JPS586794Y2 - Multi-stage sprocket assembly - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a multi-stage sprocket assembly, and more particularly, to a multi-stage sprocket assembly consisting of a cylindrical member and two or more sprockets of different diameters coupled to the outer periphery of the cylindrical member. .

Generally, in this type of assembly, the sprocket is coupled to the cylindrical member by forming a number of insertion grooves extending in the axial direction on the outer periphery of the cylindrical member, and by providing a screw on the outer periphery of one axial end of the cylindrical member. sprockets having protrusions on the inner periphery of the center hole are fitted successively at regular intervals from the large diameter sprocket through spacers, and a screw is provided on the inner periphery of the center hole of the smallest diameter sprocket to form the cylindrical shape. The sprockets are connected by screwing onto the threads of the members, or by providing screws on the entire outer periphery of the cylindrical member and screwing all the sprockets.

Therefore, in the coupling structure configured as described above, it becomes troublesome to couple and detach the sprocket to the cylindrical member, and in particular, the sprocket screwed onto the cylindrical member tightens during use, making it difficult to remove it. was there.

Therefore, the present invention was devised in view of the above-mentioned problems.The purpose of the present invention is to provide a multistage sprocket that can be easily connected to and removed from a cylindrical member without using any special tools. The object is to provide a sprocket assembly.

That is, the present invention eliminates the structure in which the sprocket is attached to the cylindrical member by screwing and is connected to the cylindrical member, and includes an insertion groove extending in the axial direction on the outer periphery of the cylindrical member, and an insertion groove extending in the axial direction on the outer circumference of the cylindrical member. A circumferential engagement groove continuous to the insertion groove is formed at one end in the axial direction, and a protrusion that can be inserted into the insertion groove is provided protrudingly on the inner periphery of the center hole of the sprocket. A fixed ring is formed that can be inserted into the insertion groove and has a protrusion that can be inserted into the engagement groove, and unevenness that engages with each other is formed between the opposing surfaces of the fixed ring and the sprocket. This is a characteristic feature.

Hereinafter, typical embodiments of the assembly of the present invention will be described based on the drawings.

In the figure, reference numeral 1 denotes a cylindrical member, on its outer circumferential surface, there are a number of insertion grooves 11 along the axial direction with one axial end open, and a circumferential direction continuous with the insertion grooves 11 on the one axial end side. A retaining groove 12 is formed.

This cylindrical member 1 constitutes a driving member of a multi-stage freewheel, and has a ratchet 13 on its inner periphery that engages with a pawl of a driven member of the freewheel, and a pole provided on both sides of the ratchet 13 in the axial direction. I have race 14.15.

Further, 2... are sprockets that are coupled to the cylindrical member 1 constructed as described above, and each of these sprockets 2...
* have different diameters, and a protrusion 21 that can be inserted into the insertion groove 11 is provided protruding from the inner periphery of the center hole.

These sprockets 2... may be individually fitted into the cylindrical member 1 via the protrusions 21, and assembled with constant spacing maintained by the spacers 3.
As shown in FIG. 1, before inserting the sprocket into the cylindrical member 1, the
... are connected in advance into a unit by using connecting members 4 such as bolts, nuts or other caulking pins at regular intervals, and this sprocket unit is inserted into the cylindrical member 1. You can accomplish it as you wish.

Thus, the sprocket 2 having the smallest diameter is supported so as to be elastically displaceable in the axial direction via an elastic member 6 such as a coil spring.

That is, the minimum diameter sprocket 2 and the sprocket 2
The spacer 3 is not interposed between the sprocket 2 and the sprocket 2 adjacent to the sprocket 2, but the elastic member 6 is provided so that the sprocket can be displaced in the axial direction via the elastic member 6.

The sprocket 2 having the smallest diameter is provided with an engaging portion 22 that engages with a locking body 52 of the fixed ring 5, which will be described later.

The fixing ring 5 is for fixing the sprocket 2, which is inserted into the outer periphery of the cylindrical member 1 as described above, to the cylindrical member 1, and is mainly molded from synthetic resin such as elastic Duracon. That's what I do.

As shown in FIGS. 2 and 4, this fixed ring 5 has a protrusion 51 on its inner periphery that has a width that allows it to be inserted into the insertion groove 11 and a wall thickness that allows it to be inserted into the engagement groove 12. A large number of locking bodies 52 are provided at the same pitch intervals as the grooves 11, and a plurality of locking bodies 52 are provided on the side surface of the fixed ring 5 to engage with the engaging portions 22 of the minimum diameter sprocket 2.

The locking body 52 is for preventing rotation when the fixed ring 5 is inserted into the cylindrical member 1 through the insertion groove 11 and the engagement groove 12. Although the stopper 52 is constituted by a cylindrical protrusion, it may also be a concavo-convex strip extending in the radial direction or a ratchet.

In this case, the engaging portion formed on the sprocket 2 is also formed into an uneven strip or a ratchet.

Further, in the figure, reference numeral 55 denotes a rotation operation part such as a knurling provided on the outer peripheral surface of the fixed ring 5.

Reference numeral 7 designates an elastic ring interposed between the end of the insertion groove 11 and the sprocket 2 that is inserted into the insertion groove 11, and an elastic piece 71 that can be fitted into the insertion groove 11 on the inner periphery. have.

Although this elastic ring 7 is not necessarily necessary to carry out the present invention, when the sprocket 2 is inserted into the cylindrical member 1 and fixed with the fixed ring 5, even if there is a dimensional tolerance in the axial direction,
This is preferable because this tolerance can be absorbed by the elastic ring 7 and the sprocket 2 can be fixed without wobbling.

Moreover, even if this elastic ring 7 is not used, the sprocket 2
．． The above tolerance can be absorbed by utilizing the elastic deformation of the elastic material 6 interposed between the two in the axial direction.

Next, a method of assembling the sprocket 2 to the cylindrical member 1 in the assembly constructed as above will be explained.

First, the sprockets 2 are inserted into the cylindrical member 1, and the projections 21 from the large-diameter sprocket 2 are sequentially inserted into the insertion groove 11 via the spacer 3 and the elastic member 6.

If the elastic ring 7 is used at this time, the elastic ring 7 is inserted before the large-diameter sprocket to be inserted first is inserted.

Next, among the sprockets 2 inserted as described above, the fixed ring 5 is placed on the outside of the sprocket 2 with the smallest diameter located at one end in the axial direction of the cylindrical member 1, and the protrusion 51 is placed in the insertion groove 1.
After this insertion, the protrusion 51 is positioned in the engagement groove 12, the fixed ring 5 is rotated, and the protrusion 51 is fitted into the engagement groove 12. .

At this time, the locking body 52 formed on the fixed ring 5 is engaged with the engaging portion 22 of the minimum diameter sprocket 2, but this engagement is achieved by pressing the minimum diameter sprocket 2 in the axial direction. This can be easily done by displacing the elastic member 6 against the elastic member 6.

If the locking body 52 is a ratchet, the sprocket 2 can be displaced in the axial direction by forcibly rotating the fixed ring 50 without performing the above-described pressing operation.

The engagement of the locking body 52 with the engaging portion 22 prevents the fixed body 5 from rotating.

Further, during this engagement, the protrusion 51 engages with the end surface between the insertion grooves 11 and 11 while being engaged with the engagement groove 12, and this engagement causes the fixed ring 5 to move in the axial direction. Movement is also prohibited.

In the embodiments described above, the minimum diameter sprocket 2 is elastically displaceable in the axial direction, but the fixed ring 5 is configured to be elastically displaceable in the axial direction, and the locking body 52 is configured to be elastically displaceable in the axial direction. It may be configured to be elastically displaceable.

When the fixed ring 5 is configured to be elastically displaceable, the thickness of the protrusion 51 is made thinner than the groove width of the engagement groove 12 so that it can be elastically deformed within the groove width, and the locking When the body 52 is configured to be elastically displaceable, the locking body 52 is shaped as a cylinder or a sphere separately from the fixed ring 5, and the fixed ring 5 has a recess for receiving the locking body 52. A recess is formed, and the locking body 52 is received in this recess via a spring.

As described above, according to the present invention, the sprocket can be made immovable in the cylindrical member by the simple operation of inserting the sprocket into the cylindrical member, then inserting the fixed ring and rotating it. Compared to the conventional method of attaching by screwing, it is easier to attach and remove.

Moreover, since it can be installed without screwing, no special tools are required.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view showing an embodiment of the assembly of the present invention, Fig. 2 is a cross-sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is a cross-sectional view taken along the line ■-■ in Fig. 1. FIG. 4 is a sectional view of the fixed ring, and FIG. 5 is a partially cutaway front view of the cylindrical member. 1... Cylindrical member, 2... Sprocket, 5... Fixed ring, 6... Elastic member, 1
1...Insertion groove, 12...Engagement groove, 21
, 51... protrusion, 52... locking body.

Claims (1)

[Scope of utility model registration request] A multi-stage sprocket assembly in which two or more sprockets of different diameters are connected to a cylindrical member, and a large number of sprockets are inserted into the outer peripheral surface of the cylindrical member along the axial direction with one axial end open. a groove and a circumferential engagement groove continuous with the insertion groove on one axial end side of the cylindrical member, and a protrusion that can be inserted into the insertion groove on the inner periphery of the center hole of the sprocket. forming a fixed ring with a protrusion that can be inserted into the insertion groove and can be inserted into the engagement groove;
A multi-stage sprocket assembly, characterized in that unevenness that engages with each other is formed between opposing surfaces of the fixed ring and the sprocket.