JPH10281171A - Friction type rigid shaft coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction type rigid shaft coupling performing rapid and easy work to intercouple shafts, compact, reduced in weight and inertia efficiency, simplified in structure, and reduced in cost. SOLUTION: A friction type rigid shaft coupling comprises a pair of shaft fastening parts 8 and 9 arranged at both sides of a nut part 6; a fastening sleeve 2 having a shaft hole 5 in which shafts X and Y are fitted; and a pair of fastening rings 3 and 4 fitted in the outer peripheral surfaces of respective shaft fastening part. The concentric cylindrical outer peripheral surfaces 10 and 11 of shaft fastening parts 8 and 9 are fitted in the concentric cylindrical inner peripheral surfaces 14 and 16 of the fastening ring and eccentric cylindrical outer peripheral surfaces 12 and 13 are respectively fitted in eccentric cylindrical inner peripheral surfaces 15 and 17. By rotating the fastening rings 3 and 4 based on a fastening sleeve 21, radial displacement in an axial direction occurs to the fastening parts 8 and 9, and the shafts X and Y are fictionally and respectively fixed on the inner peripheral surface of a shaft hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction type rigid shaft coupling for connecting two opposing shafts and transmitting rotation between the two shafts.

[0002]

2. Description of the Related Art Conventionally, a shaft coupling used for transmitting rotation between two opposing shafts, for example, between a motor shaft and a ball screw shaft, has conventionally been a friction type having a structure as shown in FIGS. Rigid shaft couplings are used.

[0003] The shaft coupling shown in FIG. 17 has an inner ring C1 fitted externally across a shaft A1 and a shaft B1 whose end faces are opposed to each other.
And a pair of tapered rings D1 and E fitted on a middle and high tapered surface formed on the outer periphery of the inner ring C1.
1 and a plurality of tightening bolts F1 arranged at regular intervals in the circumferential direction of the respective tapered rings D1 and E1 to draw the tapered rings D1 and E1 in the axial direction.

In this shaft coupling, when the tightening bolt F1 is tightened, the tapered ring D1 and the tapered ring E1 approach each other, and the tapered surface of the outer periphery of the inner ring C1 is pressed radially inward.
The inner peripheral surface of the tapered ring D1 is pressed against the respective outer peripheral surfaces of the shaft A1 and the shaft B1, and the tapered ring D1 and the two shafts A1, B1
The shaft A1 and the shaft B1 are fastened via the shaft coupling by the friction therebetween.

The shaft coupling shown in FIG. 18 has an inner ring C2 fitted over the shaft A2 and the shaft B2, an outer ring D2 concentrically disposed outside the shaft, and an outer periphery of the inner ring C2. A pair of tapered rings F2, G2 fitted from both sides between a middle and high tapered surface formed on the inner surface of the outer ring D2 and a tapered surface formed on the inner periphery of the outer ring D2. Taper ring F
2, a plurality of tightening bolts H2 for drawing the two G2s in the axial direction.

In this shaft coupling, when the tightening bolt H2 is tightened, the tapered ring F2 and the tapered ring G2 approach each other, and wedges are formed on both sides of the annular gap between the tapered surface of the inner ring C2 and the tapered surface of the outer ring D2. 17, these tapered rings F2 and G2 press the tapered surface of the outer periphery of the inner ring C2 radially inward in the same manner as that of FIG. 17 described above, and by the elastic deformation of the inner ring C2,
The shaft A2 and the shaft B2 are fastened.

At this time, the tapered rings F2 and G2 receive a radially outward reaction force from the inner ring C2, but the tapered rings F2 and G2 expand radially outward due to the tapered surface of the inner periphery of the outer ring D2. Deformation is suppressed,
The two shafts A2 and B2 can be more firmly fastened than the shaft coupling of FIG. 17 described above.

[0008]

In the conventional shaft coupling as described above, when fastening two shafts, it is necessary to equally tighten a large number of tightening bolts. There is a necessary problem, and it is necessary to secure a large working space in the axial direction of the shaft coupling for tightening the tightening bolts arranged in the axial direction.

Further, since the outer diameter of the shaft coupling is larger than the diameter of the shaft to be fastened, a large mounting space is required.
In addition, there has been a problem that the weight and the inertia rate are increased. Furthermore, since the inner and outer peripheral surfaces of the components of the shaft coupling are machined into tapered surfaces, high machining accuracy is required,
Since a large number of bolt holes and screw holes need to be machined, there is also a problem that the manufacturing cost is increased.

Therefore, the present invention solves the above-mentioned problems of the prior art, and enables quick and easy fastening work between shafts, as well as compactness, low weight and low inertia, simple structure and low cost friction. It is an object of the present invention to provide a rigid shaft coupling.

[0011]

In order to achieve the above object, a friction-type rigid shaft coupling according to the present invention comprises a nut capable of engaging with a tool and a pair of shaft tightening members provided on both axial sides of the nut. And a fastening sleeve in which an axial hole opened in the end face of each shaft fastening portion is formed in the axial direction, and respectively fitted to the pair of shaft fastening portion outer peripheral surfaces, using a tool. A pair of rotatable tightening rings.

[0012] The pair of shaft fastening portions are respectively
A concentric cylindrical outer peripheral surface formed concentrically with the shaft hole; an eccentric cylindrical outer peripheral surface which is adjacent to the concentric cylindrical outer peripheral surface in the axial direction and is eccentric with respect to the center of the shaft hole; The outer peripheral surface adjacent to the nut portion of the eccentric cylindrical outer peripheral surface and the eccentric cylindrical outer peripheral surface protrudes radially outward beyond the other outer peripheral surface, and the pair of tightening rings is provided for each of the corresponding shaft tightening portions. It has a concentric cylindrical inner peripheral surface and an eccentric cylindrical inner peripheral surface fitted to the concentric cylindrical outer peripheral surface and the eccentric cylindrical outer peripheral surface, respectively. The two shafts fitted into the shaft holes from the end surfaces of the shaft tightening portions by frictional fixing are frictionally fixed on the inner peripheral surfaces of the shaft holes, respectively, and fastened.

[0013]

When two shafts are fastened by the friction type rigid shaft coupling of the present invention, the shaft ends on opposite sides of these shafts are inserted into the shaft holes from both sides of the tightening sleeve. And first,
The nut portion at the center of the tightening sleeve and one of the tightening rings are respectively held by a tool such as a spanner, and the tightening ring is rotated relative to the tightening sleeve to tighten.

When the tightening ring rotates with respect to the shaft tightening portion of the tightening sleeve, the concentric cylindrical inner circumferential surface of the tightening ring fitted to the concentric cylindrical outer circumferential surface of the shaft tightening portion. The center of rotation and the center of rotation of the eccentric cylindrical inner peripheral surface cause a slight displacement between the eccentric cylindrical inner peripheral surface of the fastening ring and the eccentric cylindrical outer peripheral surface of the shaft tightening portion fitted to it. A surface pressure is generated over a substantially half circumferential portion between them.

[0015] Further, between the concentric cylindrical inner peripheral surface of the fastening ring and the concentric cylindrical outer peripheral surface of the shaft tightening portion to be fitted thereto, the surface pressure and the semicircular portion opposite to the semicircular portion are applied. A balanced surface pressure is generated.

As a result, the shaft tightening portion is elastically displaced in the radial direction, and at the position of the shaft tightening portion, one shaft is tightened to the inner peripheral surface of the shaft hole and frictionally fixed. At this time, the tightening ring is self-locked to the shaft tightening portion by the frictional force, and the state in which the shaft is frictionally fixed to the inner peripheral surface of the shaft hole of the tightening sleeve is maintained. Similarly, by rotating and tightening the other fastening ring with a tool, both shafts are firmly fastened via the fastening sleeve.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a first embodiment of a friction type rigid shaft coupling (hereinafter simply referred to as a shaft coupling) of the present invention, and FIG. 2 is a side view thereof. And two tightening rings 3, 4 in total.

A shaft hole 5 is formed in the tightening sleeve 2 so as to penetrate in the axial direction. The shaft hole 5 has an axis X on the driving side and an axis Y on the driven side that are opposed on a coaxial line. It is designed to be inserted from both sides.

A nut 6 is formed at the axial center of the tightening sleeve 2. The nut portion 6 includes:
Its outer peripheral surface is formed by a hexagonal prism-shaped tool engaging surface 7 similar to the side surface of the nut or bolt head, and a tool such as a wrench can be engaged here.

A pair of shaft tightening portions 8 and 9 are continuously provided on both sides of the nut portion 6 in the axial direction. The outer peripheral surfaces of these shaft tightening portions 8 and 9 are concentric cylindrical outer peripheral surfaces 10 and 11 formed concentrically with the shaft hole 5 and eccentric cylindrical outer peripheral surfaces 12 that are axially adjacent to these. , 13.

The concentric cylindrical outer peripheral surfaces 10 and 11 are formed concentrically with the shaft hole 5, respectively.
The centers O ′ of 2 and 13 are eccentric by a small distance e from the center O of the shaft hole 5.

The outer diameters of the eccentric cylindrical outer peripheral surfaces 12 and 13 are smaller than the outer diameters of the concentric cylindrical outer peripheral surfaces 10 and 11 and are adjacent to both sides of the nut portion 6.
The outer peripheral surface 11 is formed so as to protrude radially outward beyond the eccentric cylindrical outer peripheral surfaces 12 and 13 at both ends of the tightening sleeve 2.

On the other hand, the outer peripheral surfaces of a pair of tightening rings 3 and 4 which are fitted on both sides of the tightening sleeve 2 are each turned by a tool such as a spanner like the tool engaging surface 7 of the tightening sleeve 2. It is formed in a hexagonal column shape so that it can move.

Further, a concentric cylindrical inner peripheral surface 14 and an eccentric cylindrical inner peripheral surface 15 which are fitted to the concentric cylindrical outer peripheral surface 10 and the eccentric cylindrical outer peripheral surface 12, respectively, are formed on the tightening ring 3. The attached ring 4 has a concentric cylindrical inner peripheral surface 16 fitted to a concentric cylindrical outer peripheral surface 11 and an eccentric cylindrical outer peripheral surface 13 respectively.
And an eccentric cylindrical inner peripheral surface 17 are formed.

When the shaft X and the shaft Y are fastened by the shaft coupling 1 configured as described above, the nut 6 of the fastening sleeve 2 is sandwiched by a tool such as a spanner, and the fastening rings 3 and Each of the nuts 4 is rotated and tightened with respect to the nut part 6 with a tool such as a spanner.

FIGS. 3 and 4 are cross-sectional views taken along line AA and line BB in FIG. 1 as viewed in the direction of the arrows. In these figures, when a tightening force is applied to one of the tightening rings 3 in the clockwise direction indicated by the arrow N from the original position on the tightening sleeve 2, the shaft tightening portion 8 is moved in the position of FIG. Since the eccentric cylindrical inner peripheral surface 15 of the tightening ring 3 is fitted to the eccentric cylindrical outer peripheral surface 12, the tightening ring 3 tends to rotate around the center O '.

On the other hand, in the position shown in FIG. 4, the concentric cylindrical inner peripheral surface 14 of the tightening ring 3 and the concentric cylindrical outer peripheral surface 1 of the shaft tightening portion 8 are located.
Because it is fitted to 0, it is about to rotate around the center O. As a result, the wall thickness between the eccentric cylindrical outer peripheral surface 12 of the shaft tightening portion 8 and the inner peripheral surface of the shaft hole 5 increases in the moving direction of the tightening ring 3 in the shaft tightening portion shown in FIG. In the portion a of FIG. 8, as shown in FIG. 5, the shaft tightening portion 8 acts like a wedge on the tightening ring 3 moving in the direction along the outer peripheral surface of the shaft X, and Eccentric cylindrical inner peripheral surface 15 and shaft tightening portion 8
A large surface pressure is generated between the eccentric cylindrical outer peripheral surface 12 and the eccentric cylindrical outer peripheral surface 12.

The surface pressure acts on a half-peripheral portion of the eccentric cylindrical outer peripheral surface 12 to elastically displace the shaft tightening portion 8 in the radial direction. A fastening force F is exerted.

On the other hand, in the remaining half circumference including the portion B in FIG. 3, as shown in an enlarged view of FIG. Since the thickness is reduced, no clamping force is applied to the axis X.

Further, between the concentric cylindrical inner peripheral surface 14 of the tightening ring 3 and the concentric cylindrical outer peripheral surface 10 of the shaft tightening portion 8 fitted thereto, a half-peripheral surface on which the surface pressure acts. A surface pressure balanced with the surface pressure is generated in a half circumferential portion opposite to the portion. As a result, the half circumferential portion of the inner circumferential surface of the shaft hole 5 of the shaft tightening portion 8 at the position shown in FIG. 4 exerts a tightening force F ′ balanced with the tightening force F on the shaft X, and The shaft X is frictionally fixed to the fastening sleeve 2 by friction between the peripheral surface and the outer peripheral surface of the shaft X.

On the other hand, the shaft Y is also frictionally fixed to the tightening sleeve 2 by rotating and tightening the tightening ring 4, so that the shaft X and the shaft Y are firmly fixed via the shaft coupling 1. Will be concluded.

At this time, the tightening rings 3 and 4 are self-locked to the tightening sleeves 8 and 9 by frictional forces, respectively, so that there is no possibility of loosening due to rotational vibration of the shaft. In addition, both axes X,
To release the fastening of Y, the fastening rings 3 and 4 may be turned in a direction opposite to the direction in which the fastening rings 3 and 4 are fastened to the fastening sleeves 8 and 9.

FIG. 7 is a longitudinal sectional view showing a second embodiment of the friction type rigid shaft coupling according to the present invention. In the shaft coupling 1A of this embodiment, two shafts to be fastened have different thicknesses. The case applies. That is, an axial hole 5A is formed between one end surface of the tightening sleeve 2 of the shaft coupling 1A and the axial center, and an axial hole 5B is formed between the other end surface and the axial center.

The shaft holes 5A and 5B are centered on the same axis but have different inner diameters, and the drive-side shaft X 'and the driven-side shaft Y' having different diameters are fitted respectively. In addition,
In FIG. 7, shaft holes 5A and 5 indicated by the same numbers as those in FIG.
Portions other than B have the same structure as that of the above-described first embodiment, and a description thereof will not be repeated.

FIG. 8 is a longitudinal sectional view showing a third embodiment of the friction type rigid shaft coupling according to the present invention, FIG. 9 is a side view thereof, and FIG.
FIG. 9 is a cross-sectional view taken along the line CC in FIG. 8 and viewed in the direction of the arrow. The tightening sleeve 2 of the shaft coupling 1B has an outer peripheral surface side and a shaft hole 5 at one location in the circumferential direction over the entire length thereof. A slit S is formed to communicate with the inner peripheral surface side.

8 to 10, the portions denoted by the same reference numerals as those in FIG. 1 have the same structure as that of the first embodiment except for the slit S. In this embodiment, the slit S
Is provided, the elastic deformation of the tightening sleeve 2 in the radial direction becomes easy, and the torque required for tightening the tightening rings 3 and 4 can be reduced.

FIG. 11 is a longitudinal sectional view showing a fourth embodiment of the friction type rigid shaft coupling according to the present invention, FIG.
FIG. 13 is a cross-sectional view taken along the line DD in FIG.

In this embodiment, the shaft tightening portions 8 and 9 in which the tightening sleeves 2 of the shaft coupling 1C are provided on both sides of the nut portion 6 are provided.
Is divided by four slits S ′ formed at 90-degree intervals in the circumferential direction, and these divided parts are connected by the nut 6. (Note that only one shaft tightening portion 8 is shown in the drawing.) By forming the slit S ′, the tightening ring 3 is formed.
The elastic deformation of the shaft tightening portion where the shaft 4 is fitted is facilitated, and the torque required for tightening the tightening rings 3 and 4 can be reduced as in the third embodiment.

The shaft coupling 1C of the present embodiment is similar to the above-described first and third embodiments except that a slit S 'is formed.
It has the same configuration as the shaft coupling of the embodiment. In this embodiment, the number of slits S 'is four, but the number of slits may be increased or decreased as needed.

FIG. 14 is a longitudinal sectional view showing a fifth embodiment of the friction type rigid shaft coupling according to the present invention, FIG. 15 is a side view thereof, and FIG.
FIG. 6 is a cross-sectional view taken along the line EE in FIG. 14 and viewed in the direction of the arrow. The shaft coupling 1D of this embodiment also has a clamping sleeve 2 'and two It is composed of a total of three parts, namely, attachment rings 3 'and 4'.

The principle that the shafts X and Y are fastened by relatively rotating the two fastening rings 3 'and 4' with respect to the fastening sleeve 2 'is the same as that of the shaft coupling of each embodiment described above. In the same manner, in the shaft coupling 1D of this embodiment, concentric cylindrical outer peripheral surfaces formed on shaft tightening portions 8 'and 9' provided on both sides of the nut portion 6 of the tightening sleeve 2 '. 10 ', 11' are arranged on both ends of the tightening sleeve 2 'apart from the nut part 6, and have eccentric cylindrical outer peripheral surfaces 12', 1 '.
3 ′ is disposed adjacent to both sides of the nut portion 6.

In this embodiment, the fastening sleeve 2 '
Tightening ring 3 'to each shaft tightening part 8', 9 '
In order to be able to fit 4 ′, the outer diameters of the eccentric cylindrical outer peripheral surfaces 12 ′ and 13 ′ are opposite to the shaft couplings of the above-described embodiments.
The eccentric cylindrical outer peripheral surface 1 which is larger than the outer diameter of the concentric cylindrical outer peripheral surfaces 10 ′ and 11 ′ and is adjacent to both sides of the nut portion 6.
The outer peripheral surfaces 2 ′ and 13 ′ are formed so as to protrude radially outward beyond the concentric cylindrical outer peripheral surfaces 10 ′ and 11 ′ at both ends of the tightening sleeve 2 ″.

The concentric cylindrical inner peripheral surface 14 'and the eccentric cylindrical inner peripheral surface 15' fitted on the concentric cylindrical outer peripheral surface 10 'and the eccentric cylindrical outer peripheral surface 12' are respectively provided on the tightening ring 3 '.
Is formed, and the concentric cylindrical outer peripheral surface 1 is formed on the tightening ring 4 '.
A concentric cylindrical inner peripheral surface 16 'and an eccentric cylindrical inner peripheral surface 17' are formed to fit into the 1 'and the eccentric cylindrical outer peripheral surface 13', respectively.

In the shaft coupling described in each of the above-described embodiments, the tool engagement surface of the nut portion of the tightening sleeve and the outer peripheral surface of the tightening ring are formed in a hexagonal column shape like the head and nut of the bolt. Although the wrench is engaged, the outer peripheral surface of the nut portion and the tightening ring may be any shape as long as it can be rotated or held by a tool such as a wrench or a plier. Alternatively, a projection, a groove, a hole, or the like for tool engagement may be formed on the outer peripheral surface so as to be rotatable with a key spanner or the like.

[0045]

As described above, according to the friction-type rigid shaft coupling of the present invention, a conventional structure in which a pair of tapered rings are pulled in the axial direction by a plurality of tightening bolts to fasten the shafts to each other. Compared to the shaft coupling, the shafts can be fastened to each other only by the operation of tightening a pair of tightening rings with a tool such as a wrench on the tightening sleeve. Space required for work can be reduced.

Further, the number of parts can be reduced because no tightening bolt is used, and the manufacturing cost can be reduced because it is not necessary to machine bolt holes and screw holes and to machine a tapered surface that requires high precision. be able to.

Further, since the outer diameter of the shaft coupling is small and the weight and the rate of inertia can be reduced, it can be suitably used for fastening shafts rotating at high speed. Furthermore, when the tightening ring is tightened, a large frictional force generated by the wedge action between the eccentric cylindrical inner circumferential surface and the eccentric cylindrical outer circumferential surface of the shaft tightening portion of the tightening sleeve causes the tightening ring to be tightened on the tightening sleeve. On the other hand, the shafts are self-locked, and there is no possibility of loosening due to the rotational vibration of the shafts, so that the shafts can be securely and accurately fastened to each other.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a friction type rigid shaft coupling according to the present invention.

FIG. 2 is a side view showing a first embodiment of the friction type rigid shaft coupling according to the present invention.

FIG. 3 is a cross-sectional view taken along the line AA in FIG.

FIG. 4 is a cross-sectional view taken along a line BB in FIG.

FIG. 5 is an enlarged cross-sectional view of a part A in FIG. 3;

FIG. 6 is an enlarged cross-sectional view of a part shown in FIG. 3;

FIG. 7 is a longitudinal sectional view showing a second embodiment of the friction type rigid shaft coupling according to the present invention.

FIG. 8 is a longitudinal sectional view showing a third embodiment of the friction type rigid shaft coupling according to the present invention.

FIG. 9 is a side view showing a third embodiment of the friction type rigid shaft coupling according to the present invention.

FIG. 10 is a sectional view taken along the line CC in FIG.

FIG. 11 is a longitudinal sectional view showing a fourth embodiment of the friction type rigid shaft coupling according to the present invention.

FIG. 12 is a side view showing a fourth embodiment of the friction type rigid shaft coupling according to the present invention.

FIG. 13 is a sectional view taken along the line DD in FIG. 11 and viewed in the direction of the arrow;

FIG. 14 is a longitudinal sectional view showing a fifth embodiment of the friction type rigid shaft coupling according to the present invention.

FIG. 15 is a side view showing a fifth embodiment of the friction type rigid shaft coupling according to the present invention.

FIG. 16 is a sectional view taken along the line EE in FIG. 14 and viewed in the direction of the arrow;

FIG. 17 is a longitudinal sectional view showing an example of a conventional friction type rigid shaft coupling.

FIG. 18 is a longitudinal sectional view showing another example of the conventional friction type rigid shaft coupling.

[Explanation of symbols]

 1, 1A, 1B, 1C, 1D Shaft coupling 2 Tightening sleeve 3, 4 Tightening ring 5, 5A, 5B Shaft hole 6 Nut part 7 Tool engagement surface 8, 9 Shaft tightening part 10, 10 ', 11, 11 'Concentric cylindrical outer peripheral surface 12, 12', 13, 13 'Eccentric cylindrical outer peripheral surface 14, 14', 16, 16 'Concentric cylindrical inner peripheral surface 15, 15', 17, 17 'Eccentric cylindrical inner peripheral surface surface

Claims (1)

[Claims] A nut portion capable of engaging with a tool, and a pair of shaft tightening portions provided continuously on both axial sides of the nut portion;
A pair of fastening sleeves each having an axial hole formed in the end face of each shaft fastening portion formed in the axial direction therein, and a pair of shaft fastening portions each fitted on the outer peripheral surface of the shaft fastening portion and rotatable by a tool. A pair of shaft tightening portions, each of which is axially adjacent to the concentric cylindrical outer peripheral surface and the concentric cylindrical outer peripheral surface formed concentrically with the shaft hole, and is located at a center of the shaft hole. With the eccentric cylindrical outer peripheral surface being eccentric, the outer peripheral surface adjacent to the nut portion of the adjacent concentric cylindrical outer peripheral surface and the eccentric cylindrical outer peripheral surface projects radially outward beyond the other outer peripheral surface. The pair of tightening rings has a concentric cylindrical inner peripheral surface and an eccentric cylindrical inner peripheral surface fitted to a concentric cylindrical outer peripheral surface and an eccentric cylindrical outer peripheral surface of each corresponding shaft tightening portion, respectively. The rotation of each tightening ring causes a radial elastic displacement in the corresponding shaft tightening portion. A friction type rigid shaft coupling characterized in that both shafts fitted into the shaft hole from the end surfaces of the respective shaft tightening portions are respectively frictionally fixed and fastened on the inner peripheral surface of the shaft hole. .