MXPA99005695A - Improved wheel hub for longer wheel life - Google Patents

Abstract

A wheel hub is provided for use in combination with conventional depressed center grinding wheels. The hub includes a generally cylindrical aperture bushing. A disc shaped flange extends radially from a medial portion of the bushing and terminates at a peripheral lip. The bushing is adapted to extend through a central bore of the wheel so that the lip engages the backing face of the wheel proximate an outermost circumference of the depressed center. A grinding face end of the bushing is flangeable radially outward to engage the front grinding face of the wheel and mechanically capture the wheel between the grinding face end and the flange. The flange, lip and backing face form a cavity into which epoxy resin is placed to chemically bond the hub to the wheel. The combination of mechanical fastening and chemical bonding adequately secures the hub to the wheel, nominally without requiring the flange to extend over the stub. The present invention thus advantageously enables the wheelto be ground nominally to the stub, to provide improved wheel utilization.

Description

IMPROVED WHEEL BEARING PARAVIDA OF MORE DURABLE WHEEL BACKGROUND OF THE INVENTION FIELD OF THE INVENTION This invention relates to abrasive grinding wheels, and more particularly to an improved wheel hub for mounting a grinding wheel to a grinding apparatus.

BACKGROUND INFORMATION The grinding machines that use abrasive grinding wheels mounted on them can be used to perform many different grinding operations. The varied operations have led to the development of a wide variety of shapes and sizes of the grinding wheel. One type of grinding wheel in particular is the wheel with depressed center, characterized in that the central portion of the wheel is compensated in axial direction from the periphery of the wheel. The wheel thus has a concave-convex stop portion, in which a grinding surface has a depressed or concave central portion and an opposing reinforcing surface has a raised or convex central portion. This design allows the user to perform surface grinding operations using the grinding surface that has the central portion depressed. Frequently, such operations are carried out on surfaces of metal, masonry or concrete and the like, using portable grinding machines. Wheels with depressed centers are classified by the American National Standards Institute (ANSI) as type 27 and 28 ground wheels. The means by which a grinding wheel is secured to the axis of the grinding machine are particularly important in the case of wheels with depressed center. In general, the mounting means must be capable of supporting the wheel perpendicular to the axis during the grinding operations, and must provide support to the wheel to distribute the stresses away from the central mounting opening, where tensions tend to be concentrated. The mounting means must also be firmly secured to the abrasive wheel, to prevent any slippage between them. In addition, the mounting means for the type 27 and 28 wheels have generally been provided with extra support for the periphery of the wheel, as well as for the central portion of the reinforcement surface (not grinder) of the wheel to withstand stresses additional costs imposed by surface grinding operations. To meet these requirements, it is common to provide type 27 and 28 wheels with a hub having a flange that extends over the raised center portion, the concave-convex stop portion, and over and in contact with the peripheral portion of the wheel , to resist lateral pressure or otherwise the uneven force applied to the grinding surface of the wheel. The opposite surface of the wheel is provided with a flange contained completely within the depressed area thereof. Although said hub construction can produce satisfactory results in many cases, it is not without disadvantage. In particular, the extension of the flange beyond the high stop portion of the reinforcing surface tends to limit the life of the wheel. In this regard, the wheel must be replaced before it is lowered to the diameter of the reinforcing flange to avoid potentially damaging contact between the reinforcing flange and the workpiece. Accordingly, the grinding wheels that use this hub construction tend to be discarded, a substantial portion of the valuable and otherwise usable abrasive remaining thereon. Said lower relative use of the wheel tends to add an inconvenient cost to the grinding operations in terms of the cost of the wheel and the labor costs associated with the frequency of removal and installation of the same. There is thus a need for an improved grinding wheel hub that overcomes the drawbacks of the prior art.

BRIEF DESCRIPTION OF THE INVENTION In accordance with one embodiment of this invention, a grinding wheel hub is provided for mounting an abrasive grinding wheel on a grinding apparatus. The hub is adapted for use with an abrasive grinding wheel of the type having a mounting opening centrally disposed therein, and a grinding surface and a reinforcing surface disposed on opposite sides of the abrasive grinding wheel. The grinding wheel hub includes an opening bushing of substantially cylindrical configuration, adapted for extension through and in engagement with, the surface of the mounting opening. A grinding surface fastener is disposed on the opening bushing and adapted to extend radially outwardly from the mounting opening to mesh with the grinding surface of the wheel. A reinforcing flange of substantially diskid shape extends radially outwardly from the opening bushing member, and is adapted to be superimposed with the reinforcing surface. An annular gear surface is located along the periphery of the reinforcing flange, and is adapted to mesh with the reinforcing surface of the wheel. The reinforcement flange has a bonding surface adapted to face the reinforcement surface, and is dimensioned and configured to provide a cavity between the reinforcement flange and the reinforcement surface of the grinding wheel when the annular gear surface meshes with the reinforcement flange. reinforcement surface. The cavity is adapted to receive a binder therein for attaching the grinding wheel hub to the abrasive grinding wheel. The present invention provides, in a second aspect, a grinding wheel assembly adapted to be mounted on a grinding apparatus. The assembly includes an abrasive grinding wheel having a depressed center, a mounting opening centrally disposed therein, and a grinding surface and a reinforcing surface disposed on opposite sides of the abrasive grinding wheel. The assembly also includes a grinding wheel hub of the invention and a mechanical and chemical bond between the hub and the wheel. In a third aspect of the present invention, there is provided a method for mounting an abrasive grinding wheel on a grinding apparatus, the abrasive grinding wheel having a mounting opening disposed centrally therein, and a grinding surface and a reinforcing surface disposed on opposite sides of the abrasive grinding wheel. The method includes providing a grinding wheel hub having an opening bushing of substantially cylindrical configuration, adapted for extension through and in engagement with, the surface of the mounting opening. A grinding surface fastener is disposed on the opening bushing and is adapted to extend radially outwardly from the mounting opening to mesh with the grinding surface of the wheel. A reinforcing flange of substantially discoid shape is disposed on the opening bushing member, extending radially outwardly thereof, and is adapted to be superimposed with the reinforcing surface. The reinforcement flange is provided with a joint surface adapted to face the reinforcement surface. An annular gear surface is provided along a periphery of the reinforcing flange, and is adapted to mesh with the reinforcing surface of the wheel. A binding agent is applied to the surface adapted to face the reinforcement surface. The opening bushing is subsequently inserted through and in engagement with, the surface of the mounting aperture, so that the annular gear surface is engaged with the reinforcing surface of the wheel. The fastener of the grinding surface is then engaged with the grinding surface of the wheel, so that the wheel is captured between the fastener of the grinding surface and the reinforcement flange, and the binding agent joins the grinding wheel hub to the wheel . The foregoing and other features and advantages of this invention will be more readily apparent upon reading the following detailed description of various aspects of the invention, considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of the wheel hub in accordance with the present invention; Figure 2 is an elevation and cross-sectional view of the wheel hub of the present invention, taken along line 2-2 of Figure 1; Figure 3 is a view similar to that of Figure 2 of the present invention on an enlarged e, with separate portions and portions thereof shown in imaginary lines; Figure 4 is a bottom view of the wheel hub of Figures 1 and 2, with portions thereof shown in imaginary lines; Figure 5 is a schematic enlarged cross-sectional view taken along line 5-5 of Figure 4, with portions thereof separated; and Figure 6 is a view similar to that of Figure 2, where the wheel hub is fully installed in a mounting aperture of a grinding wheel.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES Briefly described, the invention includes a wheel hub 10 for use in combination with a conventional depressed center grinding wheel 12 (Fig. 6) having a generally flat depressed center 13, concave-convex stop portion 23, and nominally grinding portion. 25. The wheel hub 10 (Fig. 2) includes a generally cylindrical opening bushing 14. A disc-shaped flange 16 extends radially from a middle portion of the bushing, and terminates in a peripheral lip 18. The bushing 14 (Fig. 6) is adapted to extend through the central hole 21 of the wheel 12, so that the lip 18 engages with the reinforcing surface 32 of the wheel close to an outermost circumference of the depressed center 13, or the joint of the depressed center 13 and the stop portion 23 as shown in the shoulder 30. One end of the grinding surface 29 (Fig. 2) of the bushing 14 is radially outwardly beveable to engage with the surface is front grinder 34 of the wheel 12, and mechanically capture the wheel between the end of the grinding surface 29 and the flange 16. The flange 16, the lip 18 and the reinforcing surface 32 form a cavity 20 in which an adhesive, such as an epoxy resin, it is placed to chemically bond the hub 10 to the wheel 12. This combination of mechanical fastening and chemical bonding suitably ensures the hub to the wheel without requiring the flange 16 to extend over the stop 23 and / or over the grinding portion 25. The present invention thus advantageously allows the wheel 10 to be nominally lowered completely up to the stop 23, to provide for improved utilization of the wheel with respect to the prior art. For purposes of definition throughout this description, the terms "axial" and "coaxial" will refer to a direction substantially parallel to the axis of rotation of the wheel hub 10 and / or the grinding wheel 12. The terms "transverse" and "radial" will refer to directions substantially orthogonal to the axial or coaxial direction. Referring now to the drawings in detail, as shown in Figures 1 and 2, the opening bushing 14 is substantially cylindrical, extending from the end of the grinding surface 29 to the end of the reinforcing surface 28 (Fig. 2). ). The end of the reinforcing surface 28 is provided with a hexagonal head 31. A central hole 26 extends axially along the length of the bushing. The bushing has a predetermined outside diameter d sufficient to allow the end of the grinding surface 29 of the bushing 14 to be received slidably within the central opening 21 of the grinding wheel 12 (Fig. 6). The central hole 26 and the hexagonal head 31 facilitate attachment of the wheel hub 10 to a conventional grinding apparatus (not shown) in a manner familiar to those skilled in the art. The disk-shaped flange 16 extends radially from a middle portion of the bushing 14, and ends in a peripheral lip 18. The lip 18 is generally cylindrical, depending on the flange 16 in the axial direction towards the end of the grinding surface 9 of the bushing. The lip 18 thus provides a flange 16 with a generally concave surface, including the cavity 20, which faces the end of the grinding surface 29 of the hub 14. The cavity 20 is adapted to receive a binder such as an epoxy resin in the same, to chemically join the hub 10 to the grinding wheel 12 as will be described later. The lip 18 terminates in an annular wheel gear surface 22 adapted to mesh with the reinforcing surface 32 of the grinding wheel 12. In a preferred embodiment, as shown, the surface 22 meshes with the reinforcing surface 32 close to the junction of the depressed center 13 and the stop portion 23, or the shoulder 30, as shown in Figure 6. As best shown in Figure 3, an axial cross section of the wheel gear surface 22 is preferably disposed at a predetermined oblique angle to the radial direction. Since the hub 10, including the wheel gear surface 22, is symmetric about the axis a, the angle a thus provides a surface 22 with a generally frusto-conical configuration. The angle is nominally determined to level the curvature of the angle a of the reinforcing surface 32 at the gear point therewith, as will be described in greater detail below. In a preferred embodiment, as shown, the angle is approximately 19 degrees. The size of the wheel gear surface 22 is predetermined to provide a contact area between the surface 22 and the reinforcing surface 32, sufficient to nominally prevent the loss of epoxy resin from the cavity 20 once the hub is installed on the wheel 12, as shown in figure 6. Furthermore, the cavity 20 is provided with a predetermined axial dimension d to minimize the thickness of the epoxy resin layer disposed therein, while providing sufficient free space to nominally avoid the direct contact between the flange 16 and the reinforcing surface 32. In this respect, the dimension d preferably varies as a function of the radial distance from the opening bushing 14, where said dimension is relatively large immediately to the bushing 14, and decreases progressively towards the lip 18. This variation requires a larger free space due to washers or increased wheel thickness next to the central opening 21, and a smaller clearance to the edge of the depressed center 13 as the reinforcing surface 32 begins to hunch or move away from the flange 16 in the concave-convex stop portion 23. Referring now to FIGS. 5, the flange surface 16 defining the cavity 20 is provided with a series of discontinuities or grooves 24 which serve to increase the surface area of contact with the epoxy resin. In a preferred embodiment, as shown, the discontinuities 24 comprise a plurality of substantially V-shaped or radially extending sawtooth-shaped slots, as shown in Figure 5. The slots are preferably spaced apart around the tab at an angular range of approximately 3 degrees. The contact surface area increased with the epoxy resin serves to advantageously decrease the force per unit area generated between the resin and the hub during the grinding operations. This serves to effectively increase the total amount of force that the combination of the wheel and the mace is able to withstand. The hub 10 can be manufactured from any number of materials capable of providing the necessary structural characteristics such as, for example, an alloy or metallic material. In a preferred embodiment, the hub 10 is made of a steel alloy of relatively high zinc content. An example of a suitable material is a zinc alloy marketed under the trademark "Zamac 3" available from Celtio Metal, Inc., Sapula, Oklahoma. The hub can be formed by any convenient method, including, for example, casting, forging or powder metal forming. In a preferred embodiment, the hub 10 is formed by casting. The hub 10 is installed on the wheel 12 filling the cavity 20 with a suitable binder such as an epoxy resin as described above. The end of the grinding surface 29 (Fig. 1) of the bushing 14 is then inserted into the central opening 21 of the wheel 12., until the wheel gear surface 22 meshes with the reinforcing surface 32 of the wheel, nominally at the shoulder 30 thereof, as shown in Fig. 6. Once this is arranged, the end of the surface grinder 29, which extends a predetermined distance beyond the grinding surface 34, is then stamped or flanged in a conventional manner to extend the walls thereof radially outward and form an annular flange 36, as shown in the figure 6. The molding 36 serves to engage the grinding surface 34 around the perimeter of the central opening 21 to capture the wheel 12 between the molding and the flange 16 and thus complete the assembly of the hub 10 on the wheel 12. After After sufficient time has elapsed to allow the epoxy resin to be cured, the hub and wheel assembly can be used in a conventional manner in combination with a grinding apparatus. As shown in Figure 6 and as described above, the diameter of the flange 16, including the lip 18, is predetermined to be substantially coextensive with that of the depressed center 13 of the wheel 12. In this regard, the lip 18 is Nominally extends to the shoulder 30 disposed at the junction of the depressed center 13 and the stop portion 23. In a preferred embodiment as shown, the lip 18 is provided with a diameter of approximately 5 cm to be used on an ANSI type wheel. 27 conventional 11.4 cm diameter. It is also contemplated that a 5 cm diameter hub may be used in conjunction with a type 27 wheel of 12. 7 cm in diameter. In the preferred embodiment of type 27 wheel, the coaxial height of the lip 18 is 0.46 cm, resulting in a cavity 20 for the binder having a coaxial dimension cM of 0.21 cm in the lip 18. The flange 16 used in this embodiment contains slots 24 to increase the bonding surface area. In an alternative embodiment of the type 27 wheel, assembled without slots 24 in the flange 16, the coaxial dimension of the cavity is 0.05 cm in the lip 18, to ensure the attachment of the flange 16 to the reinforcing surface 30 of the wheel 12. As described above, the wheel gear surface 22 is preferably disposed at an oblique angle to about 19 degrees to level the curvature of the reinforcing surface 32 of a type 27 wheel of 11.4 cm diameter to a diameter of about 5 cm thereon. In case the 5 cm hub is used in combination with a type 27 wheel of 12.7 cm diameter, the angle α may be reduced, as required, to facilitate the surface engagement: surface of the surface 22 with the reinforcement surface thereof. The present invention thus safely engages the wheel 12 with a relatively small overall diameter, nominally without overlapping the flange 16 on the stop portion 23 and / or the grinding portion 25. This feature allows the wheel to be grinded up to the stop 23 without There is a risk of accidental contact of the hub 10 with the work piece. This invention thus allows the improved wheel to be used for a longer period of time compared to the prior art hub configurations, which typically engage the wheel above and radially beyond the concave-convex or abutment portions thereof. In this regard, it has been shown that the present invention provides an increase of approximately 10% in the life of the wheel with respect to the wheels of the prior art. Although the grinding wheel hub of the present invention has been demonstrated and described in combination with grinding wheels with depressed center, the person skilled in the art should recognize that the hub can be used in combination with grinding wheels of substantially any configuration including, but not limited to. a, conventional cup wheels, disc wheels, depressed wheels, type wheels 27 and 28, or any other grinding wheel having a depressed center and a central mounting aperture, without departing from the spirit and scope of the present invention.

Claims (24)

NOVELTY OF THE INVENTION CLAIMS

1. - A grinding wheel hub (10) for mounting an abrasive grinding wheel (12) having a depressed center (13) on a grinding apparatus, the abrasive grinding wheel (12) having a mounting opening (21) centrally disposed in the same, and a grinding surface (25) and a reinforcing surface (32) disposed on opposite sides of the abrasive grinding wheel (12), said grinding wheel hub (10) characterized in that it comprises: an opening bushing (14) of substantially cylindrical configuration, adapted for coaxial extension through and in engagement with, the surface of the mounting opening (21); a grinding surface fastener (29, 36) disposed on said opening bushing (14) and adapted to mesh with the grinding surface (34) of the wheel; a reinforcing flange (16) extending substantially radially outwardly from said opening bushing member (14), and adapted for alignment superimposed with the reinforcing surface (32); an annular gear surface (22) disposed along a periphery (18) of said reinforcing flange (16), and adapted for surface engagement: surface with the reinforcing surface (32) of the wheel (12); said reinforcement flange (16) having a joining surface (22) adapted to face toward the reinforcing surface (32); said joining surface (22) being dimensioned and configured to provide a cavity (20) between said reinforcing flange (16) and the reinforcing surface (32) of the grinding wheel (12) when said annular gear surface (22) is engaged with the reinforcing surface (32), the cavity (20) being adapted to receive a binding agent thereon for joining said grinding wheel hub (10) to the abrasive grinding wheel (12).

2. The grinding wheel hub (10) according to claim 1, further characterized by an abrasive grinding wheel (12) is mounted on the grinding wheel hub (10) and: the abrasive grinding wheel (12) further includes a depressed substantially flat center (13), the mounting opening (21) being centrally disposed within the depressed center (13). ); said reinforcing flange (16) has a substantially concave surface adapted to face toward the reinforcing surface (32); and said annular gear surface (22) is adapted to mesh with the reinforcing surface (32) of the wheel (12) proximate a circumference more external to the depressed center (13).

3. The grinding wheel hub (10) according to claim 1, further characterized in that said fastener of the grinding surface comprises one end of the grinding surface (29) of said opening bushing (14), said end of the grinding surface being adapted to be flanged radially outwardly from the mounting opening (21) to mesh with the grinding surface (34).

4. - The grinding wheel hub (10) according to claim 2, further characterized in that it comprises a peripheral lip (18) that substantially axially depends on a terminal circumference of said flange (16), said peripheral lip (18) terminating in said annular gear surface (22).

5. The grinding wheel hub (10) according to claim 4, further characterized in that said reinforcing flange (16) and said peripheral lip (18) define said substantially concave surface.

6. The grinding wheel hub (10) according to claim 5, further characterized in that the cavity (20) is defined by said opening bushing member (14), said reinforcing flange (16) and said peripheral lip (18), in combination with the reinforcing surface (32) of the abrasive grinding wheel (12).

7. The grinding wheel hub (10) according to claim 1, further characterized in that the binder is disposed within the cavity (20) for attaching the grinding wheel hub (10) to the abrasive grinding wheel (12).

8. The grinding wheel hub (10) according to claim 1, further characterized in that said flange (16) further comprises a plurality of surface irregularities (24) adapted to provide a textured surface area to mesh with the adhesive .

9. The grinding wheel hub (10) according to claim 8, further characterized in that said plurality of surface irregularities (24) comprises a plurality of grooves extending radially from said opening (21).

10. The grinding wheel hub (10) according to claim 2, further characterized in that said annular gear surface (22), in an axial cross section thereof, is disposed at an oblique angle with respect to the direction coaxial, said annular gear surface (22) being adapted for superimposed gear with a portion of the reinforcing surface (32).

11. The grinding wheel hub (10) according to claim 10, further characterized in that said annular gear surface (22) is disposed at an angle of approximately 19 degrees with respect to the coaxial direction.

12. The grinding wheel hub (10) according to claim 11, further characterized in that an abrasive grinding wheel (12) is mounted on the grinding wheel hub (10), and the abrasive grinding wheel (12) includes a substantially depressed depressed center (13) moving away in a radially outward direction in a substantially concave-convex stop portion (23), the generally concave-convex stop portion (23) moving radially outwardly therefrom in a portion grinder (25), said annular gear surface (22) being adapted to mesh with the reinforcing surface (32) of the abrasive grinding wheel (12) proximate the distance from the depressed center (13) in the concave-convex stop portion (2. 3).

13. - The grinding wheel hub (10) according to claim 12, further characterized by the abrasive grinding wheel (12) comprises an ANSI type 27 wheel.

14. The grinding wheel hub (10) according to claim 7, further characterized in that the binder is an epoxy resin adhesive.

15. A grinding wheel assembly (fig.6) adapted to be mounted on a grinding apparatus, characterized in that it comprises: an abrasive grinding wheel (12) having a depressed center (13) and a mounting opening (21) arranged centrally therein, and a grinding surface (25) and a reinforcing surface (32) disposed on opposite sides of the abrasive grinding wheel (12); the grinding wheel hub (10) according to claim 1; and a binder between the reinforcing surface (32) and the wheel hub (10).

16. A method for mounting an abrasive grinding wheel on a grinding apparatus, the abrasive grinding wheel (12) having a substantially flat depressed center (13), a mounting opening (21) centrally disposed within the depressed center, and a surface grinder (25) and a reinforcing surface (32) disposed on opposite sides of the abrasive grinding wheel (12), said method comprising: providing a grinding wheel hub (10) having an opening bushing (14) of substantial configuration cylindrical, adapted for coaxial extension through and in engagement with, the surface of the mounting opening (21); inserting the opening bushing (14) through and in engagement with, the surface of the mounting opening (21); making a grinding surface fastener (36) on the opening bushing (14) by flanging one end of the opening bushing (14) to engage a portion of the grinding surface (25) of the wheel (12) within the depressed center of the wheel (13); applying a binding agent to a joining surface of a reinforcing flange (16), the reinforcing flange (16) having a substantially discoid shape and an annular gear surface (22) along an outermost circumference of said flange of reinforcement (16), and the joining surface being adapted for alignment superimposed with the reinforcing surface (32) of the abrasive wheel (12); arranging the reinforcement flange (16) on the opening bushing (14) to mesh with the annular gear surface (22) with the reinforcing surface (32) of the wheel (12); wherein the wheel (12) is captured between the grinding surface holder (36) and the reinforcing flange (16), and the binding agent joins the reinforcing flange (16) of the grinding wheel hub (10) to the reinforcement surface (32) of the wheel (12).

17. The method according to claim 16, further characterized in that: the abrasive grinding wheel (12) has a depressed substantially flat center (13), said mounting opening (21) being centrally disposed within said depressed center (13). ); said step of providing the reinforcing flange (16) with a joining surface further comprises the step of providing the reinforcing flange (16) with a substantially concave surface adapted to receive the binder therein; and said annular gear surface (22) is adapted for surface gear: surface with the reinforcing surface (32) of the wheel (12) next to a periphery of the depressed center (13).

18. The method according to claim 17, further characterized in that said step of providing the reinforcing flange (16) with a concave surface further comprises the steps of providing a peripheral lip (18), substantially axially depending on a terminal circumference of said flange (16), and terminating the peripheral lip (18) on the annular gear surface (22).

19. The method according to claim 16, further characterized in that the binder comprises an epoxy resin.

20. The method according to claim 16, further characterized in that it comprises the step of providing the concave surface with a plurality of surface irregularities (24) adapted to provide a textured surface area to mesh with the binder.

21. The method according to claim 19, further characterized in that said plurality of surface irregularities (24) comprises a plurality of grooves extending radially from said opening.

22. - The method according to claim 16, further characterized in that the annular gear surface (22) is in gear superposed with a portion of the reinforcing surface (32).

23. The method according to claim 22, further characterized in that said annular gear surface (22), in an axial cross section, is disposed at an oblique angle with respect to the axial direction of said hub (10), said surface of annular gear (22) being adapted for superposed gear with a portion of the reinforcing surface (32) disposed at an oblique angle with respect to the axial direction of the abrasive grinding wheel (12).

24. A grinding wheel hub (10) for mounting an abrasive grinding wheel (12) on a grinding device, the abrasive grinding wheel (12) having a substantially flat depressed center (13), a mounting opening (21) disposed centrally within the depressed center (13), and a grinding surface (25) and a reinforcing surface (32) disposed on opposite sides of the abrasive grinding wheel (12), said grinding wheel hub (10) comprising: a bushing opening (14) of substantially cylindrical configuration, adapted for coaxial extension through and in engagement with, the surface of the mounting opening (21); a grinding surface fastener (36) disposed on said opening bushing (14) and adapted to mesh with the grinding surface (25) of the wheel (12); a reinforcement flange (16) of substantially discoid shape extending radially outwardly from said opening bushing member (14), and adapted for alignment superimposed with the reinforcement surface (32); said reinforcing flange (16) having a substantially concave surface adapted to face toward the reinforcing surface (32); an annular gear surface (22) disposed along a periphery of said reinforcing flange (16) and adapted for surface engagement: surface with the reinforcing surface (32) of the wheel (12) proximate to a further circumference external of the depressed center (13); characterized further in that said substantially concave surface of said flange (16) provides a cavity (20) between said reinforcing flange (16) and the reinforcing surface (32) of the grinding wheel (12) when said annular gear surface (22) ) is engaged with the reinforcing surface (32), the cavity (20) being adapted to receive a binder therein for joining said grinding wheel hub (10) to the abrasive grinding wheel (12).