JPH05126116A - Key - Google Patents

Abstract

PURPOSE:To provide a key connecting a driving shaft to a driven shaft, of simple structure as well as of high mass productivity, which can be mounted, in particular, without, applying shock to a bearing part. CONSTITUTION:A taper pin 3 of circular cross section, the outer periphery of which is formed on a taper surface 1, is provided, while a screw part 2 is provided on one end part of the outer periphery. A pair of long thin blocks 5 are provided, while a taper recessed part 4 to be fitted to the taper surface 1 is formed on one side surface of each of the blocks. A fastening means 6 is screwed in the screw part 2 of the taper pin 3, and the taper pin 3 is moved relatively in the axial direction to the block 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key for connecting a drive shaft and a driven shaft, and in particular, the key can be securely fixed in a key groove without impacting the bearing when the key is mounted. Regarding

[0002]

2. Description of the Related Art The relationship between a key connecting a drive shaft and a driven shaft and a key groove is generally H7 fitting. That is, the width of the key is smaller than the key groove by 0 to 3/100 mm. Such a key is inserted into the key groove of the drive shaft and the driven shaft, a screw for fixing the key is attached, and the tip is pressed against the key to fix the key. Since there is a maximum gap of 3/100 mm in the width direction (rotational direction) between the key and the key groove, a shock is applied to the key each time the shaft rotates in the forward and reverse directions, Will move 3/100 mm in the keyway in the direction of rotation. The more often this is done, the greater the tolerance. Therefore, such a key cannot be used for a servo motor that requires accurate power transmission between a drive shaft and a driven shaft.

Therefore, in such a servo motor, extremely strict working precision is required so that the tolerance between the key and the key groove is 0, and such a key may be hammered into the key groove or pressed by hydraulic pressure. Was there. According to the former, there is a risk of damaging the bearing when hitting the key,
The key must be typed in carefully and by a skilled person. Even with the latter, careful work is required to prevent damage to the bearing during press fitting. Further, both of them have a drawback that a very strict cutting and polishing work is required for manufacturing the key and the key groove, which requires a lot of man-hours.

[0004]

Therefore, there is a demand for a key that can be easily installed by anyone without damaging the bearing of such a precision machine, and has a simple structure and excellent mass productivity. Was there.

[0005]

Therefore, the present invention has the following constitution in order to solve the above problems. That is, the key of the present invention has a tapered pin 3 having a circular cross section and an outer periphery formed on the tapered surface 1, and a screw portion 2 is provided on the outer periphery of one end portion in the longitudinal direction thereof. At the same time, it has a pair of elongated blocks 5, and a tapered concave portion 4 which is aligned with the tapered surface 1 is formed on each side surface. The fastening means 6 is screwed to the threaded portion 2 of the taper pin 3, and the relative rotation of the fastening means 6 causes the taper pin 3 to move axially relative to the blocks 5 and 5.

[0006]

As shown in FIGS. 1 and 2, a pair of blocks 5 face each other in opposite directions, and a taper pin 3 is arranged between them so as to be combined to form a key groove between a drive shaft 7 and a driven shaft 8. Insert as shown in FIG. Then, the fastening means 6 is screwed onto the screw portion 2 and is rotated to move the taper pin 3 relative to both the blocks 5 and 5. Then,
The interval between the pair of blocks 5 is widened, and the key is pressed against the key groove. The rotational power of the drive shaft 7 is transmitted to the driven shaft 8 via the pair of blocks 5 and the taper pin 3. or,
The key can be removed by loosening the fastening means 6.

[0007]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a perspective view showing each component of the key of the present invention, and FIG. 2 is a side view showing its assembled state, and FIG.
[Fig. 4] is a transverse sectional view showing a usage state of the key. FIG. 4 is a perspective view showing another embodiment of the taper pin 3. The key of this embodiment is composed of a pair of elongated blocks 5 and taper pins 3.
And fastening means 6. The taper pin 3 has a circular cross section and a tapered outer circumference, and the threaded portion 2 is formed at one end of the taper on the small diameter side. At the same time, a wrench hole 10 is formed on one end surface thereof. Instead of the wrench hole 10, a notch 11 into which the tip of a minus driver is fitted may be formed as shown in FIG.

Next, each of the pair of blocks 5 has a tapered recess 4 having a semicircular cross section formed on one side surface of an elongated bar having a rectangular cross section. The tapered recess 4 is aligned with the tapered surface of the tapered pin 3. The outer diameter of the screw portion 2 of the taper pin 3 is smaller than the minimum radius of the taper surface 1. As a result, as shown in FIG. 2, when the taper pin 3 is sandwiched between the pair of blocks 5, the tip of the taper recess 4 is prevented from coming into contact with the screw portion 2.
The pair of blocks 5 and the taper pin 3 may be manufactured by cutting, or may be manufactured by casting, rolling, press molding or the like. When cutting, a pair of blocks 5
Can be manufactured as follows. That is, a pair of blocks having a semi-circular recess having the same minimum radius as the tapered recess are formed. These blocks can be easily manufactured by conventional techniques such as drawing.

The semi-circular flat surface of such a block is polished. Then, the polished flat surfaces are brought into contact with each other and fastened by a chuck so as to press the two blocks into pressure contact with each other, and held so that a circular hole is formed at the center thereof. And the reamer for taper hole processing is used for the circular hole (
It is inserted while rotating relative to a pair of blocks) to form a tapered hole. Each cross section of the taper hole formed in this way becomes a core circle. The cross section of the tapered recess of each block is an accurate semicircle. The taper of the tapered hole is 1/50 as an example. When the taper hole is 1/50, many commercially available taper reamers can be used. Along with that, 1 / that matches this tapered hole
It is possible to use 50 taper pins that are already commercially available in large numbers for other applications. It suffices to form the threaded portion 2 on the outer periphery of the taper side end of such a commercially available taper pin and to provide the wrench hole 10 or the notch 11 on the end surface.

The key thus constructed can be used by cutting it at an appropriate position according to the length of the key groove of the drive shaft 7 and the driven shaft 8 to be mounted. Then, the pair of blocks 5 and the taper pin 3 are combined and inserted into the key groove of the drive shaft 7 and the driven shaft 8. And
The nut forming the fastening means 6 is attached to the threaded portion 2 of the taper pin 3.
At the same time, the tip of the wrench or the tip of a screwdriver is fitted into the wrench hole 10 or the notch 11 on the end face of the taper pin 3 to prevent rotation and rotate the nut with a spanner or the like. Then, the taper pin 3 moves in the nut direction, and the interval between the pair of blocks 5 increases. As a result, the pair of blocks 5 are firmly fixed to the key groove. This state is shown in FIG. 3, and a small gap 9 is formed between the pair of blocks 5. The smaller the gap 9 is, the more preferable. For example, 0.2
mm to 0.5 mm.

[0011]

According to the key of the present invention, the taper pin 3 is axially moved with respect to the blocks 5 and 5 by rotating the fastening means 6 while the pair of blocks 5 and the taper pin 3 are combined and inserted into the key groove. Therefore, the key can be easily fastened and fixed in the key groove by expanding the pair of blocks 5 between them. Then there is no gap (backlash) between the key and the keyway,
It becomes possible to accurately transmit the rotation of the drive shaft to the driven shaft. Moreover, since the fastening means 6 is screwed to the threaded portion 2, anyone can easily attach the key without impacting the bearings of the drive shaft 7 and the driven shaft 8 when attaching the key. There is no risk of damaging the bearing. Further, by loosening the fastening means 6, the key can be easily taken out. Moreover, the key of the present invention has a simple structure, is easy to manufacture, and is excellent in mass productivity.

[Brief description of drawings]

FIG. 1 is a perspective view showing components of a key of the present invention.

FIG. 2 is a side view showing an assembled state of the key of the present invention.

FIG. 3 is a cross-sectional view showing a usage state of the key of the present invention.

FIG. 4 is another embodiment of the taper pin 3 constituting the key of the present invention.

[Explanation of symbols]

 1 taper surface 2 screw part 3 taper pin 4 taper recess 5 block 6 fastening means 7 drive shaft 8 driven shaft 9 small gap 10 wrench hole 11 notch

Claims (1)

[Claims] 1. A taper pin (3) having an outer periphery having a circular cross section formed on a tapered surface (1), and a threaded portion (2) provided on the outer periphery of one end in the longitudinal direction, and the tapered surface (1). The taper pin (3) is screwed into the pair of elongated blocks (5) and (5) each having a matching taper recess (4) formed on one side surface thereof and is relatively rotated by being screwed into the screw portion (2). And a fastening means (6) for axially moving the blocks relative to the blocks (5) and (5).