JPH064099Y2 - Keyway of bottom hole of rotating shaft - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a keyway for a bottomed hole of a rotary shaft as an element of a machine, and particularly to a keyway having good precision and workability.

[Conventional technology]

FIG. 3 is a cross-sectional view of a conventional example, and FIG. 4 is a front view of FIG. 3. A rotary shaft 31 is provided with a hole 32 having a bottom 32a for a shaft (not shown) to be connected. . In order to machine the key groove 33 in the hole 32 with a slotter, an escape hole 34 for the slotter is provided at the back of the hole 32.

[Problems to be solved by the device]

The above-described conventional technique has the following problems because the hole 32 is not a through hole but a bottom.

a) In slotter, the accuracy of the key groove is poor.

b) If the key groove is deep, it tends to have a gradient, and if it is too deep, the slotter blade will break and remain inside, resulting in defective machining.
There is a risk that it cannot be processed.

c) Processing time is long.

An object of the present invention is to provide a technique that facilitates the processing of the key groove of the bottomed hole of the rotary shaft and that can obtain a highly accurate key groove.

[Means for Solving the Problems]

The present invention is a keyway for a bottomed hole of a rotary shaft, in which a bottomed hole of the rotary shaft is provided with an axial keyway communicating with an outer cylindrical surface, and a cylinder is fitted to the cylindrical surface.

[Action]

The axial keyway that communicates with the outer cylindrical surface of the bottomed hole can be machined from the outer surface of the cylindrical surface with, for example, a milling machine. When the cylinder is fitted to the cylindrical surface, the rotary shaft having the bottomed hole with the key groove is completed.

〔Example〕

FIG. 1 is a sectional view of the embodiment, and FIG. 2 is a front view of FIG.

In these figures, the rotary shaft 1 is provided with a hole 2 having a bottom 2a for a shaft (not shown) to be connected. A cylinder 4 is further fitted to the cylindrical surface 1a on the outer periphery of the shaft 1, and the key groove 3 extends from the hole 2 of the shaft 1 to the cylindrical surface 1a.
It is provided in the axial direction so as to communicate with a. Therefore, before fitting the cylinder 4, the key groove 3 can be easily processed from the outside of the cylindrical surface 1a with a milling machine or the like.

The bottom of the key groove 3 is formed by the inner diameter of the cylinder 4 and forms an arc, but it does not matter. This is because a large gap is generally provided in the depth direction of the key groove. For example JIS B
According to 1301 and 1303, the key height is 7 mm, the hole side height is 3 mm, and the groove side depth is 3.3 mm to 3.5 mm. If the length of the cylinder 4 is larger than the depth of the hole 2, the cylinder 4 is fitted into the solid portion of the shaft 1 so that the fitting becomes stronger, but the length of the cylinder 4 is smaller than the depth of the hole 2. Good. Further, the length of the cylinder 4 may be shorter than the length of the key groove. At this time, since the shaft 1 has a C-shaped cross section, the fitting with the cylinder 4 is weakened, but if the key is finally used to connect with the shaft to be connected, the fitting is sufficiently strong. In addition, the end of the shaft 1 is preliminarily lengthened so that the keyway 3
The above process may not be performed on the above-mentioned end, and the excess end may be cut off at the end.

[Effect of device]

In this invention, an axial key groove communicating with the outer cylindrical surface is provided in the bottomed hole of the rotary shaft, and the cylinder is fitted into the cylindrical surface, so that the key groove is on the bottomed hole side. Nevertheless, machining can be performed from the outside of the cylindrical surface, and there is an effect that the accuracy is good and the workability is good even in a deep key groove.

[Brief description of drawings]

1 is a sectional view of the embodiment, FIG. 2 is a front view of FIG. 1, FIG. 3 is a sectional view of a conventional example, and FIG. 4 is a front view of FIG. 1,31 ... Rotary shaft, 2,32 ... Hole, 3,33 ... Keyway,
4 ... Cylinder.

Claims (1)

[Scope of utility model registration request] 1. A keyway for a bottomed hole of a rotary shaft, wherein a bottomed hole of the rotary shaft is provided with an axial keyway communicating with an outer cylindrical surface, and a cylinder is fitted to the cylindrical surface.