JPS5969565A - Stepless speed change gear - Google Patents

Abstract

PURPOSE:To obtain the simple constitution of the captioned apparatus at low cost by forming each semicircular groove in which the center of rotation of a steel ball is automatically determined through the equilibrium of the forces at three points at which the steel ball contacts under pressure, on a driving-side member and a trailing-side member, in a stepless speed change gear in utilization of steel ball. CONSTITUTION:An input shaft 9 and an output shaft 10 are supported through bearings 33, 34, 36 and 37 onto the brackets 7 and 8 which constitute a part of a housing, and an input-side drive cone 28 which point-contacts with the outer periphery of a steel ball 21 and whose outer surface is curved in concaved form is installed at the edge of the input shaft 9 through a spline part 9a. An output- side drive plate 35 having a semicircular groove 35a which point-contacts with the steel ball 21 is fixed at the edge of the output shaft 10, and an outer ring 22 having a conical surface 22a which press-contacts with the steel ball 21 is fixed onto the inner peripheral surface of the housing 6. The input-side drive cone 28 is shiftable in the axial direction through a pin 31 and a positioning plate 29, by the revolution of a nut 32, and thus transmission ratio can be varied.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuously variable transmission using spheres.

A conventional device of this type is shown in FIG.

Figure 1 is a partial sectional view showing a conventional device, and in the figure f
il is a steel ball (generally a sphere), (2) is a spindle shaft inserted into the center hole of the steel ball fil, and (3) is a steel ball (11
needle bearing between (2) and spindle shaft (4)
(4a) is the iris plate (4
), through which the spindle shaft (2) passes, a cam groove (
4b) is a worm wheel provided on the outer periphery of the iris plate (4), and (5) is a worm wheel (41).
) is the worm gear provided, (6) is the housing, (
7) and (8) are +61 and (7) respectively in brackets.
), (3) are collectively called the housing structure, and (7
a), (8a) u each bracket) (7),
(8) Groove provided inside, (9) is a human-powered shaft (general (
F is a first rotating shaft), and nd is an output shaft (generally a second rotating shaft). The axes of the axes (9) and t+1 coincide, and if we consider rectangular coordinates with the X axis as the center of the axes, the cross section shown in Figure 1 is a cross section taken by a plane that includes the X axis, and the steel ball (
1) A plurality of steel balls (1) are provided on a plane perpendicular to the X-axis so that the center of each law is at a point at a distance r from the X-axis, that is, on the circumference of a circle with a radius r. Arranged so that the distance between centers is uniform. (14(7a'), (8
In the direction a), the projection on a plane perpendicular to the X-axis extends in the radial direction with the X-axis as the center, and the cam groove (4a) is connected to the spindle axis ( 2) is constructed in such a shape that both ends thereof fit into the grooves (7a) and (8a) and move.

(11) is an outer ring;
0 is the input side drive cone (drive cone
), (13 is the output side drive cone, (14 is the input side pressure roller, (19 is the output side pressure roller, QQFi bearing, αη is lubricating oil, 08 and α scratches are oil seals. Outer ring 0 The outside of mark 1 ball (1) is pressed against the drive cone 02, and the target is pressed against the steel ball (1) to transmit rotation by friction. The lubricating oil (1η) is provided in order to apply pressure to the ball (1) and support the bearing oeFi output shaft +1[) with the bracket (8), and is contained in an oil tank formed within the housing structure.

Next, the operation will be explained. When the worm gear (5) is rotated by the handle (not shown), the worm wheel (
4b) through which the iris plate (4) rotates around the X-axis. At this time, the grooves (7a), (8a) and the cam groove (
The positional relationship of 4a) has changed, and the spindle axis (2) is
It will be tilted from a direction parallel to the axis.

FIG. 2 is an explanatory diagram for explaining the operation of the device shown in FIG.
The same symbols as in the figure indicate the same parts, N1 is the input rotation speed, N
2 is the output rotation speed % R1 + R2 is the contact radius of the drive cone (12, (13), r + rl
2 are the drive cones (12, (13) of the steel ball (1), respectively.
If the contact radius and θ are the inclination of the spindle shaft (2), then N2=dimension N1, and the deceleration is at r 1 > r 2, and when θ is in the opposite direction to the example shown in Fig. 2, r , < r
2, and the speed is increased.

In this case, each drive cone vt, ai is the axis (9), +1 from the pressure roller (141, (1!3 K)
At the same time, the drive cone fl'A, (11) is pressed toward the center by an axial component force corresponding to the transmitted torque, and each drive cone Q
A pressing force necessary for frictional transmission is generated between 3 and 03 and the steel ball (1). Further, the steel ball (1) is subjected to an inward pressing force by the outer ring α° C., so that the balance between each pressing force is maintained.

By the way, the pressing force required for friction transmission increases as the torque to be transmitted increases, so it is only necessary to apply a large pressing force only on the low-speed rotation side where the torque is large, but with the structure shown in Figure 1, In order to balance the pressing force, a similarly large pressing force acts on the high-speed rotation side. Applying an excessive pressing force on the high-speed rotation side often causes large friction losses, so the upper limit of the allowable pressing force is limited, and this becomes the upper limit of the pressing force on the low-speed rotation side. However, if the pressing force on the low-speed rotation side is low, slippage will occur when the rotational torque is large, and this slippage must be limited to a predetermined value or less. Therefore, the upper limit of the pressing force on the high-speed rotation side is This limits the torque on the rotating side, which in turn limits the capacity of transmitted horsepower. Furthermore, as is clear from Fig. 1, the structure in which a spindle shaft is provided on a sphere and the inclination angle of the spindle shaft is controlled requires a large number of parts, requires high-precision machining, and not only increases manufacturing costs.
As mentioned above, the disadvantages are that the transmitted horsepower is limited and the durability is also low.

This invention was made to eliminate the drawbacks of the conventional apparatus as described above, and will be described in detail below with reference to the drawings.

FIG. 3 is a partial sectional view showing an embodiment of the present invention.
), (7), (8), +9), 110,
(1η, θ~, (11u*1) Indicates the part corresponding to the same reference numeral in the figure, (9a) is the spline part provided on the input shaft (9), and C21 is a steel ball (generally a sphere). be.

First and second rotation axes +91, the axial direction of fIO is
In the case of Fig. 1, the centers of a plurality of steel balls (al) are arranged on a plane perpendicular to the X-axis, on a cylinder at a distance r from the X-axis, with uniform distances between the centers. is similar to
Also, as in the case of FIG. 1, the cross section of FIG. 3 shows a cross section along a plane including the X-axis. (c) is a conical surface (22a) fixed to the housing structure and in pressure contact with the steel ball Q.
) having an outer ring;
(C) is an input side drive cone whose outer circumferential surface is concavely curved and makes point contact with the outer circumference of one ball Q1).
), the handle is a fixed plate for positioning the input side drive cone example, the tAH fixed plate handle and the input side drive cone (
c) Thrust bearing between C), Kura Yu is a fixed plate @
A plurality of pins are installed in the bracket (7) and pass through the bracket (7). Six of them are gear shifting nuts. By rotating them left and right, the input side is connected via the pin 3, fixed plate (c), and thrust bearing part. Move the drive cone @ in the X-axis direction.

0], (b) is a bracket (7) that supports the input shaft (9).
), the output side drive plate is in point contact with the outer periphery of the steel ball e21), and this output side drive plate cI is the output shaft (
Fixed at 11K.

Fig. 4 is an explanatory diagram for explaining an example of the operation of the device shown in Fig. 3. For each steel ball η, the center of the steel ball is the origin and the axis is parallel to the direction of the input axis (9) (X-axis direction). The direction is the X axis,
A plane containing the axis and the Also, point A is the contact point between the input side drive cone (c) and steel ball Q1), point B is the contact point between the output side drive brake) 05 and steel ball e2), and point 0 is the contact point between the outer ring (c) and the steel ball e2). At the contact point with the steel ball 01), the suppressing force at each contact point A, B, and C is as shown in the figure (FA
, FB, Fo.

is rotated around the Y axis by an angle β, which is the angle
=β, and then rotate the YOM plane around the ξ-axis by an angle θ, so that point B will be on the ξ-axis.

In this case, the coordinate transformation formula is as follows.

) By the way, regarding the coordinate axes shown in Fig. 4, as long as the position of the positioning fixed plate on the X axis is fixed,
The positions of points A, B, and C are fixed, and it can be seen that the center point Of of one ball 01) is fixed by being supported by these three points. Therefore, the pressing force, FA* FB , Fc
It suffices as long as they maintain vectorial equilibrium, and there is no limit as in the case of FIG. 1 where the pressure on the low-speed rotation side and the pressure on the high-speed rotation side are unequal to be in balance. Therefore, in the device shown in FIG. 3, both the low-speed rotation side and the high-speed single rotation side require a pressing force that is just the same according to the load torque, and requires only the minimum pressing force necessary for frictional transmission.

Regarding the coordinate axes shown in Fig. 4, the steel ball (1) is ξ
Rotation around the axis is free, so it rotates around the ξ axis. On the other hand, when viewed from the coordinate axis with one point on the X-axis as the origin, the input drive cone (C) is rotating instead of the X-axis, so point A also rotates, and the steel ball ■】) rotates due to this rotation. In response to this, in addition to rotation around the ξ axis, planetary motion occurs with revolution, and this motion is transmitted from point B to the output side drive plate (to).

Input rotation speed is NIN% Output rotation speed is N. 07% The distance from the X-axis to AA is R1, and the distance from the X-axis to the 0 point is R
3% If the distance from the ξ-axis to point A is rl, and the distance from the ξ-axis to point 0 is fr, then 3 is obtained.

When changing the gear ratio, rotate the gear nut 64 to the right or left to change the axial position of the input drive cone (7), thereby changing the position between points A and B on the x-y-z coordinates in Figure gK4.
, by changing the position of C, R1°R3*rl in equation (2)
Change the value of e r3. A change in the position of point B with respect to the x-y-z coordinates results in a change in the ξ axis, and thus F
Changes in the value of or will affect the gear ratio of N0UT/3NIN.

As described above, in this invention, the semicircular grooves of the input shaft drive cone, outer ring, and output side drive plate are configured so that the center of rotation of the steel ball is automatically determined by the balance of the forces of the three points pressing against the steel ball. This makes it possible to provide a continuously variable transmission device that has a small number of parts, a simple structure, can be manufactured at low cost, and has a small size and long life.

Note that even if the input and output shafts are reversed, the operation is the same except that the gear ratio is reversed; It can be operated on either the left or right side of the rotation direction of the shaft.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view showing a conventional device, FIG. 2 is an explanatory diagram explaining the operation of the device shown in FIG. 1, FIG. 3 is a partial cross-sectional view showing an embodiment of the present invention, and FIG. The figure is an explanatory diagram illustrating the operation of the apparatus shown in FIG. 3. (6) -- Housing, (7), (8) Bracket, (9) Input shaft, (11 Output shaft,
0η...Lubricating oil, Q8. QI...Oil seal,
(c)...Steel ball, (to)...outer ring, (c)
...Input side drive cone, (G)...Output side drive plate, (35a)...Semilunar groove. In the middle of the figure, the symbol -@iFi indicates the same or a corresponding part. Agent Shin Kuzuno - Figure 4 7

Claims (1)

[Claims] A first rotational axis, when the axial direction of the first rotational axis is the X-axis, has centers at points equidistant from the X-axis in a plane perpendicular to X@, and has a center-to-center distance. A plurality of spheres are uniformly arranged, and the first rotation axis is configured to accommodate the plurality of spheres, to freely rotate around the X-axis, and to fix the position in the X-axis direction. a housing structure to hold the housing structure; a plane fixed to the housing structure and including the X-axis has one side that is tangent to the outer periphery of the sphere; and the - an outer ring configured such that the contact position between the side and the sphere changes; and an outer ring that is connected to be slidable in the X-axis direction with respect to the first rotation axis and fixed with respect to rotation around the X-axis; has a concave curved shape, the cut surface of the plane including the X axis maintains one point contact with the outer periphery of the sphere, and the point of contact is determined by the position relative to the center of the sphere in the X axis direction. The cut surface of the drive cone and the plane including the X axis maintains one point contact with the outer periphery of the sphere at a point opposite to the contact point with the outer ring and drive cone, and the contact point is above the center position of the sphere. We have a drive plate that has a semicircular groove with a concave curve that changes depending on the change in distance from the X-axis, and forms the rotation axis of this drive plate, whose axis coincides with the X-axis, and the housing structure allows rotation around the X-axis. is free and
゛The position in the X-axis direction is fixed at a position opposite to the first rotating shaft, or the relative position in the X-axis direction of the second rotating shaft, the first rotating shaft, and the drive cone is adjusted. A continuously variable transmission device comprising means.