Method for adjustment of machine parts

For adjustment of the relative positions of two machine parts, at least one of the machine parts is provided with projections outwardly formed by stamping, the projections having contact surfaces which lie against the other machine part. The adjustment is performed by setting the projections back under the influence of a pressing force according to requirements. By this operation a relatively large contact surface can be provided. The deformation process takes place exclusively in the transition region between the projection and the rest of the machine part. The restoring forces are relatively small and relatively constant over the entire restoring range.

FIELD OF THE INVENTION 
The invention relates to a method for adjusting the relative positions of 
two juxtaposed machine parts by the deformation of projections formed on 
at least one of the machine parts. 
BACKGROUND OF THE INVENTION 
A method of this type is disclosed in U.S. Pat. No. 3,455,617. For the 
axial mounting of a bearing in a housing, a flange with a sleeve-shaped 
extension is provided which is pressed against an outer ring of the 
bearing, which is thereafter supported in the housing. The flange is 
accordingly bolted to the housing. In order to compensate for 
manufacturing tolerances, the front face of the sleeve-shaped extension is 
provided with an annular projection which has an axially pointed 
longitudinal section. The projection is plastically deformed, i.e. coined, 
when pressed against the outer ring, until the flange attains its axial 
position by contact against the housing. After the plastic deformation of 
the material at the tip of the projection, the material in the remaining 
areas undergoes elastic restoring forces, so that after this procedure a 
typical axial attachment with prestress is attained. The geometric form of 
the projection and the use of the area of plastic deformation by 
compression of the material greatly limits the range of manufacturing 
tolerances which this method can accommodate. The material of the annular 
peaked projection undergoes, as is evident from the drawing of the cited 
reference, relatively short axial strain displacement up to the 
compression limit, beyond which further deformation is in practice no 
longer possible. Furthermore, the reaction force progressively increases 
because of the geometric shape of the projection so that the prestress 
produced thereby is directly dependent on the tolerance range being 
compensated for. This is unacceptable for the application of the rolling 
bearing. A further disadvantage is the relatively small surface area of 
contact between the projection and the outer ring, which for alternative 
applications leads to deformation of the attached machine parts. In 
contrast to the type of attachment disclosed in the cited reference, the 
known process can also be used for adjustment of the relative positions of 
machine parts, wherein the deformable projection determines the mutual 
distance between the machine parts. 
BRIEF SUMMARY OF THE INVENTION 
The object of the invention is to provide a method of the foregoing type by 
which a large adjustment range with optimization of the constancy of the 
deformation forces and an enlarged contact surface on each projection are 
obtained. 
In accordance with the invention the object is attained by: 
(a) the use of machine parts with projections stamped out during 
manufacture on at least one of the machine parts, each projection having a 
planar contact surface; and 
(b) setting back of the projections by plastic deformation of the 
transition region between each projection and the rest of the machine part 
by mutual pressing of the machine parts, each contact surface being 
substantially unchanged during the assembly of the machine parts. 
The manufacture of the projections according to step (a) presupposes a 
machine part which can be manufactured by a stamping operation. The 
material portion ensures that a predetermined thickness will not be 
exceeded in the are of the locus of stamping. The projections are each 
manufactured by outwardly forming a portion of the material in the 
thickness direction from the backside of the material. Because by this 
operation a material portion is displaced relative to the rest of the 
material, the work done in deformation being necessary only in the area of 
the line of contact, i.e. the transition from the projection to the rest 
of the machine part. Each projection can for this reason be advantageously 
relatively large and have a correspondingly large contact surface. The 
stamping operation can, for example, be performed by a stamping tool which 
displaces the projection up to the transition region. 
The foremost advantage of the method according to the invention is realized 
during the assembly according to step (b). Here each projection is set 
back to the required height under the force of the machine parts being 
pressed against each other. This occurs without deformation of the 
projection, i.e. substantially without alteration of the already large 
contact surface. By setback of the projections, only the transition region 
between each projection and the rest of the machine part is compressed, 
i.e. flow-deformed to a smaller dimension. Because the material in this 
region is greatly stretched in step (a), the restoring forces are 
relatively small and above all are relatively constant over the entire 
restoring range. In principle, each projection can in this way be set back 
to its original position, i.e. until the projection is level with the rest 
of the machine part. In this way an extremely large adjustment range is 
provided. 
In accordance with a variation of the method of the invention, machine 
parts with projections manufactured by means of embossment are used. A 
transition region remains between the projection and the rest of the 
machine part, whereby this operation can be likened to shallow drawing and 
is especially suitable for small material thicknesses such as sheet metal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In the machine part 1 shown in FIG. 1, a projection 2 has been formed by 
the use of a stamping tool (not shown) driven outwardly in the direction 
of the thickness of the material. In contrast to the conventional stamping 
operation, the material portion of the projection 2 is not completely 
separated from the remainder of the machine part 1, but rather is 
connected by a transition region 3 over about one-third of the total 
thickness of the material. The surface 4 cut by the stamping punch 
substantially conforms to the shape of the peripheral surface 5 of the 
projection 2. As a result of this operation the transition region 3 is 
subject to greater tensile stresses, so that a stretched structure is 
produced. Already at the start of stamping the rim 6 and corner zone 7 are 
slightly rounded through inward and outward displacement of corresponding 
material portions respectively. The projection 2 formed in this way has 
essentially the thickness of the starting material and a planar surface 8 
for contacting a second machine part 9. 
By adjusting the relative positions of both machine parts 1 and 9, a 
pressing force F can be applied to the upper surface of machine part 1 (as 
seen in FIG. 2) by the use of a tool (not shown). The relative distance 
between the machine parts is reduced by means of force F and the support 
of the other machine part 9, while the projection 2 is pushed back in the 
direction of its original position. At the same time the previously 
greatly stretched transition region 3 is plastically compressed, the 
rounding of the corner zone 7 substantially disappears, and interstice or 
seam 10 is formed by that material which is deformed during setback of the 
projection, but which is unable to join with the material of the 
undeformed portion of the machine part 1. The thickness of the projection 
2 and especially the contact surface 8 are unchanged. The necessary 
deformation occurs exclusively in the transition region 3 and in the 
contiguous regions. In the embodiment depicted in FIG. 2, the projection 2 
is pushed back about one-third of the material thickness. A complete 
setback is, however, possible, since a sufficient portion of flow-deformed 
material will remain in the still connected transition region 3. 
In accordance with the embodiment shown in FIGS. 3 and 4, a machine part 1 
made of thin material, e.g. sheet metal, is used out of which the 
projection 2 is formed by embossment. By this operation a larger 
transition region 3 can be formed, partly by the drawing of material from 
respective sheet metal portions and partly by bending deformation. The 
punch of the work tool (not shown) is therefore smaller in profile than 
the corresponding die. For this reason the thickness of the transition 
region 3 relative to the original thickness, i.e. relative to the 
remainder of machine part 1, is also reduced. In this manner the 
projection 2 can, as shown in FIG. 3, be formed outwardly to a depth 
substantially greater than the thickness of the material. 
The material of the transition region 3 is compressed by setting the 
projection 2 back, as shown in FIG. 4, whereby as a result of flow 
deformation the thickness of the material in the transition region 3 is 
increased. Also in accordance with this embodiment, the relative large 
contact surface 8 is unchanged and it is possible to set the projection 2 
back to its original position with suitable pressing force. 
For all embodiments the size of the projection 2 has not been described, 
since the dimensions can be selected within wide limits to satisfy the 
respective requirements, and independently therefrom the deformation 
operation can be confined only to the transition region 3. 
The foregoing description of the preferred embodiments is presented for 
illustrative purposes only and is not intended to limit the scope of the 
invention as defined in the appended claims. Modifications may be readily 
effected by one having ordinary skill in the art without departing from 
the spirit and scope of the invention concept herein disclosed.