JPH07145822A - Preload control mechanism - Google Patents

Abstract

PURPOSE:To facilitate the control of preload by engaging a cylinder which is driven with oil supplied from an oil passage to a shaft member and pressing an inner ring with a piston which is brought into contact with the inner ring of an angular bearing. CONSTITUTION:Taper roller bearings 17, 18, a cylinder 19, and an output gear 20 are fastened to an output shaft 10 with a lock nut 21, and a sealed space is formed inside the cylinder 19. When oil is filled in an oil passage 27 and an adjusting screw is fastened, oil pressure is applied to pistons 24, 24 of the cylinder 19. By the oil pressure, the piston 24 on the bearing 17 side presses an inner race 17b against a piston gear 12, and the piston 24 on bearing 18 side presses an inner race 18b against an outer gear 20 to apply preload taper roller bearings 17, 18. By adequately controlling the fastening of the adjusting screw 29, each preload value of the taper roller bearings 17, 18 can be adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preload adjusting mechanism for adjusting a preload on an angular bearing by using a cylinder.

[0002]

2. Description of the Related Art Conventionally, in various vehicles such as forklifts, power from an engine transmitted to a transmission is transmitted to an axle by a differential device.

As shown in FIG. 5, the differential device 51 is closed by a housing 52 and a cover 53.
An output shaft 54 that rotates according to the rotation of an input shaft (not shown) to which the power from the transmission is input is disposed in the housing 52 and the cover 53. The output shaft 54 includes a tip portion 55, a pinion gear 56, and a shaft portion 57, and the tip portion 55 is the housing 52.
It is rotatably supported by a roller bearing 58 provided at. The shaft portion 57 is rotatably supported by first and second taper roller bearings 60 and 61 via a retainer 59 fixed to the housing 52.
The first taper roller bearing 60 is arranged with its one side in contact with the pinion gear 56. Further, the shaft portion 57 is provided between the first and second taper roller bearings 60 and 61.
By disposing the cylindrical spacer 62 and the shim 63 which are fitted in, the predetermined space is maintained. An output gear 64 fitted to the shaft 57 is disposed on the other side of the second taper roller bearing 61. Then, by tightening the lock nut 65 from the base end side of the output shaft 54, the first and second taper roller bearings 60 and 61 and the output gear 64 are tightened and fixed. At this time, the inner races 60a and 61a of the first and second taper roller bearings 60 and 61 are pressed against the first and second taper roller bearings 60 and 61 by the spacer 62 and the shim 63, and preload is applied. To be

This preload is to counteract the thrust force acting on the output shaft 54 when the vehicle moves forward and backward, and to prevent the first and second taper roller bearings 60 and 61 from rattling. That is, when the vehicle moves forward, the output shaft 54 rotates in the direction of arrow A1 (clockwise when viewed from the tip 55 side), and the thrust force in the direction of arrow A2 (cover 53 side to housing 52 side). Works. Therefore,
If the preload does not act on the first and second taper roller bearings 60 and 61, the second taper roller bearing 61 will rattle. When the vehicle moves backward, the output shaft 54 rotates in the direction of arrow B1 (counterclockwise when viewed from the tip 55 side), and the thrust force in the direction of arrow B2 (from the housing 52 side to the cover 53 side) is increased. work. Therefore, if the preload is not acting, the first taper roller bearing 60 will rattle. Therefore, by tightening the lock nut 65 with a predetermined tightening torque, a preload of a predetermined value acts on the first and second taper roller bearings 60 and 61, and the first and second taper roller bearings 60 and 61 6
It is designed to prevent the rattling of 1.

The preload value applied to the first and second taper roller bearings 60 and 61 is calculated by measuring the starting torque of the output gear 64.

[0006]

However, when the lock nut 65 is tightened with a predetermined tightening torque, the preload value calculated from the starting torque of the output gear 64 at that time is outside the allowable range of the predetermined value. In such a case, it is necessary to adjust the preload by replacing the shim 63 with a shim 63 having a different thickness. Therefore,
In order to replace the shim, the output gear 64, the second taper roller bearing 61, etc. have to be removed from the output shaft 54, and the assembling work has to be carried out again, and it takes time and effort to adjust the preload. There is.

Further, the shim 63 is preloaded on the first and second taper roller bearings 60 and 61 due to the shim 63 being depressed or deteriorated due to a change in thrust force due to forward and backward movement of the vehicle. There is a problem of disappearing.

The present invention has been made to solve the above problems, and an object thereof is to provide a preload adjusting mechanism capable of easily adjusting the preload applied to the angular bearing.

[0009]

In order to solve the above problems, the invention according to claim 1 forms an oil passage in a shaft member axially supported by an angular bearing, and uses oil from the oil passage. The gist of the invention is to mount a driven cylinder on a shaft member, bring the piston of the cylinder into contact with the inner ring of the angular bearing, and press the inner ring with the piston to preload the angular bearing.

The gist of the invention according to claim 2 is that in the preload adjusting mechanism according to claim 1, adjusting means for adjusting the preload is provided in the oil passage formed in the shaft member.

According to a third aspect of the present invention, in the preload adjusting mechanism according to the second aspect, the adjusting means is an adjusting screw screwed onto the shaft member to adjust the volume of the oil passage formed in the shaft member. The summary will be given.

[0012]

Therefore, according to the first aspect of the invention, the cylinder is driven by the oil from the oil passage formed in the shaft member, and the piston of the cylinder presses the inner ring of the angular bearing to cause the angular contact. The bearing is preloaded. Therefore, by using the cylinder, the angular bearing can be easily preloaded.

According to the invention described in claim 2, in the invention described in claim 1, the preload applied to the angular bearing is performed by operating an adjusting means to adjust the oil pressure of the oil in the oil passage. Therefore, the preload applied to the angular bearing can be easily adjusted without removing the angular bearing from the shaft member.

According to the invention of claim 3, in the invention of claim 2, since the adjusting means is an adjusting screw,
By rotating the adjusting screw, the volume of the oil passage can be adjusted to easily adjust the oil pressure of the oil in the oil passage, that is, the preload applied to the angular bearing.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the preload adjusting mechanism of the present invention is embodied as a differential device in various vehicles such as forklifts will be described below with reference to FIGS.

FIG. 1 shows a differential device 1 for transmitting power from a transmission to a wheel shaft. This differential device 1 is closed by connecting and fixing a housing 2 and a cover 3 with bolts 4, and one side of an input shaft 5 arranged in the differential device 1 projects from the cover 3. The input shaft 5 is connected to a transmission (not shown) via a propeller shaft 6 so as to transmit the power from the engine transmitted to the transmission into the differential device 1.

An input gear 7 is fixed to the input shaft 5, and the input gear 7 is rotatably supported by a ball bearing 8 provided in the housing 2 and a ball bearing 9 provided in the cover 3. It is supported. That is, the input shaft 5
Is rotated integrally with the input gear 7, so that the input shaft 5
The power transmitted to the input gear 7 is transmitted to the input gear 7.

An output shaft 10 as a shaft member having a circular cross section is arranged in the differential device 1.
The output shaft 10 includes a tip portion 11, a pinion gear 12 and a shaft portion 13. The tip portion 11 is rotatably supported by a roller bearing 14 provided in the housing 2, and the pinion gear 12 is formed on the cover 3 side of the tip portion 11. The pinion gear 12 forms a truncated cone that is tapered toward the tip 11. As shown in FIG. 3, the pinion gear 12 has a plurality of tooth portions 15 formed at equal intervals.

The shaft portion 13 serves as an angular bearing for receiving a thrust direction (axial direction) force and a radial direction (radial direction) force applied to the output shaft 10 via a retainer 16 fixed to the housing 2. First taper roller bearing 17 and second taper roller bearing 18
Is supported by. The first and second taper roller bearings 17 and 18 are outer races 17a and 18a fixed to the inner peripheral surface of the retainer 16, inner races 17b and 18b as inner rings fixed to the outer peripheral surface of the shaft portion 13, and outer races. 17a, 18a and inner race 17b, 1
A plurality of frustoconical rollers 17c, 1 disposed between 8b
And 8c.

The inner peripheral surfaces of the outer races 17a, 18a are formed obliquely with respect to the shaft portion 13 so as to taper toward the sides facing each other. Similarly, Inner Race 1
The outer peripheral surfaces of 7b and 18b are also formed obliquely with respect to the shaft portion 13 so as to taper toward the sides facing each other. Further, the rollers 17c and 18c are arranged so that the conical trapezoidal tapered portions face each other. That is, the inner peripheral surfaces of the outer races 17a and 18a and the inner race 17
Since the outer peripheral surfaces of b and 18b are formed obliquely with respect to the output shaft 10, both the thrust direction force and the radial direction force that act when the output shaft 10 rotates are related to the first and second directions.
It can be received by the second taper roller bearings 17 and 18.

One end of the first taper roller bearing 17 is in contact with the pinion gear 12. Also, the first and second
Cylinder 1 between the tapered roller bearings 17 and 18
9 is provided, and the output gear 20 engaged with the input gear 7 is fitted to the other end of the second taper roller bearing 18. Then, by tightening the lock nut 21 from the other end side of the shaft portion 13, the inner race 17
The b, 18 b, the cylinder 19, the output gear 20, and the like are fixed to the output shaft 10.

That is, the power transmitted to the input gear 7 is transmitted through the output gear 20 to the output shaft 10, that is, the pinion gear 1.
2 is transmitted. The pinion gear 12 is engaged with a ring gear 22 connected to a wheel shaft (not shown), and the power transmitted to the pinion gear 12 is transmitted to the wheel shaft via the ring gear 22.

FIG. 2 shows the cylinder 19 fitted to the output shaft 10. The cylinder 19 is formed in a cylindrical shape and is fitted and fixed to the shaft portion 13. As shown in FIGS. 1 and 2, a plurality of (four in this embodiment) through holes 23 extending in the longitudinal direction are formed in the thick portion of the cylinder 19. Cylindrical pistons 24 are inserted on both sides of each through hole 23 and are slidably provided in the through hole 23. On the other hand, on the inner peripheral surface of the cylinder 19, the through holes 23 are formed at positions corresponding to the respective through holes 23 from the inner peripheral surface.
An oil hole 25 is formed so as to penetrate therethrough.

Further, as shown in FIGS. 1 and 3, the oil groove 2 is formed in the shaft portion 13 of the output shaft 10 at a portion corresponding to the oil hole 25.
6 is formed in an annular shape along the outer periphery of the shaft portion 13, and the oil groove 26 is formed through an oil passage 27 and a connecting hole 28 formed in the longitudinal direction from the central portion of the other end of the shaft portion 13. It is in communication. That is, by supplying oil from the opening 27a of the oil passage 27, the oil is filled in the through holes 23, the oil holes 25, the oil grooves 26, and the oil passage 27, and the opening 27a is formed.
With respect to the oil passage 27, the oil passage 27 is screwed with an adjusting screw 29 that is sealed so that oil does not leak from the oil passage 27.
Block 7 In this way, each through hole 23, oil hole 25,
With oil filled in the oil groove 26 and the oil passage 27,
When the adjusting screw 29 is tightened, the volume of the oil passage 27 is reduced and hydraulic pressure is applied to each piston 24. With this oil pressure,
The piston 24 arranged on the side of the first taper roller bearing 17 slides toward the side of the inner race 17b, presses the inner race 17b against the pinion gear 12, and preloads (preloads) the first taper roller bearing 17. Call. Further, the piston 24 arranged on the side of the second taper roller bearing 18 slides toward the inner race 18b, presses the inner race 18b against the output gear 20, and preloads the second taper roller bearing 18 concerned. . That is, by screwing in the adjusting screw 29, the preload applied to each of the first and second taper roller bearings 17 and 18 increases. Further, by loosening the adjustment screw 29, the preload applied to the first and second taper roller bearings 17 and 18 is reduced. Therefore, by adjusting the screwing degree of the adjusting screw 29, the first and second taper roller bearings 17, 18 are
The preload applied to is adjusted.

An O-ring 30 is fitted on the outer peripheral surface of the piston 24 so as to seal the space between the O-ring 30 and the inner peripheral surface of the through hole 23 formed in the cylinder 19.
Similarly, the O-ring 3 fitted to the inner peripheral surface of the cylinder 19
1, the outer peripheral surface of the shaft portion 13 is sealed.

Next, the operation and effect of the preload adjusting mechanism configured as described above will be described. First, the output shaft 10 is provided with first and second taper roller bearings 17, 1.
8, the cylinder 19, the output gear 20, etc. are the lock nut 2
Each of the through holes 23 and the oil holes 2 in the state of being tightened with 1.
5, oil is filled in the oil groove 26 and the oil passage 27, and the adjusting screw 29 is tightened. Then, hydraulic pressure is applied to each piston 24. Due to this hydraulic pressure, the piston 24 arranged on the side of the first taper roller bearing 17 slides toward the inner race 17b and presses the inner race 17b against the pinion gear 12, so that the first taper roller bearing 1
Preload 7 Further, the piston 24 arranged on the second taper roller bearing 18 side slides on the inner race 18b side, and the inner race 18b is connected to the output gear 2
The second taper roller bearing 18 is preloaded by pressing it to zero. That is, the preload value of each of the first and second taper roller bearings 17 and 18 can be adjusted by appropriately adjusting the degree of tightening of the adjusting screw 29.

The value of the preload applied to the first and second taper roller bearings 17 and 18 is the output gear 20.
The starting torque applied to the is measured and calculated from the measured value. That is, by appropriately adjusting the tightening degree of the adjusting screw 29 while measuring the starting torque applied to the output gear 20, the first and second tapered roller bearings 1
The preload value of 7, 18 is set to a predetermined value.

As described above, when the power from the transmission is transmitted to the input shaft 5 in a state where the first and second taper roller bearings 17 and 18 are subjected to the predetermined preload, the input gear 7 and the output gear 5 are transmitted. It is transmitted to the output shaft 10 and further to the pinion gear 12 via 21 and the like. And
The power transmitted to the pinion gear 12 is transmitted to the wheel shaft via the ring gear 22.

At this time, when power for advancing the vehicle is transmitted from the transmission, the output shaft 20 rotates in the direction of arrow A1 (clockwise when viewed from the tip 11 side). At this time, thrust force acts on the output shaft 10 in the direction of arrow A2 (from the cover 3 side to the housing 2 side). Then, the force by which the piston 24 arranged on the first taper roller bearing 17 side pushes the inner race 17b increases by the thrust force. Further, the force of the piston 24 arranged on the second taper roller bearing 18 side to press the inner race 18b is reduced by the thrust force. However, if the thrust force is smaller than the preload applied to the second taper roller bearing 18 in advance, the piston 24 presses the inner race 18b against the output gear 20, so that the output shaft 10 rotates in a stable state.

When the power for moving the vehicle backward is transmitted from the transmission, the output shaft 20 is indicated by the arrow B1.
Rotate in the direction (counterclockwise when viewed from the tip 11 side). At this time, thrust force acts on the output shaft 10 in the direction of arrow B2 (from the housing 2 side to the cover 3 side). Then, the force by which the piston 24 disposed on the first taper roller bearing 17 side pushes the inner race 17b is reduced by the thrust force. Further, the force of the piston 24 arranged on the second taper roller bearing 18 side to push the inner race 18b increases by the thrust force.
However, if this thrust force is smaller than the magnitude of the preload applied to the first taper roller bearing 17 in advance, the piston 24 presses the inner race 17b against the pinion gear 12, and the output shaft 10 rotates in a stable state.

As described in detail above, according to this embodiment,
The cylinder 19 can be used for the first and second tapered roller bearings 17 and 18 to easily preload them. At this time, when the output shaft 10 rotates, the output shaft 1
Even if the thrust force applied to 0 fluctuates, the fluctuation does not damage the cylinder 19 and the first and second taper roller bearings 17 and 18, and the life of the mechanism for preloading and the differential device 1 is improved. To do.

Further, by changing the hydraulic pressure in the cylinder 19, the first and second taper roller bearings 17,
The value of the preload for 18 can be set freely. In this case, the preload applied to the first and second tapered roller bearings 17 and 18 can be easily adjusted by adjusting the degree of tightening of the adjusting screw 29. Therefore, when adjusting the preload to a predetermined size, the first and second taper roller bearings 17 and 18 are
Checking the preload value calculated from the output gear 20 without removing the adjustment shaft 2 from the output shaft 10
By adjusting the tightening degree of 9, the preload of a predetermined value can be set easily and accurately.

When the thrust force applied to the first and second roller taper bearings 17 and 18 is smaller than the preload, the second roller taper bearing 18 is moved forward.
However, when moving backward, the first roller taper bearing 17
It is possible to prevent a phenomenon of rattling or swinging around the output shaft 10. Therefore, the life of the first and second roller taper bearings 17 and 18 can be improved.

The present invention is not limited to the above embodiments, but may be carried out as follows without departing from the spirit of the invention. (1) In the above embodiment, the preload of the first and second taper roller bearings 17 and 18 is calculated by measuring the starting torque applied to the output gear 20. this,
For example, when assembled, the retainer 16, the first and second taper roller bearings 17 and 18 are connected to the output shaft 10.
Rotate the retainer 16 with it assembled to
The preload of the first and second taper roller bearings 17 and 18 may be calculated from the starting torque.

(2) In the above embodiment, the first and second taper roller bearings 17 and 18 whose rolling elements are rollers (rollers) are used as the angular bearings. For this, an angular bearing (angular ball bearing) in which the rolling elements are balls (balls) may be used.

(3) In the above embodiment, the inner peripheral surfaces of the outer races 17a and 18a and the inner races 17b and 18b.
Shaft 1 so that the sides where the outer peripheral surfaces of the
It may be assembled obliquely with respect to 3. In this case, roller 1
7c and 18c also have a thicker side facing each other.

(4) In the above embodiment, the cylinder 33 having the cylindrical piston 32 shown in FIG. 4 may be fitted to the shaft portion 13 of the output shaft 10. (5) In the above embodiment, the cylinder 19 was driven by oil, but various working fluids such as air may be used.

(6) In the above embodiment, the pistons 24 are arranged on both sides of the cylinder 19, and one cylinder 19
The two bearings 17, 18 were preloaded. A cylinder may be arranged in each of the bearings 17 and 18, and each cylinder may be configured to preload the corresponding bearing. At this time, the cylinder may be arranged outside the bearings 17 and 18 instead of between the bearings 17 and 18.

The output shaft 10 may be supported by one bearing.

[0040]

As described above in detail, according to the present invention, there is an excellent effect that the preload applied to the angular bearing can be easily adjusted.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a differential device in an embodiment embodying the present invention.

FIG. 2 is a perspective view showing a cylinder fitted to an output shaft in one embodiment.

FIG. 3 is a perspective view showing an output shaft in one embodiment.

FIG. 4 is a sectional view showing a cylinder in another example.

FIG. 5 is a cross-sectional view showing a conventional differential device.

[Explanation of symbols]

10 ... Output shaft as shaft member, 17, 18 ... First and second taper roller bearings as angular bearing, 1
7b, 18b ... Inner race as inner ring, 19 ... Cylinder, 24 ... Piston, 27 ... Oil passage, 29 ... Adjusting screw 32 ... Piston, 33 ... Cylinder as adjusting means.

Claims (3)

[Claims] 1. An oil passage is formed in a shaft member axially supported by an angular bearing, and a cylinder driven by oil from the oil passage is fitted on the shaft member, and a piston of the cylinder is mounted on the angular bearing. A preload adjusting mechanism that abuts against the inner ring of the above and presses the inner ring with the piston to preload the angular bearing. 2. The preload adjusting mechanism according to claim 1, wherein the oil passage formed in the shaft member is provided with adjusting means for adjusting the preload. 3. The preload adjusting mechanism according to claim 2, wherein the adjusting means is an adjusting screw screwed onto the shaft member to adjust the volume of the oil passage formed in the shaft member.