JP3056936B2 - Drive shaft - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft having an annular recess on the outer periphery of a fitting surface, and a boss fitted to the shaft. The present invention relates to a drive shaft that can select locking / unlocking of the spline connection by providing a spline connection with a provided yoke and including a connection device that controls movement of a lock ball in a radially outward direction. The present invention relates to a drive shaft suitable for connecting an agricultural tractor and its working machine.

[0002]

2. Description of the Related Art A drive shaft having such a connecting device is
This is known from Japanese Utility Model Laid-Open No. 5-3649. As shown in FIG. 10 (a), the connecting device of the drive shaft described in the above publication slides by the extension of a return spring disposed between the connecting device and the outer wall of the flange of the yoke, and the guide hole of the boss. A restraining ring which is held at a position above the lock ball by a stopper provided in the vicinity of the lock ball and prevents the lock ball from moving outward in the radial direction to enable the locking, and an inner diameter somewhat larger than the outer diameter of the stopper The outer surface is spring-loaded by a leaf spring, moves integrally with an adjacent restraining ring by pressing the return spring, and is positioned above the lock ball so that the lock ball moves radially outward. It comprises a retaining ring for alleviating movement inhibition and enabling the release, and an operating sleeve for accommodating the restraining ring and the retaining ring.

As shown in FIG. 11 (a), this drive shaft locks the spline connection between the boss of the yoke 4 'and the shaft 3' when the retaining ring 8 'is positioned above the lock ball 5'. Release is possible, and the shaft 3
Is pulled out, the retaining ring 9 'is eccentric with respect to the inner peripheral surface of the operating sleeve 10' due to the spring load of the leaf spring 14 '(FIG. 11B), so that a part of the side wall of the retaining ring 9' By abutment with the stopper 13 ', the retaining ring 9' can be stopped at a position above the locking ball 5 ', whereby the shaft 3' and the yoke 4 'are again formed.
Is only required to insert the shaft 3 'into the boss. At the moment when the insertion is completed, the retaining ring 9 ', which is eccentric with respect to the inner peripheral surface of the operation sleeve 10', is concentric by the locking ball pushing force due to the insertion of the shaft 3 ', and the outer periphery of the stopper 13' The movement that engages the surface will occur,
The locking ring 8 'also moves to a position above the lock ball 5' to automatically generate the lock (FIG. 1).
0 (a)).

When the drive shaft is used to connect an agricultural tractor and its working machine, for example, the drive shaft is used under bad conditions such as a paddy field. And penetrates from the gap generated between them, and the muddy water that has entered adheres to the inner peripheral surface of the operation sleeve due to the action of centrifugal force due to rotation, and the muddy water is dried and deposited as mud and firmly adheres to the inner peripheral surface. There was a tendency to stick.

[0005]

In the drive shaft connecting device described in the above-mentioned publication, both leg portions of the leaf spring 14 ', which is always in contact with the inner peripheral surface of the operation sleeve 10', move while pressing the inner peripheral surface thereof. By doing so, when the mud is adhered to the inner peripheral surface of the operation sleeve 10 'for locking and releasing, both leg portions of the leaf spring 14' can move smoothly on the inner peripheral surface. And as a result, the locking
There was a problem that release could not be performed smoothly.

Accordingly, an object of the present invention is to optimize the shape and arrangement of a leaf spring for spring-loading a retaining ring so that a shaft and a yoke can be used even under bad conditions such as paddy fields where mud is present. Of spline connection
An object of the present invention is to provide a drive shaft having a coupling device capable of performing release smoothly.

[0007]

In order to achieve the above object, the present invention provides a shaft having an annular recess on the outer periphery of a fitting surface, and a boss fitted with the shaft, the boss locking the annular recess. The locking and unlocking of the spline connection can be selected by providing a connecting device for controlling the outward movement of the locking ball in the radial direction by forming a spline connection with a yoke having a guide hole for a plurality of lock balls. The connecting device slides under the tension of the return spring disposed between the outer wall of the flange of the yoke and is held at a position above the lock ball by a stopper provided near the guide hole of the boss. And a restraining ring that prevents movement toward the outside and enables the locking, and an inner diameter that is slightly larger than the outer diameter of the stopper, and the outer surface is a leaf spring. By pressing the return spring, it moves integrally with the adjacent restraining ring, and is positioned above the lock ball to relieve the lock ball from moving outward in the radial direction. In a drive shaft including a retaining ring for enabling release and an operation sleeve for accommodating the restraining ring and the retaining ring, the leaf spring includes a body portion and both legs, and has a U-shaped cross section as a whole. The drive shaft is characterized in that the leaf spring is arranged such that the body part is always in contact with the inner peripheral surface of the operation sleeve, and both legs are in contact with the outer surface of the holding ring with the holding ring interposed therebetween. Further, it is more preferable to provide a muddy water drain hole in the operation sleeve corresponding to the radially outward position of the holding ring.

[0008]

According to the drive shaft of the present invention, even if mud adheres to the inner peripheral surface of the operation sleeve, the leaf spring does not normally operate as in the drive shaft described in the above-mentioned publication, and the operation sleeve Can smoothly move between the concentric position and the eccentric position. Also,
By providing a mud drainage hole in the operation sleeve corresponding to the radially outer position of the retaining ring,
Mud is deposited on the inner peripheral surface of the operation sleeve before it is solidified and can be removed before firmly sticking, so that the above-mentioned smooth movement of the retaining ring is further ensured.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of a drive shaft according to the present invention will be described with reference to the drawings. FIG. 1 is a one-side sectional view of a main part of a drive shaft in a state where a shaft is locked to a yoke, and FIGS. 2A and 2B are a one-side sectional view and a side view of a yoke.
FIG. 3 shows a plan view of the shaft. In the drawing, 1 is a drive shaft, 2 is an annular recess, 3 is a shaft, 4 is a yoke, 4
a is a boss, 4b is a flange, 5 is a lock ball, 7 is a coupling device, 8 is a restraining ring, 9 is a holding ring, 10 is an operation sleeve, and 14 is a leaf spring. The drive shaft 1 has three guide holes provided at regular intervals (120 ° intervals) along the outer periphery of the boss 4a of the yoke 4 in the annular recess 2 of the shaft 3 by fitting the shaft 3 to the boss 4a of the yoke. The lock balls 5 respectively arranged in the lower part 6 are dropped, and the movement of the lock balls in the radial direction is controlled by the coupling device 7 to lock and release the spline connection between the boss 4a of the yoke and the shaft 3. Can be selected. In this embodiment, the number of the lock balls 5 is three. However, the number of the lock balls 5 may be two or more, and there is no particular limitation.

The coupling device 7 includes a restraining ring 8 for preventing the lock ball 5 from moving outward in the radial direction, a retaining ring 9 for relaxing the movement of the lock ball 5 from moving outward in the radial direction, and a restraining ring. 8 and an operation sleeve 10 for accommodating the holding ring 9. The retaining ring 9 has an inner diameter D that is somewhat larger than the outer diameter of the stopper 13. That is, when locking, the restraining ring 8 must be moved to a position above the lock ball 5, and accordingly, the retaining ring 9 also needs to move and be able to fit with the stopper 13. In addition, since the retaining ring 9 needs to be stopped at a position above the lock ball by abutting a part of the side wall of the retaining ring with the stopper after the shaft is pulled out from the boss, the outer surface 9a of the retaining ring 9 is a leaf spring. The spring is loaded by 14 so that the retaining ring 9 is eccentric with respect to the inner peripheral surface of the operating sleeve.

The leaf spring 14 includes a body portion 14c and both leg portions 14c.
a, 14b having a U-shaped cross-section
Are always in contact with the inner peripheral surface of the operation sleeve 10 and the two legs 14
As for a and 14b, the outer surface 9a of the retaining ring 9 was spring-loaded so as to sandwich the outer surface 9a of the retaining ring 9. In addition,
The present invention is particularly characterized by the shape and arrangement of the leaf spring 14, and the other components do not need to be modified.

Next, the operation of the drive shaft connecting device 7 will be described. 4 (a) and (b) to 7 (a) and (b)
Is a one-side cross-sectional view of a main state of a series of operations until the shaft 3 and the yoke 4 are unlocked from the spline connection and the shaft 3 is pulled out from the yoke 4, and the radius of the holding ring 9 with respect to the inner peripheral surface of the operation sleeve 10. 8 (a) and 8 (b) to 9 (a) and 9 (b) show the spline coupling by inserting the shaft 3 into the yoke 4. One-side cross-sectional view of the main state of a series of operations until locking of the
Are schematically shown so that the relative position of the holding ring 9 with respect to the inner peripheral surface in the radial direction can be understood.

When unlocking the spline connection between the shaft 3 and the yoke 4 and pulling out the shaft 3 from the yoke 4, first, the connecting device 7 is connected to the return spring 12.
Is moved leftward from the position shown in FIG. 4A to the position shown in FIG. 5A. Due to this movement, the holding ring 9 is disposed above the lock ball 5. At the position shown in FIG. 4A, the retaining ring 9 is fitted with the stopper 13 so that the leaf spring 14
5 is concentric with the inner peripheral surface of the operation sleeve 10 without being affected by the spring load due to
In the position shown in FIG. 5A, the spring is released from the stopper 13 and moves to a position eccentric to the inner peripheral surface of the operation sleeve 10 under the action of the spring load of the leaf spring 14 (FIG. 5).
(B)). At this time, the outer surface 9a of the retaining ring of the leaf spring 14
Is pushed back with a force opposing the force of the spring load, the lock ball 5 can move outward in the radial direction, whereby the locking of the spline connection can be released.

Next, as shown in FIG. 6A, the shaft 3 is pulled out from the boss 4a of the yoke 4. During this withdrawal, the lock ball 5 is inserted into the annular recess 2 of the shaft 3.
And is pushed up onto the outer surface of the shaft 3,
The holding ring 9 overcomes the spring load of the leaf spring 14 by this pushing-up force and moves to a concentric position with respect to the inner peripheral surface of the operation sleeve 10 (FIG. 6B). Then, FIG.
As shown in (a), the shaft 3 is completely pulled out from the boss of the yoke 4. At this time, the retaining ring 9 moves to the eccentric position again under the influence of the spring load due to the leaf spring 14 because the force of pushing up the lock ball by the shaft 3 disappears (FIG. 7B). Since the retaining ring 9 is at the eccentric position, a part of the side wall of the retaining ring 9 abuts against the stopper 13, and the retaining ring 9 can be stopped at a position above the lock ball 5.

Thereafter, when the shaft 3 is reinserted into the yoke 4 to lock the spline connection, the retaining ring 9 is stopped at a position above the lock ball 5 as shown in FIG. Boss 4
The spline connection can be performed only by the operation of inserting the shaft 3 into the shaft a (see FIG. 8A). At the moment when the insertion is completed, the holding ring 9 eccentric with respect to the inner peripheral surface of the operation sleeve 10 is moved. When the lock ball is pushed upward by the insertion of the shaft, the lock ball is concentrically moved to engage with the outer peripheral surface of the stopper 13. Therefore, as shown in FIG. To automatically generate the lock.

As another embodiment, as shown in FIG. 12, four mud drain holes 15 are provided at equal intervals (90 ° intervals) in the operation sleeve corresponding to the radially outer position of the holding ring. Is provided. The number of the muddy holes 15 is not particularly limited, but is preferably 3 to 4.

As described above, in any of the embodiments, the holding ring 9 can smoothly move between the eccentric position and the concentric position, and the operating sleeve 1 can be moved.
Even when mud adhered to the inner peripheral surface of the shaft 0, the influence was hardly affected, and the locking and release of the spline connection between the yoke 4 and the shaft 3 could be performed smoothly. In addition, what has been described above is merely an embodiment of the present invention, and various changes can be made within the scope of the claims.

[0018]

According to the present invention, even if the mud adheres to the inner peripheral surface of the operation sleeve 10 due to centrifugal force when used under bad conditions such as paddy fields or the like where mud is present, the above-mentioned publication is disclosed. Holding ring 9 in the inner peripheral surface as in the drive shaft described in 1 above.
The drive shaft used to connect the agricultural tractor to its working machine
The spline connection between the shaft 3 and the yoke 4 can be smoothly locked and released. Further, by providing the muddy water drain hole 15 in the operation sleeve, the locking and releasing of the spline connection can be performed more smoothly.

[Brief description of the drawings]

FIG. 1 is a one-side cross-sectional view of a main part of a typical drive shaft 1 according to the present invention.

FIG. 2A is a one-side sectional view of a yoke 4;
(B) is a side view thereof.

FIG. 3 is a plan view of the shaft 3. FIG.

FIG. 4A is a one-side sectional view of a main part of a drive shaft according to an embodiment showing a locked state of a spline connection between a shaft 3 and a yoke 4, and FIG. 4B corresponds to FIG. Then, the operation sleeve 10, the leaf spring 14, and the holding ring 9
FIG. 3 is a diagram schematically illustrating only the portion of the holding sleeve 9 extracted from the operating sleeve 10 so that the relative position of the holding ring 9 with respect to the inner peripheral surface of the operating sleeve 10 in the radial direction can be understood.

FIG. 5A is a one-side cross-sectional view of a main part of a drive shaft according to an embodiment showing a state in which locking of a spline connection between a shaft 3 and a yoke 4 becomes releasable;
In correspondence with (a), only the operation sleeve 10, the leaf spring 14, and the holding ring 9 are extracted and schematically shown so that the relative position of the holding ring 9 with respect to the inner peripheral surface of the operation sleeve 10 in the radial direction can be understood. FIG.

FIG. 6A is a view showing a state in which a shaft 3 is moved from a boss 4a of a yoke 4;
FIG. 3 is a half sectional view of a main part of the drive shaft according to the embodiment showing a state in which the operating sleeve 10, the leaf spring 14, and the holding ring 9 correspond to FIG.
FIG. 3 is a diagram schematically illustrating only the portion of the holding sleeve 9 extracted from the operating sleeve 10 so that the relative position of the holding ring 9 with respect to the inner peripheral surface of the operating sleeve 10 in the radial direction can be understood.

FIG. 7A is a one-side sectional view of a main part of a drive shaft according to an embodiment showing a state where a shaft 3 is completely separated from a boss 4a of a yoke 4, and FIG. Correspondingly, the operating sleeve 10, the leaf spring 14, and the retaining ring 9
FIG. 3 is a diagram schematically illustrating only the portion of the holding sleeve 9 extracted from the operating sleeve 10 so that the relative position of the holding ring 9 with respect to the inner peripheral surface of the operating sleeve 10 in the radial direction can be understood.

FIG. 8A is a half sectional view of a main part of a drive shaft according to an embodiment showing a state in which the shaft 3 is being inserted into the boss 4a of the yoke 4; FIG. 4 is a one-side cross-sectional view of a main part of a drive shaft according to an embodiment showing a state in which locking can be released;
In correspondence with (a), only the operation sleeve 10, the leaf spring 14, and the holding ring 9 are extracted and schematically shown so that the relative position of the holding ring 9 with respect to the inner peripheral surface of the operation sleeve 10 in the radial direction can be understood. FIG.

9A is a one-side sectional view of a main part of a drive shaft according to an embodiment showing a locked state of a spline connection between a shaft 3 and a yoke 4, and FIG. 9B is a sectional view of FIG. Correspondingly, the operating sleeve 10, the leaf spring 14, and the retaining ring 9
FIG. 3 is a diagram schematically illustrating only the portion of the holding sleeve 9 extracted from the operating sleeve 10 so that the relative position of the holding ring 9 with respect to the inner peripheral surface of the operating sleeve 10 in the radial direction can be understood.

FIG. 10 (a) is a one-side cross-sectional view of a main part of a conventional drive shaft, and FIG. 10 (b) corresponds to (a), in which only the operation sleeve 10, the leaf spring 14, and the holding ring 9 are provided. FIG. 4 is a diagram schematically illustrating the state where the holding ring 9 is extracted and the relative position in the radial direction of the holding ring 9 with respect to the inner peripheral surface of the operation sleeve 10 is known.

11A is a one-side sectional view of a main part of a conventional drive shaft, and FIG. 11B is a view corresponding to FIG. 11A, in which only the operation sleeve 10, the leaf spring 14, and the holding ring 9 are provided. FIG. 4 is a diagram schematically illustrating the state where the holding ring 9 is extracted and the relative position in the radial direction of the holding ring 9 with respect to the inner peripheral surface of the operation sleeve 10 is known.

12A is a one-side sectional view of a main part of a drive shaft according to an embodiment showing a locked state of a spline connection between a shaft 3 and a yoke 4, and FIG. 12B corresponds to FIG. Then, the operation sleeve 10, the leaf spring 14, and the holding ring 9
FIG. 3 is a diagram schematically illustrating only the portion of the holding sleeve 9 extracted from the operating sleeve 10 so that the relative position of the holding ring 9 with respect to the inner peripheral surface of the operating sleeve 10 in the radial direction can be understood.

[Explanation of symbols]

 1 Drive shaft 2 Annular recess 3 Shaft 4 Yoke 4a Boss 4b Flange 5 Lock ball 6 Guide hole 7 Connecting device 8 Retaining ring 9 Retaining ring 9a Outer surface of retaining ring 10 Operating sleeve 11 Outer wall of yoke flange 12 Return spring 13 Stopper 14 Plate Spring 14a, 14b Leg of leaf spring 14c Body of leaf spring 15 Mud drain hole

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16D 1/10 F16B 21/16

Claims (2)

(57) [Claims] 1. A spline for a shaft having an annular recess on the outer periphery of a fitting surface, and a yoke having a plurality of lock ball guide holes for locking the annular recess, the boss having a boss fitted to the shaft. Locking and unlocking the spline connection by providing a coupling device for controlling the outward movement of the locking ball in the radial direction, the coupling device being disposed between the yoke flange and the outer wall. The return spring slides and is held at a position above the lock ball by a stopper provided in the vicinity of the guide hole of the boss to prevent the lock ball from moving outward in the radial direction, thereby enabling the locking. The restraining ring has an inner diameter somewhat larger than the outer diameter of the stopper, and the outer surface is spring-loaded by a leaf spring to press the return spring. A retaining ring that moves integrally with the adjacent restraining ring and is positioned above the lock ball to relax the lock ball from moving outward in the radial direction to enable the release, and a restraining ring and retaining. An operating sleeve for accommodating a ring, wherein the leaf spring comprises a body portion and both legs, and
The leaf spring has an operating switch.
Always keep in contact with the inner surface of the leave, and both legs hold the retaining ring.
Between the retaining ring and the outer surface of the retaining ring.
Drive shaft, characterized in Rukoto. 2. The drive shaft according to claim 1, wherein a mud drainage hole is provided in the operation sleeve corresponding to the radially outer position of the retaining ring.