JPH0794850B2 - Overload clutch - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called overflow clutch that prevents torque transmission when an overload is applied to a driven portion.

Conventional technology and its problems Conventionally, it is provided between the drive section and the driven section of the torque transmission mechanism, and when the load torque exceeds a predetermined value, the drive torque is released and the drive side and driven side mechanisms are damaged. There is an overload clutch such as a ball clutch and a roller clutch as a kind of safety device for preventing the above.

The structure is such that the torque transmission element is held by the torque transmission element holding penetrating portion formed on one of the hub and the driven plate, and the pressure plate presses the bottom portion of the torque transmission element holding formed on the other of the hub and the driven plate to apply torque. Transmission is performed, and torque transmission is interrupted by causing the torque transmission element to escape from the bottom portion having the torque transmission element holding portion against the pressing force at the time of overload.

Therefore, at the time of the escape, the torque transmission element holding penetrating portion has a shape such that the torque transmission element penetrates through the torque transmitting element holding penetrating portion so that the torque transmitting element can move within the torque transmitting element holding penetrating portion (for example, in the case of a ball, , In the case of a roller, a square hole was provided, and a constant gap was provided between them.

Therefore, the torque transmission element is held in a so-called loosely fitted state within the torque transmission element holding penetrating portion.

However, with such a configuration, when the rotation direction of the drive side of the overload clutch changes, the gap becomes backlash, the relative position of the hub and the driven plate is deviated, and the position between the drive side and the driven side is changed. There was a problem that deviation occurred.

Further, even if the rotation direction is constant, the position of the hub or the driven plate having the torque transmission element holding bottom portion and the driven plate or the hub having the torque transmission element holding penetrating portion after the overload is eliminated is the gap. It had a problem that it changed by the amount.

Further, in order to reduce the influence of the gap, if the processing precision is increased by performing strain removal after the heat treatment in order to reduce the gap, there is a problem that the processing is time-consuming and costly. .

MEANS FOR SOLVING PROBLEMS AND ACTION The present invention is to hold a torque transmission element by a plurality of torque transmission element holding penetrating portions formed on one of a hub or a driven plate and to form the torque transmission element on the other of the hub or the driven plate by a pressure plate. In the overload clutch, the torque transmission element holding bottom portion is pressed to transmit the torque, and the torque transmission element escapes from the torque transmission element holding bottom portion against the pressing at the time of overload. The transmission element holding penetrating portion is formed in a V-shaped notch surface that extends radially toward the outer periphery, and the torque transmission element holding bottom portion is formed in a radial V-shaped groove, and the torque transmission element is formed on the pressure plate with the torque transmission element. Centripetal force and torque for pressing and holding the transmission element holding penetrating portion between the V-shaped notches. An overload clutch having a pressing inclined portion having an axial pressing component force for engaging and pressing the transmission element in the V-shaped groove of the bottom portion holding the torque transmission element so as to be disengageable in the axial direction. By the centripetal force component and the axial component force generated by pressing the torque transmission element, the torque transmission element has a V-shaped notch surface of the torque transmission element holding penetrating portion and the torque transmission element holding bottom portion during torque transmission. Each V is pushed into the V-shaped groove of
It engages with the V-shaped groove in a state of being sandwiched between the V-shaped notched surfaces by two-point contact, and at the time of overload, the torque transmission element is retained while being held between the V-shaped notched surfaces. It moves axially from the V-shaped groove of the bottom portion of the torque transmission element holding bottom against the axial force component of the inclined portion, escapes, and moves to the flat portion of the driven plate to release the overload.

Therefore, the torque transmission element is always contacted between the notched surfaces by the pressing force component of the inclined portion in the centripetal direction without being loosely fitted between the V-shaped notched surfaces of the torque transmission element holding penetrating portion, so that the torque transmission element is pressed and pinched. Since there is no gap, backlash does not occur.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings by taking a ball clutch as an example.

The hub 10 has a flange 13 formed at the center of the tubular portion 11, and a set screw 12 for rotating in cooperation with the shaft A is projected on the inner peripheral surface of the hub 10.

The collar 13 (Fig. 2) has a V extending radially toward the outer circumference.
A plurality of torque transmission element holding penetrating portions (hereinafter, simply referred to as penetrating portions) 14 formed between the V-shaped notched surfaces are provided at unequal intervals. In addition, the reason for setting the unequal intervals is to limit the meshing point in one rotation to one place. A steel ball 1 serving as a torque transmission element is provided in the valley portion 14a of each penetration portion 14.
5 is pushed in by the configuration described later.

A disk-shaped driven plate 17 is provided on the cylindrical portion 11 on the left side in FIG. 1 of the collar 13 so as to rotate with a radial bearing 16 interposed.

As shown in FIG. 3 and FIG. 4, on the right side surface 17a of the driven plate 17 facing the collar 13, as shown in FIGS. 3 and 4, a plurality of torque transmission element holding bottom portions (hereinafter simply referred to as V-shaped grooves into which the steel balls 15 are inserted). A bottomed portion 18 is radially cut in the same position facing the penetrating portion 14 in the radial direction. A flat portion 19 is formed between the penetrating portions 14. A thrust bearing 20 is interposed between the right side surface 17a and the collar 13.

A screw 21 is formed on the left end of the tubular portion 11 of the hub 10, and a fixing nut 22 is screwed into the screw 21. The set screw 23 provided on the fixed nut 22 presses the lock plug 24 to the screw 21 at the tip,
It is intended to prevent the fixing nut 22 from loosening. A thrust bearing 25 is interposed between the fixed nut 22 and the driven plate 17. The fixing nut 22 serves to apply an appropriate preload to the thrust bearings 25, 20 and hold the driven plate 17 so as to be rotatable relative to the hub 11.

A pressure plate 30 is loosely fitted in the tubular portion 11 on the right side of the collar 13 of the hub 10. Near the outer periphery of the surface 30a where the pressure plate 30 faces the flange 13, a pressing inclined portion 31 formed of a conical surface having a downward slope toward the axis A is formed. The pressing inclined portion 31 presses the steel ball 15 against the valley portion 14a of the penetrating portion 14 and the bottomed portion 18 by a coil spring 34 described later.

A thread 32 is formed on the right end of the hub 10 to
33 is screwed.

The adjusting nut 33 adjusts the force with which the pressure plate 30 presses the steel ball 15 by interposing a plurality of coil springs 34 and thrust bearings 35 between the pressure plate 30 and the lock at the tip of the set screw 36. Screw plug 37
It is pressed against 32 and prevented from loosening.

Next, for example, the operation will be described with the axis A as the driving side and the driven plate 17 as the driven side.

First, when no overload is applied, the steel ball 15 has a bottomed portion 18 due to the axial force component P (FIG. 1) parallel to the axis A among the component forces generated by the pressing of the pressing inclined portion 31. On axis A
Centering direction force component F perpendicular to the
The hubs 1 are pressed at the same time between the notched surfaces forming 14a.
It is supported by 0 and driven plate 17, respectively. Therefore, since the steel ball 15 is pressed into and engaged with the bottomed portion 18 which is a V-shaped groove, the entire ball clutch rotates integrally and the rotational torque of the shaft A is connected to the driven plate 17. Is transmitted to a mechanism (not shown).

Next, when the driven plate 17 is overloaded, the shaft A continues to rotate despite the rotation of the driven plate 17 being blocked, so that the steel ball 15 resists the axial component force P. In FIG. 1, it moves to the right in the axial direction, escapes from the bottomed portion 18, transfers to the flat portion 19 (FIG. 5), and is pressed between the notched surfaces forming the flat portion 19 and the valley 14a. During this time, the pressure plate 30 is driven by the steel balls 15 and driven by the plate 17.
Be kept away from.

As a result, the hub 10 can idle and the rotational torque can be released.

However, the steel ball 15 has a pressing force component F in the centripetal direction of the pressing inclined portion 31.
Are held in a state of being sandwiched between the V-shaped notch surfaces that form the valleys 14a of the penetrating portions 14.

As described above, according to the ball clutch of the embodiment of the present invention, the steel ball 15 has the valley portion 14 of the penetrating portion 14 due to the pressing inclined portion 31.
Since the structure is supported between the notched surfaces forming a and the bottomed portion 18 which is a V-shaped groove, and is supported between the hub 10 and the driven plate 17 without floating, the rotation direction of the hub 10 is Even if changed, the phase of the hub 10 and the driven plate 17 does not deviate.

Further, as shown in FIG. 6, the position of the collar of the hub and the position of the driven plate may be reversed from those in FIG. In this case, a bottomed portion 52 is formed on the flange 51 of the hub 50, and a V-shaped penetrating portion 54 having a valley portion 54a is formed on the driven plate 53. 55
Is a retaining ring that regulates the position of the driven plate 53. In the case of this embodiment, since the through portion 54 is a through hole, it is not necessary to prevent the ball from coming out by forming the left end of the outer periphery of the pressure plate 30 into a sleeve shape as in the case of FIG.

It should be noted that the penetrating portion 14 is not limited to the above embodiments.
54, and the bottomed portions 18, 52 may be formed at equal intervals in a radial pattern.

EFFECTS OF THE INVENTION As described above, according to the overload clutch of the present invention, the torque transmission element does not loosely fit into the torque transmission element holding penetrating portion and does not float by the centripetal direction pressing component force of the pressing inclined portion of the pressure plate. Since it is pressed and sandwiched between the V-shaped notched surfaces of the portion, a gap is not created between the torque transmission element and the V-shaped notched surface of the penetrating portion, and therefore backlash in the circumferential direction is prevented. Since it does not occur, the relative position of the hub and the driven plate does not deviate, and the position deviates between the drive side and the driven side.
Further, even after the overload is eliminated, the torque transmission element moves in the axial direction by the axial component force of the pressure plate and surely enters the bottom portion of the torque transmission element holding portion, so that the re-engagement is ensured.

Further, since the shape of the torque transmission element holding penetrating portion is formed by the V-shaped notch surface, the torque transmission element is surely pressed and sandwiched between the notch surfaces by the centripetal direction pressing force. The processing is easy and the cost can be reduced without requiring the accuracy of.

[Brief description of drawings]

FIG. 1 is an embodiment of the present invention, FIG. 1 is an axial sectional view, and FIG.
The figure shows the hub as viewed in the direction of line 2-2 in FIG. 1, and FIG. 3 shows the driven plate as viewed in the direction of line 3-3 of FIG.
FIG. 6 is a view of FIG. 3 viewed from the direction of line 4-4, FIG. 5 is an operation view in which torque transmission is cut off in FIG. 1, and FIG. 6 is an axial sectional view showing another embodiment. 10,50 …… Hub 13,51 …… Temperature 14 …… Torque transmission element holding through part 15 …… Torque transmission element 17,53 …… Driven plate 18 …… Torque transmission element holding bottom 19 …… Flat part 30… … Pressure plate 31 …… Pressing inclined part 54 …… Torque transmission element holding penetrating part

Claims (1)

[Claims] 1. A torque transmission element holding through portion formed on one of a hub and a driven plate holds a torque transmission element, and a pressure plate presses a torque transmission element holding bottom portion formed on the other of the hub and the driven plate. In an overload clutch that transmits torque, and that the torque transmission element escapes from the bottom portion with the torque transmission element holding against the pressure when overloaded, the torque transmission element holding penetrating portion is radiated toward the outer periphery. Formed in a V-shaped notch surface that extends in the same direction, the bottom portion of the torque transmission element holding portion is formed in a V-shaped groove in the radial direction, and the torque transmission element is formed on the pressure plate, and the V-shaped notch surface of the torque transmission element holding through portion is formed. Centrifugal force component that presses and holds the torque transmission element sandwiched between the torque transmission element and the torque transmission element An overload clutch in which a pressing inclined portion having an axial pressing component force that engages and presses in a V-shaped groove having a bottom portion so as to be disengageable in the axial direction is formed.