JP2638944B2 - Preload setting mechanism - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for setting a preload on a bearing such as a tapered roller bearing which receives a load not only in a radial direction but also in a thrust direction. The present invention relates to a configuration for preventing the rotation of.

2. Description of the Related Art A mechanism of this type is described in, for example, Japanese Patent Application No. 1-87915, which is briefly described as follows. That is, FIG. 3 is a partial cross-sectional view of the four-wheel drive transfer, and particularly shows a support portion of the ring gear mount case 2 for transmitting the power distributed by the center differential 1 to the rear wheel side. The ring gear mount case 2 is rotatably supported by a tapered roller bearing 4 fitted on the inner periphery of a transfer case 3, and a center differential 1 disposed on the inner periphery thereof.
One of the side gears 5 is spline-fitted, and the pinion gear 7 revolves as the differential case 6 rotates, whereby torque is distributed to the left and right side gears 5 and 8, and the ring gear mount case 2 is mounted together with the one side gear 5. It is designed to rotate. As the ring gear mount case 2 rotates, a load is applied to the bearing 4 that supports the ring gear mount case 2 in the axial direction (thrust direction), so that a preload is applied to support the load. That is, an adjust nut 10 is disposed on the opposite side of the bearing 4 from the ring gear mount case 2 with a shim 9 interposed therebetween, and the adjust nut 10 is screwed into a screw portion 12 formed on the inner peripheral surface of the transfer case 3. Then, by screwing in here, the bearing 4 is pressed in the thrust direction to give a predetermined preload. Further, a lock plate 13 for preventing the rotation of the adjust nut 10 is fitted into the adjust nut 10, and the lock plate 13
13 is engaged with a lock bolt 14 inserted from the upper surface side of the transfer case 3, and its rotation is prevented.

FIGS. 4 and 5 show the conventionally used adjusting nut 10 and lock plate 13. FIG. That is, as shown in FIG. 4, the adjusting nut 10 is a member having a substantially short cylindrical shape or a ring shape, and has a male screw portion 15 screwed to the screw portion 12 on its outer peripheral surface.
Is formed, and a shoulder is formed at a rear end opposite to the tip to be brought into contact with the shim 9, and a slight ring-shaped ridge 16 is formed on the outer periphery of the shoulder, and A plurality of (specifically, 16) engagement grooves 17 are formed at equal intervals on the inner peripheral side of the shoulder at a constant pitch.

On the other hand, as shown in FIG. 5, the lock plate 13 has a shape in which a plurality of protruding pieces are projected from the ring-shaped substrate portion 18 in the axial direction. Four engagement claws 19 which engage the engagement groove 17 with a predetermined engagement gap angle (ie, play in the circumferential direction) are provided on the periphery.
Are formed at regular intervals, and at three equally spaced locations on the outer peripheral edge of the substrate portion 18 are small claws 20 which engage the protrusions 16 from the outer peripheral side to attach the lock plate 13 to the adjust nut 10.
In order to engage the tip of the lock bolt 14 at three equally spaced locations on the outer periphery, three locking grooves 21 Are formed.

In the above-described preload setting mechanism, first, the adjusting nut 10 is screwed into the screw portion 12 of the transfer case 3 to press the bearing 4 in the thrust direction until the starting torque of the ring gear mount case 2 reaches a predetermined value. Thereafter, the lock plate 13 is fitted into the rear end of the adjustment nut 10. In that case, lock plate
Adjust the circumferential direction so that one of the locking grooves 21 formed on the outer circumference of 13 is located directly above, that is, at a position corresponding to the lock bolt 14, and in this state, adjust the engaging claw 19 with the adjusting nut.
10 and the small claw 20 is
To be engaged. Therefore, the lock plate 13 is integrated with the adjust nut 10 in the rotation direction, and the lock plate 13 is prevented from rotating by the lock bolt 14, so that the adjust nut 10 is eventually prevented from loosening.

Problems to be Solved by the Invention The lock bolt 14 serves only to stop the rotation of the lock plate 13, and usually only one lock bolt is provided on the upper surface of the transfer case 3. When mounting on the nut 10, it is necessary to select the mounting posture with respect to the adjust nut 10 so that one of the locking grooves 21 is on the upper side. However, in the above-described conventional mechanism, four locking claws 19 are provided at equal intervals and three locking grooves 21 are provided at equal intervals in the lock plate 13, and the relative positional relationship between the two in the rotation direction is determined. Since there are three types, and there are 16 locking grooves 17 formed in the adjust nut 10, the locking grooves 21 of the lock plate 13 are provided.
Will be indexed at a pitch of 7.5 degrees, as determined by 360 degrees / (16 × 3) = 7.5 degrees. On the other hand, there is an engagement gap of about 5 degrees between the adjusting nut 10, the lock plate 13, and the lock bolt 14. Therefore, considering this engagement gap, the lock plate 13 can be indexed at a pitch of 7.5 degrees-5 degrees = 2.5 degrees. Conversely, if the adjusting nut 10 is screwed in such a way that a rotation of 2.5 degrees or less is required to match the locking groove 21 on the outer periphery of the lock plate 13 with the locking bolt 14, the adjusting nut 10 No matter what phase the lock plate 13 is set in and fitted, it means that the locking groove 21 does not coincide with the lock bolt 14, so conventionally, in such a case, the adjusting nut 10 is further tightened. Then, the phase of the engagement groove 19 is shifted, and in this state, the lock plate 13 is attached to the adjustment nut 10 and the lock bolt 14 must be engaged with the engagement groove 21. As a result, conventionally, there has been a problem that the preload becomes equal to or larger than a predetermined value.

The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a preload setting mechanism that does not require the tightening of an adjust nut when mounting a lock plate.

Means for Solving the Problems In order to achieve the above object, the present invention provides a mechanism for determining a locking groove of a lock plate, which is mechanically determined, by setting an engagement gap between components existing in an actual component. The angle is set to be equal to or less than the angle. More specifically, the present invention provides an adjust nut that presses a bearing in the axial direction, in which a plurality of m first engagement portions are provided at regular intervals on a circumference of a predetermined radius at a constant pitch p, A second engagement portion that engages the lock plate for preventing rotation of the adjustment nut with a small engagement gap angle with the first engagement portion to prevent relative rotation with the adjustment nut; In a preload setting mechanism provided with a third engaging portion disposed on a circumference so as to engage with a locking portion provided at a portion with a small engaging gap angle, n pieces of the third engaging portions are provided. The position in the circumferential direction with respect to any one of the second engagement portions is provided with a different displacement including zero with respect to an integral multiple of the pitch p, and 360
The value of degree / (m × n) is equal to or less than an angle obtained by adding an engagement gap angle between the first engagement portion and the second engagement portion and an engagement gap angle between the engagement portion and the third engagement portion. Is set to.

In the preload mechanism of the present invention as well, a preload is given by tightening the adjustment nut and pressing the bearing in the axial direction, and the lock plate is relatively attached to the adjustment nut by the first engagement portion and the second engagement portion. Rotation is stopped by non-rotatably mounting and engaging the third engaging portion of the lock plate with a locking portion provided on the fixed portion. In the case where any one of the third engagement portions of the lock plate is made to coincide with the engagement portion, in the present invention, the indexing pitch determined by the mechanism of the third engagement portion, that is, the angle of 360 degrees / (m × n) is set. , The angle of the engagement gap between the first engagement portion of the adjustment nut and the second engagement portion of the lock plate, and the engagement between the third engagement portion of the lock plate and the engagement portion of the predetermined fixed portion Since the angle is equal to or less than the angle obtained by adding the engagement angle, that is, the angle of the play, no matter what phase the tightening phase of the adjust nut has at the time of completion of the tightening, any one of the third engaging members of the lock plate attached thereto The joint always coincides with the locking part. Therefore, in the present invention, it is not necessary to retighten the adjust nut when mounting the lock plate.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings.
In the embodiment described below, the present invention is applied to a mechanism for applying a preload to the above-described tapered roller bearing 4 that supports the ring gear mount case 2, and therefore, in the following description, parts different from the above-described configuration will be described. And the same parts are given the same reference numerals as those in the drawings, and the description thereof will be omitted.

FIGS. 1A and 1B show a lock plate 30 used in a preload setting mechanism according to an embodiment of the present invention.
In the lock plate 30 shown here, four engaging claws 31 and five locking grooves 32 are formed. That is, the adjust nut 10 is provided at four locations on the inner peripheral edge of the ring-shaped substrate portion 33.
An engagement claw 31 that fits into the engagement groove 17 at a predetermined engagement gap angle (that is, play) α is formed integrally with and protrudes in the axial direction. By protruding the pair of tongue pieces in the same direction as the engagement claws 31, five locking grooves 32 are formed at equal intervals. The locking groove 32 is for preventing the rotation of the lock plate 30 by inserting the distal end portion of the lock bolt 14, and as shown in an enlarged manner in FIG. Is larger than the diameter of the tip of the lock bolt 14, and an angle β corresponding to the dimensional difference is the engagement gap angle. Further, since the locking grooves 32 are provided at equal intervals on the circumference, each interval (pitch angle) is 72 degrees. One of them is in phase with one of the engaging claws 31 as shown in FIG. 1 (A). Therefore, when the lock plate 30 is mounted on the adjust nut 10, the lock groove 32 having the same phase as the engagement claw 31
17 is in phase with the other locking grooves 32 in the circumferential direction with respect to the locking grooves 32, that is, the locking grooves 32 with respect to any of the engaging grooves 17. In the circumferential direction, the angle obtained by dividing the pitch of the engaging groove 17 (360 degrees ÷ 16 = 22.5 degrees) into five equal parts is sequentially accumulated as a deviation to an integral multiple of the pitch angle of the engaging groove 17. Angle position. That is, if the second, third,... Locking grooves are counterclockwise with respect to the uppermost locking groove 32 in FIG. This is the position in degrees,
(22.5 degrees x 3 + 22.5 degrees x 1/5) and the third locking groove is also located at 144 degrees, which is (22.5 degrees x 6
+22.5 degrees × 2/5), and the fourth locking groove is at a position of 216 degrees, which is (22.5 degrees × 9 + 22.5 degrees × 3/5) and the fifth The locking groove is located at 288 degrees, (2
2.5 degrees x 10 + 22.5 degrees x 4/5). Thus, each locking groove
The position of 32 in the circumferential direction is a position having a shift different from an integral multiple of the pitch of the engagement groove 17, more precisely, a shift in which 1/5 of the pitch is sequentially accumulated.

In the lock plate 30 shown in FIG. 1, a minute claw 34 that catches on the ridge 16 formed on the outer peripheral shoulder of the adjust nut 10 is provided between each locking groove 32.

As shown in FIG. 3, the lock plate 30 is tightened until the preload of the bearing 4 reaches a specified value, specifically, the starting torque of the ring gear mount case 2 reaches a specified torque. The engaging nut 31 is fitted to the adjusting nut 10 so that the engaging nail 31 fits into the engaging groove 17 and the minute nail 34 is hooked on the ridge 16 for use. In that case,
The engaging claws 31 provided on the lock plate 30
Therefore, the lock plate 30 can be mounted in a state where the lock plate 30 is rotated by an angle obtained by adding the engagement gap angle α to the pitch (22.5 degrees) of the engagement grooves 17. In that case, the lock plate 30 is provided for three pitches of the engagement groove 17 (22.5 degrees × 3 =
67.5 degrees) Each time it is rotated, the arrangement of the locking grooves 32 is in the direction opposite to the direction in which the lock plate 30 was actually rotated.
It becomes the same as the state rotated 1/5 pitch. Therefore, according to the lock plate 30, the engagement groove 17
The locking groove 32 can be moved in the circumferential direction by one-fifth of the pitch p, in other words, the mechanism has an adjustment angle of 360 ° ÷ (16 × 5) = 4.5 °. , Which is smaller than the engagement gap angle between the parts (α + β = about 5 degrees),
32 always matches the lock bolt 14, so that both can be engaged.

In the above embodiment, 16 equally-spaced engagement grooves 17 are provided.
The configuration in which five locking grooves 32 for engaging with the lock bolts 14 are provided at equal intervals has been described. However, the present invention is not limited to the above-described embodiment, and the point is that the lock plate is formed on an adjust nut. It is sufficient that the arrangement state of the locking grooves formed in the lock plate is substantially changed at an angle equal to or less than the engagement gap angle of each part as the integer number of rotations of the engagement groove pitch is rotated. Therefore, the number of the engagement grooves and the locking grooves is not limited to the number shown in the above-described embodiment, and the locking grooves need not be at regular intervals. No need to be. If this is expressed by a generalized equation, the number of engagement grooves is m, and the number of engagement grooves having different shifts each being an integral multiple of the pitch of the engagement grooves is n. Assuming that the engagement gap angles between the components described above are α and β, {360 degrees {(m + n)} ≦ (α + β).

In the above embodiment, a groove is formed in the adjust nut, and a projection as an engaging portion to be fitted in the adjust nut is formed in the lock plate. However, this unevenness relationship is opposite to that of the above embodiment in the present invention. Is also good. Further, the locking portion for stopping the rotation of the lock plate is not limited to the above-described lock bolt, but may have another configuration as long as it has the same rotation preventing function.

Effect of the Invention As is apparent from the above description, according to the preload setting mechanism of the present invention, even if the plurality of third engagement portions are actually provided with a wide interval (pitch angle), the lock plate can be adjusted with the adjustment nut. By rotating the engagement groove by an integral multiple of the pitch of the engagement groove, the position of the third engagement portion moves in the circumferential direction substantially at an angle smaller than the pitch of the first engagement portion in the adjust nut. That is, since the movement angle is equal to or less than the engagement gap angle of each part, the third engagement portion always coincides with the locking portion provided on the fixed portion,
As a result, according to the mechanism of the present invention, the rotation can be stopped via the lock plate without retightening the adjustment nut, and the preload applied to the bearing can be set to an expected value.

[Brief description of the drawings]

1 (A) is a front view of a lock plate used in the present invention, FIG. 1 (B) is a longitudinal sectional view thereof, FIG. 2 is an explanatory view for explaining an engagement gap angle, and FIG. FIG. 4 (A) is a sectional view of the adjusting nut, FIG. 4 (B) is a front view thereof, and FIG. 5 (A) is a front view of a conventional lock plate in a wheel drive transfer. FIG. 2 (B) is a longitudinal sectional view thereof. 2 ... Ring gear mount case, 3 ... Transfer case, 4 ... Tapered roller bearing, 10 ... Adjust nut, 12 ... Screw, 14 ... Lock bolt,
17 ... engagement groove, 30 ... lock plate, 31 ... engagement claw,
32: locking groove, α, β: engagement gap angle.

Claims (1)

(57) [Claims] An adjusting nut for pressing a bearing in the axial direction thereof is provided with a plurality of m first engaging portions provided at regular intervals on a circumference of a predetermined radius at a constant pitch p, and the rotation of the adjusting nut is controlled. A second engaging portion that engages with the first engaging portion with a slight engagement gap angle to prevent the lock plate from rotating relative to the adjusting nut; In a preload setting mechanism provided with a third engaging portion disposed on the circumference so as to engage with the stop portion at a small engaging gap angle, the n third engaging portions may be connected to any of the second engaging portions. The position in the circumferential direction with respect to the engaging portion is provided with different deviations including zero with respect to an integral multiple of the pitch p, and 360
The value of degree / (m × n) is equal to or less than an angle obtained by adding an engagement gap angle between the first engagement portion and the second engagement portion and an engagement gap angle between the engagement portion and the third engagement portion. A preload setting mechanism, wherein the setting is set to: