FR2697304A1 - Bearing body made of plastic. - Google Patents

Abstract

The invention relates to a plastics bearing housing produced by an injection molding process. The bearing body 1 comprises a steel propeller 3 embedded in the plastic material of the bearing body which surrounds the seat 4 for the outer ring 13, 14 of a bearing 5 in the bore of the bearing body. A prefabricated plastic support ring 2, on the peripheral surface of which the steel propeller 3 is placed, is overmolded by the plastic material of the bearing body 1. Advantages: Precise positioning of the support ring and the propeller in the mold during the manufacture of the bearing housing.

Description

The invention relates to a body of plastics

bearing made of plastic

  manufactured by an injection molding process, which body of

  binding comprises a steel helix which surrounds the mounting surface of the bore being concentric thereto and is embedded in the material constituting the bearing body. It is known to drown a steel helix in the material constituting the bearing body in order to reinforce it and to avoid creep of the plastic material under the tensile and compressive stresses that appear during operation and, consequently,

  to avoid a detrimental change in the adjustment conditions of the pa-

  A steel propeller of this type can also eliminate the effects of

  negative effects of the thermal expansion of the bearing and rolling body

  mounted in it on the adjustment of the bearings.

  In an injection molding process for the manufacture of a bearing body known from EP 91850281 6, the plastic-coated steel helix is placed in the mold and is held in the desired position, concentric to the bore of the bearing body, by sliding positioning means until the plastic material is injected into the mold A certain

  stage of the injection, the positioning means are removed and the

  ply of plastic material cavities left The steel propeller is as well

  coated on all sides with plastic material.

  This process requires on the one hand expensive molding tools

  and on the other hand a complex ordering process during the operation.

  molding, so that the propeller is overmolded by the material of the

  bearing body in the exact position desired.

  The object of the present invention is to create a body of

  the type indicated in the introduction which can be manufactured in such a way

  However, the steel helix is securely overmolded concentrically to the bore of the bearing housing.

  The problem is solved by means of a prefabricated support ring

  plastic brick which is embedded in the bearing housing and

  on the peripheral surface of which is placed the steel propeller.

  Advantages provided by the invention include the fact that one can use a simple molding tool without special sliding means for positioning or other means for receiving and immobilizing the steel propeller, the ring

  support fulfilling this function Furthermore, it is possible to

  brick the bearing body in a single continuous operation

  sure that the position of the propeller will not be changed under the pressure of the incoming plastic position that is no longer warranted to this

  moment in the known state of the art.

  According to another characteristic of the invention, the bore of the support ring can be arranged directly in the form of a bearing and receive all or only part of the ring.

  the outer surface of a bearing, thus ensuring a perfect positioning

  concentricity of the propeller with respect to the bearing.

  The use of the support ring is particularly advantageous

  in the case of two bearings arranged side by side, mutual

  aligned inside the bearing body which are overmolded by

  the plastic material at the time of manufacture of the bearing body.

  The bearings are then inserted and immobilized in the bore of the

  support ring, making it possible to place in the mold a pre-assembly

  appeared to be formed of the support ring, the two bearings aligned

  a concentric steel helix.

  When the bore of the support ring only covers a part

  the outer ring of the bearing, the exact positioning of the wheel

  is assured while the bearing ring is directly

  turned by the plastic material constituting the bearing body, for

  form a particularly reliable overmolding assembly.

  When a certain axial distance is required between the bearings, this can be obtained in a simple manner by projections or a circular rib formed on the support ring. A rib of this type can be provided with molded elements which are elastic in the axial direction, which exert an axial force on the outer races of the bearing when, during the injection molding operation of the bearing body, said rings are pressed against the elastic elements and that shoulders forming surfaces

  of support are formed on the bearing housing on the outside front faces

  This allows, for example, to compensate for

  by simple means the width tolerance of the bearings and the tolerances in length of a spacer ring placed between the inner rings of the bearings Elastic elements of this type formed on the rib also make it possible to axially shift the bearings.

  outer rings compared to the inner rings which are now

  naked at a distance from one another by a spacer ring

  spacing of this type can be centered by a radial-turned collar

  inwardly formed in the bore of the support ring or by

  isolated fingers; this facilitates the setting up of the whole

  ble in the mold as the subsequent mounting of a tree.

  Providing the support ring with axial extensions which extend at a radial distance from the bearing surface for the bearing ring and

  on the outer surface of which the propeller is placed and

  ments consisting of ring segments spaced apart in the di-

  peripheral rectification, one obtains a particularly good overmolding of the support ring by the material of the bearing body; Moreover the elasticity of the extensions allows the reinforcement action of the propeller

  to practice freely on the bearings for the bearing ring.

  Various examples of embodiments of the invention are described below.

  These are shown in FIG. 1, a longitudinal section of a flanged bearing housing and

  figure 2, a longitudinal section of a second mode of

a bearing body.

  The bearing body shown in FIG. 1 is made of

  plastic molding according to an injection molding process and has a support ring 2 also made of plastic and a propeller

3 steel.

  Two ball bearings 5, 6 whose inner rings 7, 8 are held on a shaft 11 by two elastic rings 9, 10 are

  mounted in bore 4 of bearing housing 1.

  The support ring 2 has a circular rib 12 directed

  inwards which acts as an axial stop for the outer rings.

  13, 14 of the bearings and determines their mutual distance On the body of the support ring 2 are formed axial extensions 15, 16 which, preferably, form three ring segments distributed on the circumference of the support ring 2 The propeller 3 steel is arranged

  on the outer surface of the body of the support ring and the extensions

  15, 16, being concentric to the bores of the bearing ring 2 receiving the bearings or to the bore 4 of the bearing body 1; she is

  immobilized in the axial direction by elevations 17, 18 ra-

  diales provided at the ends of the extensions 15, 16.

  It can be seen that the steel helix 3 can be mounted on the plastic support ring 2 before the bearing body is made and that the assembly formed of the support ring 2 and the steel helix 3 can be set up. place in the mold to make the bearing body 1

  complete, no particular intervention in the mold being necessary.

sary.

  The bearings 5, 6 can be threaded into the body of

  tie together with the spacer ring 19 inserted in

  the inner rings 7, 8, the support ring 2 ensuring an alignment

  Bearing ring 2 additionally presents in its

  bore a collar 29 directed radially inwards which limits the

  movement of the spacer ring 19 in the axial direction so that the shaft can be mounted without difficulty Naturally independent fingers turned radially inwards can

  be provided in place of the collar 29.

  It is also possible to mount the bearings 5, 6 and the spacer ring 19 in the bores of the support ring 2 before the

  injection molding of the bearing body 1 so as to obtain a

  seems preassembled, formed of aligned bearings 5, 6 arranged

  this one of the other, the spacer ring 19, the support ring 2 and the concentric helix to the bearings 5, 6, which assembly can be placed directly in the mold The bearings for the bearings in the support ring 2 having a depth less than the length of the outer rings 13, 14 of said bearings, the outer rings 13, 14 are overmolded directly by the plastic material during the molding of the body

  bearing, thus ensuring very good seating.

  The flanged bearing body according to FIG. 2 comprises a ring

  modified support The circular core 21 of the support ring 20 is

  view of elements 22, 23 elastic in the axial direction which are each formed by a circular radial groove The bearing body 26 has here at the ends of its bore shoulders 27, 28 forming surfaces

  bearing which encloses the outer rings 13, 14 of the bearings.

  The preassembled assembly formed of the steel propeller 3, the support ring 20, the bearings 5, 6 and the spacer ring 19 has been placed

  in the mold for producing the bearing body 26 and the bearing rings

  have been pushed axially by the parts of the mold which seal the front of the bearing, until the inner rings 7,

  8 abut against the spacer ring 19 and the outer rings

  13, 14 press against the elastic elements 22, 23 Thus all the axial tolerances on the bearing rings and the ring

spacing were eliminated.

  An arrangement of this type of the support ring makes it possible to obtain, by simple means, an offset of the outer rings 13, 14 of the

  bearings with respect to the inner rings 7, 8, for example -

  as in the embodiment of FIG. 1, the inner rings

  7, 8 are held on the shaft 11 by elastic rings 9, 10 or

reported items.

  In both embodiments, the invention is described using flanged bearing bodies; it is obvious that the invention can be applied in the same way to other bearing bodies, such as for example crapaudines Similarly one can imagine using a net or

  a similar arrangement in place of the steel propeller.

Claims (9)

  1 Plastic bearing housing manufactured by a process   injection molding die, comprising a steel helix which surrounds   re the range for the bearing race in the bore of the body of pa-   bind concentrically to it and is embedded in the material constituting   characterized in that a prefabricated plastic support ring (2, 20) on the peripheral surface of which the steel helix (3) is placed is embedded in the body of the bearing (1, 26).   Bearing housing according to Claim 1, characterized by the   the bore of the support ring (2, 20) constitutes at least one   tially the bearing housing (1, 26) for the roller bushing   is lying. Bearing housing according to Claim 2, characterized in that two rolling bearings (5, 6) are arranged side by side mutually aligned in the bore of the support ring (2, 20).   and overmoulded therewith by the material of the bearing body (1, 26).   Bearing housing according to claim 3, characterized by the   the depth of the bores of the support ring (2, 20) which   the outer rings (13, 14) of the bearings (5, 6) are   greater than the width of said outer rings (13, 14).   Bearing body according to Claim 4, characterized by the   radial projections against which the   external bearings (13, 14) are arranged between the   wise of the support ring (2, 20) which receive the outer rings (13, 14) bearings.   Bearing housing according to Claim 4, characterized in that a circular rib (12, 21) against which the bearing outer rings (13, 14) rest is arranged between the   bores of the support ring (2, 20) which receive the outer rings res (13, 14) bearings.   Bearing housing according to Claim 5 or 6, characterized in that it is provided between the bores of the support ring (2, 20).   a collar (29) turned radially inwards or fingers inde-   pendants which center a spacing ring (19)   placed between the inner rings (7, 8) of the bearings (5, 6).   Bearing housing according to Claim 6 or 7, characterized in that the collar (21) has on its end faces   elastic elements in the axial direction against which   and the outer rings (13, 14) of the bearings.   9 bearing housing according to claim 8, characterized in that the elastic elements are formed by portions (22, 23) of the collar (21) which extend obliquely towards the outer rings   Bearings (13, 14) between said parts and the body of the   let (21), radial grooves (24, 25).   Bearing body according to one of the claims   preceding, characterized in that the body of the support ring (2,   20) has axial extensions (15, 16) which are arranged radially   remote from the bearing surface for the bearing ring in the bore (4) of the bearing body, are embedded in the body material   bearing (1, 26) and on the outer surface of which the Steel lice (3).   11 Bearing housing according to Claim 10, characterized in that the axial extensions (15, 16) consist of at   at least three segments formed on each side of the body of the ring Harbor.   12 Bearing housing according to claim 10 or 11, characterized   in that radially outwardly oriented elevations (17, 18) are formed at the ends of the extensions (15, 16) at the   to immobilize the steel propeller (3) in the axial direction.