JPS6258422B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power transmission device using a belt, which is used, for example, in an automobile to transmit engine rotation to auxiliary equipment such as an air pump, water pump, fan, compressor, alternator, etc. and is valid.

Conventionally, belt-type power transmission devices in which the main shaft of a fixed pulley is fixed to the drive shaft with bolts are disclosed in Japanese Utility Model Application No. 54-12679 and Japanese Utility Model Application No. 53-78378.
However, when removing the fixed pulley from the drive shaft, there was a problem in that the main shaft of the fixed pulley was tightly fitted to the drive shaft, so it could not be easily removed.

The present invention has been made in view of the above points, and
It is an object of the present invention to provide a power transmission device whose fixed pulley can be easily removed.

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2 attached. In the figure, 1 is a drive shaft, which in this example is a crankshaft of an automobile engine. (The direction of rotation is represented by p.) A main shaft 11 is integrally fixed to the drive shaft 1 with a bolt 15 and a key (not shown). Note that among the bolts 15, the end surface 1a of the drive shaft 1
An annular groove 15a is formed at a portion opposite to the gap between the main shaft 11 and the opposite end surface 11a of the main shaft 11, and the locking ring 3 is fitted into this annular groove 15a. A slight gap is provided between the end surface 11a of the main shaft 11 and the opposing front end surface 3a of the retaining ring 3, and between the end surface 1a of the drive shaft 1 and the opposing rear end surface 3b of the retaining ring 3.

A dry bearing 12 is driven into the movable pulley 14 and slides along the main shaft 11 in the axial direction as the movable pulley 14 moves. A fixed pulley 13 is integrally fixed to the main shaft 11 with a nut 2.

The fixed pulley 13 and the movable pulley 14 form a driving pulley 10. Therefore, the width and diameter of the driving pulley 10 is variable, and an initial setting load is applied by the spring 16 to move the movable pulley 14 toward the fixed pulley 13. In other words, the width of the driving pulley 10 is changed. It acts in the direction of narrowing. Note that both fixed and movable pulleys 14 are made of a relatively lightweight metal material such as aluminum alloy in order to reduce the weight of the device.

Further, reference numeral 17 denotes a stationary cam that is integrally fixed to the main shaft 11 and has an operating surface 17a. A movable cam 18 is integrally fixed to the movable pulley 14 and has an operating surface 18a having the same angle as the operating surface 17a of the fixed cam 17. (See FIG. 2) The fixed cam 17 and the movable cam 18 form a drive cam mechanism 19. This cam mechanism 19 has working surfaces 17a and 1 of both cams 17 and 18.
Since 7b is always in contact, both cams 17 and 18
When a relative movement occurs between them, a force determined by the angle of the working surfaces 17a, 18a is applied to the working surfaces 17a, 18a according to the load torque. The drive pulley 10 having the above structure is attached and detached as follows.

First, when assembling the drive side pulley 10, in this case, the movable pulley 1
4, the dry bearing 12 and the movable cam 18 are driven in and fixed, and the main shafts 11, 12 and the fixed cam 17 are driven in and fixed. Insert into. Then, the fixed pulley 13 is inserted into the main shaft 11 and fixed with the nut 2, and the driving pulley 10 and the main shaft 11 are connected. Next, the bolt 15 is loosely fitted into the bolt through hole 11b of the main shaft 11, and the engagement ring 3 is attached to the annular groove 15a exposed on the end surface 11a side of the main shaft 11.
Finally, screw the bolt 15 into the screw hole 1b formed in the end surface 1a of the drive shaft 1, and at the same time
1 is fitted onto the drive shaft end face 1a, and the assembly of the drive side pulley 10 is completed.

In the driving pulley 10 having this configuration, the set load of the spring 16 can be adjusted by adjusting the tightening force of the nut 2, and the movable pulley 14 and the fixed pulley 1
If only nut 3 needs to be removed, this can be done by removing nut 2.

On the other hand, when removing the drive-side pulley 10 from the drive shaft 1 with both the movable and fixed pulleys 14 and 13 still assembled, it is sufficient to loosen the bolt 15. comes into contact with the main shaft end face 11a, and the main shaft 11 is pulled out from the drive shaft 1 by the locking ring 3.

Therefore, no special tool is required to pull out the main shaft 11 from the drive shaft 1, and the main shaft 11 can be removed at the same time by simply loosening the bolt 15 with a simple tool such as a spanner.

Reference numeral 21 is a driven shaft supported by a bearing (not shown) and mounted on an engine block or the like.
A dry bearing 22 is driven into the movable pulley 24 similarly to the drive side unit 10, and is capable of sliding on the driven shaft 21 in the axial direction. 23
is a fixed pulley, and the driven shaft 21 is connected with a key (not shown).
It is integrally fixed to. A V-groove portion 23a is formed in this fixed pulley 23, and power is transmitted to automobile complex machines such as an air pump, water pump, fan, compressor, and alternator via a V-belt 41. In addition,
In FIG. 1, only two V-grooves 23a are shown, but in reality, a large number of V-grooves 23a are provided.

And this fixed pulley 23 and movable pulley 2
4 forms a driven pulley 20. Like the driving pulley 10, this driven pulley 20 is also made of a relatively lightweight aluminum alloy and has a variable width and diameter. A spring 27 is used for initial setting and acts in a direction to move the movable pulley 24 away from the fixed pulley 23, that is, in a direction to make the driven pulley 20 wider.

28 is a fly weight that has a roller shape.
Holder 29 and fixing plate 25 with inclined surface 29a
A plurality of pieces (six pieces in this example) are housed in the space formed by . In addition, 26 connects the fixed plate 25 to the driven shaft 21.
Nut 30 is a pin that fixes the holder 29 to the movable pulley 24. The flyweight 28 rotates together with the movable pulley 24 and pushes the holder 29 by the centrifugal force generated by the rotation.

A fixed cam 31 is integrally formed with the fixed pulley 23, and like the fixed cam 17 of the drive unit 10, it has an operating surface 31a formed into a calculated straight line and at a constant angle. There is. However, this working surface 31a is the fixed side cam 17 on the drive side.
It is in the opposite direction. Reference numeral 32 denotes a movable side cam, which is integrally formed with the movable pulley 24.
It has a working surface 32a having the same angle as 1a. A driven side cam mechanism 33 is formed by these cams 31 and 32, and like the driving side cams 17 and 18, these driven side cams 31 and 32 are also made of a material with excellent chipping resistance and wear resistance. has been done.

40 is a driving pulley 10 and a driven pulley 2
This is a variable speed V-belt that is stretched between the drive pulley 10 and the driven pulley 20, and is made of rubber with a strong core.

Next, the operation of the power transmission device having the above configuration will be explained.

As the engine speed increases from idling, the driving pulley 10 and driven pulley 20 also rotate at high speeds, and as a result, the centrifugal force of the flyweights 28 increases, acting on the inclined surface 29a of the holder 29, causing the holder 29 to The component of the force that presses the movable pulley 24 toward the fixed pulley 23 through In a range smaller than the proportional force, the movable pulley 24 does not move in the axial direction, and transmission is performed at a predetermined constant speed ratio.

Next, when the force acting to move the movable pulley 24 due to the centrifugal force of the flyweight 28 exceeds a force proportional to the total load of the springs 16 and 27, the movable pulley 24 moves toward the fixed pulley 23, and as a result, the driven pulley 24 moves toward the fixed pulley 23. The width of the side pulley 20 becomes narrower, and the part where the V-belt 40 contacts becomes farther away from the driven shaft 21, and the drive side pulley 1 becomes narrower to compensate for this.
The contact position of the V-belt 40 at 0 is closer to the drive shaft 1, and therefore, the movable pulley 14 is separated from the fixed pulley 13 in order to make the drive-side pulley 10 wider.

Therefore, in this state, the distance from the V-belt 40 abutting position to the central axis changes sequentially in both the driving and driven pulleys 10 and 20, and regardless of the change in the rotational speed of the driving pulley 10, The side pulley 20 always rotates at a constant rotation speed.

As the engine speed increases further, the driving pulley 10 becomes the widest and stops at that state, the driven pulley 20 becomes the narrowest and stops at that state, and from then on, the engine (driving pulley The rotation speed of the driven pulley 20 also increases in accordance with the rotation speed of the driven pulley 20. However, in this case, the distance from the central axis to the variable speed V-belt 40 is smaller at the driving pulley 10 and larger at the driven pulley 20, so the engine speed is transmitted to the driven pulley 20 at a constant reduction ratio. become.

Next, the operation of the driven side cam mechanism 14 will be briefly explained.

When the load of the auxiliary equipment received via the V-belt 41 suddenly increases, a load corresponding to the load torque acts on the working surfaces 31a and 32a of both the fixed side and movable side cams 31 and 32 of the driven side cam mechanism 33. It's summery.
That is, in this case, as shown in FIG.
a and 32a are inclined with respect to the axial center of the driven shaft 21, so that the load component in the axial direction of the driven shaft 21 urges the driven pulley 20 in the wider direction to help the set load of the spring 27. It becomes power. Therefore, when the load on the auxiliary equipment suddenly increases, the cam mechanism 3 acts to bias the spring 27, thereby reducing the change in the rotation speed of the driven pulley 20 due to the sudden change in load.

Note that although the above-mentioned examples are desirable embodiments of the present invention, the present invention has various other embodiments.

That is, in the drive-side pulley 10 of the above example, the fixed-side and movable-side pulleys 13 and 14 are attached to the main shaft by nuts 2, and the main shaft 11 is attached to the drive shaft by bolts 15. 1
However, as shown in FIG. 3, the attachment may be performed using only bolts 15. Particularly in this case, the amount of protrusion of the bolt 15 from the main shaft 11 is significantly reduced, and the axial length of the drive pulley 10 can be shortened, which is an excellent effect.

In the embodiment shown in FIG. 3, a threaded groove 11c is formed on the end surface 11a side of the bolt through hole 11b of the main shaft 11, while a threaded portion 15b is formed only at the tip of the bolt 15. is the threaded part 15b
This is to enable temporary fixation between the main shaft 11, the fixed pulley 13, and the movable pulley 14 by screwing into the thread groove 11c of the main shaft 11.

The driving pulley 10 shown in FIG.
After the temporary fixation, push the bolt 15 further toward the main shaft 11 side, and then press the rear end 15 of the threaded part of the bolt 15.
Fit the locking ring 3 into the small diameter part between the main shaft end face 11a and the bolt 15, and then tighten the bolt 15
The fixation is completed by screwing it into the screw hole 1b. Of course, even on the side shown in FIG.
a, and when the bolt 15 is loosened, the main shaft 11 can be separated from the drive shaft 1 at the same time.

Further, in the above example, the fly weight 28 is provided on the driven pulley 20, but the fly weight 28 may be provided on the driving pulley 10 if necessary.

Further, in the above-described embodiments, the device of the present invention was used for power transmission between an automobile engine and an auxiliary machine, but it goes without saying that the device of the present invention can be applied to other uses. If there is only one rotating machine, the V groove 23a can be eliminated and the driven shaft 2
Of course, the rotation may be transmitted directly by the rotation.

As explained above, in the power transmission device of the present invention,
A locking member is disposed on the bolt at a position facing the gap between the end surface of the drive shaft and the end surface of the main shaft, and this locking member locks with the end surface of the main shaft of the main shaft, so that the main shaft cannot be driven. When removing the main shaft from the shaft, simply loosening the bolt causes the main shaft to be pulled out from the drive shaft by the locking member, which has the excellent effect of being able to be easily removed with an extremely simple operation.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the device of the present invention;
FIG. 2 is an explanatory diagram showing an exploded view of the drive-side cam mechanism of the device shown in FIG. 1, and FIG. 3 is a sectional view showing another example of the device of the present invention. DESCRIPTION OF SYMBOLS 1... Drive shaft, 3... Locking ring forming a locking member, 11... Main shaft, 13... Fixed pulley, 14
...Movable pulley, 15...bolts.

Claims (1)

[Claims] 1. A drive shaft that rotates in response to driving force, a main shaft that fits onto the end face of this drive shaft and rotates integrally with the drive shaft,
A bolt passes through a bolt through hole formed in the axial direction of the main shaft and is screwed into a threaded hole on the end face of the drive shaft to fix the drive shaft and the main shaft, and a bolt is fixed to the main shaft and is integrated with the main shaft. A rotating fixed pulley and a movable pulley arranged opposite to the fixed pulley and movable in the axial direction of the main shaft, and a position of the bolt facing the gap between the end face of the drive shaft and the end face of the main shaft. A locking member that can be locked to an end face of the main shaft is disposed, and when the bolt is loosened, the locking member is locked to the end face of the main shaft so that the main shaft is pulled out from the drive shaft. A power transmission device featuring: