|
(11) | EP 0 370 179 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
|
|
|
|
|||||||||||||||||||||||
| (54) | Universal stripper for the inner ring of cylindrical ball bearings |
| (57) The invention makes known a universal stripper for the inner rings of cylindrical
ball bearings. It comprises a metal structure (2) presenting at one end a stripper
head (3) suited to match the ring (10) to be removed and at the opposite end a bottom
with a hole (5) with a thrusting screw (4) suited to thrust with its tip on the hub
(11) on which the inner ring is mounted. The removal of the ring (10) in relation
to the hub (11) occurs by reaction to the axial thrust exerted against the hub (11)
by the screwing of the thrusting screw (4) on the bottom (5} of the metal structure
(2). The matching of the stripper head (3) with the metal structure (2) occurs through
a threaded junction, while a plurality of centering screws (9) make the stripper head
(3) integral with the ring (10) to be removed. |
[0002] It is known to those skilled in the art, that the removal of the inner ring of a ball bearing from the hub on which it is mounted is a difficult and toilsome operation. In fact, on the market there are no specific tools to be employed for such purpose, so that usually the operation is performed with the largest variety of improvised tools or, at best, by using the regular ball-bearing strippers.
[0003] However, the use of the regular ball-bearing strippers for removing the inner rings of the ball-bearings from the hubs on which they are mounted, presents some inconveniences.
[0004] The main inconvenience is represented by the fact that, if the inner ring of the ball-bearing is mounted against a vertical shoulder surface, such as a flange or a spacing ring for instance, the removal of the ball-bearing ring becomes extremely toilsome. In fact, it becomes very difficult to insert the terminal part of the jaws of the stripper between the vertical shoulder surface and the ball-bearing ring, in order to exert on the latter the axial force necessary for the removal.
[0005] In order to avoid this inconvenience, the jaws of the stripper are usually clamped in the sliding track of the balls belonging to the ring that needs to be removed, thus obtaining, as a rule. a better interference.
[0006] However, even this solution presents some inconveniences, due to the fact that because of the rather large dimensions of the terminal part of the stripper jaws and of the semi-round profile of the ball sliding track of the ring to be removed, it is impossible to obtain a sufficient grip between the stripper and the ring, which is necessary, in order to exert the secure and abrupt axial force insuring the removal. This inconvenience becomes more pronounced particularly when the rings to be removed are inner ball-bearing rings having rather reduced dimensions.
[0007] Another inconvenience is represented by the fact that ball-bearing strippers are usually tools of large bulk and they create, therefore, transportation problems and handling difficulties while in use.
[0008] Moreover, the stripper jaws are held in reciprocal tension by springs which can easily break, thereby causing further complications in the use of the stripper.
[0010] The main purpose of the invention is to make known a universal stripper for the inner rings of cylindrical ball bearings allowing the easy removal of said inner rings from the hubs on which they are mounted, even in those cases wherein said inner rings are supported against vertical shoulder surfaces.
[0011] Another purpose of the invention is to make known a universal stripper for the inner rings of ball bearings which is easy to manufacture and to use, has a light weight and small dimensions. Not the least purpose of the invention is to make known a universal stripper for the inner rings of ball-bearings whose operation offers the highest reliability.
[0012] The above-mentioned purposes and others which will be better understood hereafter are reached by realizing a universal stripper for the inner rings of cylindrical ball bearings which, in accordance with the patent claims, comprises a stripper body which is clamped on the inner ring to be removed and a reaction element which exerts the axial force on the hub and transmits it to the stripper body, and which is characterized in that the stripper body comprises:
- a metal structure having essentially a tubolar shape presenting at one end a stripper head which has an inner ring-shaped surface with several diameters, such as to allow said stripper head to rest against the vertical wall of the ring to be removed, said ring-shaped surface presenting a plurality of radial threaded holes, equally distributed along the circumference and holding screws whose tips clamp in the sliding track of the ring and at the other end a bottom with a hole and a thread wherein a screw having its axis coinciding with the axis of the hub is screwed; said screw exerting the axial thrust which is necessary for the removal of the inner ring of the ball bearing which is mounted on said hub. The invention makes available a tool which has the advantages of being specific for the removal of the inner rings of cylindrical ball bearings, of being inexpensive, light in weight, easy to handle and, above all, reliable in its operation.
[0013] Moreover, this tool is universal because of a plurality of stripper heads, each with a different internal diameter so as to fit inner rings of cylindrical ball bearings with corresponding diameters.
[0014] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific example, while indicating a preferred embodiment of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description and from the drawings wherein:
- Fig. 1 represents a longitudinal cross-section of the universal stripper according to the invention at the beginning of the operation for the removal of the ring;
- Fig. 2 represents the stripper of Fig. 1 during the removal of the ring;
- Fig. 3 represents a cross-section of the tubular-shaped metal structure of the stripper head;
- Fig. 4 represents one of the ring-clamping screws of the stripper head.
[0015] As can be observed in Fig. 1, the stripper according to the invention, which is indicated as a whole with 1, comprises a metal structure 2 having a tubular shape, which presents at one of its ends the stripper head 3 and at its other end the thrusting screw 4 which matches the fixed bottom 5 of the metal structure 2.
[0016] The stripper head 3 consists of a round flange 6 having an inner thread 7, through which it matches the metal structure 2, while at the opposite end it presents, as can be observed in Fig. 3, a plurality of threaded through-holes 8, arranged radially, preferably at 60 degrees from one another, which are suited to receive each a screw 9 which will be clamped on the ring to be removed. The screws 9 are tightened in the holes 8 of flange 6 and they are those elements, which, when, properly maneuvered, make flange 6 integral with the ring which needs to be removed from hub 11 on which it is mounted. Moreover, the screws 9 do not protrude beyond the vertical profile 40 of flange 6, so as to allow the removal of ring 10, even when the latter is pressed against a vertical shoulder.
[0018] First of all flange 6 will be slid over the ring 10 which is to be removed; the flange and the ring will then be made integral by tightening the clamping screws 9.
[0019] As can be observed in Fig. 4, the tip of each screw 9 is tapered following a profile 12, at the apex of which a ball 13 is inserted; the task of said ball 13 is to insure the centering of each screw 9 in the sliding track 14 of the bearing balls belonging to ring 10 and, as a consequence, also the centering of flange 6.
[0020] After flange 6 has been made integral with ring 10 by tightening the screws 9 within track 14 of the ring, structure 2 will be matched with flange 6. To this purpose structure 2 is complete with a thread 15 which matches the inner thread 7 of flange 6; structure 2 is screwed within flange 6 until the thrusting screw 4 pushes with its tip against hub 11 on which a pressing disc 16, has been set. As can be observed in Fig. 1. tip 17 of the thrusting screw 4 also presents a taper 18 at the apex of which a ball 19 is inserted. Ball 19 has the task of insuring the co- axiality of the direction of thrust of screw 4 in relation to the axis 20 of hub 11. More specifically, in order to insure said co-axiality between hub 11 and the tip-ball 19 of screw 4, the pressing disc 16 is inserted; this disc has in its center a seat 21 within which ball 19 will rest, thereby insuring the co-axiality between the direction of thrust and axis 20 of hub 11.
[0021] Now the stripper 1 is ready to perform the removal of ring from hub 11, which occurs by screwing the thrusting screw 4 by acting on hexagon 22.
[0022] The removal of ring 10 occurs because the screwing of screw 4 creates a thrust along axis 20 of hub 11 in the direction 23; said thrust consequently causes on structure 2 as a reaction a traction force along the same axis in the direction 24. Said traction force of structure 2 is trasmitted through flange 6 to the inner ring 10 which is to be removed. The removal is completed when, by continuing the screwing action of the thrusting screw 4, the inner ring 10 has reached its final position and is level with the pressing disc 16, which also has the task of supporting the inner ring 10, when the latter begings to come off hub 1.
[0023] On the basis of what has been described, it can be understood that the the stripper according to the invention reaches all the proposed purposes.
[0024] First of all it has been seen that the presence of the screws 9, complete with the tip-ball 13 permits an extremely stable contact between flange 6 and the inner ring 10 which is to be removed, thereby preventing the two parts from coming apart during the removal operation.
[0025] It has also been seen that the shape of flange 6 and the position of the screws 9 are such as to allow the removal of ring 10, even when the latter is pressed against vertical shulder surfaces.
[0026] It can also be observed that thanks to the small dimensions of flange 6 and of structure 2 a universal stripper having an extremely small bulk and being very easy to handle, has been obtained.
[0027] Moreover, it can be observed that the lack of springs, of joints and similar makes the stripper according to the invention highly reliable.
[0028] It has also been observed that, since a plurality of stripper heads, each having a different inner diameter, is available, it is possible to remove inner rings of cylindrical ball bearings of different diameters
[0029] The stripper according to the invention is particularly suited for the removal of the inner rings of cylindrical ball bearings which are mounted on the wheel-hubs of automative vehicles and cars in particular. It is however understood that the stripper according to the invention can advantageously be used also in industrial applications of various types, such as, for instance, for the removal of the inner rings of cylindrical ball bearings mounted on the shafts of electric motors, of turbines and similar.
[0030] Moreover, by varying the profile of the stripper head, it can also be used to an advantage for the removal of various mechanical elements. During the manufacturing stage the stripper according to the invention may undergo changes and modifications having the purpose of improving its performance or of increasing its versatily of application; said changes and modifications will, however, not exceed the scope of the present invention.
1. A universal stripper for the inner ring of cylindrical ball-bearings, comprising
a stripper body, which is clamped on the ring to be removed, and a reaction element
exerting an axial thrust on the hub (11) and transmitting it to the stripper body,
characterized in that said stripper body comprises:
- a metal structure (2) having an essentially tubular shape, presenting at one end a stripper head (3) having in its interior a ring-shaped surface with a plurality of diameters, such as to allow said head to rest laterally against the ring (10) to be removed, said ring-shaped surface presenting a plurality of radial thereaded holes (8} equally distributed along the circumference, and lodging each a screw (9) whose tip clamps within the track (l4) of the ring (10),
and at the other end a bottom with a hole and a thread wherein is screwed a screw (4) having its axis coinciding with the axis (20) of hub (11), said screw exerting on the hub the thrust necessary for the removal of the ring mounted on said hub.
- a metal structure (2) having an essentially tubular shape, presenting at one end a stripper head (3) having in its interior a ring-shaped surface with a plurality of diameters, such as to allow said head to rest laterally against the ring (10) to be removed, said ring-shaped surface presenting a plurality of radial thereaded holes (8} equally distributed along the circumference, and lodging each a screw (9) whose tip clamps within the track (l4) of the ring (10),
and at the other end a bottom with a hole and a thread wherein is screwed a screw (4) having its axis coinciding with the axis (20) of hub (11), said screw exerting on the hub the thrust necessary for the removal of the ring mounted on said hub.
2) A universal stripper for the inner rings of cylindrical ball bearings according
to claim 1, characterized in that the stripper head (3) has the shape of a round flange
(6), one end of which presents an inner thraad (7} suited to match the corresponding
thread (15) of the metal structure (2), while its opposite end presents a plurality
of radial, threaded through-holes (8) suited to receive each a screw (9) for the centering
of the flange (6) on the ring to be removed.
3) A universal stripper according to claim 2, characterized in that the metal structure
(2) of the stripper body can selectively match through its thread (15) any one of
a plurality of stripper heads (3), with different inner diameters, each of which is
suited to help in the removal of the inner rings of cylindrical ball bearings having
the corrispondent diameter.
4) A universal stripper for the inner rings of cylindrical ball bearings according
to claim 2, characterized in that each centering screw (9) has at the apex of its
tapered tip (12) a centering ball (13).
5) A universal stripper for the inner rings of cylindrical ball bearings according
to claim 1, characterized in that the thrusting screw (4) presents a centering ball
(19) lodged at the apex of the taper (18) of its tip (17).
6) A universal stripper for the inner rings of cylindrical ball bearings according
to claim 1, characterized in that the thrusting screw (4) exerts the axial thrust
on the hub (11) through the interposition of a pressing disc (16) having a seat (21)
for the centering of the centering ball (19) of the thrusting screw (4).