JP2001124102A - Joint structure of rotary shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint structure of a rotary shaft capable of joining a rotary shaft without applying excessive force, and being lightly rotated even when the centers of a rotor and a shaft are slightly disagreed with each other, or the rotor is slightly inclined. SOLUTION: This joint structure has a projecting side joint 31 having a cylindrical part, a recessed side joint 30 comprising a circular space part 16c capable of freely fitting the cylindrical part 19, at least one projection 22 formed in the direction crossing a rotary shaft of the projecting side joint, a groove 16d formed on the recessed side joint and enabling the projection to be entered therein, and a ring-shaped member 21 mounted on an outer periphery of the cylindrical part and having a toroidal-shaped outer peripheral surface, and the toroidal-shaped outer peripheral surface of the ring member is slidably contacted with an inner peripheral surface of the circular space part 16c. As a shaft 19 as the cylindrical part is oscillatable, the disagreement of the center of the hole 16c with that of the shaft 19 can be absorbed by the oscillation, even when the disagreement exists.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for connecting two rotating shafts arranged substantially on the same axis, and more particularly to a joint structure between a rotary sensor and a shaft connected thereto.

[0002]

2. Description of the Related Art As a non-contact type rotary sensor using a Hall element, the applicant has proposed a non-contact type rotary sensor shown in FIG. 3 in Japanese Patent Application No. 11-255409. The rotary sensor 10 includes a first stator 11 having two magnet-facing sides 11a and 11b, a second stator 12 having one magnet-facing side 12a, and a Hall element 13 disposed therebetween. Movable magnet 14, 1
5 and a rotor 16 for fixing these movable magnets.

The three magnet facing sides 11a, 11b, 1
2a are arranged on the same circular arc, and substantially form a circle as a whole. On the other hand, the movable magnets 14 and 15 are curved plate-like magnets having the same center of curvature as the arc on the side facing the magnet, and are arranged along the arc, and the rotor 16 rotates along the arc as shown by the arrow.

In this example, when the movable magnets 14 and 15 move along a circular arc, the magnetic flux passing through the Hall element 13 changes. By detecting this, the rotation angle of the rotor can be detected. Since the lengths of the two magnet-facing sides 11a and 11b of the first stator 11 can be freely set, a desired use angle can be set, and the resolution can be increased within that range.

FIG. 4 is a sectional view showing a state where the rotary sensor is assembled, and FIG. 5 is a sectional view taken along line BB of FIG. As shown in FIG. 4, a first stator 11 and a second stator 12 are provided in a case 17, and a Hall element 13 is inserted between them.

The space in which these are fitted in the case 17 is closed by a cover 18. The cover 18 has a center pin 18a, which passes through the first stator 11 and In the bearing hole 16a.

Usually, the rotor 16 is provided with
Due to the attraction force of 5, the plate magnets 14 and 15 generate a biasing force to approach the first and second stators 11 and 12, but the center pin 18 a causes the bearing hole 16 a of the rotor 16 to move.
The operation accuracy is maintained by the slight play between the center pin and the bearing hole being brought to one side, so that the rotor 16 can rotate lightly. Further, even when the rotor 16 is displaced in the length direction of the center pin 18a, the rotor 16 is attracted to a certain position by the attraction between the plate-like magnets 14, 15 and the first and second stators. As described above, this type of rotary sensor has the advantage that the rotor is less likely to oscillate even with vibration, and as a result, the output does not fluctuate.

A hole 16b is formed on the opposite side of the rotor 16, and a mating shaft 19 is fitted into the hole 16b.
As shown in the figure, at the tip of the shaft 19, there is a cut portion 19a called a D-cut due to its cross-sectional shape.
b also has the same shape as the D cut portion 19a of the shaft portion, and when the D cut portion 19a fits into the hole 16b, one rotation can be transmitted to the other.

[0009]

However, when the shaft 19 and the hole 16b are fitted together, it is only necessary that both cores completely coincide with each other. However, in reality, there is usually some deviation. is there.

For example, if there is a shift δ as shown in FIG.
Both are deformed little by little, such as by bending the shaft 19 or tilting the rotor 16 and joining. For this reason, an excessive force is applied to both the shaft and the rotor, the fitting between the bearing hole 16a of the rotor and the pin 18a becomes tight, and the rotation of the shaft 19 and the rotor 16 becomes heavy.

Further, there is a slight play between the center pin 18a and the hole 16b. As described above, the play is offset by the attraction of the magnet. The rotor 16 is always in a state where the neck is inclined. Therefore, when the rotor 16 rotates around the shaft 19 as a core, there is a problem that the center is shifted between the center of the first stator 11 and the center of the rotor 16 and an accurate output change does not occur.

The present invention has been conceived in view of such a fact. Even if there is a slight deviation between the two shaft cores, such as the rotor and the shaft, or if one of the shafts is slightly inclined, an excessive force is applied. It is an object of the present invention to propose a joint structure of a rotating shaft that can be coupled without adding a shaft and that can rotate lightly.

[0013]

In order to achieve the above object, the present invention provides a convex joint having a cylindrical portion, a concave joint having a circular space into which the cylindrical portion is loosely fitted, and a convex joint. One or more protrusions formed in one of the side joint and the concave side joint and formed in a direction crossing the rotation axis; a groove formed on one of the other such that the protrusion enters; A ring-shaped member provided on the outer periphery and having a toroidal outer peripheral surface, wherein the toroidal outer peripheral surface of the ring-shaped member comes into sliding contact with the inner peripheral surface of the circular space portion.

A structure in which an annular expansion suppressing member is fitted to the outside of the concave joint, or a pin in which the protrusion penetrates the cylindrical portion and protrudes to both sides, the groove allows the pin to enter. As described above, the concave joint may be formed at positions that are both ends of the string.

Alternatively, one of the concave side joint and the convex side joint is integrally connected to a rotor of a rotary sensor, and the rotary sensor has a first stator in which two magnet-facing sides are spaced apart on the same arc. And a second intermediate portion between the two magnet facing sides and having one magnet facing side in the arc shape.
A rotor having a stator, a Hall element provided between the first and second stators, and two plate-shaped magnets arranged along an arc outside the three magnet-opposing sides; Are rotatably supported on the side facing the first stator by a center pin.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view showing an example in which the joint structure of a rotating shaft according to the present invention is applied to a rotary sensor.
FIG. 2 is a view of a main part of the joint structure, and FIG.
FIG. 2A is a cross-sectional view, and FIG. 2B is a bottom view of FIG. Portions that are the same as those described in the conventional example are denoted by the same reference numerals, and different configurations will be mainly described.

The portion of the rotor 16 to which the mating shaft 19 is fitted is a hollow pipe having a hole 16c as a circular space, and the four grooves 1 are arranged at substantially equal intervals from the tip end surface.
6d is formed in a direction parallel to the central axis. These grooves 16d are two sets of grooves facing each other, but one set of grooves 1
6d and 16d are arranged at both ends of an arbitrary chord of the hole 16c, and are formed so as to be aligned on one straight line. In the embodiment, this string has the diameter of the hole 16c.

Further, on the outer side, an expansion suppressing member 20 formed of a C ring formed by bending a steel round bar into a C shape is fitted. The expansion suppressing member 20 is for suppressing the hole 16c from the outside by elasticity of the C-ring so as not to expand. The above configuration on the rotor 16 side is referred to as a concave side joint 30.

The shaft 19 on the partner device side as a cylindrical portion
Is a round cylinder not cut into a D-shape unlike the conventional example. And at this tip,
An arc-shaped groove is formed in which a ring-shaped member 21 made of a C-ring is fitted. This ring-shaped member 21
Is a steel round bar bent into a C-shape, and the outer peripheral surface 21a
Is the same toroidal surface as the outside surface of the donut.

At a position slightly away from the ring-shaped member 21 of the shaft 19, a projection 22 formed of a pin penetrating the shaft 19 is provided. Pin is shaft 1
9 and is firmly fixed. Protrusion 22
Project on both sides of the shaft 19 and have a concave joint 30
Since the pair of grooves 16d, 16d formed on both sides of the chord are located on the both sides of the string, it is possible to enter these grooves 16d. Protrusion 2
The thickness of 2 is a thickness that is lightly pressed into the groove 16d. The joint portion of this cylindrical portion on the shaft side is
I will say that.

The shaft 19 itself has a hole 16 in the rotor 16.
The relationship is smaller than the diameter of c, a gap is formed, and the fitting is loose. However, the outer diameter of the ring-shaped member 21 fitted near the tip of the shaft 19 is slightly larger than the hole 16c, and is large enough to be lightly press-fitted and fit. Then, the protrusion 22 of the shaft 19 is inserted into the groove 16 of the rotor 16.
When the shaft 19 is lightly pressed into the hole 16c in accordance with the distance d, the projection 22 fits into the groove 16d and the ring-shaped member 21 fits into the hole 16c without any gap as shown in FIG. The expansion suppressing member 20 is moved from the outside of the hole 16 c to the hole 16.
In order to prevent c from expanding and to prevent play between the groove 16d and the projection 22. The groove 16d is sufficiently deep, and the protrusion 22 is located far away from the bottom of the groove 16d. The depth at which the shaft 19 is inserted is the plate-like magnet 1
The position of the rotor 16 when attracted to a certain position is adjusted by the attraction force between the first and second stators 4 and 15.

It is assumed that the shaft 19 is connected to, for example, a throttle valve, and the opening of the throttle valve is transmitted as rotation of the shaft 19. In that case, when the shaft 19 rotates, the rotation is caused by the protrusion 22 and the groove 1.
The rotation of the rotor 16 is transmitted by the fitting of 6d, and the rotation angle is detected by the rotary sensor 10.

In the case where the rotor 16 and the shaft 19 are connected, there is a shift δ as described with reference to FIG. The shaft 19 is inclined with respect to the hole 16c as shown by the imaginary line 19 'in FIG. However, the outer peripheral surface 21 of the ring-shaped member 21
Since a is a toroidal surface, it can always be kept in sliding contact with the inner wall of the hole 16c, and the displacement δ is absorbed without difficulty. Further, the projection 22 can also swing in the groove 16d as shown by the arrow. That is, even if there is a deviation δ, the shaft 19
Is in a state in which the head can be swung, no force such as bending is applied to any of them, and the rotation can be performed by rotating lightly. On the other hand, the rotor 16 also swings at a slight angle as described above, but with this configuration, this swing of the rotor 16 is also allowed.

At this time, the axial distance a between the ring-shaped member 21 fitted to the shaft 19 and the projection 22 is preferably as small as possible. The smaller the distance b between the ring-shaped member 21 and the expansion suppressing member 20, the better, and preferably 0. With the above configuration, the swing angle becomes large, the operation becomes light, and the rattling is eliminated, so that the operation hysteresis does not occur.

Further, the plate magnets 14 and 15 are attached to the rotor 16.
And the load caused by the first and second stators 11 and 12, the rotation center of the rotor hardly changes due to the load.
The force is hardly applied to the joint between the rotor 16 and the shaft 19.

In the above structure, smooth operation cannot be obtained for the entire 360 °, and the range of smooth operation is about 120 °. However, there are many devices with a rotation range of 90 ° or less, such as when used for a throttle body.
That's enough.

[0027]

As described above, according to the present invention, a convex joint having a cylindrical portion, a concave joint having a circular space in which the cylindrical portion is loosely fitted, a convex joint and a concave joint are provided. One or more protrusions formed in one of the joints in a direction crossing the rotation axis, a groove formed on the other such that the protrusions enter, and fitted on the outer periphery of the cylindrical portion. A ring-shaped member having a toroidal outer peripheral surface, and the toroidal outer peripheral surface of the ring-shaped member comes into sliding contact with the inner peripheral surface of the concave joint, so that the concave joint and the convex joint Even if there is a misalignment between the cores, the joint can be absorbed and connected by swinging the joint. And since no excessive force is applied to either side, smooth and accurate operation is possible.

By adopting a structure in which an annular expansion suppressing member is fitted to the outside of the concave joint, it is possible to prevent the circular hollow portion of the concave joint from enlarging and causing rattling and inaccuracies.
One of the concave-side joint or the convex-side joint is integrally connected to a rotor of a rotary sensor, and the rotary sensor has a first stator in which two magnet-facing sides are spaced apart on the same arc; A second stator intermediate the magnet-facing sides and having the one magnet-facing side in the arc shape, a Hall element provided between the first and second stators, and a circular arc outside the three magnet-facing sides. And a rotor having two plate-shaped magnets arranged in such a manner that the rotor facing the first stator is rotatably supported by a center pin. , Because the rotor itself can be swung, the friction is small,
Smooth and accurate joint operation can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment in which a joint structure of a rotating shaft according to the present invention is applied to a rotary sensor.

FIG. 2 is a view of a joint structure portion of FIG. 1; FIG.
FIG. 2A is a cross-sectional view, and FIG.

FIG. 3 is a diagram of a conventional example of a rotary sensor.

FIG. 4 is a sectional view showing an assembled state of the rotary sensor of FIG. 3;

FIG. 5 is a sectional view taken along line BB of FIG. 4;

FIG. 6 is a view of a joint portion between a rotor and a shaft of the rotary sensor of FIG. 4;

[Explanation of symbols]

 11 First stator 11a, 11b Opposite sides of (two) magnets 12 Second stator 12a Magnet opposite sides 13 Hall element 14, 15 Plate magnet 16 Rotor 16c Circular space 16d Groove 18a Center pin 19 Shaft (column) 20 Expansion Opening suppression member 21 Ring-shaped member 21a Outer peripheral surface 22 Projection 30 Concave joint 31 Convex joint

Claims (4)

[Claims] 1. A convex joint having a cylindrical portion, a concave joint having a circular space portion into which the cylindrical portion is loosely fitted, and a rotary shaft in one of the convex joint and the concave joint. A ring-shaped member having one or more protrusions formed in the intersecting direction, a groove formed on one of the other such that the protrusions enter, and a toroidal outer peripheral surface provided on the outer periphery of the cylindrical portion; Wherein the outer peripheral surface of the toroidal shape of the ring-shaped member is in sliding contact with the inner peripheral surface of the circular space portion. 2. A joint structure for a rotating shaft according to claim 1, wherein an annular expansion suppressing member is fitted outside said concave joint. 3. The method according to claim 1, wherein the projection is a pin that penetrates through the cylindrical portion and protrudes to both sides, and the groove is formed at a position at both ends of a chord of the concave joint so that the pin can enter. The joint structure for a rotating shaft according to claim 1 or 2, wherein: 4. A first stator in which one of the concave-side joint and the convex-side joint is integrally connected to a rotor of a rotary sensor, and the rotary sensor has two magnet-opposed sides spaced apart on the same arc. A second stator intermediate the two magnet-facing sides and having one arc-facing side in the arc shape; a Hall element provided between the first and second stators; A rotor having two plate-shaped magnets arranged along an outer arc, and the rotor facing the first stator is rotatably supported by a center pin. The joint structure for a rotating shaft according to any one of claims 1 to 3.