JP2566874B2 - Centrifugal clutch - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal clutch, and is used, for example, for transmitting a rotational torque of a drive unit such as an engine to a load side such as a propeller and wheels.

[0002]

2. Description of the Related Art As a centrifugal clutch, a centrifugal flapper that swings by centrifugal force has hitherto been brought into contact with a rotating body on a driven side, or powder that is blown off by a centrifugal force is interposed between a driving side and a driven side. In general, the type of transmitting torque by doing so. In such a centrifugal clutch, the clutch is engaged when the rotational speed and accordingly the centrifugal force becomes larger than a certain level, and the transmission torque increases as the rotational speed increases,
The clutch is slipped against over torque. However, with this type of clutch,
Since the torque transmission and the slip action of the clutch are performed by the frictional force, the operation is not constant, and the on / off timing of the clutch and the transmitted torque are inaccurate.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems in the prior art and to provide a centrifugal clutch in which the on / off timing of the clutch and the transmission torque are constant.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a centrifugal clutch having a single-leaf rotating hyperboloid on its outer peripheral surface.
An inner ring of the inner ring raceway surface and the inner having an inner ring raceway surface consisting of
Outer ring with outer ring raceway consisting of single-leaf rotating hyperboloid on the circumference
Linearly contact the raceway formed by the outer ring raceway surface of
As described above, a rolling bearing clutch portion in which a plurality of rollers are arranged to be inclined, a first urging means for urging the inner ring or the outer ring in a direction to widen the space between the raceways, and the inner ring or the outer ring are rotated. A second urging means for urging the inner ring or the outer ring in a direction in which the displacement portion is attached to the rotating portion on the drive side and is displaced according to the rotational speed; Movement stopping means for stopping the movement of the inner ring or the outer ring in a direction in which the space between the tracks is narrowed at a predetermined position.

[0005]

[Operation] According to the present invention, the inner ring or the outer ring is rotated from the drive side, but since the first urging means for urging the inner ring or the outer ring is provided in the direction of widening the space between the raceways, this When the force is applied, the inner and outer races are not in pressure contact with each other, so that torque is not transmitted between them. as a result,
No load start on the drive side is possible.

Further, the second urging means is attached to the rotating portion on the drive side so that the inner ring or the outer ring is urged in the direction in which the space between the tracks is narrowed by the displacing portion which is displaced according to the rotational speed. The urging forces of the first and second urging means act on the inner ring or the outer ring from mutually opposite directions. Then, when the rotational speed on the drive side becomes higher than a certain value and the second biasing force becomes larger than the first biasing force, the inner ring or the outer ring moves and the track interval becomes narrow.

On the other hand, since the inner and outer races and the rollers are formed so as to form a rolling bearing clutch, the action as the one clutch can be reliably obtained between the inner and outer races. That is,
By setting the rotation direction in which torque is transmitted from the drive side to the clutch direction, if the raceway gap becomes narrower as described above, the inner and outer races will contact each other, and the inner race or outer race will become narrower in the direction in which the raceway gap becomes narrower. It is moved and the clutch between the inner and outer wheels is instantaneously clutched, and the driving torque is transmitted during this period. Therefore, if one of the inner ring and the outer ring is connected to the drive side and the other is connected to the load side, or if it is configured as a driven shaft on the load side, torque is transmitted to the load side.

As described above, when the load side is stationary,
When the drive side has a constant rotation speed and the clutch is turned on, a very large impact torque is transmitted from the load side to the drive side due to the rotational inertia of the load side.
However, in the centrifugal clutch of the present invention, since the movement stopping means for stopping the movement of the inner ring or the outer ring in the direction of narrowing the space between the raceways at a predetermined position is provided, even if the inner and outer rings are clutched as described above, The inner ring or the outer ring is not pushed beyond a predetermined position, the torque corresponding to the predetermined position is transmitted between the inner ring and the outer ring, and the impact torque beyond that causes relative rotation between the inner ring and the outer ring. In this case, the inner ring or the outer ring is pushed in by the rolling due to the rotation of the rollers, so that the operation is extremely stable, and the movement amount when the inner ring or the outer ring moves to a predetermined position or the twist angle between the inner and outer rings in between. Correspondingly, a constant torque is always transmitted. Therefore, if the torque corresponding to the predetermined position is set to, for example, the rated torque for the rated rotational speed of the driving side, the rated torque is accurately transmitted from the driving side to the load side while avoiding the impact torque. It will be.

Next, when the rotational speed on the drive side is decreased, the urging force of the displacement portion of the second urging means becomes smaller and the urging force of the first urging means becomes larger. Therefore, the orbital spacing tends to widen, but while the torque is being transmitted from the drive side to the driven side, the pulling force between the inner and outer wheels via the rollers is sufficiently large that the clutch will not turn off and low rotation speed will occur. Torque can be transmitted up to. Then, when the rotation speed is sufficiently reduced and the transmission torque between the inner and outer wheels is reduced, or when the rotation is stopped and the transmission torque between the inner and outer wheels is lost, the inner ring or the outer ring is urged by the urging force of the first urging means. Energized to widen the track spacing, the clutch is turned off and the next no-load start is possible.

In such a centrifugal clutch, the clutch is instantly turned on when the urging force of the second urging means becomes larger than the urging force of the first urging means in response to the rotational speed on the drive side. Therefore, the period is always constant.

[0011]

[Examples] Fig. 1 shows the entire structure of a centrifugal clutch of an example. The present centrifugal clutch is provided between a crankshaft 101 of an engine 100 such as an outboard motor of a small boat and a propeller shaft 102 to which a propeller (not shown) is attached.
Then, a plurality of rollers 3 are provided on the raceway 4 formed integrally with the propeller shaft 102 between the inner ring 1 and the outer ring 2 and the central shaft 1b.
Rolling bearing clutch portion arranged to be inclined from a cross section including the above, a coil spring 5 as a first urging means for urging the outer ring 2 in a direction to widen the space between the raceways 4, and a drive side for driving the outer ring 2. Is provided with a displacing portion 7a which is attached to the crankshaft 101, which is a rotating portion of the bearing, through the supporting member 6 and which is displaced according to the rotational speed. Centrifugal force weight 7 as a force means
And a stopper ring 8 and a thrust bearing 9 as movement stopping means for stopping the movement of the outer ring 2 in a direction in which the distance between the raceways 4 is narrowed at a predetermined position.

The propeller shaft 102, which also serves as the inner ring 1,
Engine casing 103 and crankshaft 1 respectively
It is supported by the ball bearing 104 and the needle bearing 105 from the end of 01, and the axial position on one side is regulated by the ball bearing 104.

The outer ring 2 is connected to the crankshaft 101 via the key 106, the intermediate member 10 and the ball spline 11, and the torque is transmitted between the outer ring 2 and the crankshaft 101 in the axial direction. Support member 6 and intermediate member 10
Is regulated in position by the crankshaft 101 on one end side in the axial direction and by the shaft end of the propeller shaft 102 via the thrust bearing 12 on the other end side, whereby the centrifugal force weight 7 is positioned. The stopper ring 8 for stopping the movement of the outer ring 2 in the axial direction is fixed in the present embodiment, but its axial position may be adjusted by a screw or the like. Reference numeral 107 is a bearing that supports one end of the crankshaft 101. Reference numeral 13 is a retainer that holds the positions between the many rollers 3. The roller 3 has a cylindrical or conical shape.

One end of the centrifugal force weight 7 is rotatably supported by the support member 6, and the rotation of the crankshaft 101 receives a centrifugal force proportional to the square of its rotational speed. And
The displacement portion 7a axially pushes the outer ring 2 with a force corresponding to the moment associated with the centrifugal force. On the other hand, coil spring 5
The outer ring 2 is pulled in the opposite direction by the same force as the displacement portion 7a of the centrifugal weight 7 pushes the outer ring 2 when the crankshaft 101 rotates at a predetermined rotation speed. Therefore, below a predetermined rotation speed, the outer ring 2 is pulled in a direction that widens the space between the raceways 4, and when the crankshaft 101 reaches a higher rotation speed, the outer ring 2 is pushed in a direction that narrows the space between the raceways 4. . Here, the predetermined rotation speed is, for example, near the rated rotation speed of the engine 100 at the rated output.

Inner ring 1 constituting the rolling bearing clutch portion
The raceways 1a and 2a of the outer ring 2 are single-leaf rotating hyperboloids obtained by rotating the hyperbola shown in the following equation around the central axis 1b. yi ² / ai ² −xi ² / bi ² = 1 yo ² / ao ² −xo ² / bo ² = 1

Here, x _i and x _o are distances from the origins of the inner ring raceway surface 1a and the outer ring raceway surface 2a in the direction of the central axis 1b, and y _i and y _o are arbitrary cross sections including the central axis 1b. The distances from the central axis 1b of the inner ring raceway surface 1a and the outer ring raceway surface 2a at, and ai, bi, ao, and bo are constants. Now, the distance from the central axis 1b to the center of the raceway 4 on the reference surface (the origin surface of the hyperbola) on the small diameter side of the inner and outer rings is F, the radius when the roller 3 is cylindrical and the inclination angle is β.
As an example, when F = 9, r = 1.5, and β = 15 °, the values of ai, bi, ao, and bo are about,
It becomes 7.5, 30.7, 10.5 and 36.2. By making the inner-outer ring raceway surface such a single-lobed rotating hyperboloid, the roller is wound between the inner-outer ring within a length (about 2 to 3 times the diameter of the roller) where the roller acts as a wedge. When the clutch is engaged, it makes a perfect linear contact, and functions as a rolling bearing clutch.

In FIG. 2, the relative rotation between the inner and outer races causes a twist angle between the inner and outer races, and when the outer race 2 moves in the direction of narrowing the space between the raceways 4, the amount of movement and the twist angle are transmitted between the inner and outer races. Shows the relationship with the torque. Based on such torque transmission characteristics of the rolling bearing clutch, for example, the engine 1
When 00 and the crank shaft 101 is to T ₁ rated torque when rotating at rated speed, torque transmitted between the inner and outer rings is set to a predetermined position in the axial direction of the stopper ring 8 so that T _1. That is, when the inner and outer races rotate relative to the lock side, the outer race 2 is screwed in and moved in the direction in which the distance between the raceways 4 is narrowed by the movement amount δ ₁ (corresponding to the twist angle α ₁ ) shown in the figure. The stopper ring 8 is positioned so that the outer ring 2 is stopped at the position.

In the above description, the relative rotation of the inner and outer wheels on the lock side means that the crankshaft 101, the intermediate member 10 and the outer wheel 2 rotate left as viewed from the right side in FIG. 2 is a rotation that moves from left to right and narrows the space between the orbits 4. In this case,
The inner and outer races are locked, the two rotate together, torque is transmitted between them, and the propeller shaft 102 rotates.

Since the torque transmitted between the inner and outer races is generated by the wedge action due to the rolling of the rollers 3, the amount of movement of the outer race 2 is different from the case of a normal centrifugal clutch that depends on solid or fluid friction. Corresponding to a constant and stable torque. Therefore, according to the present centrifugal clutch, the transmission torque can be set accurately.

With the above structure, this centrifugal clutch operates as follows. When the engine 100 is started and the crankshaft 101 rotates to the lock side, the rotation is transmitted to the support member 6 and the intermediate member 10 via the key 106, and the centrifugal force weight 7 and the outer ring 2 rotate to the lock side. However, while the rotation speed of the crankshaft 101 is slow, the tension of the coil spring 5 is larger than the pushing force of the centrifugal weight 7 and the outer ring 2 is pulled in the direction to widen the space between the raceways 4, so that the rotation on the lock side is increased. Nevertheless, there is no clutch between the inner and outer wheels, so the propeller shaft 102 does not rotate. As a result, the engine can be started without a load even when the propeller (not shown) is in a submerged state of use.

Next, the engine 100 and the crankshaft 101
When the rotation speed of the motor reaches the rated speed, the pushing force of the centrifugal weight 7 becomes larger than the tensile force of the coil spring 5, the space between the raceways 4 is narrowed, and the inner and outer rings are pressed against the rollers 3. Since the rotation at this time is on the lock side, this pressure contact causes the outer ring 2 to be instantly further advanced in the direction of narrowing the space between the raceways 4, and the inner and outer rings are completely clutched, so that the propeller shaft 102
Is rotated. And at this time, the propeller shaft 102
The load torque on the propeller shaft 102 side becomes a peak torque much larger than the rated torque of the engine due to the inertia of the propeller and the rotational resistance of the propeller when it is underwater. However, the stopper ring 8 and the thrust bearing 9 stop the movement of the outer ring 2 toward the lock side at a predetermined position, the torque of the rated torque T ₁ or more shown in FIG. While transmitting the torque T ₁ , further torque is released by the relative rotation between the inner and outer wheels. Then, when the torque T ₁ is transmitted to the propeller shaft 102 side so that the rotation thereof reaches a certain speed, the torque on the propeller shaft 102 side decreases and the transmission torque becomes T ₁ or less. Relative rotation of stops. As a result, all the engine torque is transmitted to the propeller shaft 102 side with the clutch between the inner and outer wheels engaged, and a steady operation state is realized.

On the other hand, when the engine speed is lowered,
The pushing force of the displacement portion 7a of the centrifugal force weight 7 becomes small, and the outer ring 2 is pulled by the coil spring 5 in the direction to widen the track spacing, but the rotation direction of the outer ring 2 is the lock side, and the torque is transmitted between the inner and outer rings. Since the clutch is engaged between them, the rotational speed on the propeller shaft 102 side is sufficiently reduced and the transmission torque between the inner and outer wheels is sufficiently reduced, or the rotation is stopped and the transmission torque between the inner and outer wheels is lost. The clutch state is maintained and the propeller can be operated at low speed. Then, when the engine is stopped and torque transmission is lost, the outer ring 2 is pulled by the coil spring 5 to widen the raceway intervals, the clutch is turned off, and the vehicle is ready for the next no-load start.

As described above, if such a centrifugal clutch is equipped, the engine can be automatically started without a load, overtorque operation can be avoided, and operation can be performed only by operating the accelerator. The operation is extremely simple and the engine operating condition is maintained in good condition.

In the above description, the case where the main centrifugal clutch is provided between the engine and the propeller has been described, but it goes without saying that the present apparatus is not limited to such applications. The present invention can be applied to all machines or the like that need to start a drive device with a load or a low load and cut over torque.

In the above description, the outer ring is set to the drive side and the inner ring is set to the load side. However, depending on the machine to which the present device is applied, the drive side may be connected to the inner ring and the driven side ( A configuration in which the load side) is connected to the outer ring is naturally possible. Further, in the present embodiment, the outer ring is movable in the axial direction, but the axial position of the outer ring may be fixed and the inner ring may be movable in the axial direction. Further, it goes without saying that the inner ring and the driven shaft may be configured separately.

[0026]

As described above, according to the present invention, the on / off timing of the clutch and the accuracy of the transmission torque can be improved by utilizing the torque absorbing function of the rolling bearing clutch.

[Brief description of drawings]

FIG. 1 is a sectional view of a centrifugal clutch of an embodiment.

FIG. 2 is a torque curve diagram with respect to an outer ring movement amount of the device.

[Explanation of symbols]

 1 inner ring 2 outer ring 3 roller 4 raceway 5 coil spring (first urging means) 7 centrifugal weight (second urging means) 8 stopper ring (movement stop member) 9 thrust bearing (movement stop member)

Claims (1)

(57) [Claims] Claim: What is claimed is: 1. An inner ring gauge having a single-leaf rotating hyperboloid on the outer peripheral surface.
Single leaf rotation on the inner ring raceway surface and inner peripheral surface of the inner ring with road surface
The outer ring raceway of an outer ring having an outer ring raceway surface composed of hyperboloids
A rolling bearing clutch section in which a plurality of rollers are arranged so as to be in linear contact with a raceway formed by a surface, and a first biasing member for urging the inner ring or the outer ring in a direction to widen the space between the raceways. A biasing means, and a displacement portion that is attached to a rotating portion on the drive side that rotates the inner ring or the outer ring and that is displaced in accordance with the rotation speed, the inner ring or the above-mentioned inner ring or the direction in which the space between the tracks is narrowed by the displacement portion. A centrifugal clutch, comprising: a second urging means for urging the outer ring; and a movement stopping means for stopping the movement of the inner ring or the outer ring in a direction that narrows the space between the tracks at a predetermined position.