JP2021032400A - Non-stage transmission - Google Patents

Abstract

To provide a compact non-stage transmission which prevents slippage without requiring hydraulic pressure.SOLUTION: The non-stage transmission includes: a hub 1; a plurality of radially-extending arms 2 which is attached to the hub 1 to allow identical rotation; and an annular gear 3 which can engage with a gear part 2b provided to the plurality of arms 2. The tip end of the plurality of arms 2 can engage with a chain or belt. Each of the plurality of arms 2 can relatively rotate about a reference point C with the hub 1. By providing rotational force to the annular gear 3 which engages with each of the plurality of arms 2, each of the plurality of arms 2 relatively rotates about the reference point C with the hub 1 such that an effective diameter of a sprocket which is an engagement point with the chain or belt becomes deformable.SELECTED DRAWING: Figure 1

Description

The present invention relates to a continuously variable transmission that does not require a hydraulic speed change operation.

Conventionally, a CVT pulley used in a continuously variable transmission consists of a fixed flange having a long shaft portion and a movable flange slidably fitted in the shaft portion, and the movable flange slides on the shaft portion. The width of the two flanges can be adjusted steplessly.

U.S. Pat. No. 3,914,410

However, the conventional continuously variable transmission requires a very high oil pressure in order to obtain the frictional force between the belt and the pulley. The generation of high oil pressure causes a transmission loss of the entire power unit. Further, in a region where the gear ratio is high, the belt and the pulley slip. The total weight of these pulleys and the oil pressure generating mechanism is large.

The present invention does not require hydraulic pressure, can continuously change gears by adding power such as a motor, does not generate rotational slip, can reduce the weight of the entire mechanism, and can suppress the length in the axial direction. The purpose is to provide a continuously variable transmission.

The basic configuration consists of two sets of input and output sprockets, each of which can change the effective diameter, a chain or belt wound around the sprockets, and a speed change drive mechanism for changing the effective diameter of each of the sprockets. Each of the sprockets is composed of a hub, a plurality of arms attached to the hub and extending radially to enable the same rotation, and a gear that can mesh with a gear portion provided on the plurality of arms. The tip of the arm can mesh with the chain or belt. Each of the plurality of arms is axially supported by a mounting portion with the hub and can move relatively.

When a rotational force is applied to the gear, each of the plurality of arms moves relative to the mounting base point with the hub, and the effective diameter of the sprocket serving as the meshing point with the chain or belt can be changed. .. The input / output rotation can be changed by changing the effective winding diameter of each sprocket wound around the chain or belt. By driving the rotation of the gear with a motor or the like via a worm gear, the rotation of the gear can be maintained or driven without being affected by the input / output torque.

According to the configuration described above, the use of a motor for shifting does not require hydraulic pressure, meshing with a chain or belt does not generate rotational slip, and does not require axial movement like a pulley. With a compact mechanism, stepless shifting is possible.

It is a figure which shows the whole picture of this invention. FIG. 1 is a cross-sectional view of one side of two sets of sprocket mechanisms.

First, of course, the same reference numerals on different drawings identify structural elements that are identical or functionally similar. Further, the present invention is not limited to the specific embodiments, procedures, materials and modifications described herein, and of course modifications may be made to itself. Further, the terms used in the present specification are merely intended to explain a specific aspect, and are not intended to limit the scope of the present invention. The scope of the present invention is specified only by the appended claims.

Unless otherwise specified, all technical and scientific terms used herein have the same meaning as those normally understood by those with ordinary knowledge in the technical field to which the present invention belongs. All of the methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In the problem-solving means of the present invention shown in FIG. 1, there are two sets of sprocket mechanisms in which the effective diameters of the input shaft A and the output shaft B can be changed, and each sprocket has an extremely small effective diameter on the input shaft side. The position where the effective diameter on the output shaft side is maximum is shown, and the belts hung on the two sets of sprockets draw a trajectory 4, and the output rotation is decelerated with respect to the input rotation. Each sprocket is configured in the same manner, and has a hub 1 that transmits input and output of rotational force and six arms 2 that are connected to the hub 1, and each arm 2 rotates in the same manner as the hub 1. Since it is axially supported by the hub 1, relative movement is possible. FIG. 1 shows a movable image of the arm 2, and one of the arms 2 is operating in a trajectory Y with reference to the axis C. Further, each of the arms 2 has a gear portion 2b, and teeth are cut with respect to a support shaft with the hub 1. Each of the gear portions 2b of the arm 2 meshes with the internal teeth of the annular gear 3, and the rotation of the annular gear 3 causes the six arms 2 meshing with the annular gear 3 to synchronize with each other. Can make the same movement. Further, each of the arms 2 has a tooth portion 2a that meshes with the belt, and corresponds to the tooth of the sprocket mechanism described above. The shape of the tooth portion 2a is such that the effective diameter of the sprocket can be meshed with the belt to be engaged in all states from the minimum position to the maximum position.

From the state shown in FIG. 1, when the annular gear 3 on the input side is given a clockwise rotation and the annular gear 3 on the output side is given a counterclockwise rotation in synchronization, each annular gear 3 is given an annular rotation. Each of the arms 2 meshing with the gear 3 is movable, and the effective diameter of the sprocket is maximized on the input side and minimized on the output side. The change allowance of the effective diameter as a sprocket in the embodiment shown in FIG. 1 can be X. Thus, the output rotation is accelerated with respect to the input rotation, and the intended shift can be freely performed by giving rotation to the annular gear 3.

In the embodiment shown in FIG. 1, the length of the arm 2 is as long as possible so as to allow a large change allowance for the effective diameter as a sprocket, and the effective diameter is minimized so as not to interfere with the adjacent arm 2. The curved shape has been devised for the purpose of doing so.

In the embodiment shown in FIG. 1, teeth are also cut on the outer diameter side of the annular gear 3 for each input and output, and the worm gear 5 is meshed with each other. By driving the worm gear with a motor, it is possible to give each of the annular gears three rotations.

As described above, according to the stepless automatic transmission according to this embodiment, no hydraulic pressure is required, the belt meshes with the belt, so that rotational slip does not occur, and the stepless speed change is performed by a compact mechanism. It is possible to do it only by inputting from.

A Input shaft B Output shaft C Arm movable shaft X Effective diameter change allowance Y Arm track 1 Hub 2 Arm 2a Arm tooth 2b Arm gear 3 Ring gear 4 Belt track 5 Worm gear

Claims (3)

A continuously variable transmission equipped with a sprocket whose effective diameter can be changed, a chain or belt wound around the sprocket, and a speed change drive mechanism for changing the effective diameter of the sprocket. It is composed of a plurality of radially extending arms attached to the hub and enabling the same rotation, and a gear that can mesh with a gear portion provided on the plurality of arms. The tips of the plurality of arms can mesh with the chain or belt. Each of the plurality of arms can rotate relative to the base point with the hub, and by applying a rotational force to the gears that mesh with the plurality of arms, each of the plurality of arms can rotate from the base point with the hub. A continuously variable transmission characterized in that the effective diameter of a sprocket, which is a meshing point with the chain or belt, can be changed by performing relative rotation. The continuously variable transmission according to claim 1, wherein the plurality of arms are curved so as to minimize the effective diameter of the sprocket in a folded state. The continuously variable transmission according to claim 1, wherein a worm gear is used to drive the gear.

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