JP2514578Y2 - Axle bearing structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a structure of a bearing portion of a driven axle in a vehicle.

[Prior Art] In a semi-floating type axle support structure in which both ends of an axle cylinder are supported by a vehicle frame by leaf springs or the like, the base end of the axle is spline-fitted to the boss portion of the lateral bevel gear of the differential gear. The tip side is supported by a bearing on the end of the axle cylinder as disclosed in Japanese Utility Model Laid-Open No. 55-61004. The outer ring of the bearing is supported by the axle cylinder so as not to move in the axial direction, while the inner ring is fitted onto the large-diameter shaft portion of the axle and between the step portion on the tip side and the holding cylinder press-fitted into the large-diameter shaft portion. It is clamped so that it cannot move in the axial direction.

The outer diameter of the large-diameter shaft part that fits the inner ring of the bearing and the holding cylinder is the same, and the length of the large-diameter shaft part is the shaft of the holding cylinder because the holding cylinder is press-fitted from the base end side of the axle. It is only slightly longer than the directional length, and the base end side of the axle is thinner than the large diameter shaft portion. On the other hand, the axial length of the axle portion (spline shaft portion) that is spline-fitted to the boss portion of the lateral bevel gear of the differential device is naturally required to have a dimension capable of transmitting drive torque. It is longer than the axial length of the large diameter shaft.

However, in the structure of the bearing portion of the conventional axle described above,
When an excessive axial force acts on the axle, such as when the bearing seizes, slippage occurs between the holding cylinder that suppresses the axial movement of the bearing and the axle, causing the axle to slip out of the bearing and then the side of the differential. If the vehicle also comes out of the bevel gears, the vehicle may overturn while traveling.

[Problems to be Solved by the Invention] In view of the above problems, an object of the present invention is to continuously support an axle safely when an axial movement occurs in a large-diameter shaft portion of the axle and to cause an abnormal situation for a driver. To prevent accidents before they occur,
It is to provide a structure of a bearing portion of an axle.

[Means for Solving the Problem] In order to achieve the above object, the structure of the present invention supports an outer ring of a bearing on an axle cylinder so as to be immovable in the axial direction, and an inner ring is fitted onto a large-diameter shaft portion of the axle. The axial length of the large-diameter shaft part, which is sandwiched so as to be axially immovable between the step portion on the tip side and the holding cylinder press-fitted on the large-diameter shaft part, and the holding cylinder is externally fitted, is defined as The end portion is longer than the axial length of the portion that is spline-fitted to the boss portion of the lateral bevel gear of the differential gear.

[Operation] When the axle moves axially with respect to the bearing of the axle cylinder, even if the spline shaft portion at the base end portion of the axle comes out of the spline hole in the boss portion of the lateral bevel gear, the axial direction of the spline fitting portion Since the axial length of the large-diameter shaft portion on which the holding cylinder is fitted is longer than the length, the tip end side of the axle is still supported by the bearing. However, since the driving force is not transmitted to the axle, the vehicle will stop naturally and an accident can be prevented.

[Embodiment of the Invention] FIG. 1 is a plan sectional view of a structure of a bearing portion of an axle according to the present invention, and FIG. 2 is a plan sectional view of a differential device. A large-diameter shaft portion 2c supported by a bearing 16 is formed on the tip end side of the axle 2, and the tip end side of the large-diameter shaft portion 2c has a large diameter from the step 2d.
The brake drum 8 and the disk portion 9a of the wheel 9 are superposed on the flange 2e at the end portion and fixed by the bolt 7 and nut.

The bearing tube 6 is joined to the outer end of the axle tube 3 made of steel pipe by welding, the outer ring of the bearing 16 is fitted in the hole of the bearing tube 6 and pressed against the step portion 5. A retaining ring 17 is attached to the end wall of the bearing tube 6.
And the back plate 12 supporting the brake shoe 10 are overlapped,
It is connected by a plurality of bolts 13 and nuts 14, so that the outer ring of the bearing 16 cannot move axially. The inner ring of the bearing 16 is fitted onto the large-diameter shaft portion 2c of the axle 2 and is press-fitted onto the large-diameter shaft portion 2c. It is pinched. The seal member 4 is mounted between the bearing cylinder 6 and the holding cylinder 15. The base end side of the large-diameter shaft portion 2c of the axle 2 is a small-diameter shaft portion 2b, which is inserted into the axle cylinder.

As shown in FIG. 2, the base end portion 2a of the axle 2 is a spline shaft, and is fitted in the spline hole of the boss portion of the side bevel gear 29 of the differential gear. The axle cylinder 3 is coupled to both side walls of the case 21 that houses the differential device, and the rear portion of the case 21 is covered with a cover 32.
Closed by. The propulsion shaft 22 is supported by the bearing 23 on the front end portion 21a of the case 21, and the bevel gear 24 formed on the inner end portion of the propulsion shaft 22 is meshed with the crown bevel gear 25. The crown bevel gear 25 is coupled to the flange 26a integral with the gear box 26 by bolts 31.

The gear box 26 has hollow shaft portions 26b integrally formed on both side walls,
The bearing 30 is rotatably supported on both side walls of the case 21. Actually, a pair of bevel gears 27 is rotatably supported by a fixed shaft 28 in a gear box 26 formed by combining two divided bodies, and the pair of bevel gears 27 has the side bevel gears 29 described above. It is meshed. The pair of lateral bevel gears 29 are supported on the side walls of the gear box 26 so as not to move in the axial direction.

As described above, the axle 2 has a large-diameter tip portion that is used as the bearing 16
It is supported on the axle cylinder side by the
Is assembled through the hollow shaft portion 26b of the gear box 26 into the spline hole of the lateral bevel gear 29.

By the way, conventionally, the axial length L of the large diameter shaft portion 2c is slightly smaller than the length of the holding cylinder 15 because the large diameter shaft portion 2c is press-fitted into the holding cylinder 15 from the base end side of the axle 2. It's just getting longer. Therefore, if the restraint force of the holding cylinder 15 is lost, even if the axle 2 comes out of the bearing 16, as long as the base end portion of the axle 2 is spline-fitted to the boss portion of the side bevel gear 29, it still remains. Since the driving force is transmitted to the wheels, the driver cannot detect the abnormal situation. If the axle 2 slips out of the lateral bevel gear 29, the force to restrain the axle 2 is lost and the vehicle may suddenly roll over while traveling.

According to the present invention, the length L of the large diameter shaft portion 2c to which the holding cylinder 15 is fitted is the length of the portion where the base end portion 2a of the axle 2 fits into the spline hole of the boss portion of the side bevel gear 29. It is made sufficiently longer than the length s. Therefore, when an excessive axial force is applied to the axle 2, the retaining cylinder 15 loses its restraining force, and even if the axle 2 moves in the axial direction, the retaining cylinder 15 moves from the large diameter shaft portion 2c. Before coming off
The base end portion 2a of the axle 2 comes out of the boss portion of the side bevel gear 29. At this time, the driving force is not transmitted to the axle 2,
The vehicle loses propulsion and stops naturally. If the driver senses this abnormal situation and evacuates the vehicle to a safe place, the vehicle accident can be prevented.

[Advantages of the Invention] As described above, the present invention supports the outer ring of the bearing on the axle cylinder so as not to move in the axial direction, and fits the inner ring onto the large-diameter shaft portion of the axle and the step portion on the tip side and the large-diameter shaft. The axial length of the large-diameter shaft part, which is sandwiched so as to be axially immovable between it and the holding cylinder that is externally fitted under pressure, and the axial length of the large-diameter shaft part is the lateral end of the differential device Since it is longer than the axial length of the part that is spline-fitted to the boss of the bevel gear, it is press-fitted to the axle and regulates the axial movement of the bearing by making a slight change to the shape of the conventional axle. Even if the holding function of the holding cylinder is impaired, the propulsive force of the vehicle is cut off by disengaging from the lateral bevel gear of the differential gear before the axle comes out of the bearing. Therefore, the vehicle will stop naturally, and if the driver senses this situation and evacuates the vehicle to a safe place, it is possible to prevent a rollover accident due to a drop of the axle.

[Brief description of drawings]

FIG. 1 is a plan sectional view of a structure of a bearing portion of an axle according to the present invention, and FIG. 2 is a plan sectional view of a differential device showing a configuration of a base end portion of an axle. 2: Axle, 2a: Base end, 2C: Large diameter shaft, 3: Axle cylinder, 5: Step,
15: Holding tube, 16: Bearing, 29: Side bevel gear

Claims (1)

(57) [Scope of utility model registration request] 1. A holding method in which an outer ring of a bearing is supported by an axle cylinder so as not to be axially movable, and an inner ring is externally fitted to a large-diameter shaft portion of the axle and press-fitted to a step portion and a large-diameter shaft portion on the tip side. The axial length of the large-diameter shaft part, which is sandwiched so as to be immovable in the axial direction between the cylinder and the holding cylinder, is spline-fitted to the boss part of the lateral bevel gear of the differential gear. The structure of the bearing portion of the axle is characterized in that it is longer than the axial length of the mating portion.