FIELD OF TECHNOLOGY

The present invention relates to a bearing system for motorcycle hubs.

BACKGROUND OF THE INNOVATION

In a conventional bearing system for motorcycle hubs having a pair of ball bearings, each one end of the hubs, the size of the two ball bearings of the pair are the same. Each one of the two bearings, has one external ring ball bearing and another internal ring ball bearing.

As such, each of the two bearings are each held in tandem by a pair of rings comprising the external ring and an internal ring. A spacer is disposed on the outer surface of an axial shaft engaging the outer ball bearing to the inner ball bearing; ends of the spacer are in contact with the internal rings holding the ball bearings. The spacer is used as a stopper against both the outer and inner bearings.

The length of the spacer is vital because, if the spacer is lengthier than the nominal length of the axial shaft, the spacer would over-press the internal rings of the ball bearings, outwardly off-setting the alignment of the internal rings and the external rings, and If the spacer is shorter than the nominal length of the axial shaft, there is a chance of over- tightening of bolt and nut, inwardly off-setting the alignment of the internal rings and the external rings. In both instances, bearing stiffness would occur.

Hence, there is a need change in the typical design system of a motorcycle hub having at least two bearings with the same inner diameter, and at least one spacer positioned between the two bearings, to resolve the technical problem relating to bearing stiffness. SUMMARY OF THE PRESENT INNOVATION

One embodiment of the invention relates to a bearing system for motorcycle hubs, comprising: a central hub body: an axial shaft positioned within the central hub body; a spacer disposed along the axial shaft; a first ball bearing and second ball bearing, wherein each of the ball bearing having an internal ring and an outer ring; where the first ball bearing fitted on one end of the spacer; and where the second ball bearing fitted on the other end of the spacer and affixed on top of the spacer for positioning the internal ring and the outer ring in their respective positions, characterized in that the outer ring of the second ball bearing on one side is in contact with the hub body, while the internal ring of the second ball bearing positioned on the spacer with a circlip, such that the internal ring and outer ring of the second ball bearing slide and find right alignment for reducing resistance.

Preferably, diameter of outer ring of ball bearing is bigger than diameter of internal ring of ball bearing.

Preferably, the second ball bearing forms a spacing of ~ 0.50 mm between the outer ring and the central hub body.

Preferably, the internal ring of the bearing not in touch with a shoulder of the hub.

Preferably, the internal ring aligned to the outer ring in working condition.

Preferably, diameter of outer ring of ball bearing is bigger than diameter of internal ring of ball bearing.

Further, the bearing system comprising at least on group of bearing on each end of the spacer.

The bearing system as claimed in claim 1 , wherein outer ring of outer ball bearing is fitted on a circlip placed affixed on top of a spacer disposed along an axial shaft, whereas the internal ring of inner ball bearing is fitted for directly touching an end of the spacer.

Preferably, length of the spacer is at least equal to the nominal length of the axial shaft. Preferably, the circlip are used to lock the outer ball bearing and inner ball bearing in their respective positions, solving the technical problem relating to bearing stiffness.

Preferably, the ball bearing structured such a way that, the bearing detached when the spacer fitted in the hub is pulled.

The present innovation consists of features and a combination of parts hereinafter fully described and illustrated in the accompanying drawings, it being understood that various changes in the details may be made without departing from the scope of the innovation or sacrificing any of the advantages of the present innovation.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify various aspects of some embodiments of the present innovation, a more particular description of the innovation will be rendered by references to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the innovation and are therefore not to be considered limiting of its scope. The innovation will be described and explained with additional specificity and detail through the accompanying drawings in which:

Figure 1 illustrates one embodiment of a ball bearing system.

Figure 2 illustrates another embodiment of a ball bearing system.

Figure 3 illustrates detail view of a bearing of the ball bearing system as shown in Figure 2.

Figure 4 illustrates alternative embodiment of a ball bearing system having an inner diameter bigger than the axle of the wheel.

Figure 5 illustrates detail view of a bearing of the ball bearing system as shown in Figure 4.

Figure 6 illustrates method of replacement of a ball bearing system.

DETAILED DESCRIPTION OF THE INNOVATION

One embodiment of the invention relates to a ball bearing system for motorcycle hubs, wherein the size of an outer ball bearing is different from that of an inner ball bearing. The diameter of outer ring of ball bearing is bigger than diameter of internal ring of ball bearing.

As illustrated in figure 1 , motorcycle hub having an outer ring (101 ) of first or outer ball bearing is fitted on a circlip (105) fastener disposed along a spacer (102) disposed affixed on top of an axial shaft, whereas the internal ring (103) of second or inner ball bearing is positioned for above of the spacer (102), where the second or inner ball bearing will be free to slide and find the right alignment on the bearing axis, with the ability to slide axially without interference. The length of the spacer (102) is at least equal to the nominal length of the axial shaft. Circlip (105) are used to lock the outer ring (101 ) and internal ring (103) of the ball bearing in their respective positions, solving the technical problem relating to bearing stiffness.

Another embodiment of the invention provides a ball bearing system for motorcycle hubs, wherein the size of an first ball bearing is different from that of an internal ring (103). The first ball bearing is bigger than second ball bearing. The first ball bearing is fitted on a circlip (105) placed affixed on top of a spacer (102) disposed along an axial shaft, whereas the second ball bearing is fitted for directly touching an end of the spacer (102). The length of the spacer (102) is at least equal to the nominal length of the axial shaft. Circlip (105) are used to lock the first ball bearing and second ball bearing in their respective positions, solving the technical problem relating to bearing stiffness as illustrated in Figure 2. In this instance, only one end of the spacer (102) touches a first ball bearing (i.e., of the inner ball bearing). When an over-tightening of nut and bolt occurs during wheel assembly onto the motorcycle hub, the spacer (102) would press the internal ring (103) of the first ball bearing only - alleviating problems relating to bearing stiffness. The constraint between the motorcycle hub and the bearings is stable by interference, where the diameter of the bearings have to be bigger than the holes in the hub. The bearings are forced into the hub by the use of a press. The bearings are located or positioned near to a shoulder hub (104) at the mating part within the hub.

As illustrated in figure 3, at least one bearing (on the left) has the outer ring (101 ) that on one side is in contact with the hub shoulder (104), while the other bearing on another side (on the right) is in contact with its inner ring with the central spacer (102). The other bearing is not in contact with the shoulder (104) of the hub. Furthermore, preferably there will a spacing around ~ 0.50 mm, between the outer ring (101) of the bearing and the shoulder (104) of the hub. The spacing has an important role in the operation of the hub, in which it provide to correct the inevitable tolerance of the length of the central spacer (102). This also will prevent the shoulder (104) overriding of the contact ellipse of the ball and the generation of the edge load. Thus, this improves the noise level and life of the wheel bearing.

In fact, if this space was not there and the spacer was shorter than necessary, the bearing would work incorrectly. The contact area between the ball and the inner ring is an ellipse that in normal condition is in the center of the raceway. If the spacer is short, once the wheel axle is tightened, the contact ellipse will not be centered in the raceway and a part of the ellipse will be out of the contact zone between the two components, this will greatly reduce the life of the bearing. Hence, this shows the importance of the length of the spacer in addition to the position of the shoulder (104) in the hub.

The central spacer has an important role in the correct operational life of the hub.

In addition to the above aspects, when an operator assemble the wheel, the user have to be aware of the system of bearings because the user have to follow a precise method of installing hub components to have the correct fitting of the wheels on the motorbike.

The main problem with the traditional bearing system is that, if at least one bearing doesn’t work or not align properly, the bearing system does not work properly. The problem of the bearing that not work perfectly on its axis happen when the spacer and the shoulders (104) of the hubs are not correctly positioned or dimensioned.

In a traditional hub the outer ring is locked in a specific position. This happens for interference between the hub and the outer ring or through the use of circlips. The inner ring is locked in a specific position. This happens due to the tightening of the wheel pin which crushes rings, spacers and forks.

If the outer ring and the inner ring are not aligned, the bearing will be not able to run in its tolerance but it will be withheld, braked, or will not run properly. This will lead traditional hub to increase wear and premature failure of the bearings. Another cause of non-alignment of the rings in traditional hub is known by the incorrect assembly of the bearings. Incorrect assembly pressure does not allow the rings to be aligned once the pin is tightened. The interference mounting pressure needs to be equal to the pressure exerted by the pin when tightened.

However, the mounting pressure of the bearings is often not followed as the end user does not use special tools such as a hydraulic press but makeshift tools. Foremost, it known that the central spacer could not have the nominal length due to machining tolerances.

Therefore, the main feature of the present bearing system is that one of the two sets of bearings is not constrained in at least one of the two rings of which it is composed. The inner ring or outer ring will be free to slide to find the right alignment on the bearing axis, this because the bearings mounted without interference, and with the ability to slide axially

In the figures above you can see two ways to slide, on the spacer, the inner ring of the bearing in order to have a perfect alignment regardless of the incorrect length of the spacer or the incorrect machining tolerance of the bearing seats or the incorrect mounting pressure of the bearings. Such that the inner ring will always be aligned with the outer ring as it is not constrained by anything in the axial direction. Therefore, the ideal working condition for the bearing will always be assured.

The present bearing system for motorcycle hubs having at least one bearing of the two sets of bearings is not locked position, where the bearing having two rings of which it is composed by sliding the ring on the spacer or inside the bearing housing. This will allow the bearing having adjustable position of the parts of the ball or roller bearing, hence the adjustable position or alignment will allow maximum bearing life.

In addition to this, the central spacer has usually a thickness of few millimetres, 2 or 3 millimetres, and it is realized in aluminium. These two features involve the fact that the spacer has not a great mechanical resistance, and if a user, when fit the wheel on the motorcycle, over-tighten the wheel axle, the user could deform quite easily the spacer with the result of shortening it. This means that, if the spacer becomes shorter than the correct length, the bearing is pulled on the shoulder (104) of the hub and it would work with the inner ball that not touch the rings of the bearing in a vertical way but inclined causing a premature bearing failure and a very difficult hub rotation. As illustrated in figure 4, alternative embodiment of the invention provides a ball bearing system using of the following components such as a pair of bearings (401 ,403) in contact with the hub shoulder (404) having an inner diameter bigger than the axle of the wheel, and one or more spacer (402).

As illustrated in figure 5, this type of system, one bearing or one group of bearings if there are two or more bearings side by side has the same features of the proposed system ball bearing system. This bearing is fitted in the hub by interference and has an outer ring is in contact with the shoulder of the hub or with a circlip, and an internal ring is in contact with the spacer on one end. This bearing or group of bearing is fully constrained.

The other bearing (or group of bearings) instead of having an outer ring in contact with the shoulder of the hub or with a circlip and the inner ring free, the other bearing not axially constrained to any component, and not axially constrained from the spacer. This bearing or group of bearings has the outer ring constrained because is fitted in the hub by interference while the inner ring is not constrained in axial direction, where it can be seen two different configuration of bearings and spacers in which the bearings have the inner ring not constrained in axial direction.

Hence, this proves that the inner ring free bearing will work in every situation in the ideal conditions because the inner ring will be aligned to the outer ring. Even if the user, when the user fit the wheel on the motorcycle, over-tighten the bolt and nut. The bearings also works in ideal conditions even if the user deform the spacer and make it shorter than the nominal length. This due to the bearing having both its rings aligned and consequently the internal ball touch the rings in vertical way, this will extend the working life, ensuring longer maintenance intervals and a smoother of the wheel compared to the standard bearing system.

As illustrated in figure 6, the bearings are components subject to wear and therefore have to be replaced periodically. With the traditional system of bearings, the substitution of the bearings is not a very easy operation. In fact the user have to move the central spacer to create a space to pull the bearing with a long but quite thin tool. This means that the bearing will be pulled out not perfectly on its axis and this provide a damage the bearing seat on the hub. The method of replacing bearings (601 ) with present bearing system is much easier than the traditional system. In fact, to remove the bearing (or group of bearings) the user required to directly the spacer fitted in the hub, and the bearing (601 ) will come out perfectly via its axis without damaging the bearing seat. Further, to remove the other side bearing or group of bearings, by using a cylindrical tool (602) with an external diameter bigger than the inner ring of the bearing is suffice to remove the other side bearing (601 ).

The present innovation may be embodied in other specific forms without departing from its essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the innovation is, therefore indicated by the appended claims rather than by the foregoing description. All changes, which come within the meaning and range of equivalency of the claims, are to be embraced within their scope.