JPH0160384B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotation transmission device that drives a rotating shaft, and particularly when a hydrostatic bearing is used in the support of a main shaft that requires a large driving force, such as in a cam copying machine. The present invention relates to a rotation transmission device that can be applied to devices that require low noise and low vibration.

A conventional device of this kind is shown in FIG. 1, in which numeral 1 denotes a housing, which has an inner hole 1a formed therein and is supported by a bed 2. Reference numeral 3 denotes a bearing, which is fitted and fixed in the inner hole 1a, and annular gaps 3b are formed in the inner peripheral surface near both ends of the bearing surface 3a, which is bored concentrically with the inner hole 1a. ing. Reference numeral 4 denotes a main shaft, which has a flange portion 4a formed at one end, a tapered portion 4b at the other end, and a screw 4c cut into the shaft end surface in the direction of the central axis.

Further, a fluid supply/discharge path (not shown) is communicated with the bearing 3, and the pressure fluid supplied from the fluid supply device (not shown) generates a static pressure in the gap 3b corresponding to the outflow resistance. The main shaft 4 is rotatably supported by this static pressure. A thrust plate 5 is fastened to the end face of the bearing 3 and rotatably supports the main shaft 4. Reference numeral 6 is a pulley, which is fitted and supported by the tapered portion 4b of the main shaft 4, and has stepped portions 6a on the outer peripheral surface of both ends.
A belt 7 for transmitting power is wound along the outer peripheral surface of the pulley 6 between the stepped portions 6a. Reference numeral 8 designates a mounting bolt which is screwed into the screw 4c, thereby holding the pulley 6 through the end washer 9. Reference numeral 10 is a pulley which is engaged with an output shaft 12 of an electric motor 11 supported within the bed 2, and the belt 7 is tensioned around the outer peripheral surface of the output shaft 12. Reference numeral 13 designates a bracket for the electric motor 11, and a plurality of mounting holes are drilled around the periphery of the bracket.Mounting bolts 14 are passed through these mounting holes and screwed onto the bed 2, thereby attaching the bracket to the motor 11. 13 is fixed.

However, with the above configuration, for example, when the high-speed rotational accuracy of the main shaft 4 is set to 0.1 μm or less, various problems occur and it is difficult to obtain the desired rotational accuracy.

That is, the factors and phenomena that can be considered as these problems are: (1) The bending moment due to the torque of the electric motor 11 and the tension of the belt 7 acts directly on the tapered portion 4b.

(2) Since the thickness or rigidity of the belt 7 is not uniform, the tension of the belt 7 fluctuates intermittently, and the resulting bending moment acts directly on the tapered portion 4b.

(3) Vibrations generated by the rotation of the electric motor 11 act on the tapered portion 4b of the main shaft 4 via the pulley 10, belt 7, and pulley 6.

As a result, the spindle 4 causes a whirling phenomenon, which adversely affects the precision of high-speed rotation of the spindle 4. As a countermeasure against such a phenomenon, it may be possible to increase the rigidity of the main shaft 4 and the bearing 3, but this is not preferable because it causes an increase in the size of the device and an increase in manufacturing costs. Furthermore, a coupling equipped with a load reducing device or a vibration isolating device may be considered as a substitute for the pulley 6, but this does not completely eliminate the influence of the bending moment on the main shaft 4.

The present invention solves the above problems and provides a rotation transmission device that can separate torque and bending moment, transmit only torque to the main shaft, and prevent vibrations in the system from affecting the main shaft. .

In order to achieve the above object, the present invention includes a hollow boss disposed with a gap around a main shaft rotatably supported by a housing via a bearing and supported by the housing; A pulley that rotates via the main shaft, a coupling boss supported by the main shaft, and a pin that is simultaneously inserted via an elastic body into holes opened in the opposing surfaces of the coupling boss and the pulley, respectively. That is.

2 and 3 showing embodiments of the present invention will be explained below. Note that the same parts as in FIG. 1 are designated by the same reference numerals. Reference numeral 15 is a hollow pulley, and stepped portions 15a are formed on the outer peripheral surface of both ends of the pulley 15. Reference numeral 15b is an inner hole with a diameter larger in the vicinity of both ends than in the center, into which a pair of rollers fit the bearing 16. This rolling bearing 16 is composed of an outer ring 16a that fits on the pulley 15, an inner ring 16b that fits on a boss 18 (described later), and balls 16c inserted between them. There is. Reference numeral 18 is a boss, a flange portion 18a is formed in one body, the inner peripheral surface thereof is formed to have a gap 20 with respect to a main shaft 26 to be described later, and a mounting hole is drilled concentrically with the central axis in the peripheral portion thereof. , is fixed to the housing 1 with mounting bolts (not shown). 18b is a small diameter part of the boss 18,
A screw 18c is formed on the outer circumferential surface of the shaft end, and a nut 19 is screwed into the screw 18c to hold the rolling bearing 16 through and hold the inner ring 1.
Holds 6b. 18d is an inner hole of the boss 18, and the inner hole 18d concentrically surrounds the main shaft 26 having an inner hole 26a, and has an annular gap 20 therebetween. Numeral 21 is a coupling boss having an inner hole 21a, and is pressed and supported on the outer circumferential surface of the shaft end of the main shaft 26 via a connecting body 22, which will be described later. 15c and 21b are open holes at one end facing each other, and a main shaft 26 is formed on the opposing shaft end surfaces of the pulley 15 and the coupling boss 21.
A plurality of pins are formed at equal intervals on the same circumference centered on the central axis of the pulley 15, and a cylindrical pin 23 is inserted into the pin through an annular rubber body 24 to connect the pulley 15 and the coupling boss. 21 are fitted with a certain gap 25 between them. 22 is a connecting body, which includes an outer ring member 22a and an inner ring member 22b.
and two pressure ring members 22c and 22d inserted between them. The outer ring member 22c has an outer circumferential surface fitted into the inner circumferential surface of the inner hole 21a, and the inner circumferential surface is formed into two tapered surfaces such that the center portion thereof has the smallest diameter. The inner ring member 22b has an inner circumferential surface fitted onto the outer circumferential surface of the main shaft 26, and the outer circumferential surface has two tapers having the same inclination angle as the tapered surface of the outer ring member 22a so that the center portion has the largest diameter. forming a surface.

The two pressure rings 22c and 22d are inserted between the tapered surfaces of the outer ring member 22a and the inner ring member 22d so as to face each other, and are fastened together with pressure bolts 22f. pressure bolt 2
When 2f is tightened, the outer peripheral surface of the outer ring member 22a and the inner ring member 22b approach each other.
The inner circumferential surface of the holder is moved outward. 27
is the thrust plate.

With the above configuration, bending moment and torque originating from the belt 7 act on the pulley 15 when the electric motor 11 rotates. This bending moment is transferred to the housing 1 through the rolling bearing 16.
It acts on the boss 18 fixed to. This boss 18
It is clear that the bending moment does not act on the main shaft 26 because the gap 20 is provided between the main shaft 26 and the main shaft 26 . Furthermore, the damping effect of the 24 rubber bodies into which the pins 23 are fitted helps to reduce the bending moment. Also, the torque is pulley 1
5 to the pin 23 and the rubber body 24, and is transmitted to the main shaft 2 via the coupling boss 21 and the connecting body 22.
6 to rotate. On the other hand, the output shaft 1 of the electric motor 11
The vibrations generated as the belt 2 rotates are attenuated by the belt 7, but this damping effect is not sufficient and is transmitted to the pulley 15, albeit slightly. This vibration system is damped by the frictional resistance unique to the balls 16c of the rolling bearing 16. The air gap 20 also serves to isolate the boss 18 and the main shaft 26 with respect to vibrations as well as the bending moments described above. On the other hand, vibrations reaching the rubber body 24 are attenuated by the damping effect of each rubber body 24. Therefore, vibrations are not propagated to the main shaft 26. In the above embodiment, the bending moment is applied to one end of the main shaft passing through the bearing 3 that supports the main shaft 26, but two bearings 3
Even if the main shaft 26 is arranged at a distance from each other, and the main shaft 26 is arranged so as to pass through between the bearings 3, and a bending moment is applied between both the bearings 3, the intended purpose cannot be sufficiently achieved. The present invention also includes such application examples.

As described above, the present invention comprises: a hollow boss disposed with a gap around a main shaft rotatably supported by a housing via a bearing; and a hollow boss supported by the housing; A pulley that rotates at the same time, a coupling boss supported by the main shaft, and a pin that is simultaneously inserted through an elastic body into holes opened in the opposing surfaces of the coupling boss and the pulley, respectively. It is possible to prevent the bending moment due to the tension of the belt 7 from acting on the main shaft 26, and also to prevent the vibration system generated by the electric motor 11 from propagating to the main shaft 26. This has the effect that the whirling phenomenon of the main shaft 26 can be eliminated and the high-speed rotation accuracy of the main shaft 26 can be significantly improved.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the conventional device, Fig. 2 is a sectional view of an embodiment of the inventive device, and Fig. 3 is a sectional view of an embodiment of the device of the present invention.
The figure is a detailed view of FIG. 2. 1...Housing, 15...Pulley, 16...
Rolling bearing, 18...Boss, 20...Gap, 2
1...Cup ring boss, 23...Pin, 24...
...Rubber body, 25...Gap, 22...Connection body, 26
...Main axis.

Claims (1)

[Claims] 1 A main shaft whose one end is rotatably supported by a housing via a bearing, a hollow boss into which the other end of the main shaft is inserted through the air and supported by the housing, and a bearing is attached to this boss. A pulley rotatably supported through the pulley, a coupling boss supported by the main shaft, the outer circumferential surface of which is covered with an elastic material, and which are simultaneously inserted into holes opened in opposing surfaces of the coupling boss and the pulley, respectively. A rotation transmission device characterized by being provided with a pin.