JPH0581780B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a continuously variable transmission used in vehicles, general industrial machinery, and the like.

(Prior art) Continuously variable transmissions include mechanical, hydraulic, and electric types. Among these, mechanical continuously variable transmissions can be roughly divided into three types: friction wheel type, wrap-around conduction type, and link device freewheel type. There are different types, and this invention belongs to the friction wheel type.

Conventional friction wheel type continuously variable transmissions attempt to change the input/output rotation ratio by changing the effective diameter of the friction wheel. Typical examples include the Beyer continuously variable transmission, the ring cone continuously variable transmission, Known examples include the Hainow continuously variable transmission, the Coppu continuously variable transmission, and the Pemberly continuously variable transmission.

(Problems to be Solved by the Invention) The friction wheel type continuously variable transmission described above is prone to slipping because it uses frictional force to change gears.
In particular, it has the disadvantage that it tends to slip when starting, and there is a problem that this tends to occur when starting under a heavy starting load, such as when a truck is loaded with a heavy load, and solving this problem is an issue. It had been.

The object of the present invention is to solve the above-mentioned problems and provide a continuously variable transmission capable of transmitting large torque without slipping during startup.

(Means for Solving the Problems) In order to achieve the above object, this invention rotatably supports an input shaft and an output shaft arranged in parallel in a main body housing, and a shaft is attached to the input shaft and output shaft. Identical pinions located on the same plane perpendicular to the center are each installed, and an identical annular ring gear with teeth on the inner and outer peripheries is arranged outside both pinions so that the inner teeth can mesh with the pinions. A pair of friction wheels, each of which has a conical surface facing the ring gears, are fitted on both sides of the ring gears in a non-rotatable but slidable manner to the input shaft and output shaft. An idle gear is interposed between the two ring gears that meshes with the external teeth of the two ring gears, so that when the internal teeth of one of the ring gears mesh with the pinion, Set the center distance between both ring gears so that the center of the ring gear matches the center of the input shaft or output shaft, and A frame-shaped shift frame that rotatably supports a positioning gear that meshes with the external teeth of the two ring gears is provided at each of two locations distributed from the center line on the outside so as to be movable in the direction of the center line. This continuously variable transmission is configured to move the two ring gears and one idle gear integrally in the direction of the center line by moving the shift frame to perform continuous speed change.

Note that, since the pinion engages intermittently with the internal teeth of the ring gear, it is provided with a synchronization mechanism to prevent interference between the teeth during engagement.

(Function) When starting at the lowest speed, the ring gear on the input shaft side is positioned eccentrically with respect to the input shaft and the friction wheel, and a portion of both sides are in contact near the center of the friction wheel, causing the ring gear to interact with the friction wheel. The contact surface of the ring gear is narrow and slips are likely to occur, but since the internal teeth mesh with the pinion, slips do not occur during startup, and the rotation of the input shaft at this time is dependent on the number of internal teeth of the ring gear. The rotation is reduced to the ratio of the number of teeth to the pinion to rotate the ring gear on the input shaft side, and is further transmitted to the ring gear on the output shaft side as rotation in the same direction via the idle gear.

At this time, the output shaft and the friction wheel of the ring gear on the output shaft side are aligned, and both sides of the ring gear are in uniform contact with the outer circumference of the friction wheel, and the frictional conduction force is maximized, without slipping. The rotation of the ring gear is directly transmitted to the output shaft.

Next, when the shift frame is moved in the direction from the input shaft to the output shaft along the center line perpendicular to both the center lines of the input and output shafts, both ring gears sandwiched between the positioning gears on both sides The idle gear moves integrally with the shift frame, and the inner teeth of the ring gear on the input shaft side disengage from the pinion, and while power is transmitted through friction with the friction wheel, the contact points on both sides move toward the outer periphery of the friction wheel. The rotation speed is gradually increased as the ring gear moves in the direction, and when the center of the ring gear coincides with the center of the input shaft and the friction wheel, both sides are in full contact with the friction wheel, and the rotation of the ring gear matches the rotation of the input shaft. be the same.

At this time, the ring gear on the output side gradually moves as the shift frame moves, and the contact points with the friction wheels on both sides gradually move toward the center, and as the radius of the contact point becomes smaller, the friction wheels move at the rotational speed of the ring gear. Finally, the internal teeth mesh with the pinion of the output shaft, and the rotation of the ring gear is directly transmitted to the output shaft, and the rotation speed of the output shaft increases to the rotation speed of the ring gear (same as the rotation speed of the input shaft). The ratio of the number of internal teeth to the number of pinion teeth is increased to achieve the highest rotation speed.

That is, the minimum and maximum rotational speeds of the output shaft are expressed by the following equations.

Minimum output shaft rotation speed = Input shaft rotation speed x Number of pinion teeth ÷ Number of internal teeth of ring gear Maximum output shaft rotation speed = Input shaft rotation speed x Number of internal teeth of ring gear ÷ Number of pinion teeth If you want to obtain a larger gear ratio can be realized by combining the device of the present invention with two stages, three stages, etc.

(Example) The present invention will be described in detail below based on an example shown in the drawings.

The drawings show a preferred embodiment of the continuously variable transmission of the present invention, and Fig. 1 is an internal side view showing the gear position relationship at the lowest deceleration with one side of the main body housing, which can be divided into two at the center, removed. FIG. 2 is an internal side view showing the gear positional relationship at maximum speed, FIG. 3 is a central cross-sectional view, and FIG. 4 is an end view.

In the figure, reference numerals 1 and 1a denote a main body housing, which is symmetrically divided into two parts, has mounting seats 2 and 2a at the lower part, is secured around the periphery with bolts 3, and has a continuously variable transmission mechanism incorporated therein.

4 is an input shaft, and 5 is an output shaft, both of which are rotatably supported by bearings 6, 6a in the main body housings 1, 1a, and are parallel to each other with a predetermined interval. protrudes in the opposite direction.

7 and 7a are pinions, which connect the input shaft 4 and the output shaft 5.
The pinion 7 is mounted on the input shaft 4 and the output shaft 5, respectively, with the center of the thickness of the pinion 7 aligned on a plane perpendicular to the main body 1, 1a, that is, on a plane that coincides with the mating surface of the main bodies 1 and 1a. In order to prevent the teeth from interfering with each other when meshing with the internal teeth, the tips of the teeth are rounded and have a synchronized structure with a slight play between them and the shaft in the direction of rotation.

Examples of this synchronization structure are shown in FIGS. 5 and 6, in which the width w of the keyway 9 of the pinion 7 is made wider than the thickness t of the key 8 fitted to the input shaft 4 and the output shaft 5, and the key 8 and the keyway Curved leaf springs 10, 10 are inserted along both sides of the key 8 into the gap between the key 8 and the key 9, and when the key 8 does not rotate (no load), the key 8 is in the state shown in FIG. , and during rotation (under load), one leaf spring 10 is in the state shown in FIG. 6B.
is pressed flat by the load, and the key 8 and keyway 9
The rotation is transmitted by being sandwiched between one side of the .

11, 11a are ring gears, and pinions 7, 7a are attached to the input shaft 4 and output shaft 5, respectively.
are arranged in an annular shape on the outside of the pinion, and have the same inner teeth 12, 12a and outer teeth 13, 13a on the inner and outer peripheries, and the inner teeth 12, 12a can mesh with the pinions 7, 7a, respectively. Furthermore, both sides have an inverted conical surface 14 with a thinner thickness on the inner circumferential side,
14a.

15, 15a are friction wheels, which connect the input shaft 4 and the output shaft 5.
A pair of gears facing each other with the ring gears 11 and 11a in between are spline-fitted to each other so as to be non-rotatable and slidable. A pinion is formed on the conical surfaces 16, 16a to coincide with each other, and a pinion is provided at the center of the conical surfaces 16, 16a to avoid interference with the pinions 7, 7a when the friction wheels 15, 15a approach the pinions 7, 7a. Threads 17, 17a having a diameter slightly larger than the outer diameter of the ring gears 11, 11a are formed, and the conical surfaces 16, 16a are pressed against the inverted conical surfaces 14, 14a of the ring gears 11, 11a. It is biased via a spring 18 between the two.

A spline shaft cylinder 19 is fitted on both sides of the pinions 7, 7a of the input shaft 4 and the output shaft 5, respectively, and is fixed by a fixing pin 20, so that the friction wheel 1
5 and 15a are fitted together, respectively.

21 is a shift frame with two ring gears 1
Make it almost rectangular in shape surrounding the outside of 1, 11a,
Two frames on the left and right sides are connected with a connecting part 21a at the center in the longitudinal direction, and are arranged at appropriate intervals, and the left and right frames are connected at the center of the connecting part 21a by an idle gear shaft 22, and The positioning gear shaft 23 connects two locations at both ends of the input shaft 4 and the output shaft 5 vertically from the center line X perpendicular to the center lines of the input shaft 4 and output shaft 5, One end of the shift rod 24 is connected to one end of the shift rod 24, which penetrates the main bodies 1 and 1a and projects to the outside.

As shown in FIG. 3, the idle gear shaft 22 has an idle gear 25 and a needle bearing 26.
The idle gear 25 is located between the two ring gears 11, 11a and meshes with both the ring gears 11, 11a. The center distance between the two ring gears 11 and 11a is set such that the center of the other ring gear 11 or 11a coincides with the center of the input shaft 4 or the output shaft 5 when the other ring gear 11 or 11a meshes with the input shaft 4 or the output shaft 5.

Further, as shown in FIG. 7, the positioning gear shaft 23 has a positioning gear 27 that meshes with the ring gear 11 or 11a, and a needle bearing 28.
The ring gear 1 is rotatably supported via the ring gear 1.
The planar positions of 1 and 11a are maintained.

29 is a guide wheel, which has flanges at both ends, and whose outer periphery touches the outside of the upper and lower sides of the shift frame 21;
In addition, two guide roller shafts 30 on each side are supported at both ends by the main body housings 1 and 1a, with the thickness of the shift frame 21 being sandwiched between the flanges at both ends.
The shift frame 21 is rotatably supported by the shift frame 21 so as to be movable in the longitudinal direction.

In the figure, 31 indicates an oil seal, and 32 indicates a bush.

In the above configuration, in the state shown in FIGS. 1 and 3, the shift frame 21 is in a position far to the right when facing the figure (hereinafter words indicating direction will be referred to as facing the figure). In this state, the pinion 7 on the input shaft 4 side is meshing with the internal teeth 12 of the ring gear 11, and the inverted conical surfaces 1 on both sides of the ring gear 11 are engaged with the inner teeth 12 of the ring gear 11.
4 is a conical surface 16 near the center of the friction wheels 15, 15;
16 in a linear contact at a position corresponding to the center line X.

At this time, the center of the ring gear 11a on the output shaft 5 side is aligned with the axis of the output shaft 5, and the ring gear 11a
The inverted conical surfaces 14a on both sides of 1a are friction wheels 15a, 1
The entire surface is in contact with the conical surfaces 16a, 16a of 5a.

In this state, the rotation of the input shaft 4 is controlled by the ring gear 1.
The rotation of the ring gear 11 is transmitted through the idle gear 25 to the ring gear 11a on the output shaft 5 side as the same rotation in the same direction. The rotational speed is transmitted to the output shaft 5 via the friction wheels 15a, 15a, and outputted at the same rotation speed as the ring gears 11, 11a, that is, the minimum rotation speed.

In this case, the rotation of the input shaft 4 is caused by the rotation of the ring gear 1, which is most likely to slip on the input shaft side.
1 and the friction wheels 15, 15, and the transmission is transmitted to the ring gear 11a on the output shaft side by meshing of the gears. In 11a, the inverted conical surface 14a is a friction wheel 15
It is in full contact with a and 15a over the entire circumference,
Slip is almost impossible, and rotation can be reliably transmitted even when the starting load is large.

Next, in order to change the rotation ratio, when the shift frame 21 is moved from the state shown in FIG. 1 to the left by pulling the shift rod 24, the ring gears 11, 11
a, the idle gear 25, and the four positioning gears 27 move together with the shift frame 21, and the pinion 7 on the input shaft side disengages from the internal teeth 12 of the ring gear 11, and the input shaft 4 is frictionally transmitted from the friction wheels 15, 15 to the ring gear 11.

In this state, since it is rotating, there is inertia, and torque transmission is not required as much as when starting up, and frictional force alone can be sufficient to transmit the torque.

Thus, the friction wheels 15, 15 of the ring gear 11
As the contact position gradually approaches the outer periphery of the friction wheels 15, 15, the rotation speed of the ring gear 11 gradually increases and approaches the rotation speed of the input shaft 4, and finally the shift frame 21 reaches the position shown in FIG. , the center of the ring gear 11 is the input shaft 4 and the friction wheels 15,1.
Coinciding with the center of 5, the inverted conical surfaces 14, 14 on both sides
are in full contact with the outer peripheries of the conical surfaces 16, 16 of the friction wheels 15, 15, and the rotation speed of the ring gear 11 becomes the same as the rotation speed of the input shaft 4.

The rotation of the ring gear 11 on the input shaft side is always transmitted in the same direction and at the same rotation speed to the ring gear 11a on the output shaft side. Friction wheel 15 as 20 moves
The rotation of the friction wheels 15a, 15a is gradually increased as the friction wheels 15a, 15a move toward the center of the ring gear 11a, and finally the internal teeth 12a of the ring gear 11a move toward the pinion 7a.
The output shaft 5 rotates directly from the ring gear 11a through the pinion 7a to the maximum rotation speed.

(Effects of the Invention) According to the continuously variable transmission of the present invention as described above, when the ring gear and the friction wheel combined on both the input shaft side and the output shaft side are maximally eccentric, there is no slip between them. When this is likely to occur, the pinions attached to the input and output shafts mesh with the internal teeth of the ring gear and rotation is transmitted, so slips do not occur, and if the engine is started with these pinions and ring gear meshed, For example, even when a large starting torque is required, such as when trying to start a truck with a heavy load, it is possible to prevent slips in the continuously variable transmission and achieve reliable starting.

[Brief explanation of the drawing]

The drawings show preferred embodiments of the invention,
Figure 1 is a side view of the internal structure with one side of the main housing divided into two parts removed, showing the gear-related positions at the lowest speed, and Figure 2 is a side view of the internal structure showing the gear-related positions at the highest speed. Figure 3 is a sectional view along the line of Figure 1, Figure 4 is a cross-sectional view of Figure 1.
An end view seen in the direction of the arrow, Figure 5 is Figure 3-
Fig. 6 is an enlarged sectional view taken along the line shown in Fig. 5, where A is no load (no rotation), B is
indicates the load (rotation) time. Figure 7 is a sectional view along the line of Figure 1, and Figure 8 is a cross-sectional view along the line of Figure 1.
FIG. 1, 1a...Main housing, 4...Input shaft,
5...Output shaft, 7,7a...Pinion, 11,1
1a...Ring gear, 12, 12a...Internal teeth, 1
3, 13a... External tooth, 14, 14a... Inverted conical surface, 15, 15a... Friction wheel, 16, 16a...
Conical surface, 18... Spring, 19... Spline shaft cylinder, 21... Shift frame, 25... Idle gear, 27... Positioning gear, X... Center line.

Claims (1)

[Claims] 1. An input shaft and an output shaft arranged in parallel are rotatably supported in the main body housing, and the input shaft and the output shaft are provided with the same pinion located on the same plane orthogonal to the shaft center. An identical ring gear having an annular shape and teeth on the inner and outer peripheries is arranged on the outside of both the pinions so that the inner teeth can mesh with the pinion, and on both sides of the ring gears, opposite to the ring gear are arranged. A pair of friction wheels each having a conical surface are fitted onto the input shaft and the output shaft so as to be non-rotatable and slidable, respectively, and biased in a direction to sandwich the ring gear between the two. An idle gear that meshes with each of the external teeth is interposed between the ring gears, so that when the internal teeth of one of the ring gears mesh with the pinion, the center of the other ring gear coincides with the center of the input shaft or output shaft. Set the center distance between both ring gears so that the center distance between the two ring gears should be set, and set two locations on the outside of the two ring gears in the direction of the center line perpendicular to the center lines of the input shaft and output shaft, separated from the center line. A frame-shaped shift frame that rotatably supports a positioning gear that meshes with the external teeth of the two ring gears is provided to be movable in the direction of the center line, and by moving the shift frame, the two A continuously variable transmission characterized in that a ring gear and one idle gear are integrally moved in the direction of the center line to continuously change speed.