JPH05280608A - Belt type continuously variable transmission - Google Patents

Abstract

PURPOSE:To provide a belt type continuously variable transmission which dispenses with the enlargement of a size of one of bearings for supporting a transmission pulley and is capable of, reducing the diameter so much and standing long use. CONSTITUTION:A belt type continuously variable transmission has a transmission pulley 5 in which a pitch diameter R1 of a belt 9 arranged between a movable flange 19 and a fixed flange 17 is varied by an axial movement of the movable flange 19, operation means 39, 63, 65 which adjust a transmission ratio by axially moving the movable flange 19, and a pair of bearings 21, 23 which support a rotary shaft 15 of the transmission pulley 5. The bearings 21, 23 are arranged with substantially the same distances (a), (a) respectively from a power point 67 when a load to be applied to the pulley is a maximum value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt type continuously variable transmission.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 63-9546 discloses a "movable pulley position detecting device". FIG. 2 shows a speed change pulley 201 for a belt continuously variable transmission that constitutes this device. In the belt type continuously variable transmission, a movable flange 207 is axially moved with respect to a fixed flange 205 integrated with a rotary shaft 203. Then, the belt 209 moves in the axial direction, the pitch diameter R changes, and the gear ratio is adjusted.

[0003]

SUMMARY OF THE INVENTION A belt type continuously variable transmission is designed such that a drive side shift pulley has a maximum belt pitch diameter and a driven side shift pulley has a minimum belt pitch diameter (minimum gear ratio). The speed change operation is performed until the belt pitch diameter of the speed change pulley is minimum and the belt pitch diameter on the driven side is maximum (the speed ratio is minimum). Each speed change pulley on the drive side and the driven side supports this. There are situations where the axial load on the pair of bearings is maximum.

However, as shown in FIG.
Has a large deviation between the center 215 of the bearings 211 and 213 supporting the rotary shaft 203 and the load point 217 of the belt 209. Therefore, if the bearings 211 and 213 have the same diameter, the bearing 213 with the larger load comes first. Wears out and shortens the life of the entire device. For this reason, a large bearing 213 is used for the purpose of making the life of the bearing 211 substantially the same as that of the bearing 211, and the device has a large diameter. This is particularly disadvantageous for in-vehicle devices, for example.

Therefore, it is an object of the present invention to provide a belt type continuously variable transmission which does not require one of the bearings for supporting the speed change pulley to be large in size, and can be made to have a small diameter and to have a long service life. ..

[0006]

SUMMARY OF THE INVENTION A belt type continuously variable transmission according to the present invention includes a speed change pulley in which a pitch diameter of a belt mounted between a movable flange and a fixed flange is changed by axial movement of the movable flange, and a movable pulley. As described above, the flange is provided with an operating means for axially moving and adjusting the speed change ratio, and a pair of bearings for supporting the rotary shaft of the speed change pulley. These bearings are belts when the load applied to the pulley is maximum. It is characterized in that they are arranged almost equidistant from the load point by.

[0007]

When the load applied to the speed change pulley is maximum, the bearing supporting the rotary shaft is arranged so as to be substantially equidistant from the load point of the belt. Therefore, the load that each bearing bears at the maximum load will be substantially equal, and unlike the conventional example, one bearing will not be particularly large and durability will be impaired even if each bearing has almost the same diameter. In addition, the bearing portion of the device can be made small in diameter, and the life can be kept long.

[0008]

EXAMPLE One example will be described with reference to FIG. FIG. 1 shows a mechanical supercharger 3 driven by an engine via a belt type continuously variable transmission 1 of this embodiment. The left and right directions are the left and right directions in FIG. 1, and members and the like without reference numerals are not shown.

As shown in FIG. 1, the belt type continuously variable transmission 1 includes a drive pulley 5 (driving-side shifting pulley), a driven pulley 7 (driven-side shifting pulley), and a belt 9 connecting these. I have it. Further, the mechanical supercharger 3 includes a speed increasing unit 11 and a centrifugal compressor type supercharger 13.

The drive pulley 5 is a hollow shaft 15 (rotating shaft).
And a movable flange 19 connected to the hollow shaft 15 so as to be movable in the axial direction. The hollow shaft 15 is supported on a support shaft 25 via bearings 21 and 23, and the support shaft 25 includes a bolt 27 and a nut 2.
It is fixed to the casing 31 of the speed increasing unit 11 by means of 9. The belt 9 is attached to the V groove 33 formed between the flanges 17 and 19, and the movable flange 19 is disposed between the hollow shaft 15 and the retainer 37 positioned by the snap ring 35. The belt 9 is pressed by the fixing flange 17 and is given tension. The fixing flange 17 is provided with a screw hole 41 for fixing the belt pulley, and the drive pulley 5 is connected to the crankshaft of the engine via a belt transmission mechanism including this belt pulley, and is rotationally driven by the driving force of the engine. To be done.

The driven pulley 7 has a hollow shaft 47 and a cam member 49 which are press-fitted into the input shaft 43 of the speed increasing portion 11 and are prevented from falling off by a nut 45, a fixed flange 51 integral with the hollow shaft 47, and a cam. The movable flange 53 is connected to the member 49 via an engagement portion 50 provided so as to be movable in the axial direction. The input shaft 43 is supported by the casing 31 via bearings 57 and 59. A belt 9 is attached to a V groove 61 formed between the flanges 51 and 53 to connect the driven pulley 7 to the drive pulley 5.

Cam surfaces 63, 63 are formed on the cam member 49 and the movable flange 53, respectively, and a fly weight 65 is arranged between them. When the driven pulley 7 rotates, the centrifugal force of the fly weight 65 causes the cam surface 63,
The movable flange 53 is pressed against the fixed flange 51 side by the generated cam thrust force.

When the rotational speed of the drive pulley 7 increases as the engine rotational speed increases, the cam thrust force increases and the flange spacing of the driven pulley 7 narrows, the belt pitch diameter R ₂ thereof increases, and the tension of the belt 9 increases. The flange spacing on the drive pulley 5 side becomes wider, and the belt pitch diameter R ₁ becomes smaller, so that the speed increasing ratio decreases.
Further, when the engine speed decreases, the cam thrust force decreases and the force of the disc spring 39 of the drive pulley 5 increases the belt pitch diameter R _{1 and} decreases the belt pitch diameter R ₂ to increase the speed increasing ratio. Thus, the fluctuation range of the rotational speed of the driven pulley 7 is suppressed to be smaller than the fluctuation range of the engine rotational speed, and the rotational speed of the driven pulley 7 is kept substantially constant as the engine rotational speed increases. Fly weight 65
The cam surfaces 63, 63 and the disc spring 39 constitute an operating means.

The support shaft 25 is adjusted so as to be parallel to the central axis of rotation of the driven pulley 7 when it is attached to the casing 31, and the fixed flanges 17 and 51 are arranged axially opposite to each other.

FIG. 1 shows a state in which the load applied to the drive pulley 5 is maximum. In this state in which the maximum load is applied, the bearings 21 and 23 of the drive pulley 5 have the load points 67 of the belt 9 (in this case, the belt 9). (Equal to the center of). In this way, since the bearings 21 and 23 are equally loaded at the maximum load, it is not necessary to make one of the bearings particularly large, unlike the conventional example. Figure 1
As shown in (1), even if the diameters are almost the same, only one of them does not wear first, and the life of the entire device can be kept long.
Further, since a large bearing is not used, the bearing portion of the device does not have to have a large diameter. Also in the driven pulley 7, the load point of the belt is arranged so as to be substantially at the center of the bearings 57 and 59 when the maximum load is applied, so that the same effect as the drive pulley 5 side is obtained.

In this way, the belt type continuously variable transmission 1 is constructed.

The speed increasing unit 11 is a planetary gear type speed change mechanism, an internal gear 69 is integrally formed on the right end side of the input shaft 43, and a pinion gear 71 is supported by a pinion shaft 73 via a bearing 72. ing.
The pinion shaft 73 is the flange portion 7 of the casing 31.
Drop-prevention means 7 supported by 5 and comprising a screw and a ball
It is prevented from falling off by 7. The sun gear 79 is formed on the left end side of the impeller shaft 81 of the supercharger 13. The impeller shaft 81 is supported by the flange portion 75 via a unit bearing 83 and an oil film damper 85.

A speed increasing unit 11 is provided via a belt type continuously variable transmission 1.
The driving force of the engine input to the internal gear 69
The rotational speed of the impeller shaft 81 is increased through the pinion gear 71 and the sun gear 79.

Seals 87 and 89 are arranged between the input shaft 43 and the casing 31 and between the unit bearing 83 and the impeller shaft 81, respectively.
Prevents oil from leaking. The oil film damper 85 includes an oil plug 91 attached to the casing 31 and connected to an oil pump to a nozzle 93 and an oil passage 95.
Oil is supplied via and. This oil lubricates the unit bearing 83, the speed increasing portion 11 and the like, and is discharged from the discharge port to the outside of the casing 31.

An impeller 97 is press-fitted into the right end of the impeller shaft 81 of the supercharger 13, and a fall prevention member 99 is swaged to the right of the impeller 97. Compressor housing 10
Reference numeral 1 is attached to the casing 31 via a connecting member 105 engaged with the circumferential groove 103 of the casing 31 and a bolt 107.

The mechanical supercharger 3 thus constructed is assembled with the belt type continuously variable transmission 1 through the casing 31 into the engine and supercharges the engine by the pressurized intake air.

The present invention is not limited to the above-described embodiment, and the structure in which the load point of the belt in the maximum load state applied to the speed change pulley is arranged at the center of the bearing span is used for the speed change pulley on the drive side or the driven side. You may implement with a speed change pulley. Further, the bearings may be arranged at substantially equal distances with respect to the load point of the belt at the maximum load within a range in which the respective loads are substantially equal.

[0023]

According to the belt type continuously variable transmission of the present invention, the pair of bearings for supporting the speed change pulleys are arranged at substantially equal distances from the load point of the belt when the maximum load is applied to each bearing at the maximum load. Since the loads are substantially equalized, it is possible to make these bearings have substantially the same diameter, prevent an increase in the diameter of the device, and maintain a long service life.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment.

FIG. 2 is a sectional view showing a conventional example.

[Explanation of symbols]

1 belt type continuously variable transmission 5 drive pulley (speed change pulley) 9 belt 15 hollow shaft (rotary shaft) 17 fixed flange 19 movable flange 21, 23, 57, 59 bearing 39 disc spring (operating means) 63, 63 cam surface ( Operating means) 65 Fly weight (operating means) 67 Load point R ₁ Belt pitch diameter

Claims (1)

[Claims] 1. A speed change pulley in which a pitch diameter of a belt mounted between a movable flange and a fixed flange is changed by axial movement of the movable flange, and a speed change ratio is controlled by axially moving the movable flange as described above. It is provided with an operating means for adjusting and a pair of bearings for supporting the rotary shaft of the speed change pulley, and these bearings are arranged substantially equidistant from the load point by the belt when the load applied to the pulley is maximum. Belt type continuously variable transmission.