EP3168007B1

EP3168007B1 - A unit for attachment to a dismounting tool for wheel hubs

Info

Publication number: EP3168007B1
Application number: EP15194783.5A
Authority: EP
Inventors: Sten Johansson; Niklas WALLMAN
Original assignee: Wallmek I Kungalv AB
Current assignee: Wallmek I Kungalv AB
Priority date: 2015-11-16
Filing date: 2015-11-16
Publication date: 2020-05-13
Anticipated expiration: 2035-11-16
Also published as: EP3168007A1

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a tool for vehicles, more specifically the present invention relates to a tool for dismounting wheel hubs and a jaw unit used in such a tool.

BACKGROUND

A wheel hub is a vehicle component that is manufactured in a plurality of shapes and sizes in the automotive industry, moreover, it is a component that often needs to be dismounted or removed during regular maintenance of the vehicle. The wheel hub is then pulled from the spindle or wheel bearing, which often requires an operator using specialized tools. Generally vehicle repair shops are required to have the ability to handle a large number of different vehicle models either from the same or from different manufacturers. Consequently, they are then required to be able to handle wheel hubs of different dimensions, which results in that the repair shops often are forced to have a large number of tools which essentially serve the same purpose, which can be both costly and inconvenient, an example of such a tool can be found in e.g. EP 2 236 248 .
As a remedy to this, more universal dismounting tools for wheel hubs have been developed during the last decade. Generally the dismounting tools consist of some kind of supporting structure and a secondary structure having a pressing surface which is arranged around the wheel hub and pressed against the spindle or bearing to act as a counter hold. The wheel hub is then pressed out of its seat by applying a force at its back portion. An example of such a tool may be found e.g. in US 8 745 832 or in DE 20 2005 017 468 U1 . However, oftentimes wheel hubs tend to get stuck, due to contamination or corrosion, which makes them extremely hard to remove, and currently available dismounting tools often prove to be inadequate in such situations as usage of these tools often results in breaking of some vehicle component or the tool itself.
There is therefore a need for an improved dismounting tool for removing wheel hubs from bearing or spindle assemblies, and in particular a tool which is universal, cost-efficient, easy to use and capable of removing wheel hubs which are stuck without damaging the tool or any other components.
Even though the above discussion may be focused on motor vehicles, similar situations and problems are encountered in many other types of moving vehicles such as trains or trams.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a jaw unit and a dismounting tool for separating a wheel hub from a wheel bearing, which alleviates all or at least some of the above-discussed drawbacks of presently known systems.
This object is achieved by means of a jaw unit and a dismounting tool for separating a wheel hub from a wheel bearing as defined in the appended claims.
According to a first aspect of the present invention, there is provided a jaw unit for attachment to a supporting member of a dismounting tool for separating a wheel hub from a wheel bearing, said dismounting tool having a separation mode and a pull mode, wherein the jaw unit comprises:

a foot section;
a stem section having two ends and comprising a contact portion arranged at a first end of said two ends for attachment to the supporting member, and wherein said foot section is connected to said stem section at a second end of said two ends, said foot section extending in an engaging direction which is substantially perpendicular to a longitudinal axis of said stem section so to form an L-shaped structure together with said stem section;
wherein the foot section comprises a toe portion at a distal end of the foot section, said foot section and said toe portion having a planar top surface and a substantially tapered cross-section taken in a plane spanned by said longitudinal axis of the stem section and said engaging direction, so that, when in the separation mode, the wheel hub is separated from the wheel bearing when said jaw unit is moved in the engaging direction into an intermediate space between the wheel hub and the wheel bearing; and
wherein the toe portion further has a concave engagement edge arrangeable around at least a portion of a cylindrical section of said wheel hub, so that, when in the pull mode, the jaw unit acts as a counter hold when the wheel hub is moved relative to the wheel bearing in a direction substantially parallel to the longitudinal axis of said stem section.

With this design, a robust and reliable component for a dismounting tool is provided. Substantially perpendicular or parallel should in the present context be understood as exactly perpendicular/parallel or slightly less than perpendicular/parallel, i.e. extending in a direction (or along an axis) that is between 0-5degrees offset from a reference axis or plane.
The present invention is based on the realization that currently available jaw units and the corresponding dismounting tools for wheel hubs are not particularly reliable or user-friendly, in other words, they may be difficult to operate by a single operator. Therefore, by arranging the engaging front part of the jaw unit (toe portion), with a concave engagement edge (the extension axis of the engagement edge being substantially perpendicular to both the longitudinal axis of the stem section and the engaging direction) and with a substantially tapered cross-sectional shape one can efficiently provide an operator with the proper means to separate many types of wheel hubs in a quick and simple manner. The substantially tapered shape provides an initial separation so that the toe portion can be arranged in this intermediate space formed between the wheel hub and the wheel bearing so that there is a large enough contact surface between the jaw unit and the wheel bearing, when it is to be used in a pull mode, which is further optimized by the concave extension of the edge.
Furthermore, the present invention diminishes the need for an operator to have separate tools for the initial separation and for the later removal/pulling of the wheel hub from the wheel bearing which saves cost and facilitates daily operation for repair shops. This is due to the fact that the jaw unit can be used in two operating modes, where the first mode is a separation mode where the (substantially) tapered edge will act as a wedge which drastically facilitates the often very difficult initial separation. The initial separation is, as mentioned, often needed in order to create enough space to be able to position a proper counter hold for when the wheel hub is to be completely pulled away from the wheel bearing. Moreover, it is important in order to be able to pull the wheel hub from the wheel bearing safely without risking injuries due to a badly positioned counter hold. Further, it provides means for dismounting a wheel hub even when the wheel hub rigidly stuck to the wheel bearing, due to e.g. contamination or corrosion (e.g. rusting).
Further, in one exemplary embodiment the substantially tapered cross-section of the toe portion comprises a front section towards the engaging direction and a back section towards the second end of the stem section and wherein the front section has a steeper inclination than the back section. This further increases the robustness of the jaw unit. By making the inclination steeper at the front (distal) section than the back (proximal) section of the toe portion it is made more resistant to breaking off. This is due to the fact that the thickness of the edge is rapidly increasing at the front section, i.e. the material build-up is rapid. This may be very important when operating with large pressing forces. Further, by having a milder inclination at the back section the power transfer is increased once the thickness of the edge reaches an acceptable level. Moreover, the milder inclination at the back section provides a larger contact surface/interface area when the jaw unit is to act as a counter hold in the pull mode. The power transfer in the present context is to be understood as a pressing power mainly applied in a radial direction towards the wheel bearing and the wheel hub, which is transferred to an axial movement separating the two components.
In another exemplary embodiment the foot section has a substantially planar top surface on the side facing towards the stem section, and wherein an angle between the longitudinal axis of the stem section and the top surface is less than 90 degrees. Hereby the power transfer is further improved when the jaw unit is to be wedged in between the wheel hub and the wheel bearing. This is due to the fact that in some situations, when large enoguh pressing forces are applied on the jaw unit in the engaging direction (separation mode) it is prone to tilting forward slightly. Tilting forward should be interpreted as if the contact portion is slightly leaning in over the foot section of the jaw unit. Thus, by having an angle of less than 90 degrees between the substantially planar top surface of the foot section and the longitudinal axis of the stem section this tilt may be compensated for and the angle in which the toe portion engages the wheel hub assembly is optimized. In the present context, the top surface may also be interpreted as the surface portion of the foot section that is intended to abut against the wheel hub, more specifically against the portion of the wheel hub facing the wheel bearing.
In yet another exemplary embodiment the foot section further has a comprises at least one stopping member arranged on a side facing away from the stem section in order to stop the foot section from moving further than a predefined distance into an intermediate space between the wheel hub and the wheel bearing in the engaging direction. Thereby the risk of pushing the jaw unit too far in between the wheel hub and the wheel bearing is reduced. This could otherwise damage some parts of the wheel hub assembly, or possibly even the jaw unit itself. Thus, by providing a stopping member, e.g. in the form of a protrusion or similar, the jaw unit can't be pushed "too far" in between the wheel hub and the wheel bearing in the pressing mode. The side facing away from the stem section can also be understood as the bottom surface of the foot section.
In yet another exemplary embodiment the stem section comprises a through hole having a central axis substantially parallel with the engaging direction, for placement of a rod of an actuating tool. This enables compatibility with several actuating devices, such as e.g. hydraulic cylinders, pneumatic cylinders, mechanical spindles, etc. in the separation mode.
In yet another exemplary embodiment, the contact portion comprises a substantially planar contact surface, wherein said contact surface is arranged so to form an angle with the longitudinal axis of the stem section that is less than 90 degrees, said angle being located towards the engaging direction of the stem section. Similarly to embodiment where the top surface of the foot section is slightly angled, the power transfer is improved when the jaw unit is to be wedged in between the wheel hub and the wheel bearing. This is accordingly due to the fact that when the required pressing forces are applied on the jaw unit in the engaging direction (separation mode) it is prone to tilting forward slightly. As previously mentioned, tilting forward should be interpreted as if the contact portion is slightly leaning in over the foot section of the jaw unit. Thus, by having an angle of less than 90 degrees between the substantially planar contact surface of the contact portion and the longitudinal axis of the stem section this tilt may be compensated for and the angle in which the toe portion engages the wheel hub assembly is optimized. This exemplary embodiment may work as an alternative to the previously discussed embodiment where the foot section is angled, or it may be used in combination with that embodiment.
In yet another exemplary embodiment, the contact surface is treated in order to reduce friction the jaw unit is fastened to the supporting member and moved along and in contact with the supporting member. The jaw unit is intended to be moved along the engagement direction. This further improves the power transfer when the jaw unit is to be wedged in between the wheel hub and the wheel bearing, since less power is lost due to friction.
According to another aspect of the present invention, there is provided a dismounting tool having a separation mode and a pull mode for dismounting a wheel hub from a wheel bearing, wherein the dismounting tool comprises:

a supporting member;
two jaw units in accordance with the first aspect of the present invention;
at least one securing element for fastening each jaw unit to the supporting member; and
wherein the jaw units are arranged with the foot sections facing each other, such that, in said separation mode, the toe portions are moved towards each other into an intermediate space between the wheel hub and the wheel bearing in order to separate the wheel hub from the wheel bearing Hereby, a robust and versatile dismounting tool is provided.

According to one exemplary embodiment, the contact portion of the stem section comprises a guide portion engagable with a matching contact section of the supporting member, for allowing a non-rotational, sliding movement of the jaw unit along the supporting member. The contact portion and contact section may for example be a protrusion and a corresponding groove, respectively, or vice versa. Moreover this ensures that the foot sections of the jaw units can always be perfectly centered in relation to each other and to the supporting member so that no off-balance forces are applied which may damage the tool itself or a vehicle component.
With this aspect of the invention, similar advantages and preferred features are present as in the previously discussed first aspect of the invention and vice versa.
These and other features and advantages of the present invention will in the following be further clarified with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

For exemplifying purposes, the invention will be described in closer detail in the following with reference to embodiments thereof illustrated in the attached drawings, wherein:

Fig. 1 a is a perspective view of a jaw unit in accordance with an embodiment of the present invention.
Fig. 1b is a side-view of the jaw unit in Fig. 1a.
Fig. 1c is a top-view of the jaw unit in Fig. 1a.
Fig. 2a is a cross-sectional view of a jaw unit, taken along the line A-A in Fig. 1c, in accordance with an embodiment of the present invention.
Fig. 2b is a cross-sectional view of a jaw unit, taken along the line A-A in Fig. 1c, in accordance with another embodiment of the present invention.
Fig. 3a is a bottom-view of a jaw unit in accordance with an embodiment of the present invention.
Fig. 3b is a cross-sectional view of a toe portion of a jaw unit, taken along the line B-B in Fig. 3a, in accordance with an embodiment of the present invention.
Fig. 4 is a perspective view of a dismounting tool in accordance with an embodiment of the present invention.
Figs. 5a-c are side-views of a dismounting tool arranged in a separation mode in accordance with an embodiment of the invention.
Fig. 5d is a side-view of a dismounting tool arranged in a pull mode in accordance with an embodiment of the invention.

DETAILED DESCRIPTION

In the following detailed description, some embodiments of the present invention will be described. However, it is to be understood that features of the different embodiments are exchangeable between the embodiments and may be combined in different ways, unless anything else is specifically indicated. In other instances, well known constructions or functions are not described in detail, so as not to obscure the present invention.
Fig. 1a is a perspective view illustration of a jaw unit 1 according to one exemplary embodiment of the invention. To simplify the understanding of the characteristics of the jaw unit 1, it has been divided into specific sections or portions which will be referred to in the following. This is also aided by Fig. 1b in which some of the sections are roughly indicated, in a schematic side-view illustration of a jaw unit 1. The jaw unit 1 comprises a foot section 2 and a stem section 3, together forming an L-shaped structure. In other words, the foot section 2 is connected to one end of the stem section 3 and extends from the stem section in a direction 102 substantially perpendicular in reference to the stem section's longitudinal axis 101. At the other end of the stem section 3, the jaw unit has a contact portion 4 which is to engage a contact section of a supporting member of a dismounting tool. The jaw unit 1 is further provided with a guide portion 14, here in the form of a protrusion 14, which is to engage a matching recess provided on a supporting member of a mounting tool. The jaw unit 1 can be fastened to the supporting member by means of a screw or bolt which engages the matching threads in the bore hole 11. However, these features will be further explained in reference to Fig. 4. The jaw unit 1 is preferably made of some metal or metal-alloy, and manufactured in accordance with conventional methods as known in the art which are for the sake of brevity omitted in this discussion (e.g. molding, milling, etc.). This should however not be considered limiting to the invention since the jaw unit 1 can be made out of any suitable material e.g. ceramics, composite materials, etc.
The foot section 2 further comprises a toe portion 5 at a distal end of the foot section. The toe portion 5 has a substantially tapered cross-section taken in a plane comprising the longitudinal axis 101 and the engaging direction 102. In other words, a cross-section in any plane comprising two transversal axes/vectors which are parallel to the two reference axes 101 and 102. The tapered cross-sectional shape will be discussed in more detail in reference to Figs. 2a-b.
With reference especially to Fig. 1c, the foot section 2 further comprises a concave engagement edge 6, which is later on arrangeable around at least a portion of a cylindrical section of a wheel hub. The concave engagement edge can be said to have a lateral extension. This allows the jaw unit 1 to act as a counter-hold when the wheel hub is to be pulled out of the wheel bearing, i.e. pulled in a direction substantially parallel with the longitudinal axis of the jaw unit 1. The engagement edge can be seen as having an outline, extending in a direction 103 (substantially) perpendicular to a plane comprising the longitudinal axis 101 and the engaging direction 102. The foot section 2 of the jaw unit 1 further has a top surface 7, the top surface 7 is substantially planar and can thus be said to form a plane. The angle between this plane formed by the top surface 7 and the longitudinal axis of the stem section is (slightly) less than 90 degrees. This angle may for example be in the range of 86,0 degrees to 89,99 degrees, such as for example in an interval between 88,0 degrees to 89,5 degrees. In one exemplary embodiment this angle is 89,25 degrees. The three vectors/axes/ arrows 101, 102, 103 are only illustrated to elucidate the inventive concept and should not be construed as limiting to the scope of the invention. In some embodiments all of the three axes 101, 102, 103 may be perpendicular to each other, while in other embodiments only two of them may be perpendicular to each other and the third one is only slightly tilted in reference to a normal to a plane spanned by the first two.
Further, a stopping member 8 (or abutment) in the form of a protrusion can be seen in the figure. The stopping member 8 is located at a bottom side (or bottom surface) of the foot section 2, i.e. the side facing away from the stem section 3 and the contact portion 4 of the stem section. The stopping member 8 reduces the risk of the foot section 2, and in particular the toe portion 5, extending too far in between a wheel hub and a wheel bearing when being moved in the engaging direction 102. If the toe portion 5 would extend too far into an intermediate space formed between the wheel hub and the wheel bearing it may damage certain flanges or other parts of the wheel bearing or wheel hub on some particular component models. Therefore, the stopping member 8 makes the jaw unit compatible with a larger number of vehicle models as well as making it more user-friendly.
Even further, the jaw unit comprises an opening 9 or a through hole 9 in the stem section 3 of the jaw unit 1. The through hole 9 has a central axis substantially parallel with the engaging direction 102. This facilitates the operation of the full dismounting tool since a rod of an actuating tool can be placed through the opening 9. The opening is provided at the center of the stem section, thereby a balanced pressing force in the engaging direction 102 when the dismounting tool is used in a separation mode can be achieved. This will however be further explained in reference to Figs. 5a-d. The jaw unit also has a secondary hole or opening 12 in order to reduce weight and at the same time provide space for a bolt or screw which is to be positioned in the bore hole 11 during attachment of the jaw unit 1 to a supporting member.
The contact surface 10 of the contact portion 4 of the jaw unit 1, i.e. the surface intended to be in contact with the supporting member when they connected to each other, is a treated surface. Treated should in the present context be understood as controlled surface roughness (roughness value, R_a [µm]), such that the friction between the contact surface 10 and a corresponding contact section of the supporting member is reduced. The roughness value R_a is preferably in the range between 1,0 and 2,0.
Figs. 2a and 2b show two exemplary embodiments of a jaw unit 1, in a cross-sectional view. The cross-section being taken in a plane spanned by a longitudinal axis 101 of the stem section 3 and the engaging direction (102 in Fig. 1a), i.e. along line A-A in Fig. 1c. The toe portion 5 as mentioned can be said to comprise two sections, having different slope angles 21, 22. The slope angles are in reference to a reference plane 202 parallel to the top surface (7 in Fig. 1a) of the foot section 2. The slope angles 21, 22 can in the present context be between 90 and 180 degrees, where 90 degrees is a vertical slope and 180 degrees is a horizontal line, i.e. no slope. As can be seen, the front section (leftmost section in reference to the figure's orientation) has a steeper inclination in comparison to the back section (rightmost section in reference to the figure's orientation) of the toe portion 5. This type of arrangement is beneficial in terms of building a robust tool with a good power transferring construction when used in a separation mode, i.e. when the toe portion is to be wedged in between a wheel hub and a wheel bearing. This is because the build-up of material (material thickness) is rapid at a first instance, which reduces the risk of the edge breaking off when used, and thereafter the inclination angle 22 is decreased in order to optimize the power transfer (improve the wedge function) and also increases the contact surface between the jaw unit 1 and a wheel bearing when the jaw unit is used in a pull mode. However, some of these aspects will be even further described in reference to Fig. 3b.
Moreover, turning to Fig. 2b, the two sections of the toe portion 5 may also have a soft transition between each other. In other words the toe portion 5 can have a quarter-elliptic cross-section, where the term quarter-elliptic is to be understood as a segment of an ellipse that has been divided into four quadrants with a cuts along its major and minor axis. Alternatively, the cross-section of the toe portion 5 may be seen as the area between a vertical axis and an exponential curve. These shapes are considered to fall within the term substantially tapered.
Furthermore, Figs. 2a and 2b illustrate an angle 23 between a top surface (7 in Fig. 1a) of the foot section 2 and the longitudinal axis 101 of the stem section 3. In some embodiments this angle 23 may be a right angle, i.e. 90 degrees. However, in some embodiments this angle 23 may be slightly less than 90 degrees; slightly less is in the present context to be understood as between 86 and 89,99 degrees. This is beneficial in terms of achieving good alignment when the jaw unit 1 is used in a dismounting tool in a separation mode, which will be further explained in reference to Figs. 5a-d. Moreover, the jaw unit 1 may be arranged so that the angle 24 between a plane formed by the contact surface 10 of the contact portion 4 and the longitudinal axis 101 of the stem section is less than 90 degrees (e.g. some angle between 86 and 89,99 degrees). This is an alternative way to compensate for the tilting of the jaw unit 1 which may appear when it is used in a separation mode. Or in some situations if the compensation needs to be relatively large it may be divided among the angles 23 and 24. For example, if the tilt of the jaw unit 1 during use in a separation mode is 1,5 degrees, in reference to an axis parallel to the radial extension of the wheel hub and wheel bearing one may arrange that both the contact surface of the contact portion and the top surface of the foot section are angled, e.g. by arranging so that the tilt angles 23, 24 both are 0.75 degrees. Alternatively the jaw unit 1 may be viewed as if the stem section 2 is slightly angled in reference to (top) contact surface 10 of the contact portion 4, since the (threaded) bore hole 11 is always perpendicular in reference to the contact surface 10. So, if the bore hole 11 is chosen to be the point of reference, then it can be said that the stem section 2 is angled in reference to the contact surface of the contact portion 4. However, as mentioned this tilting concept and situation will be further clarified in reference to Figs. 5a-d
Fig. 3a shows the bottom side of a jaw unit in accordance with an embodiment of the present invention. Here the stopping member(s) 8 can be seen more clearly. In this particular embodiment there are two stopping members 8 on each side of the bottom surface of the foot section 2. However, there could be just a single stopping member 8 centrally placed (not shown) on the bottom surface. However, using two stopping members which are laterally displaced, a proper alignment of the jaw units may easily be achieved, since the jaw units 1 will adjust themselves when being moved in an engaging direction towards the wheel hub and wheel bearing when used in a separation mode.
Fig. 3b is an enlarged cross-sectional view of a toe portion 5, taken along the line B-B in Fig. 3a. In this figure the features of a toe portion 5 according to one exemplary embodiment is portrayed. Similarly to previous discussion, the toe portion 5 can be divided into two sections 31, 32, i.e. a front section 31 at a distal end of the toe portion 5, and a back section 32 at a proximal end of the toe portion 5. The inclination angles 21', 22' are in reference to a reference plane 202 which is parallel to the top surface of the foot section 2. The inclination of the front section 31 is steeper than the inclination of the back section 32, as indicated by the angles of inclination 21' and 31'. Where the angle of inclination 21' associated with the front section 31 is larger than the angle of inclination 22' associated with the back section 32. In the present context 90 degrees is considered to be a maximum value for the angles of inclination 21', 22', thus, in other words, the angle of inclination 21' of the front section 31 is closer to 90 degrees than the angle of inclination 22' for the back section 32. The angle of inclination 21' associated with the front section 31 can for example be in the range of 40 to 60 degrees, such as e.g. 55 degrees, while the other angle of inclination 22', i.e. the one associated with the back section 32 is in the range of 10-30 degrees such as e.g. 21 degrees.
Fig. 4 illustrates a dismounting tool 40 from a perspective view in accordance with an embodiment of the present invention. The dismounting tool 40 comprises a supporting member 45 and two jaw units 1 which are attachable to the supporting member 45. The jaw units 1 can be fastened to the supporting member 45 by means of a securing element, here in the form of a threaded screw or bolt 41. The threaded screw or bolt 41 is to engage a matching threaded bore hole 11. The supporting member 45 is further arranged with a secondary set of screws 42 or bolts 42, in order to further ensure that the jaw units 1 to do not move outwards away from each other when the dismounting tool 40 is used in a pull mode. Furthermore, the jaw unit 1 is provided with a guide portion 14, here in the form of a protrusion, arranged at the contact portion 4 of the jaw unit 1. The guide portion 14 is to engage a matching contact section 44, here in the form of a guide rail or recess, in order to enable a non-rotational, sliding movement of the jaw unit 1 along the supporting member 45. This ensures good alignment of the jaw units 1 both in reference to each other and in reference to the supporting member 45.
The supporting member 45 is provided a pair of elongated openings 46 associated with each bolt 41, in which the threaded portion of the bolt can move along a longitudinal axis of the supporting member 45, which is substantially parallel with the engaging direction of the jaw units 1. This is in order to enable the jaw units 1 to be fastened at various distances in relation to each other in order to be compatible with wheel hubs and wheel bearings of different dimensions. The complete tool 40 is similarly to the jaw units 1 made out of some suitable material, e.g. a metal or metal-alloy, which is not necessarily the same metal or metal-alloy as for the jaw units 1.
Further, there is an opening or through hole 43 on the supporting member 45. The hole 43 being placed in the middle of the supporting member 45 such that at least a part of a central axis of the hole 43 is parallel with the longitudinal axis of the jaw units 1 when they are fastened to the supporting member 45. The central axis of the hole 43 is furthermore preferably aligned with a central axis of a through hole in the wheel hub when the tool 40 is in use.
Figs. 5a to 5d serve to illustrate the operation of the dismounting tool 40 in a separation mode (Figs. 5a-c) and in a pull mode (Fig. 5d), from a side-view perspective. In more detail, Fig. 5a illustrates a dismounting tool 50 in an initial position when used in the separation mode. The jaw units 1 are arranged with their engagement edges at least partially enclosing a wheel hub/bearing assembly 51, 52. The foot sections, and in particular the toe portions of the foot sections are aligned to be wedged in between the wheel hub 51 and the wheel bearing 52. Once in the initial position, the jaw units 1 are fastened to the supporting member 45 by means of a set of securing elements 41, here in the form of a pair of bolts 41. The bolts 41 are only to be sufficiently tightened to ensure that the dismounting tool 40 (and the jaw units) stay(s) in position, but at the same time allow the actuating device 50, here in the form of a hydraulic cylinder 50, to move the jaw units 1 towards each other. This is where a treated contact surface is beneficial.
In the separation mode, a pressing/pulling rod 53 (sometimes called piston rod or rod) of a hydraulic cylinder 50, is arranged through a hole provided (9 in Fig. 1) on the stem section of the jaw units 1. A bolt 54 is arranged on the opposite side of the rod 53 to act as a counter hold for the hydraulic cylinder 50.
Fig. 5b illustrates an intermediate position of the jaw units 1 in the separation mode, and it also serves to clarify the feature with a tilted top surface of the foot section and/or tilted contact surface of the contact portion. When forces of large magnitude are applied in a direction indicated by arrows 56, the jaw units 1 may tilt or partly disengage from the supporting member 45 which results in a gap 57, indicated in the magnification in Fig. 5b. Thus, by arranging the foot sections and/or contact portions as previously described this tilt/disengagement can be compensated for and the power transfer is improved. In other words, adjusting the angle between the top surface 7 of the foot section and the longitudinal axis of the stem section where the top surface 7 is a surface located on the foot section of the jaw unit which is intended to face (or abut against) the wheel hub 51.
The next figure, Fig. 5c, illustrates a final position of the jaw units 1 in the separation mode. Here the jaw units 1 have been pressed into an intermediate space between the wheel hub 51 and the wheel bearing 52 by actuation of the hydraulic cylinder 50. The movement direction of the jaw units 1 is indicated by the arrows 55, and also by the increased separation between the two bolts 41, 42 on the supporting member 45. The toe portions of the foot sections acted like wedges when pressed in between the wheel hub 51 and the wheel bearing 52. Further one can see how the stopping members (8 in Fig. 1) kept the jaw units 1 from moving any further/too far in towards the center of the wheel hub 51.
The operational principle of the hydraulic cylinder or any other similar actuating device will not be treated in the present application, it is however considered to be known by the skilled person in the art, and described in more detail in e.g. European Patent Application No. EP15189415.1 , by the same applicant, incorporated herein by reference. Moreover, even though the present application only shows the operation of the dismounting tool 40 together with a hydraulic cylinder 50 it is not be considered limiting to the invention, other obvious actuating devices are readily compatible with the dismounting tool 40, such as e.g. a mechanical spindle, pneumatic cylinder, or the like.
In Fig. 5c the hydraulic cylinder 50 has been moved in order to facilitate the operation of the dismounting tool 40 in a pull mode. The pressing/pulling rod 53 is arranged through a through hole (43 in Fig. 4) of the supporting member. Here, in the pull mode, the force is applied along a central axis of a through hole of the wheel hub 51 and wheel bearing 52, as indicated by arrows 56, instead of in a radial direction as in the separation mode. After the dismounting tool 40 accomplished the initial separation of the wheel hub 51 and the wheel bearing 52, in the separation mode (Fig. 5a-b), the jaw units 1 act as counter-holds against a portion of the wheel bearing 52 while the wheel hub 51 is pressed out of the wheel bearing 52. The concave engagement edge of the jaw units 1 serve to maximize the contact surface between the jaw units 1 and the wheel bearing 52. The wheel hub 51 is pressed out by arranging a bolt 54 on the pressing/pulling rod 53 which pushes the wheel hub 51 towards the hydraulic cylinder 50 when the rod 53 is pulled into the cylinder body.
The invention has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting to the claim. The word "comprising" does not exclude the presence of other elements or steps than those listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

Claims

A jaw unit (1) for attachment to a supporting member (45) of a dismounting tool (40) for separating a wheel hub (51) from a wheel bearing (52), said dismounting tool having a separation mode and a pull mode, wherein said jaw unit comprises:
a foot section (2);

a stem section (3) having two ends and comprising a contact portion (4) arranged at a first end of said two ends for attachment to the supporting member (45), and wherein said foot section is connected to said stem section at a second end of said two ends, said foot section extending in an engaging direction (102) which is substantially perpendicular to a longitudinal axis (101) of said stem section so to form an L-shaped structure together with said stem section (3);

wherein the foot section comprises a toe portion (5) at a distal end of the foot section, said foot section (2) and said toe portion having a planar top surface (7) and a substantially tapered cross-section taken in a plane spanned by said longitudinal axis (101) of the stem section and said engaging direction (102), so that, when in the separation mode, the wheel hub is separated from the wheel bearing when said jaw unit (1) is moved in the engaging direction into an intermediate space between the wheel hub and the wheel bearing; and

wherein the toe portion (5) further has a concave engagement edge (6) arrangeable around at least a portion of a cylindrical section of said wheel hub, so that, when in the pull mode, the jaw unit (1) acts as a counter hold when the wheel hub is moved relative to the wheel bearing (52) in a direction substantially parallel to the longitudinal axis (101) of said stem section (3).
The jaw unit (1) according to claim 1, wherein the substantially tapered cross-section of said toe portion (5) comprises a front section towards the engaging direction (102) and a back section towards the second end of the stem section (3) and wherein the front section has a steeper inclination (21', 22') than the back section.
The jaw unit (1) according to claim 1 or 2, wherein the foot section (2) has a substantially planar top surface (7) on the side facing towards the stem section (3), and wherein an angle between the longitudinal axis of the stem section and the top surface is less than 90 degrees.
The jaw unit (1) according to any one of the preceding claims, wherein the foot section (2) further comprises at least one stopping member (8) arranged on a side facing away from the stem section (3) in order to stop the foot section (2) from moving further than a predefined distance into the intermediate space between the wheel hub (51) and the wheel bearing (52) in the engaging direction (102).
The jaw unit (1) according to any one of the preceding claims, wherein the stem section (3) comprises a through hole (9) having a central axis substantially parallel with the engaging direction (102), for placement of a rod (53) of an actuating tool (50) when in the separation mode.
The jaw unit (1) according to any one of the preceding claims, wherein said contact portion (4) comprises a substantially planar contact surface (10), wherein said contact surface is arranged so to form an angle with the longitudinal axis (101) of the stem section that is less than 90 degrees, said angle being located towards the engaging direction (102) of the stem section.
The jaw unit (1) according to claim 6, wherein said contact surface (10) is treated in order to reduce friction the jaw unit is fastened to the supporting member (45) and moved along and in contact with the supporting member.
A dismounting tool (40) having a separation mode and a pull mode for dismounting a wheel hub (51) from a wheel bearing (52), said dismounting tool comprising:
a supporting member (45);

two jaw units (1) according to any one of the preceding claims;

at least one securing element (41) for fastening each jaw unit to said supporting member; and

wherein the jaw units are arranged with the foot sections (2) facing each other, such that, in said separation mode, the toe portions (5) are moved towards each other into an intermediate space between the wheel hub and the wheel bearing in order to separate the wheel hub from the wheel bearing
The dismounting tool (40) according to claim 8, wherein the contact portion (4) of the stem section (3) comprises a guide portion (14) engagable with a matching contact section (44) of the supporting member (45), for allowing a non-rotational, sliding movement of the jaw unit (1) along the supporting member.
The dismounting tool (40) according any one of claims 8-9, wherein said supporting member (45) comprises a pair of elongated openings (46) and wherein said at least one securing element is at least one threaded bolt (41) insertable through said elongated openings in order to engage a matching bore hole (11) provided in the contact portion of each jaw unit.
The dismounting tool (40) according to any one of the claims 8-10, wherein said supporting member (45) comprises a centrally located opening (43) and wherein the opening has a central axis substantially coinciding with a central axis of the wheel bearing in order to enable placement of a rod (53) of an actuating device (50) when said dismounting tool is used in the pull mode.