JPS6034534Y2 - Kingpin bearing device for vehicle front wheel drive mechanism - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a king pin bearing device in a front wheel drive mechanism of a vehicle.

An all-wheel drive mechanism in a conventional all-wheel drive vehicle is shown in FIG.

That is, the drive rotation of the front axle shaft 1 is transmitted to the front wheel drive shaft 2 via the Barfield joint J, and the front wheels 5 are driven via the hub 7 langes 3 and wheel discs 4 connected to the shaft 2. .

Additionally, a steering knuckle 6 that covers the all-wheel drive shaft 2
The knuckle housing 7 connected to the axle housing 8 and the trunnion socket 9 connected to the axle housing 8 are automatically and freely connected via upper and lower king pins 10.11.

When steering, the knuckle arm 7a is connected to the kingpin 1.
The front wheels connected to the knuckle housing 7 are steered by rotating around 0 and 11.

Here, the king pins 10 and 11 are attached with their axes inclined at an angle of about 5 to 13 degrees with respect to the vertical direction, so that when the steering wheel is released, a force is applied that directs the front wheels in the straight direction.

By the way, conventionally, the bearings 12.13 that respectively support the upper and lower king pins 10.11 are so-called tapered roller bearings in which the transfer rollers 12a, 13a are inclined with respect to the axes of the king pins 10, 11. There is.

However, in the conventional structure in which the upper bearing 12 also uses a Taber bearing, the upper bearing 12
supports a part of the radial load acting on it with a component force in the thrust direction, so this thrust reaction force is applied from the upper king pin 10 to the lower bearing 13 via the trunnion socket 9 and the lower king pin 11. I end up getting beaten up.

For this reason, the lower bearing 13 must support the thrust reaction force in addition to the large thrust load due to the resistance force received from the ground via the front wheel, and a bearing with an extremely large load capacity is required. This resulted in increased costs and increased size.

□On the other hand, the load capacity of the upper bearing 12 in the thrust direction is sufficient as long as it can support the thrust load instantaneously generated when the front wheels bounce when the vehicle is running on rough roads. It is quite small compared to the load capacity of .

Therefore, the reality is that roller bearings have a load capacity in the thrust direction that is larger than necessary.

The present invention was devised in view of the conventional unreasonable configuration. The bearing that bears the upper kingpin is arranged so that the axis of the transfer roller is parallel to the axis of the kingpin, and the race is provided with a collar portion that supports the thrust load of the roller. By using a roller bearing with a 300mm diameter, the thrust reaction force from the upper bearing is reduced, and the thrust load applied to the tapered roller bearing that supports the lower kingpin is reduced, reducing the size and durability of the lower bearing. The present invention provides an improved king pin bearing device.

The present invention will be described in detail below based on illustrated embodiments.

In FIG. 2 showing one embodiment, the lower king pin 11 is supported by a tapered roller bearing 21 (hereinafter referred to as lower bearing 21) which is attached to the knuckle housing 7 with an outer race fixed thereto.

Here, the bearing 21 is mounted so that the axis of the roller 21a approaches the axis of the king pin 11 in a downward direction.

On the other hand, the upper king pin 10 is supported via a roller bearing 22 (hereinafter referred to as upper bearing 22) whose axis line of a roller 22a is parallel to the axis line of the king pin 10.

In this configuration, calculate the equivalent radial load (static load when the vehicle body is vertically stationary) that acts on the lower bearing 21 (see Figure 3). Now Rv a from the ground applied to the front wheels. Drag force F□: Thrust load applied to the lower bearing.

F2: Radial applied to lower bearing load F3; Radial applied to upper bearing load h: Distance between the points of action of the upper and lower bearings 1; From the point of action of the upper bearing and the ground horizontal distance from the point of application of drag force α；King pin installation angle Circle; quiet dial coefficient of lower bearing Yo: Static thrust coefficient of lower bearing Then, F1=Rvcos (1 F2=1-Rv/h F3=F2-Rvsina =Rv (1/h-sin(z) Therefore, P=Mediocre/F2+Y.

The following result is obtained: -Fl=circle・1・Rv/h×Y0・RvCO3α.

On the other hand, in the conventional structure in which a tapered roller bearing is also used for the upper bearing, a thrust reaction force f is applied from the upper bearing to the lower bearing due to the radial load F3, and this value is determined by the force transmission coefficient due to frictional resistance damping. 0
．． 6, f=0.6・F3/Y.

=0.6Rv (1/h5ina)/Y.

becomes.

As a result of this thrust reaction force being applied, the difference ΔP between the equivalent radial load P' of the lower bearing and the above P is ΔP=f·Y.

=0.6Rv (1/h 5ina) This occurs as follows.

Here, since the king pin is attached to the inner side of the vehicle body than the center of rotation of the front wheel, 1/h-8inα>0, and it is clear that the anti-thrust force f and ΔP are positive values.

As a result, in the present invention, it is possible to use a lower bearing having a smaller load capacity by the value ΔP, which makes it possible to reduce the size, weight, and cost of the bearing.

Furthermore, if a lower bearing with the same load capacity as before is used, the durability can be extended by the reduced load, and it is also possible to match the two to have the benefits of both. can.

On the other hand, the cost of the upper bearing can be reduced by using a roller bearing in which the rotating axes of the rollers are parallel, instead of the conventional tapered roller bearing.

The upper bearing receives a thrust load as a set load during assembly (this is omitted in the above analysis to simplify the explanation), and also receives a thrust load when the front wheel bounces when driving on a rough road.

In order to cope with such a thrust load, a bearing having a collar portion 22b for supporting the thrust load of the roller may be used on the inch and outer race as shown in FIG. 4 or FIG. 5.

In this case, an appropriate thrust load capacity can be obtained depending on the contact area of the collar portion 22b with the roller 22a.

As explained above, according to the present invention, in the front wheel drive mechanism for a vehicle, the upper kingpin is supported via a roller bearing whose roller axis is parallel to the axis of the kingpin. As a result, the anti-thrust force applied to the tapered roller bearing that supports the bearing can be significantly reduced, allowing the use of a small, lightweight, and low-cost bearing with a small load capacity as the lower bearing.

Furthermore, if a lower bearing with the same load capacity as conventional bearings is used, the durability of the bearing can be greatly extended, or by adopting a lower bearing with an intermediate load capacity, a compromise between the two functions can be achieved. You are also free to do so.

Furthermore, the upper bearing itself also has the advantage of being able to be used at a lower cost than a tapered roller bearing.

In addition, the upper bearing has a configuration in which the thrust load is supported by a flange formed into a race, and the roller and flange are in rolling contact and are made of a material with excellent wear resistance, so there is little wear. There are also advantages such as being able to suppress misalignment between the central axis of the king pin and the center of the joint, and improving the durability of the joint.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the main part of a vehicle front wheel drive mechanism equipped with a conventional king pin bearing device, Fig. 2 is a sectional view of the main part showing an embodiment of the present invention, and Fig. 3 is a load effect in the same embodiment. FIGS. 4 and 5 are half-sectional views of different embodiments of the upper bearing used in the improved embodiment. 5... Front wheel, 7... Knuckle housing, 9... Trunnion socket, 10...
...Upper king pin, 11...Lower king pin, 21...Taper roller bearing, 21a...
...Tara, 22...Roller bearing,
22a...Ta-ra, 22b...Brim part.

Claims (1)

[Scope of utility model registration request] In a vehicle front wheel drive mechanism in which a knuckle housing is pivotally supported on a trunnion socket via upper and lower king pins, the knuckle housing is supported via a tapered roller bearing in which the axis of the roller is inclined downward toward the axis of the king pin. The upper kingpin is supported through a roller bearing which bears the lower kingpin and has a race whose axes are parallel to the axis of the kingpin and which supports the thrust load applied to the rollers. A king pin bearing device for a vehicle front wheel drive mechanism, which is characterized by: