 is 20 or more. Generally, when the same force acts on members having the same shape but different Young's moduli, the larger the Young's modulus, the smaller the deformation. And when the same rotation is given to members having the same shape but different densities, the greater the density, the greater the force acting on the object. Therefore, the larger the Young's modulus and the lower the density, the smaller the amount of deformation caused by rotation. In the present embodiment, since the value of the Young's modulus [GPa] / density [g / cm 3 of the rotating shaft portion 421 is 20 or more, even when the turbine rotor 42 rotates at a high speed, the amount of deformation of the rotating shaft portion 421 can be small. Therefore, even when the turbine rotor 42 rotates at a high speed, the expansion of the inner diameter of the rotating shaft portion 421 can be suppressed, and the loosening of the fixing of the turbine rotor 42 to the main shaft 41 can be prevented.

[0090] [Third Embodiment]

[0091] Next, with reference to Figure 4 the air turbine handpiece 1B which is the third embodiment of the present invention will be described. It should be noted that in the following description, the same reference numerals are assigned to the constituent elements identical to those of the air turbine handpiece 1 of the first embodiment, and the description thereof is omitted or simplified. Hereinafter, the differences between the air turbine handpiece 1 of the first embodiment and the air turbine handpiece 1B of the third embodiment will be described in detail.

[0092] As Figure 4 shown, in the air turbine handpiece 1B of the present embodiment, a counterweight 48 is mounted on the turbine rotor 42. The counterweight 48 rotates integrally with the turbine rotor 42.

[0093] In the present embodiment, the rotating shaft portion 421 and the turbine blade portion 422 of the turbine rotor 42 are integrally formed of the same material. In the present embodiment, the turbine rotor 42 is formed of aluminum.

[0094] A pair of counterweights 48 are provided along the X direction on the surface on the X1 side and the surface on the X2 side of the turbine rotor 42. Both of the pair of counterweights 48 are annular with the rotation axis of the turbine rotor 42 as the center. In the present embodiment, the pair of counterweights 48 are formed in a manner of fitting with the outer peripheral surface of the main shaft 41.

[0095] The counterweight 48 is formed of a material having a density higher than that of aluminum which is the material of the turbine rotor 42. The counterweight 48 is formed of materials such as stainless steel, titanium, brass, copper-zinc-nickel alloy, and phosphor bronze, for example.

[0096] Thus, since the counterweight 48 formed of a material having a density higher than that of the material of the turbine rotor 42 is mounted on the turbine rotor 42, the moment of inertia of the turbine rotor 42 on which the counterweight 48 is mounted can be increased. Thereby, when starting to supply high-pressure air from the supply pipe of the handpiece main body 10 to the head 20, the rapid increase in the rotational speed of the turbine rotor 42 can be reduced, and the load applied to the second bearing 452 can be reduced. In addition, when the turbine rotor 42 is rotating and a cutting load is input to the turbine rotor 42 via the cutting tool 30, the stall of the turbine rotor 42 can be suppressed and the cutting force of the cutting tool 30 can be prevented from decreasing.

[0097] In addition, since the counterweight 48 can be retrofitted to the turbine rotor 42, it can be achieved by mounting the counterweight 48 on an existing turbine rotor 42, and the design change can be easily made from the existing turbine rotor 42.

[0098] In addition, even if the counterweight 48 is deformed when the turbine rotor 42 rotates at a high speed, the fixing of the turbine rotor 42 to the main shaft 41 will not become loose, so the degree of freedom in the selection of the material for the counterweight 48 is increased. For example, the counterweight 48 can also be formed of a material having a low value of Young's modulus [GPa] / density [g / cm 3 .

[0099] [Fourth Embodiment]

[0100] Next, with reference to Figure 5 the air turbine handpiece 1C as the fourth embodiment of the present invention will be described. It should be noted that in the following description, the same reference numerals are assigned to the same components as those of the air turbine handpiece 1 of the first embodiment, and the description thereof is omitted or simplified. Hereinafter, the differences between the air turbine handpiece 1 of the first embodiment and the air turbine handpiece 1C of the fourth embodiment will be described in detail.

[0101] As Figure 5 shown, in the air turbine handpiece 1C of the present embodiment, in addition to providing a sealing member 512 on the X2 side of the second bearing 452, a sealing member 511 is also provided on the X1 side of the first bearing 451.

[0102] In addition, the air turbine handpiece 1C of the present embodiment does not have a core housing 400. And the sealing member 511 is provided on the first bearing 451, and the sealing member 512 is provided on the second bearing 452.

[0103] In addition, in the present embodiment, the head cover 22 has: a substantially annular outer member 221, which is embedded in the main housing 21 and fixed; and a substantially annular inner member 222, which is fixed to the inner peripheral surface of the outer member 221.

[0104] The first bearing 451 is fixed to the inner peripheral surface of the inner member 222 of the head cover 22 via an O-ring 491, and the second bearing 452 is fixed to the inner peripheral surface of the main housing 21 via an O-ring 492.

[0105] The first bearing 451 has: an inner ring 451a and an outer ring 451b, which face each other; and balls 451c, which are located in the gap between the inner ring 451a and the outer ring 451b that face each other.

[0106] A clamping portion 451d that extends radially inward and supports the sealing member 511 from the X2 side is formed at the X1 side end of the outer ring 451b of the first bearing 451.

[0107] An extension portion 451e that extends radially outward and supports the O-ring 491 from the X2 side is formed at the X2 side end of the outer ring 451b of the first bearing 451.

[0108] An inner ring opening 451a1 is opened inside the inner ring 451a of the first bearing 451. The inner ring opening 451a1 is fixed to the outer peripheral surface of the main shaft 41. Therefore, the inner ring 451a rotates together with the main shaft 41.

[0109] A seal retaining member 521 is mounted on the X1 side of the outer ring 451b of the first bearing 451. The seal retaining member 521 is fixed to the outer peripheral surface of the outer ring 451b of the first bearing 451. The seal retaining member 521 is formed with a base portion 521a facing the X1 side of the outer ring 451b of the first bearing 451, a clamping portion 521b extending from the base portion 521a toward the X1 side and supporting the seal member 511 from the X1 side, and a locking portion 521c extending from the base portion 521a toward the X2 side, supporting the O-ring 491 from the X1 side, and being fixed to the outer peripheral surface of the outer ring 451b of the first bearing 451.

[0110] The seal member 511 is formed of an elastic material. The seal member 511 is formed of, for example, silicone rubber or fluororubber. It should be noted that the seal member 511 may also be formed of an elastic material other than silicone rubber and fluororubber. The seal member 511 has an annular shape surrounding the outer peripheral surface of the main shaft 41 and having an opening at the center portion. The seal member 511 includes an outer peripheral portion 511a having the thickest thickness and a contact piece 511b extending from the inner edge portion of the outer peripheral portion 511a toward the center of the ring. The contact piece 511b is a portion having an elastic modulus lower than that of the outer peripheral portion 511a and being easily elastically deformed. In the seal member 511, a ring opening 511c is formed at a portion closer to the center of the ring than the contact piece 511b.

[0111] The X1 side of the outer peripheral portion 511a of the seal member 511 is supported by the clamping portion 521b of the seal retaining member 521, and the X2 side of the outer peripheral portion 511a of the seal member 511 is supported by the clamping portion 451d of the first bearing 451. The outer peripheral portion 511a of the seal member 511 is clamped by the clamping portion 521b of the seal retaining member 521 and the clamping portion 451d of the first bearing 451.

[0112] The contact piece 511b of the seal member 511 is disposed in a space surrounded by the inner peripheral surface of the clamping portion 521b of the seal retaining member 521 and the outer peripheral surface of the main shaft 41. And, in a state where the turbine rotor 42 of the air turbine handpiece 1 is not operating, that is, in a state where high-pressure air is not supplied from the supply pipe of the handpiece main body 10 to the head 20, the contact piece 511b is in a state of being in contact with the outer peripheral surface of the main shaft 41.

[0113] In addition, the diameter of the ring opening 511c of the seal member 511 is configured to be smaller than the diameter of the outer peripheral surface of the main shaft 41. Therefore, in a state where the turbine rotor 42 of the air turbine handpiece 1 is not operating, that is, in a state where high-pressure air is not supplied from the supply pipe of the handpiece main body 10 to the head 20, the contact piece 511b of the seal member 511 bends toward the X1 side and contacts the outer peripheral surface of the main shaft 41 by the contact pressure generated by the elastic force. It should be noted that the position where the contact piece 511b contacts the outer peripheral surface of the main shaft 41 is the opening edge of the ring opening 511c.

[0114] Thus, when high-pressure air is not supplied from the supply pipe of the mobile phone main body 10 to the head 20 and the turbine rotor 42 does not rotate, the contact piece 511b of the sealing member 511 abuts against the outer peripheral surface of the main shaft 41, and the gap between the head cover 22 and the main shaft 41 is blocked (sealed state).

[0115] Thereby, foreign matters such as saliva and blood can be prevented from entering the interior of the movement 40.

[0116] The second bearing 452 has an inner ring 452a and an outer ring 452b that face each other, and balls 452c located in the gap where the inner ring 452a and the outer ring 452b face each other.

[0117] A clamping portion 452d that extends radially inward and supports the sealing member 512 from the X1 side is formed at the X2 side end of the outer ring 452b of the second bearing 452.

[0118] An extension portion 452e that extends radially outward and supports the O-ring 492 from the X1 side is formed at the X1 side end of the outer ring 452b of the second bearing 452.

[0119] An inner ring opening 452a1 is opened inside the inner ring 452a of the second bearing 452. The inner ring opening 452a1 is fixed to the outer peripheral surface of the main shaft 41. Therefore, the inner ring 452a rotates together with the main shaft 41.

[0120] A seal holding member 522 is installed on the X2 side of the outer ring 452b of the second bearing 452. The seal holding member 522 is fixed to the outer peripheral surface of the outer ring 452b of the second bearing 452. The seal holding member 522 is formed with a base portion 522a that faces the X2 side of the outer ring 452b of the second bearing 452, a clamping portion 522b that extends from the base portion 522a to the X2 side and supports the sealing member 512 from the X2 side, and a locking portion 522c that extends from the base portion 522a to the X1 side, supports the O-ring 492 from the X2 side, and is fixed to the outer peripheral surface of the outer ring 452b of the second bearing 452.

[0121] The sealing member 512 is formed of an elastic material. The sealing member 512 is formed of, for example, silicone rubber or fluororubber. It should be noted that the sealing member 512 may also be formed of an elastic material other than silicone rubber and fluororubber. The sealing member 512 has an annular shape that surrounds the outer peripheral surface of the main shaft 41 and has an opening at the center portion. The sealing member 512 includes an outer peripheral portion 512a with the thickest thickness and a contact piece 512b that extends from the inner edge portion of the outer peripheral portion 512a toward the center of the ring. The contact piece 512b is a portion with an elastic modulus lower than that of the outer peripheral portion 512a and is easily elastically deformed. In the sealing member 512, a ring opening 512c is opened at a portion closer to the center of the ring than the contact piece 512b.

[0122] The X1 side of the outer peripheral portion 512a of the sealing member 512 is supported by the clamping portion 452d of the second bearing 452, and the X2 side of the outer peripheral portion 512a of the sealing member 512 is supported by the clamping portion 522b of the seal holding member 522. The outer peripheral portion 512a of the sealing member 512 is clamped by the clamping portion 452d of the second bearing 452 and the clamping portion 522b of the seal holding member 522.

[0123] The contact piece 512b of the sealing member 512 is disposed in the space surrounded by the inner peripheral surface of the clamping portion 522b of the seal holding member 522 and the outer peripheral surface of the main shaft 41. Then, in a state where the turbine rotor 42 of the air turbine handpiece 1 is not operating, that is, in a state where high-pressure air is not supplied from the supply pipe of the handpiece main body 10 to the head 20, the contact piece 512b is in a state of contacting the outer peripheral surface of the main shaft 41.

[0124] In addition, the diameter of the ring opening 512c of the sealing member 512 is configured to be smaller than the diameter of the outer peripheral surface of the main shaft 41. Therefore, in a state where the turbine rotor 42 of the air turbine handpiece 1 is not operating, that is, in a state where high-pressure air is not supplied from the supply pipe of the handpiece main body 10 to the head 20, the contact piece 512b of the sealing member 512 bends toward the X2 side and contacts the outer peripheral surface of the main shaft 41 by the contact pressure generated by the elastic force. It should be noted that the position where the contact piece 512b contacts the outer peripheral surface of the main shaft 41 is the opening edge of the ring opening 512c.

[0125] In this way, when high-pressure air is not supplied from the supply pipe of the handpiece main body 10 to the head 20 and the turbine rotor 42 does not rotate, the contact piece 512b of the sealing member 512 abuts against the outer peripheral surface of the main shaft 41 and is in a state of blocking the gap between the main housing 21 and the main shaft 41 (sealed state).

[0126] Thereby, foreign matters such as saliva and blood can be prevented from entering the inside of the movement 40.

[0127] When high-pressure air is supplied from the supply pipe of the handpiece main body 10 to the head 20, the air pressure inside the movement housing 400 becomes high. When the turbine rotor 42 rotates at a specified speed or more, air leaks from the movement housing 400 through the first bearing 451 into the space where the contact piece 511b of the sealing member 511 is disposed, and leaks through the second bearing 452 into the space where the contact piece 512b of the sealing member 512 is disposed.

[0128] Then, the contact piece 511b of the sealing member 511 is expanded radially outward of the main shaft 41 by the air leaking into the space where the contact piece 511b of the sealing member 511 is disposed, and the contact piece 511b of the sealing member 511 is separated from the outer peripheral surface of the main shaft 41, and a gap is generated between the contact piece 511b of the sealing member 511 and the outer peripheral surface of the main shaft 41.

[0129] Similarly, the contact piece 512b of the sealing member 512 is expanded radially outward of the main shaft 41 by the air leaking into the space where the contact piece 512b of the sealing member 512 is disposed, and the contact piece 512b of the sealing member 512 is separated from the outer peripheral surface of the main shaft 41, and a gap is generated between the contact piece 512b of the sealing member 512 and the outer peripheral surface of the main shaft 41.

[0130] As described above, when high-pressure air is supplied from the supply pipe of the handpiece main body 10 to the head 20, the turbine blade portion 422 of the turbine rotor 42 receives the high-pressure air, whereby the turbine rotor 42 rotates, and the main shaft 41 and the cutting tool 30 rotate integrally with the turbine rotor 42. And, when high-pressure air is supplied from the supply pipe of the handpiece main body 10 to the head 20, gaps are generated between the contact piece 511b of the sealing member 511 and the outer peripheral surface of the main shaft 41 and between the contact piece 512b of the sealing member 512 and the outer peripheral surface of the main shaft 41. Therefore, the contact resistance between the main shaft 41 and the contact piece 511b of the sealing member 511 and the contact piece 512b of the sealing member 512 disappears, and the main shaft 41 is in a state where it is easy to rotate.

[0131] On the other hand, when starting from the state where the turbine rotor 42, the main shaft 41, and the cutting tool 30 rotate integrally due to the supply of high-pressure air from the supply pipe of the handpiece main body 10 to the head 20, when the supply of high-pressure air from the supply pipe of the handpiece main body 10 to the head 20 is stopped, the rotational speeds of the turbine rotor 42, the main shaft 41, and the cutting tool 30 decrease, and the air leaking into the space where the contact piece 511b of the sealing member 511 is disposed and the air leaking into the space where the contact piece 512b of the sealing member 512 is disposed decrease. When the rotational speed of the turbine rotor 42 becomes below a specified speed, the contact piece 511b of the sealing member 511 and the contact piece 512b of the sealing member 512 that are expanded radially outward of the main shaft 41 return to the state of contacting the outer peripheral surface of the main shaft 41. Then, by the contact resistance between the contact piece 511b of the sealing member 511 and the outer peripheral surface of the main shaft 41 and the contact resistance between the contact piece 512b of the sealing member 512 and the outer peripheral surface of the main shaft 41, the rotation of the turbine rotor 42, the main shaft 41, and the cutting tool 30 is braked. Thus, the sealing member 511 and the sealing member 512 also function as a quick stop mechanism for braking the rotation of the turbine rotor 42, the main shaft 41, and the cutting tool 30 when the supply of high-pressure air from the supply pipe of the handpiece main body 10 to the head 20 is stopped.

[0132] In particular, in the present embodiment, since the sealing members 511 and 512 are provided on both the X2 side of the second bearing 452 and the X1 side of the first bearing 451, even when a material with a large moment of inertia is used for the turbine rotor 42, the braking force for braking the rotation of the turbine rotor 42, the main shaft 41, and the cutting tool 30 can be further increased when the supply of high-pressure air from the supply pipe of the mobile phone body 10 to the head 20 is stopped.

[0133] As described above, the embodiments of the present invention have been described with reference to the accompanying drawings. However, the present invention is of course not limited to these embodiments. Obviously, those skilled in the art can conceive of various modification examples or correction examples within the scope described in the claims, and it can be understood that these modification examples or correction examples also naturally belong to the technical scope of the present invention. In addition, the constituent elements in the above embodiments can be arbitrarily combined without departing from the gist of the invention.

[0134] For example, in the turbine rotor 42 of the first embodiment and the second embodiment, a metal such as titanium can also be used instead of stainless steel.

[0135] In addition, for example, in the first to third embodiments, the sealing member 46 is provided on the X2 side of the second bearing 452. However, a plurality of sealing members 46 can also be provided on the X2 side of the second bearing 452, and a plurality of sealing members 46 can also be provided on the X2 side of the second bearing 452 and a plurality of sealing members 46 can be provided on the X1 side of the first bearing 451. By increasing the number of the sealing members 46, even when a material with a large moment of inertia is used for the turbine rotor 42, the braking force for braking the rotation of the turbine rotor 42, the main shaft 41, and the cutting tool 30 can be further increased when the supply of high-pressure air from the supply pipe of the mobile phone body 10 to the head 20 is stopped.

[0136] In addition, for example, in the first to third embodiments, the main shaft 41, the turbine rotor 42, the chuck mechanism portion 44, the first bearing 451, the second bearing 452, and the sealing member 46 are modularized into a movement 40 that is detachable from the head 20. However, the main shaft 41, the turbine rotor 42, the chuck mechanism portion 44, the first bearing 451, the second bearing 452, and the sealing member 46 may not be modularized.

[0137] In addition, for example, in the first to third embodiments, the sealing member 46 is provided as a member fixed to the main movement housing 401 of the movement 40. However, the sealing member 46 can also be provided on the first bearing 451 and / or the second bearing 452.

[0138] At least the following matters are described in this specification. Although the corresponding constituent elements, etc. in the above embodiments are shown as an example in parentheses, it is not limited thereto.

[0139] (1) A turbine rotor, which is the turbine rotor (turbine rotor 42) of a medical cutting instrument (air turbine handpiece 1), wherein,

[0140] the turbine rotor is formed of a metal with a density of 4.0 [g / cm 3 or more.

[0141] According to (1), by forming the turbine rotor of a metal with a density of 4.0 [g / cm 3 or more, the moment of inertia of the turbine rotor can be increased. Thereby, the rapid increase in the rotational speed of the turbine rotor can be reduced. In addition, when the turbine rotor is rotating and a cutting load is input to the turbine rotor, the stall of the turbine rotor can be suppressed and the cutting force can be prevented from decreasing.

[0142] (2) The turbine rotor according to (1), wherein,

[0143] the value of the Young's modulus [GPa] / density [g / cm 3 of the turbine rotor is 20 or more.

[0144] According to (2), since the value of the Young's modulus [GPa] / density [g / cm 3 of the turbine rotor is 20 or more, even if the turbine rotor rotates at a high speed, the amount of deformation of the turbine rotor can be small.

[0145] (3) A turbine rotor, which is the turbine rotor (turbine rotor 42) of a medical cutting instrument (air turbine handpiece 1A), wherein,

[0146] the turbine rotor has:

[0147] a substantially cylindrical rotating shaft portion (rotating shaft portion 421); and

[0148] a plurality of turbine blade portions (turbine blade portions 422), which extend radially outward with respect to the axial direction of the rotating shaft portion and have a wing shape,

[0149] the rotating shaft portion is formed of a metal with a density of 4.0 [g / cm 3 or more.

[0150] According to (3), since the rotating shaft portion is formed of a metal with a density of 4.0 [g / cm 3 or more, the moment of inertia of the turbine rotor can be increased. Thereby, the rapid increase in the rotational speed of the turbine rotor can be reduced. In addition, when the turbine rotor is rotating and a cutting load is input to the turbine rotor, the stall of the turbine rotor can be suppressed and the cutting force can be prevented from decreasing. Further, the turbine blade portion can be formed of a material that is easier to process, so even if the turbine blade portion has a complex shape, the turbine blade portion can be easily formed.

[0151] (4) The turbine rotor according to (3), wherein,

[0152] The value of the Young's modulus [GPa] / density [g / cm 3 of the rotating shaft portion is 20 or more.

[0153] According to (4), the value of the Young's modulus [GPa] / density [g / cm 3 of the rotating shaft portion is 20 or more, so that even if the turbine rotor rotates at a high speed, the amount of deformation of the rotating shaft portion can be small.

[0154] (5) A turbine rotor, which is a turbine rotor (turbine rotor 42) of a medical cutting instrument (air turbine handpiece 1B), wherein,

[0155] A counterweight (counterweight 48) is installed on the turbine rotor,

[0156] The counterweight is formed of a material having a density higher than the density of the material of the turbine rotor.

[0157] According to (5), since a counterweight formed of a material having a density higher than the density of the material of the turbine rotor is installed on the turbine rotor, the moment of inertia of the turbine rotor on which the counterweight is installed can be increased. Thereby, the rapid increase in the rotational speed of the turbine rotor can be reduced. In addition, when the turbine rotor rotates and a cutting load is input to the turbine rotor, the stall of the turbine rotor can be suppressed and the cutting force can be reduced.

[0158] (6) The turbine rotor according to any one of (1) to (4), wherein,

[0159] The metal is stainless steel.

[0160] According to (6), since the turbine rotor is formed of stainless steel, which is an easily machined material, the turbine rotor can be easily formed.

[0161] (7) The turbine rotor according to (6), wherein,

[0162] The stainless steel is austenitic stainless steel.

[0163] According to (7), since the turbine rotor is formed of austenitic stainless steel, which is a material that is not easily corroded even by hot water cleaning, the corrosion resistance is excellent. Therefore, there is no need to perform surface treatment such as coating with acid-resistant aluminum film to improve the corrosion resistance of the turbine rotor.

[0164] (8) A movement (movement 40) detachably mounted on the medical cutting instrument,

[0165] The movement includes:

[0166] The turbine rotor according to any one of (1) to (5); and

[0167] A quick stop mechanism (sealing members 46, 511, 512) brakes the turbine rotor.

[0168] According to (8), the movement mechanism detachably mounted on the medical cutting instrument has a quick stop mechanism for braking the turbine rotor. Therefore, even when a material with a large moment of inertia is used for the turbine rotor, the rotation of the turbine rotor can be stopped in a short time.

[0169] (9) The movement mechanism according to (8), wherein

[0170] the movement mechanism includes:

[0171] a main shaft (main shaft 41) having a substantially hollow cylindrical shape, the outer peripheral surface of the main shaft is fixed with the turbine rotor, and a cutting tool is inserted into the hollow interior of the main shaft; and

[0172] sealing members (sealing members 46, 511, 512) surrounding the outer peripheral surface of the main shaft, contacting the outer peripheral surface of the main shaft when the turbine rotor is not rotating, and separating from the outer peripheral surface of the main shaft when the turbine rotor rotates at a specified speed or higher,

[0173] the sealing members are the quick stop mechanism.

[0174] According to (9), the sealing members function as a quick stop mechanism for braking the rotation of the turbine rotor. Therefore, the quick stop mechanism can be provided without increasing the number of components.

[0175] (10) The movement mechanism according to (9), wherein

[0176] the circumferential line roughness Rz of the outer peripheral surface of the main shaft in contact with the sealing members is 12.5 [μm] or less.

[0177] According to (10), by setting the circumferential line roughness Rz of the outer peripheral surface of the main shaft in contact with the sealing members to be 12.5 [μm] or less, the contact resistance between the sealing members and the outer peripheral surface of the main shaft can be sufficiently ensured. Therefore, even when a material with a large moment of inertia is used for the turbine rotor, sufficient braking force for braking the rotation of the turbine rotor can be ensured.

[0178] (11) A medical cutting instrument (air turbine handpieces 1, 1A, 1B, 1C) includes the turbine rotor according to any one of (1) to (5), wherein

[0179] the medical cutting instrument includes a quick stop mechanism (sealing members 46, 511, 512) for braking the turbine rotor.

[0180] According to (11), the medical cutting instrument is provided with a quick stop mechanism for braking the turbine rotor. Therefore, even when a material with a large moment of inertia is used for the turbine rotor, the rotation of the turbine rotor can be stopped in a short time.

[0181] (12) The medical cutting instrument according to (11), wherein,

[0182] The medical cutting instrument includes:

[0183] A main shaft (main shaft 41), having a hollow substantially cylindrical shape, the turbine rotor is fixed to the outer peripheral surface of the main shaft, and a cutting tool (cutting tool 30) is inserted into the hollow interior of the main shaft; and

[0184] A sealing member (sealing members 46, 511, 512), surrounding the outer peripheral surface of the main shaft, contacting the outer peripheral surface of the main shaft when the turbine rotor is not rotating, and separating from the outer peripheral surface of the main shaft when the turbine rotor rotates at a specified speed or higher,

[0185] The sealing member is the quick stop mechanism.

[0186] According to (12), the sealing member functions as a quick stop mechanism for braking the rotation of the turbine rotor. Therefore, the quick stop mechanism can be provided without increasing the number of components.

[0187] (13) The medical cutting instrument according to (12), wherein,

[0188] The circumferential line roughness Rz of the outer peripheral surface of the main shaft in contact with the sealing member is 12.5 [μm] or less.

[0189] According to (13), by setting the circumferential line roughness Rz of the outer peripheral surface of the main shaft in contact with the sealing member to 12.5 [μm] or less, the contact resistance between the sealing member and the outer peripheral surface of the main shaft can be sufficiently ensured. Therefore, even when a material with a large moment of inertia is used for the turbine rotor, sufficient braking force for braking the rotation of the turbine rotor can be ensured.

[0190] It should be noted that this application is based on the Japanese invention application (Japanese Patent Application No. 2022-190794) filed on November 29, 2022, the content of which is incorporated herein by reference.

[0191] Explanation of reference numerals:

[0192] 1, 1A, 1B, 1C: Air turbine handpiece (medical cutting instrument);

[0193] 30: Cutting tool;

[0194] 40: Movement;

[0195] 41: Main shaft;

[0196] 42: Turbine rotor;

[0197] 421: Rotating shaft portion;

[0198] 422: Turbine blade portion;

[0199] 46, 511, 512: Sealing members (quick stop mechanism);

[0200] 48: Counterweight.

Claims

1. A turbine rotor, which is a turbine rotor of a medical cutting instrument, wherein, The turbine rotor is formed of a metal having a density of 4.0 g / cm 3 or more.

2. The turbine rotor according to claim 1, wherein, The value of Young's modulus / density of the turbine rotor is 20 or more, where the unit of Young's modulus is GPa and the unit of density is g / cm 3 .

3. A turbine rotor, which is a turbine rotor of a medical cutting instrument, wherein, the turbine rotor has: a rotating shaft portion having a substantially cylindrical shape; and a plurality of turbine blade portions, which extend radially outward with respect to the axial direction of the rotating shaft portion and have a wing shape, The rotating shaft portion is formed of a metal having a density of 4.0 g / cm 3 or more.

4. The turbine rotor according to claim 3, wherein, The value of Young's modulus / density of the rotating shaft portion is 20 or more, where the unit of Young's modulus is GPa and the unit of density is g / cm 3 .

5. A turbine rotor, which is a turbine rotor of a medical cutting instrument, wherein, a counterweight is mounted on the turbine rotor, the counterweight is formed of a material having a density higher than the density of the material of the turbine rotor.

6. The turbine rotor according to any one of claims 1 to 4, wherein, the metal is stainless steel.

7. The turbine rotor according to claim 6, wherein, the stainless steel is austenitic stainless steel.

8. A movement, detachably mounted on a medical cutting instrument, the movement comprising: the turbine rotor according to any one of claims 1 to 5; and a quick stop mechanism for braking the turbine rotor.

9. The movement according to claim 8, wherein, the movement comprises: a main shaft having a substantially cylindrical shape with a hollow interior, an outer peripheral surface of the main shaft for fixing the turbine rotor, and a hollow interior of the main shaft for inserting a cutting tool; and a sealing member surrounding the outer peripheral surface of the main shaft, contacting the outer peripheral surface of the main shaft when the turbine rotor is not rotating, and separating from the outer peripheral surface of the main shaft when the turbine rotor rotates at a specified speed or more, the sealing member being the quick stop mechanism.

10. The movement according to claim 9, wherein, a circumferential line roughness Rz of the outer peripheral surface of the main shaft in contact with the sealing member is 12.5 μm or less.

11. A medical cutting instrument, comprising the turbine rotor according to any one of claims 1 to 5, wherein, the medical cutting instrument comprises a quick stop mechanism for braking the turbine rotor.

12. The medical cutting instrument according to claim 11, wherein, the medical cutting instrument comprises: a main shaft having a substantially cylindrical shape with a hollow interior, an outer peripheral surface of the main shaft for fixing the turbine rotor, and a hollow interior of the main shaft for inserting a cutting tool; and a sealing member surrounding the outer peripheral surface of the main shaft, contacting the outer peripheral surface of the main shaft when the turbine rotor is not rotating, and separating from the outer peripheral surface of the main shaft when the turbine rotor rotates at a specified speed or more, the sealing member being the quick stop mechanism.

13. The medical cutting instrument according to claim 12, wherein, a circumferential line roughness Rz of the outer peripheral surface of the main shaft in contact with the sealing member is 12.5 μm or less.

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