JPH0160698B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a speed regulating device used, for example, in a mechanism that transmits the rotation of an automobile engine to auxiliary equipment such as an alternator, a car cooler compressor, or a hydraulic pump. .

Conventional technology Auxiliary equipment such as automobile alternators, car cooler compressors, and hydraulic pumps receive driving force from the engine crankshaft via pulleys and V-belts, and rotate in proportion to the number of rotations of the crankshaft. The number also increases and decreases. Further, the efficiency of the auxiliary machine increases approximately in proportion to the increase in the number of revolutions of the auxiliary machine, but the efficiency decreases at a certain number of revolutions or more. Therefore, rotating the auxiliary machine at a higher speed than necessary not only wastes energy, but also adversely affects the durability of the auxiliary machine. Therefore, various speed adjustment devices for adjusting the rotation speed transmitted to the auxiliary equipment have been announced. FIG. 1 shows one known example of a speed adjusting device, in which a drive pulley 2 is fitted into a spline portion 1a at the shaft end of a drive shaft 1 connected to a crankshaft. The drive pulley 2 consists of a fixed pulley 3 and a movable pulley 4. The fixed pulley 3 is fixed to the drive shaft 1 with a retaining ring 5, a washer 6, and a nut 7, and the movable pulley 4 is fixed to the drive shaft 1. A spring 10 is disposed between the fitted retaining ring 8 and the movable pulley 4 via a spring receiver 9, and the movable pulley 4 is constantly pressed in a direction approaching the fixed pulley 3. A driven pulley 12 is fitted into a spline portion 11a at the shaft end of a driven shaft 11 connected to the input shaft of the auxiliary machine, and power transmission between the driving pulley 2 and the driven pulley 12 is performed using the V belt 1.
3. The driven pulley 12 also consists of a fixed pulley 14 and a movable pulley 15. The fixed pulley 14 is fitted into the spline portion 11a of the driven shaft 11, and is fixed to the driven shaft 11 with a nut 17 via a retaining plate 16. The movable pulley 15 is fitted into a spline portion 14a on the outer peripheral surface of the fixed pulley 14, and is constantly pressed in a direction away from the fixed pulley 14 by a spring 18 disposed between the movable pulley 15 and the fixed pulley 14. There is. A sloped surface 15a is formed on the outer surface of the movable pulley 15, and a plurality of roller-shaped flyweights 19 are housed between the sloped surface 15a and the presser plate 16.

In the speed adjusting device described above, as the rotational speed of the drive shaft 1 increases, the rotational speed of the driven pulley 12 to which rotation is transmitted from the driving pulley 2 via the V-belt 13 also increases. As a result, the centrifugal force acting on the fly weight 19 also increases. The axial component of this centrifugal force is the inclined surface 15a of the movable pulley 15.
As the centrifugal force increases, the force that moves the movable pulley 15 closer to the fixed pulley 14 also increases. The axial component of this centrifugal force is the spring 10,1
In a range smaller than the force proportional to the total load of 8, the movable pulley 15 does not move, and transmission is performed between the drive shaft 1 and the driven shaft 10 at a constant gear ratio. However, when the axial component of the centrifugal force acting on the flyweight 19 exceeds a force proportional to the total load of the springs 10 and 18, the movable pulley 15 moves toward the fixed pulley 14, and the driven pulley 12
becomes narrow. As a result, the contact position of the V-belt 13 on the driven pulley 12 moves away from the driven shaft 11, and to compensate for this, the contact position of the V-belt 13 on the drive-side pulley 2 approaches the drive shaft 1. Movable pulley 4 to make 2 wider
is separated from the fixed pulley 3. In this state, the distances from the contact position of the V-belt 13 to the drive shaft 1 and driven shaft 11, which are the center axes of the drive-side pulley 2 and the driven-side pulley 12, change sequentially. Regardless of the change in the rotation speed of the pulley 2, the rotation speed of the driven pulley 12 remains constant.
In other words, the rotation speed of the driven shaft 11 remains constant regardless of the change in the rotation speed of the drive shaft 1.

Problem to be Solved by the Invention Now, as the rotational speed of the drive shaft 1 further increases, the driving pulley 2 eventually becomes the widest and does not change any further, and the driven pulley 12 also becomes the narrowest. , there is no further change, and after that, the drive shaft 1
The rotation speed of the driven shaft 11 increases in proportion to the rotation speed of the driven shaft 11 . Therefore, when driving continuously at high speeds on a highway, etc., rotation is transmitted to the auxiliary equipment even at the maximum reduction ratio of this device, but the rotation of the auxiliary equipment is proportional to the rotation of the engine crankshaft, that is, the drive shaft 1. The number increases and decreases, and the high-speed rotation state continues for a relatively long period of time, resulting in an unfavorable state for the auxiliary equipment. In addition, this speed adjustment device has a drive side pulley 2 attached to the drive shaft 1.
Since it is configured as a pair with the driven pulley 12 attached to the driven shaft 11, the structure is complicated and the number of parts is large.

Therefore, an object of the present invention is to transmit a rotational speed higher than necessary to a rotating machine driven by the rotational power of a prime mover in a device for transmitting power of a driveshaft to the driveshaft via a power transmission mechanism. It is an object of the present invention to provide a speed adjusting device with a simple structure capable of maintaining a predetermined rotational speed without any rotational speed.

Means for Solving the Problems The speed adjusting device of the present invention includes a power receiving member that receives rotational power from a drive shaft, a tapered one-way clutch interposed between the power receiving member and the driven shaft, and a tapered one-way clutch. first and second elastic members that control actuation.

The power receiving member is rotatably attached to the driven shaft via a rolling bearing, and integrally forms a shell cylinder extending outward. For example, when a belt-type power transmission mechanism is employed, the power receiving member is a pulley. The shell tube is the housing for the tapered one-way clutch.

A tapered one-way clutch consists of an outer ring fixed in the shell of the power receiving member, an inner ring attached to the driven shaft, and multiple tapered rollers arranged in a skewed manner between the inner and outer rings. . The inner ring is slidably prevented from rotating with respect to the driven shaft, for example, by spline connection.

The first elastic member is arranged so as to surround the outer periphery of the driven shaft, and is in contact with the small diameter end of the inner ring of the tapered one-way clutch to apply a predetermined axial force to the inner ring. The second elastic member is arranged so as to surround the outer periphery of the driven shaft, and is in contact with the large diameter end of the inner ring of the tapered one-way clutch to give the inner ring an axial direction opposite to that of the first elastic member.

The second elastic member reduces its axial force by centrifugal force corresponding to the rotation speed of the driven shaft, and at a preset rotation speed, the axial force becomes equal to the axial biasing force of the first elastic member. It has a predetermined radius and mass so that

Operation In the speed regulating device of the present invention, the first and second elastic members function to control the operation of the tapered one-way clutch. That is, normally, the axial force exerted by the second elastic member overcomes the axial force exerted by the first elastic member, and presses the inner ring of the tapered one-way clutch in a direction in which the tapered rollers come into pressure contact between the conical surfaces of the inner and outer rings. . Therefore, in this state, the power receiving member and the driven shaft are integrated, and the rotational power from the drive shaft is transmitted to the driven shaft. As the rotational speed of the drive shaft increases, the rotational speed of the driven shaft increases accordingly, and as a result, the diameter of the second elastic member expands and its axial length simultaneously decreases due to the action of centrifugal force. . Therefore, as the rotational speed of the driven shaft increases, the axial force being applied by the second elastic member to the inner race of the tapered one-way clutch decreases. When the force of the second elastic member becomes smaller than the force of the first elastic member, the inner ring of the tapered one-way clutch is pushed away from the outer ring by the first elastic member, and the inner and outer rings are separated. Mechanical connections loosen.

As a result, the tapered rollers roll, the slip rate of the tapered one-way clutch increases, and a difference in rotational speed occurs between the inner and outer rings. As the rotational speed of the driven shaft decreases, the centrifugal force also decreases, so the second elastic member gradually changes its initial dimension, and therefore also
Recovers a given axial force.

In this way, the rotational speed of the driven shaft is in equilibrium where the force exerted by the first elastic member and the force exerted by the second elastic member under the action of centrifugal force are balanced.
Therefore, by appropriately setting the spring force of these elastic members and the diameter and mass of the second elastic member, it is possible to maintain the rotation speed of the driven shaft constant even if the rotation speed of the drive shaft increases. can. In other words, the second elastic member plays the role of automatically controlling transmission and interruption of rotational power by the one-way clutch.

Embodiment FIGS. 2 and 3 show specific embodiments of the speed adjusting device according to the present invention, in which a double row rolling bearing 21 is connected to the shaft end of a driven shaft 20 connected to the input shaft of an auxiliary machine. A pulley 22, which is a power receiving member, is rotatably attached. The above pulley 22 is the V belt 2
3 transmits the driving force of a drive shaft (not shown). The small diameter shaft portion 20a of the driven shaft 20 and the pulley 2
A tapered one-way clutch A for transmitting the driving force transmitted to the pulley 22 to the driven shaft 20 is disposed between the shell cylinder 22a extending from the side surface of the pulley 22. Above taper one-way clutch A
is an inner ring 24, an outer ring 25, and a plurality of tapered rollers 2.
6 and a retainer 27, and the inner ring 24 is
A conical surface 24a is formed on the outer peripheral surface, and is slidably engaged with a spline portion 20b formed on the outer peripheral surface of the small diameter shaft portion 20a of the driven shaft 20 only in the axial direction. The outer ring 25 has a conical surface 25a formed on its inner peripheral surface, and is fixed to the inner peripheral surface of the shell cylinder 22a of the pulley 22. The plurality of tapered rollers 26 are
It is held and housed in a skewed state between the conical surface 24a of the inner ring 24 and the conical surface 25a of the outer ring 25 using a retainer 27. Here, the skew state is a state where the two axes are neither intersecting nor parallel, and as shown in FIGS. 2 and 3, the center of the conical surface 24a of the inner ring 24 and the conical surface 25a of the outer ring 25 is The axis K of the tapered roller 26 is inclined at a constant angle θ with respect to the generatrix m of the virtual conical surface Ic to be formed. The first elastic member 28 is
It is made of a coil spring or a disc spring, and is disposed between the shoulder 20c of the driven shaft 20 and the small diameter end of the inner ring 24, and applies an urging force that presses the inner ring 24 outward. The second elastic member 29 is a coil spring with a rectangular cross section, and is fitted into a washer 30 that abuts the large diameter end of the inner ring 24 and the extreme end of the driven shaft 20, and is locked by a retaining ring 31. The first elastic member 28 is disposed between the spring receiver 32 and the first elastic member 28 .
This applies a biasing force that presses the inner ring 24 inward against the biasing force of.

Next, the operation of the speed adjusting device having the above structure will be explained. The inner ring 24 is pressed in a direction approaching the outer ring 25 by the urging force of the second elastic member 29, and the plurality of tapered rollers 26 have conical surfaces 24a,
25a. The rotation of the drive shaft is transmitted to the pulley 22 via the V-belt 23, and the outer ring 2
5 rotates relative to the inner ring 24 in the X direction in FIG. The inclination angle θ of the axis k of the tapered roller 26 with respect to the generatrix m of the surface Ic gradually expands, and the inner ring 24 is bitten between both conical surfaces 24a and 25a.
and the outer ring 25 are mechanically connected to transmit driving force to the driven shaft 20. As the rotation speed of the drive shaft increases, the rotation speed of the driven shaft 20 also increases, and when the rotation speed exceeds a preset rotation speed, the centrifugal force acting on the second elastic member 29 increases, and the centrifugal force As a result, the elastic member 29 expands toward the outer diameter side and its axial dimension decreases. Therefore, the biasing force of the second elastic member 29 becomes smaller than the biasing force of the first elastic member 28, and the inner ring 29
moves in a direction away from the outer ring 25, that is, in an outward direction. As a result, the mechanical connection between the inner and outer rings 24 and 25 is loosened, so that the tapered roller 26
It is released from the jam between a and rolls. Therefore, the slip rate of the tapered one-way clutch A increases, creating a difference in rotational speed between the inner ring 24 and the outer ring 25. In other words, the rotation speed of the driven shaft 20 is lower than the rotation speed of the pulley 22. When the rotational speed of the driven shaft 20 becomes lower than the preset rotational speed, the biasing force of the second elastic member 29 will overcome the biasing force of the first elastic member 28, and the inner ring 24 will move against the outer ring 25. Move toward the object, that is, move inward. At this time, the tapered rollers 26 are connected to the inner ring 24 and the outer ring 25.
As the driven shaft 20 rolls in the X direction from the position A to the position B in FIG. 3 in order to mechanically connect the two, the driven shaft 20 approaches a preset rotation speed. By repeating the above operations, the rotation speed of the driven shaft 20 becomes in an equilibrium state, and becomes the preset rotation speed regardless of the rotation speed of the pulley 22.

If the rotational speed of the crankshaft or drive shaft suddenly decreases due to sudden engine braking, etc., a load will be applied in the opposite direction to the rotational direction of the pulley 22, causing the outer ring 25 to rotate against the inner ring 24 as shown in FIG. The rotational force causes the tapered roller 26 to roll in the Y direction on the conical surface 24a from the position A to the position C, and the axis k of the tapered roller 26 with respect to the generatrix m The inclination angle θ gradually decreases and the inner ring 24 and the outer ring 2 roll between the conical surfaces 24a and 25a.
5, the sudden decrease in the rotational speed of the driven shaft 22 is alleviated and no impact is transmitted to the V-belt 23.

4 to 7 show other embodiments of the second elastic member 29, which has a shape whose axial dimension effectively changes due to centrifugal force. In other words, the centrifugal force F, the mass m of the elastic member, the rotation radius r, and the rotation speed n
The ^relationship between ^the The larger the size, the greater the effect of centrifugal force. FIG. 4 shows an elastic member 41 that combines a plurality of leaf springs 40, 40, etc., each of which has thinner ends in the axial direction, FIG. 5 shows a barrel-shaped spring 42 with a larger diameter in the center, and FIGS. , is a coil spring 44 in which a plurality of weights 43, 43, . . . are fixed to the outer periphery of the coil spring of the second elastic member 29 shown in FIG.

Although the power transmission mechanism is exemplified using the pulley 22 and the V-belt 23, other equivalent mechanisms such as gears, chains, etc. may be used. The rotational speed limit of the speed adjusting device of the present invention is determined by the internal design of the tapered one-way clutch (the taper angle of the conical surface, the length of the tapered roller, the roller diameter, and the skew angle), the biasing force of the first elastic member,
Since the rotation speed can be set arbitrarily depending on the biasing force of the second elastic member and the effect of the centrifugal force, the rotation speed can be set to the optimum rotation speed for the auxiliary machine to be driven.

The present invention has been described above as a speed adjustment device that transmits the rotation of an automobile engine to an auxiliary machine.
The present invention can be applied to any device that transmits the rotational driving force of a drive shaft to a driven shaft up to a certain number of rotations.

Effects of the Invention The speed adjusting device of the present invention does not transmit rotations exceeding a predetermined rotation speed and maintains the rotation speed at a constant speed, so that a driven rotating machine can be efficiently operated. Further, the speed adjusting device of the present invention has a simple and compact structure, so it can be easily installed even in a narrow space. Further, the present invention has the effect of alleviating the impact force applied to the speed transmission mechanism etc. due to a sudden decrease in the rotational speed of the drive shaft.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a known speed adjusting device, FIG. 2 is a partial sectional view of an embodiment of the speed adjusting device according to the present invention, FIG. 3 is an enlarged view of section B in FIG. 2, and FIGS. 6 is a side view of another embodiment of the second elastic member shown in FIG. 2, and FIG. 7 is a front view of FIG. 6. 20... Driven shaft, 21... Double row rolling ball bearing,
22... Pulley, 22a... Shell tube, 23... V-belt, 24... Inner ring, 24a... Conical surface, 25...
... Outer ring, 25a ... Conical surface, 26 ... Wedge roller, 2
7... Holding tube, 28... First elastic member, 29...
...Second elastic member, 40, 40...Plate spring, 41
...Elastic member, 42...Barrel spring, 43, 43
...Weight, 44...Coil spring, A...
...Tapered one-way clutch.

Claims (1)

[Claims] 1. In a device that transmits the power of a drive shaft to a driven shaft via a power transmission mechanism, a power receiving member that is rotatably installed on the driven shaft via a rolling bearing and that integrally has a shell cylinder that extends outward. and a tapered one-way comprising an inner ring slidably prevented from rotating with respect to the driven shaft, an outer ring fixed in the shell cylinder, and a plurality of tapered rollers arranged in a skewed manner between the inner and outer rings. a first elastic member disposed on the outer periphery of the driven shaft, the first elastic member contacting the small diameter end of the inner ring of the tapered one-way clutch to apply a biasing force to the inner ring in a predetermined axial direction; , a second elastic member that comes into contact with the large diameter end of the inner ring of the tapered one-way clutch and applies an axial biasing force to the inner ring that is opposite to the biasing force of the first elastic member, the second elastic member , the axial biasing force is reduced by a centrifugal force corresponding to the rotation speed of the driven shaft, so that the axial biasing force becomes equal to the axial biasing force of the first elastic member at a preset rotation speed. A speed adjustment device characterized by: