JPS61109959A - Stepless speed change gear utilizing friction - Google Patents

Abstract

PURPOSE:To permit to simplify transmission system by a method wherein a normal revolution speed change area and a reverse revolution speed change area are formed in order not to provide a vehicle with a reverse gear. CONSTITUTION:The reverse revolution speed change area W' is produced by deviating the engaging point of friction of a rail ring with respect to a flat transmission surface 5C into the direction of the center line X-X of a conical roller 5. The rotating direction of an output shaft is changed at the boundary of a point Po whereat the speed change ring and the conical roller 5 satisfy the condition of a:b<c:d. The normal revolution speed change area W and the reverse revolution speed change area W' are formed by selecting the constants (b), (d), which have a mutual relation. Accordingly, it is not necessary to provide the vehicle with the reverse gear and the transmission system may be simplified.

Description

[Detailed description of the invention] Industrial applications.

The present invention relates primarily to the use of continuously variable friction transmissions in motor vehicles.

BACKGROUND OF THE INVENTION Internal combustion engine driven automobiles currently in use are equipped with a reverse gear for reversing, except for two-wheeled vehicles that do not require reversing.

The problem that the invention seeks to solve.

A configuration having a reversing gear in addition to the transmission has been adopted as a matter of course, but this is because no suitable transmission that eliminates the need for a reversing gear has been found. Therefore, if a transmission capable of reversing the vehicle was developed, it would bring great advantages in terms of the structure and handling of the vehicle.

The present invention provides a solution to the situation in which a reverse gear must be installed, and aims to develop a transmission that can omit the installation of a reverse gear.

Structure of the invention: In order to achieve the objective of the present invention,
One thing to note is the frictionless continuously variable transmission described in Publication No. 221.In addition to a conical surface that can change the effective radius for the speed change ring by moving the speed change ring in the axial direction, this transmission has a transmission wheel on the input shaft. A plurality of conical trochanters are provided having a concave transmission surface that is frictionally engaged with the raceway ring and a flat transmission surface that is frictionally engaged with the raceway ring so that the raceway ring is restrained from rotation or is restrained from rotating. The rotation of the speed change ring or the rotation of the orbital ring is transmitted to the output shaft depending on whether the gear ring is connected or not. To simplify the expression, if we call this type of transmission an R-type transmission, the one described in the above publication and the R-type transmission currently supplied on the market are:
At the end of the stroke toward the large diameter side of the conical trochanter, the rotational speed of the output shaft becomes 0, and at the point of maximum load torque (maximum value of torque that can be applied to the output shaft), the rotational speed of the output shaft becomes 0. Near the point.

The present invention takes into consideration the fact that all conventional vehicles, except for two-wheeled vehicles, are forced to install a reverse gear and the characteristics of the R-type transmission described above. The effective radius a of the conical surface and the distance from the point of frictional engagement between the flat transmission surface and the raceway ring to the center line of the conical trochanter are equal to the inner radius C of the speed change ring and the distance from the point of frictional engagement between the flat transmission surface and the raceway ring. Distance d to the center line of the raceway ring, a point where the relationship a:b=c=d is established is shifted toward the apex of the conical surface of the conical trochanter to provide a slight reversal speed range. It is. Here, "reverse rotation" is an expression using "normal rotation" as the direction of rotation of the output shaft in a conventional R-type transmission in which the output shaft rotates in only one direction.

Operation When the above-mentioned device according to the present invention is used in a vehicle, since the rotational speed of the output shaft is near the point O, it is possible to move not only forward but also backward without the aid of a clutch. It is meant to be. There is currently no known transmission for an internal combustion engine-driven vehicle that has such a function. There are various types of friction continuously variable transmissions whose shift range includes a point where the rotational speed of the output shaft is 0.
The torque that they can produce near the point where the rotational speed of the output shaft is D is extremely low, and the car cannot be started without the help of a clutch and without significantly increasing the engine rotational speed. It is of little practical use at this stage.

Embodiment: FIG. 1 shows a friction continuously variable transmission according to the present invention in a case where output rotation is taken out from a raceway ring. In this figure, (1) is the input shaft, (2) is the output shaft, and the transmission mechanism section (3) includes a transmission wheel (4) on the input shaft, a conical trochanter (5)
, a track ring (6), a speed change ring (7) and a speed change ring moving device (8).

Figure 2 shows an enlarged view of the main parts of the transmission wheel (4), conical trochanter (5), raceway ring (6), and speed change ring (7) in the transmission shown in Figure 1. ) at the conical surface.

The transmission surface having a concave cross-section and the flat transmission surface are shown with symbols (5a), (5b), and (5c), respectively. The rotation direction of the output shaft (2) is a point P where the speed change ring (7) and the conical rotor (5) satisfy a: b=c: d. Change as a boundary.

In the conventional R-type transmission, the speed change ring (7) is at point P.

However, in the present invention, if the interrelated constants a and a (b are decreased, d is also changed to a different extent). ), a forward speed change region W and a reverse speed change region W' are formed. As pointed out earlier, in this specification, the rotation of the output shaft of the conventional R-type transmission is referred to as normal rotation.

There are two types of R-type transmissions: those in which the rotation direction of the input shaft and the output shaft are the same, and those in which the rotation directions of the output shaft are opposite. Those that fix the raceway ring and extract the rotation of the speed change ring onto the output shaft belong to the former type. , those in which the rotation of the gear ring is restrained and the rotation of the raceway ring is extracted onto the output shaft belong to the latter category, but in this specification, the direction of rotation given to the output shaft in the gear change range W is expressed as positive. I am planning to do so.

Assuming that the effective radius a - f is as shown, the rotational speed of the input shaft is N1, and the rotational speed of the output shaft is N2, then N, , N2 in a type in which the speed change ring is rotated.
The relationship between N1. Since the relationship between N2 is expressed as follows, when bc - ad, = O holds true, in other words, when a:b=c:d holds true, the rotational speed N2 of the output shaft becomes O.

P in the figure indicates the point of maximum forward rotation speed N2 (maximum forward rotation), and P2 indicates the point of maximum speed N2 of reverse rotation (maximum reverse rotation). ) of the raceway ring relative to the center line
Since it is made to be shifted in the X direction, it is much narrower than the forward speed change range W, and is about 02, but this speed change range is sufficient for the vehicle to travel in reverse.

Effects of the Invention: The device according to the present invention is suitable for operating a load that requires a large starting torque in both positive and negative directions.

As previously pointed out, the greatest advantage of the present invention is that it simplifies the transmission system by eliminating the need for a reverse gear in the vehicle, and also facilitates maneuverability.

[Brief explanation of the drawing]

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Claims (1)

[Claims] In addition to the conical surface whose effective radius relative to the speed change ring can be changed by axial movement of the speed change ring, there is also a concave transmission surface that is frictionally engaged with the transmission wheel on the input shaft, and a flat surface that is frictionally engaged with the raceway ring. A type in which a plurality of conical rotors with a transmission surface are provided, and the rotation of the speed change ring or the rotation of the raceway ring is transmitted to the output shaft depending on whether the rotation of the raceway ring is restrained or not. In,
The effective radius a of the conical surface relative to the speed change ring, the distance b from the point of frictional engagement between the flat transmission surface and the raceway ring to the center line of the conical trochanter, the inner radius c of the speed change ring, and the above friction. Between the distance d from the engagement point to the center line of the raceway ring, the point where the relationship a:b=c:d is established is shifted toward the apex of the conical surface of the conical trochanter to create a slightly reverse speed change range. A continuously variable friction transmission characterized by the following.