JPS6130578B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transmission device for a medical handpiece that speeds up or decelerates and transmits the shaft rotational motion of a drive shaft connected to an electric or pneumatic drive device to an operating shaft.

Conventionally, in order to mechanically change the speed of the rotation of the drive shaft and transmit it to the operating shaft, several types of gear type or ball planetary type transmissions with a fixed speed ratio are prepared for each speed ratio. They were replaced and used in combination depending on the situation. As a result, the user has to deal with the trouble of replacing and combining the transmissions, and the financial burden of having to prepare several types of transmissions becomes large, and there is also the problem that the limited clinical space becomes cramped.

The present invention has been made in view of the above circumstances, and the selection of speed increase or deceleration can be made by changing the direction of connection to the drive section, and also, for either of these speed changes, a case is provided. A medical device that uses a ball planetary rotation transmission mechanism with excellent operability and low vibration, which allows the gear ratio to be changed steplessly regardless of whether it is in non-driving or driving mode by operating the operating means provided. The purpose of the present invention is to provide a transmission device for a handpiece for use in the present invention.

The transmission device for a medical handpiece of the present invention includes:
Transmission device 200 for a medical handpiece that changes the speed of two rotary shafts 100, 300, or 300', which are rotatable in opposing relation by bearings, to link the shafts.
In the transmission device 200, the rotation shaft 1
cone 22 connecting with 00, 300 or 300'
0, and a ball holder 230 that rotatably holds a plurality of balls 213 that are disposed around the outer peripheral surface of the cone body 220 and roll in contact with each other, and that moves the balls 213 back and forth along the generatrix of the cone body. , guides the forward and backward movement of the holding body 230 and guides the transmission device 200.
A funnel-shaped holder guide 240 is installed inside the case 20, and the ball holder 230 and the holder guide 240 are bent to form a funnel shape on which the balls 213 roll into contact on the inner peripheral surface. , has a conical receiver 250 connected to the rotating shaft 300 or 300', 100, and an operating means 260 for moving the ball holder 230 forward and backward, and controls the rotation of the rotating shaft 100 of the drive shaft to the driven side. rotation axis 3
A speed change transmission mechanism 21 that steplessly decelerates or speeds up steplessly to 00 or 300' and selectively transmits the transmission.
It is characterized by having a built-in 0. The rotation transmission mechanism 210 employs a ball planetary system, and the rotation shaft 100, 300 or 30
0' and a cone 220 connected to the cone 22
A plurality of balls 213 are disposed around the outer circumferential surface of the ball 2 and roll in contact with each other in a rolling manner.
13... along the generatrix of the cone; a funnel-shaped holder guide 240 that guides the forward and backward movement of the holder 230 and is installed inside the case 20 of the transmission 200; The ball holder 230 and the holder guide 240 are surrounded by a funnel shape on which the balls 213 roll in contact with each other on the inner peripheral surface, and the rotating shaft 300 or 30
0', 100, and an operating means 26 for moving the ball holder 230 forward and backward.
It is characterized by being configured with more than 0.

An embodiment of the present invention will be described with reference to the drawings.
Fig. 1 is a partially cutaway developed vertical cross-sectional view of a handpiece to which the transmission of the present invention is mounted in deceleration mode, Fig. 2 is a longitudinal cross-sectional view of the main parts of the transmission, and Fig. 3 is a cross-sectional view of the main parts of the transmission.
FIG. 4 is a perspective view of the holder guide, FIG. 5 is a perspective view of the outer portion of the holder, and FIG. 6 is a longitudinal sectional view taken along the cutting line of FIG. FIG. 7 is a perspective view of the internal division of the holding body.

In the figure, a transmission device 200 of the present invention includes two rotating shafts 100 and 30 that are rotatable in opposing relation by respective bearings in a medical handpiece body 1.
0 or 300' to link the shafts. In particular, the rotation of the driving side rotating shaft (hereinafter referred to as the driving shaft) 100 is transferred to the operating side rotating shaft (hereinafter referred to as the operating shaft) 300 or 300'. It has a built-in ball planetary rotation transmission mechanism 210 that selectively transmits data by steplessly increasing speed or steplessly decelerating the speed. The rotation transmission mechanism 210 is connected to the drive shaft 100 via an engagement sleeve 223 and an engagement sleeve 121 that engage with each other in the deceleration mode, and engages with an engagement sleeve 223 that engages with each other in the acceleration mode. Sleeve 311 or 31
1', the conical body 220 is connected to the operating shaft 300 or 300', and the balls 213, which are provided around the outer peripheral surface of the conical body 220 at intervals of 90 degrees, for example, and rotate in contact with each other, are rotated. A ball holder 230 that freely holds the balls 213 and moves them back and forth along the generatrix of the cone body 220, and a transmission device 200 that guides the movement of the holder 230 back and forth and is incorporated into the main body 1. A substantially funnel-shaped holder guide 24 that is tightly fitted inside the case 20
0, the ball holder 230 and the holder guide 240 are bent, and the ball 23 is placed on the inner peripheral surface.
The operating shaft 3
00 or 300' and are connected to the drive shaft 100 via the engagement sleeve 253 and the engagement sleeve 121 that engage with each other in the speed increase mode, and The ball holder 230 is provided with an operating means 260 for moving the ball holder 230 forward and backward. The drive shaft 100 is rotatably driven by a drive source 2 such as an electric motor or an air motor at a predetermined rotation speed that is most effective, and is supported within the drive case 10 of the main body 1 via a ball bearing. As shown in FIG. 1, the transmission 200 side has, for example, a fork shape in which a plurality of distal ends are split at an acute angle at equal intervals in the circumferential direction. A cylindrical engagement sleeve 121 is fixedly attached to the input intermediate shaft (which becomes the conical shaft 221 in the deceleration mode and the conical receiver shaft 251 in the accelerating mode) and meshes with the input intermediate shaft. The operating shaft 300 or 300' is rotatably driven by the drive shaft 100 in a speed change mode via the transmission device 200 of the present invention, and is connected to the contra-angle tool holder 30 or 300 that forms the tip of the main body 1. It is pivotally supported by a straight type tool holder 30' via a ball bearing. The transmission 20
As shown in FIG. 1, an engagement sleeve 311 having the same structure as the engagement sleeve 121 described above is fixed to the zero side, and the output intermediate shaft of the transmission (in deceleration mode, the conical receiver shaft 251 or In the fast mode, the conical shaft 221 is fixed to the conical shaft 221. The case 20 of the transmission 200 has a cylindrical shape, and is composed of two halves 20a and 20b that are screwed together to house the rotation transmission mechanism 210, and the drive part case 10 of the main body 1 is attached to both ends of the case 20. It also has a connecting screw part that can be screwed into both the tool holders 30 and 30', and the conical shaft 221 and the conical receiver shaft 251 are rotatably connected to each other via ball bearings 222 and 252, respectively. I support you. Further, the case segment 20a on the conical receiver side has notches 21a corresponding to guide grooves 242 of a holder guide to be described later. An operating sleeve 26, which will be described later, is provided on the outer periphery of the case segment 20b on the conical side.
A threaded portion 20'b is machined into which the 0' is screwed forward and backward. Engagement sleeves 223 and 25 of the same structure are provided at the ends of the respective shafts 221 and 251 and can be engaged with either of the drive shaft side engagement sleeve 121 and the actuation shaft engagement sleeve 311 or 311'.
3 is stuck. Shaft small diameter portion 2 of conical shaft 221
A coil spring 224 that applies preload for rolling contact to the ball 213 is inserted through 21', and urges the conical body 220 toward the conical receiver 250 from the shaft step. (This coil spring can also have a structure in which the conical receiver shaft 251 is provided with a small diameter portion so that the conical receiver 250 is biased toward the conical body 220 from the stepped shaft portion.) Ball planetary rotation transmission mechanism The conical body 220 of 210 has a conical shape with an apex angle of approximately 60 degrees, and has a hole 225 coaxially inserted through the small diameter portion 221' in the center thereof, and has a cylindrical protruding portion 220'. The long hole 220'a is connected to the shaft small diameter portion 221' by a pin 226 so as to be able to freely move back and forth in the axial direction and restrained in the rotational direction. By being movable in the axial direction, it not only absorbs machining errors, but also can cope with wear of the balls 213, etc., and always maintains a constant preload on the balls 213.
...can be applied. The ball holder 230 holds, for example, four rolling steel balls 213 arranged around the circumference at 90 degree intervals on the outer peripheral surface of the cone 220, and holds the balls 213 along the generatrix of the cone 220. It moves forward and backward, and the outer end 23
2', the tapered surface 2 of the operating means 260
61 and the guide rod 232 and the inner end 233'
The outer body 231 of the holding body is composed of a seat body 233 that is a concave spherical seat that contacts the ball 213, and the outer body 231 and the balls 213 are opposed to each other, and the outer end 236' is connected to the ball 213. It has a seat body 236 that is a concave spherical seat that contacts, and an inner end portion 237 is connected to the holder guide 2 by a coil spring 243.
40, the internal division body 235 of the holding body is a small-diameter guide rod that is elastically supported from the bottom of the guide groove 242, passes through the coil spring 243, and is slidably inserted into the insertion hole 244. Holder guide 2
40 has a funnel shape with an apex angle equal to or larger than that of the cone 220, and has a diameter of, for example, 90 mm in the circumferential direction.
The forward and backward movement of the ball holder 230, which holds the balls 213, is guided by four guide grooves 242 along the generatrix line, which are provided at intervals of 100 degrees. The bottom of each groove 242 seats one end of the coil spring 243, and the coil spring 24
A small hole 244 for guiding the small diameter guide rod 237 of the inner division body 235 of the holding body, which is inserted through the holding body 3, is bored in the generatrix direction. The large diameter part of the funnel shaped part 241 surrounding these four grooves 242 is a cylindrical part that supports the holder guide 240 by being fitted into the large diameter part in the case 20 of the transmission. 245 are connected together. The cylindrical portion 245 is
The guide rod 2 is coaxially aligned with the small hole 244.
The conical receiver 250 has a hole 246 in the shoulder 245' for guiding the ball holder 230, and has a funnel shape, surrounds the ball holder 230 and the holder guide 240, and has a hole 246 on the inner peripheral surface. When the balls 213 held by the holding body 230 come into contact with each other, they are rotationally driven. In this embodiment, the conical receiver 250
The conical receiver shaft 2 is coaxially centered at its top.
It is integrally connected to 51. The operating means 260 is
It consists of a short cylindrical sleeve 260' and is screwed into the threaded part 20'b on the outer periphery of the transmission case 20 via an inner periphery screw 260'. It moves forward and backward by rotating. This operation sleeve 2
A tapered surface 261 is formed at one end of the holder 60', and when the tapered surface moves in the direction of arrow A, the semicircular outer end 2 of the outer portion 231 of the holding body
32' and presses it inward in the longitudinal direction to move the holding body 230 a certain distance together with the ball 213, and when it moves in the direction of arrow B, the spring 243
The holding body 230, which is urged outward by the ball 213, is moved outward by a certain distance together with the ball 213.

To explain how to use the transmission with the above configuration, when using it in the deceleration mode, as shown in FIG. The transmission 200 is coupled to the drive unit case 10 and the tool holder 30 or 30' so as to engage the drive unit case 10 and the tool holder 30 or 30', respectively. By moving the operation sleeve 260' in the direction of arrow A, the ball holder 230 is pushed by the tapered surface 261 and moves inward, so that the ball 21
3... is a conical body 220 and a funnel-shaped conical receiver 25
If the diameter at the point of contact between the conical body 220 and the ball 213 is a, and the diameter at the point of contact between the conical receiver 250 and the ball 213 is b, then the speed reduction ratio of the ball 213 is Since it is calculated as a/(a+b) at each position, the reduction ratio gradually increases. Operation sleeve 26
0' in the direction of arrow B, the ball holder 2
30 moves outward along the tapered surface 261, the balls 213... roll near the bases of the conical body 220 and the conical receiver 250, and the reduction ratio gradually decreases. Furthermore, if several transmission devices 200 with different diameters of balls 213 are prepared, as the diameters of balls 213 are sequentially increased, the reduction ratio gradually increases, and the range of speed change can be further expanded. When used in the speed increase mode, the transmission 200 is connected to the drive unit case 10 and tools so that the conical shaft 221 is engaged with the operating shaft 300 or 300' and the conical receiver shaft 251 is engaged with the drive shaft 100. Connected to holder 30 or 30'. The speed increase ratio is the reciprocal of the speed reduction ratio and is calculated as (a+b)/a, and moving the operating sleeve 260' in the direction of arrow A increases the speed increase ratio, and vice versa. As the vehicle moves, the speed increasing ratio becomes smaller. Similarly to the above, if a ball 213 with a large diameter is selected, the speed increasing ratio gradually increases. In addition, conical receiver 2
The generatrix of 50 is not necessarily parallel to the generatrix of cone 220. Further, in this embodiment, the operating means 260 is configured to be screwed into the outer circumferential threaded portion of the case 20 of the transmission so that it can move forward and backward.
Prior art lever operations used to tighten or release the chuck of the handpiece (e.g.,
43289) may be used.

As described above, according to the transmission 200 of the present invention, the transmission 200 is connected to the handpiece body so that the conical shaft 221 is connected to the drive shaft 100 and the conical receiver shaft 251 is connected to the operating shaft 300 or 300'. A deceleration mode can be obtained by incorporating the conical shaft 251 into the drive shaft 100 so as to connect the conical shaft 221 to the operating shaft 300 or 300'. At the same time, by moving and operating the operation sleeve 260' provided on the outer periphery of the case in any of these speed change modes, the speed change ratio can be changed steplessly regardless of whether it is being driven or not. This has the extremely large effect of greatly improving operability. Further, since the ball planetary rotation transmission mechanism 210 is employed, vibrations are reduced, and discomfort caused by vibrations to the patient during treatment is significantly reduced. Furthermore, this transmission device 20
0 can change the gear ratio steplessly,
Since the air motor and electric motor, which are the drive sources, can be operated at the maximum efficient rotation speed, the efficiency of medical treatment can be improved and energy consumption can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway longitudinal sectional view of a handpiece to which the transmission of the present invention is mounted in deceleration mode, FIG. 2 is a longitudinal sectional view of the main parts of the transmission, and FIG. 4 is a perspective view of the holding body guide; FIG. 5 is a perspective view of the outer portion of the holding body; FIG. 6 is a longitudinal sectional view taken along the - cutting line of FIG. 5; The figure is a perspective view of the internal division of the holding body. Explanation of symbols, 1...Handpiece body, 20...
...Transmission case, 100...Drive shaft, 200
...Transmission device of the present invention, 210...Ball planetary rotation transmission mechanism, 213...Ball, 22
0... Cone, 230... Ball holder, 231
...External part of the holding body, 232...Guide rod at the outer end, 233...Seat body at the inner end, 233'...
The same spherical seat, 235... Internal division of the holding body, 236...
...The seat body at the outer end, 236'...The same spherical seat, 23
7... Guide rod at the inner end, 240... Holder guide, 241... Funnel shaped part, 242... Same guide groove, 245... Same cylindrical part, 250... Conical receiver, 260... ...Operating means, 261... Tapered surface, 300, 300'... Operating shaft.

Claims (1)

[Scope of Claims] 1. Two opposing rotating shafts 100, 300, or 300', each rotatable by a receiving shaft.
Handpiece transmission device 2 that changes speed and connects the shaft.
In 00, the transmission device 200 rotatably connects a cone body 220 connected to the rotating shaft 100, 300, or 300', and a plurality of balls 213 disposed around the outer peripheral surface of the cone body 220 and rolling in contact with each other. A ball holder 230 that holds the balls 213 and moves them back and forth along the generatrix of the cone;
The transmission device 2 guides the forward and backward movement of the holding body 230.
A funnel-shaped holder guide 240 is installed inside the case 20 of 00, and the ball holder 230 and the holder guide 240 are bent to form a funnel shape on the inner peripheral surface of which the balls 213 roll into contact. death,
It has a conical receiver 250 connected to the rotating shaft 300 or 300', 100, and an operating means 260 for moving the ball holder 230 forward and backward, and controls the rotation of the driving side rotating shaft 100 to the driven side. A speed change device for a medical handpiece, characterized in that a speed change transmission mechanism 210 for selectively transmitting speed by steplessly decelerating or speeding up is built into a rotating shaft 300 or 300'. 2. A guide rod 232 in which the ball holder 230 contacts the tapered surface 261 of the operating means 260 at its outer end 232', and a seat body 233 having a concave spherical seat in which the inner end 233' contacts the ball 213.
and a seat body 236 that faces the outer body 231 across the balls 213 and has a concave spherical seat with an outer end 236' in contact with the balls 213. , and the inner end 237 is connected to the holder guide 240 by the coil spring 243.
2. The transmission according to claim 1, further comprising an inner division body 235 of a holding body, which is a small-diameter guide rod elastically supported from the bottom of the guide groove 242. 3 The holding body guide 240 is connected to the conical body 220
and the conical receiver 250, a funnel-shaped portion 241 having a plurality of guide grooves 242 circumferentially bored in its funnel-shaped peripheral wall for accommodating the ball holders 230; The case 20 of the transmission 200 is connected to the large diameter end of the shaped portion 241.
2. The transmission according to claim 1, further comprising a cylindrical portion 245 fitted therein.