GB2130536A - Hub sleeve for a cycle hub - Google Patents

Abstract

The sleeve body (21) is formed as a one-piece light metal die-casting, on which two spoke flanges (23, 25) are cast or secured. On the inner circumference of the sleeve body (21) there are cast seating surfaces (33, 37) for ball bearing shells (31, 39) which are fixed axially by stop faces (35, 45) facing axially away from one another. At least one (45) of the two stop faces is provided on radially inwardly protruding ribs (43) formed integrally on the sleeve body (21) and arranged axially between the seating surfaces (33, 37); their stop face (45) merges in each case into a pocket (41) which is sunk radially outwards into the adjacent seating surface (37). While the seating surfaces (33, 37) are shaped by one common core of the same die-casting mould half, the pockets (41) in each case receive the cores of the other mould half which shape the stop face (45). The mould halves can shift radially during the die- casting without affecting the concentricity of the seating surfaces (33, 37). <IMAGE>

Description

SPECIFICATION Hub sleeve for a cycle hub BACKGROUND TO THE INVENTION The invention relates to a hub sleeve for a cycle hub and especially a hub sleeve of which the sleeve body is formed as a light metal die-casting.

It is known to cast hub sleeves for cycles or the like by the die-casting method from light metal, for example aluminum. Such hub sleeves are mounted rotatably with two ball bearings on a hub spindle. Seating surfaces for the outer bearing shells of the two ball bearings or race tracks for the balls are cast on the sleeve body. The die-casting mould in which the sleeve body is cast has at least two mould halves which as a rule cannot be aligned exactly radially of the sleeve axis.

Especially after some use the mould halves can be closed only with radial offsetting. If the seating surfaces or race tracks of the two ball bearings were to be moulded in different casting mould halves, this would result in defects of alignment of the ball bearings. In this case the seating surfaces would have to be subjected to finishing work, which is not desired. The finishing working of the diecasting should be as slight as possible and consist essentially only of a burr removal.

It is further known to form the seating surfaces for the bearing shells of the two ball bearings on one common mould half of the casting mould. In order that this mould half may be removed from the die-casting no undercuts may be present. On the other hand it must be possible to brace the two bearing shells axially against one another in order that the hub sleeve may be fixed in the axial direction on the hub spindle. In conventional hub sleeves therefore at least one of the two bearing shells had to be provided with a radially protruding collar which bears on an axial surface of the sleeve body. The additional support collar of such bearing shells is undesired since it increases the expense of manufacture.

OBJECT OF THE INVENTION It is an object of the invention to provide a hub sleeve for a cycle hub the sleeve body of which is formed as a one-piece die-casting, namely so that it is possible to use bearing shells without radial support collars.

SUMMARY OF THE INVENTION In the hub sleeve in accordance with the invention the seating surfaces of all bearing shells and race tracks if provided are formed as hitherto by means of a common casting mould half. The stop surface for the bearing shell collar, provided hitherto on the side of the bearing shell seating surface axially re mote from the other ball bearing is provided according to the invention on the side of the bearing shell seating surface axially facing the other ball bearing. The radially protruding bearing shell collar provided in conventional hub sleeves can thus be eliminated. The bearing shell rests on the axial front faces of several ribs arranged in distribution over the internal periphery of the sleeve body. Recesses or pockets are sunk, in the region of the ribs seen in the circumferential direction, into the seating surface extending axially beside the ribs.While the ribs, except for their axial front face serving as stop, are moulded together with the seating surfaces by means of the one casting mould half, the recesses formed into the seating surface and the axial front faces of the ribs are moulded by the other casting mould half. The casting mould halves no longer must be aligned radially exactly in relation to one another, since the recesses sunk into the seating surfaces take up the radial offsetting of the casting mould halves, without influencing the concentricity of the seating surfaces.

BRIEF DESCRIPTION OF DRAWINGS Examples of embodiment of the invention are to be explained in greater detail hereinafter by reference to drawings, wherein: Figure 1 shows an axial longitudinal section through a conventional hub sleeve; Figure 2 shows an axial longitudinal section through a hub sleeve in accordance with the invention, the bearing shells of which have diameters of different sizes, seen along a line Il-Il in Fig. 3; Figure 3 shows an end view of the hub sleeve seen in the direction of an arrow Ill in Fig. 2; Figure 4 shows a detail view of the hub sleeve seen in the direction of an arrow IV in Fig. 3; Figure 5 shows an axial longitudinal section through a die-casting mould for the production of the hub sleeve according to Figs. 2 to 4;; Figure 6 shows an axial longitudinal section through a hub sleeve according to the invention, the bearing shells of which have substantially equal diameters, seen along a line VI-VI in Fig. 7; Figure 7 shows an end view of the hub sleeve seen in the direction of an arrow VII in Fig. 6; Figure 8 shows another end view of the hub sleeve seen in the direction of an arrow VIII in Fig. 6 and Figure 9 shows a detail view of the hub sleeve seen along a line IX-IX in Fig. 7.

DESCRIPTION OF PREFERRED EMBODI MENTS Fig. 1 shows a conventional hub sleeve for a cycle. The hub sleeve has a hub body 3 of sleeve form formed in one piece together with a spoke flange 1 as a light metal die-casting, to which body a second spoke flange 5 is secured with axial spacing. In the region of the axially opposite ends of the sleeve body 3, annular seating surfaces 7, 9 are cast on coaxially with one another. In the seating surfaces 7, 9 bearing shells 11, 1 3 are seated with press fit, the inward curvatures of which face away from one another. The bearing shell 11 has a larger diameter than the bearing shell 1 3 and lies with its base wall against a stop face 1 5 of the sleeve body 3.Since the entire interior of the sleeve body 3 is formed without undercutting by a common casting, for the axial fixing of the bearing shell 1 3 a radially outwardly extending annular flange or collar 1 7 is formed on the outer edge of the shell 1 3 and abuts on the adjacent axial end face of the sleeve body 3. The collar 1 7 increases the production expense of the bearing shell 13.

Figs. 2 to 4 show a hub sleeve with collarless bearing shells, that is bearing shells having no stop face serving for axial fixing, radially outside their seating surface serving for radial fixing. The hub sleeve comprises a sleeve body 21 formed as one-piece light metal die-casting on to the external circumference of which a spoke flange 23 is integrally cast in the region of one of the two axial ends. A second spoke flange 25, represented in dot-and-dash lines, is subsequently secured at a distance from the spoke flange 23 on an annular seating surface 27 in the region of the other end of the sleeve body 21. A bearing shell 31, entered in dot-and-dash lines, of a ball bearing, the inner bearing taper and balls of which are not represented further, is seated in an annular surface 29 in the region of the spoke flange 23.The annular surface 29 forms a radially inwardly facing seating surface 33, which radially guides the bearing shell 31 and merges, with reduction of its diameter, into an axially outwardly facing annular shoulder 35. The bearing shell 31 is axially fixed on the annular shoulder 35.

At the axially opposite end of the sleeve body 21 there is formed a radially inwardly facing seating surface 37 for the radial guidance of a bearing shell 39, entered in dotand-dash lines, of a second ball bearing The balls and the bearing taper of the second ball bearing are not illustrated. The bearing shell 39 is seated with press fit in the seating surface 37. Into the seating surface 37 there are formed three pockets 41, offset by 120 in relation to one another in the circumferential direction, the purpose of which will be explained in greater detail below. On the side of each pocket 41 facing the other seating surface 33 there follows in the axial direction a rib 43 cast integrally on the sleeve body 21.

Each of the ribs 43 has an axially outwardly facing stop face 45, merging into the adjacent pocket 41, for the axial fixing of the bearing shell 39, which likewise has no stop collar.

The end faces 45 and the annular shoulder 35 face axially outwards away from one another, so that the cones of the two ball bearings can be braced axially against one another and the hub sleeve can be fixed axially on the hub spindle.

Fig. 5 shows a die-casting mould, consisting of two mould halves 51 and 53, for the production of the sleeve body 21. For the outer shell of the sleeve body 21 the mould halves 51, 53 are divided transversely of the sleeve axis in the region of the cast-on spoke flange 23. The spoke flange 23 forms the largest external diameter of the die casting. In every axial longitudinal plane including the sleeve axis the radial distance of each point of the outer peripheral surface of the hub sleeve body 21 from its axis of rotation is so dimensioned that with increasing axial distance from the maximum external diameter of the spoke flange 23 it exclusively decreases or at least remains constant, so that the two mould halves 51, 53, as far as the external peripheral surface is concerned, may be removed axially.The inner peripheral surface of the sleeve body 21 is substantially determined by a core projection 55 of the mould half 51.

The core projection shapes the two seating surfaces 33 and 37 for the reception of the bearing shells 31, 39. It further comprises recesses 57 for the shaping of the ribs 43.

The recesses 57 continue to the free end of the core projection 55 and in turn each receives a core projection 59 of the mould half 53. Each core projection 59 shapes the axial stop face 45 of the rib and the pocket 41 adjoining the stop face 45. The two mould halves 51, 53 can shit slightly radially in relation to one another without this influencing the coaxiality of the seating surfaces 33, 37. The offsetting is taken up by the pockets 41. For the sake of completeness in Fig. 4 the mould division limits corresponding to the core projection 59 and coinciding with the margins of the pockets 41 are entered at 60.

In conformity with the outer shell, the inner periphery of the sleeve body 21 is moulded with no undercutting. In every longitudinal axial plane which includes the sleeve axis the radial distance, starting from a point with minimum axial distance, exclusively increases or remains constant with increasing axial distance from this point.

Figs. 6 to 9 show another form of embodiment of a hub sleeve for a cycle. The hub sleeve again comprises a sleeve body 61 formed as a one-piece die-casting, to which a spoke flange is integrally cast in the region of its one axial end. In the region of its other axial end a seating surface 65 for a subsequently fitted second spoke flange 67, entered in dot-and-dash lines, is cast on the sleeve body 61. Seating surfaces 69 and 71 of circle segment form are cast on the sleeve body 61 in the region of its two ends, in which surfaces there are held bearing shells 73 and 75 respectively, entered in dot-anddash lines, which are fixed radially by press fit. The bearing shells 73, 75 together with ball rows and cones (not illustrated further), form ball bearings with which the hub sleeve is mounted rotatably on a hub spindle (not shown).The bearing shells 73, 75 are shaped without collars, that is to say they have no axial stop collar outside their peripheral surfaces formed by the seating surfaces 69 and 71. Between the bearing shells 73, 75 there extend in the axial direction four ribs 77 cast integrally on the inner pierphery of the sleeve body 61, against the axial end faces 79 and 81 of which, facing away from one another, the shell bases of the bearing shells 73 and 75 rest. The rigs 77 taper in the axial direction. At their wider ends they carry end flanges 83, the outwardly facing front faces of which form the stop faces 81. The stop faces 81 merge, on the side axially facing the seating surfaces 71, into pockets 85.The pockets 85 are seated in the circumferential direction between the seating surface segments 71 and like the pockets 41 of the hub sleeve according to Figs. 2 to 4 compensate any radial offsetting of the die-casting mould halves used in the production of the sleeve body 61. The seating surface segments 71 are adjoined in the circumferential direction between the ribs 77 by internal peripheral surfaces 87 which extend at the axially opposite end of the sleeve body 61 between the seating surface segments 69 situated there.

On this side of the sleeve body 61 the seating surface segments 69 proceed in axial extension of the ribs 77. In this way surfaces free from undercutting are produced so that the seating surface segments 71 and 69 can again be shaped by a core section of the same mould half. The inner periphery of the sleeve body 61 is accordingly of such configuration that in every axial longitudinal sectional plane including the sleeve axis the radial distance of each point of the inner peripheral surface from the axis of rotation, starting from a point with minimum distance from the axis of rotation, axially on both sides of this point, exclusively increases or at least remains constant with increasing axial distance from this point. For the rib zones of the inner periphery the minimum distance from the rotation axis lies in the region of the end flanges 83, for the zones placed between the ribs 77 it lies in the region of the seating surface segments 71.

The external periphery of the sleeve body 61 is formed without undercutting, analogously with the external periphery of the sleeve body 21 in Fig. 2, in relation to a mould division plane, in the region of the cast-on spoke flange 63.

The bearing shells 31 and 73 arranged on the widened side of the inner periphery of the hub bodies as explained above can be omitted if instead in place of the bearing seatings 33 and 69 provided in each case ball bearing race tracks shaped in accordance with the omitted bearing shells are cast on integrally.

Claims (4)

1. A hub sleeve for a cycle hub comprising: (a) a sleeve body formed as one-piece light metal die-casting and defining an axis of rotation, having an internal peripheral surface in which, in every axial longitudinal sectional plane, the radial distance of each point of the internal peripheral surface from the axis of rotation, starting from a point with minimum distance from the axis of rotation, axially on both sides of this point exclusively increases or at least remains constant with increasing axial distance from this point; (b) two spoke flanges arranged with axial spacing from one another, firmly connected with the sleeve body and protruding approximately radially from its external circumference; (c) a first seating surface formed on the internal peripheral surface of the sleeve body in the region of a first one of its two axial ends;; (d) a ball bearing shell held with press fit in the first seating surface; (e) a seating surface for a second ball bearing shell or a ball bearing race surface formed in the region of the second of the two axial ends of the sleeve body in its internal peripheral surface, with formation of an axially outwardly facing shoulder; and (f) several radially inwardly protruding ribs offset in the circumferential direction in relation to one another and arranged on the side of the first seating surface axially remote from the first end of the sleeve body are formed integrally on the internal circumferential surface of the die-casting forming the sleeve part, the axial end faces of which ribs, facing the first end of the sleeve body, form axial stop faces for the ball bearing shell held in the first seating surface; (g) said stop faces merging in the axial direction into pockets sunk radially outwards into the first seating surface and axially open to the first end of the sleeve body.

2. A hub sleeve according to Claim 1, wherein the ribs extend in the axial direction as far as the seating surface in the region of the second end of the sleeve body and with their end faces facing axially towards the second end form the shoulder serving as stop face for the second ball bearing shell held in the second seating surface.

3. A hub sleeve according to Claim 2, wherein the second seating surface extends substantially in axial projection of the ribs between their stop faces and the second end of the sleeve body and in the circumferential direction between the ribs recesses are sunk radially outwards into the seating surface and are open to the second end of the sleeve body.

4. A hub sleeve substantially as described by way of example with reference to Figs.

2-4 or Figs. 6-9 or the accompanying drawings.