ELECTRICAL CONDUCTOR FOR CONDUCTING ELECTRICAL CURRENT THROUGH A HOUSING AND METHOD FOR MANUFACTURING THE SAME

Abstract

The invention relates to an electrical conductor for conducting electrical current through a housing, wherein a sealing body made of an elastic material is arranged on the electrical conductor, wherein the sealing body encloses the electrical conductor in a first sealing section radially surrounding the electrical conductor, wherein a housing part is arranged on the electrical conductor. The housing part radially encloses at least part of the surface of the sealing body, which is not in contact with the electrical conductor in the first sealing section, in a second sealing section, wherein the elastic material of the sealing body comprises at least one hollow chamber and/or is an elastomer foam. The invention further relates to a corresponding method for manufacturing.

Claims

1. An electrical conductor for conducting electrical current through a housing, comprising: an electrical conductor rail; a sealing body of an elastic material arranged on the electrical conductor rail, wherein the sealing body encloses the electrical conductor rail in a first sealing section radially surrounding the electrical conductor rail, a housing part arranged on the electrical conductor rail, wherein the housing part radially encloses at least a part of a surface of the sealing body, which is not in contact with the electrical conductor in the first sealing section, in a second sealing section, and wherein the elastic material of the sealing body comprises at least one hollow chamber and/or is an elastomer foam.

2. The electrical conductor according to claim 1, wherein the elastic material of the sealing body is an elastomer foam with closed pores.

3. The electrical conductor according to claim 1, wherein the housing part encloses the electrical conductor rail in a third sealing section and/or fourth sealing section radially surrounding the electrical conductor rail.

4. The electrical conductor according to claim 3, wherein the third sealing section and/or fourth sealing section in each case axially adjoins the first sealing section on the electrical conductor rail.

5. The electrical conductor according to claim 1, wherein the housing part is made of a plastic.

6. The electrical conductor according to claim 1, wherein the housing part is made of a material having a higher modulus of elasticity than the elastic material of the sealing body.

7. The electrical conductor according to claim 1, wherein the electrical conductor rail comprises a rounded contour at least in the first sealing section.

8. The electrical conductor according to claim 1, wherein the electrical conductor rail and the sealing body comprise a substance-to-substance bond.

9. A method for producing an electrical conductor for conducting electrical current through a housing according to claim 1, comprising: providing an electrical conductor rail; first molding of a sealing body to a first sealing section radially surrounding the electrical conductor rail which encloses the electrical conductor rail, wherein the sealing body is formed of an elastic material with at least one hollow chamber and/or of an elastomer foam; second molding of a housing part enclosing the sealing body at a second sealing section.

10. The method according to claim 9, wherein during the second molding of the housing part, the sealing body is compressed under a molding pressure of the second molding of the housing part.

11. The method according to claim 10, wherein a volume of the sealing body is reduced to at least 97% during the second molding.

12. The method according to claim 9, wherein during the second molding of the housing part, the electrical conductor rail is enclosed by the housing part in a third sealing section and fourth sealing section.

13. The method according to claim 9, wherein during the first molding the elastic material is crosslinked to form the sealing body.

14. The electrical conductor according to claim 5, wherein the plastic is a thermoplastic.

15. The method according to claim 9, wherein the first molding is a first injection molding, and wherein the second molding is a second injection molding.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0035] The invention is explained below by means of preferred embodiments with reference to the accompanying figures. Thereby shows

[0036] FIG. 1 shows a detailed view of a cross-sectional view with an electrical conductor, a sealing body and a housing part;

[0037] FIG. 2 shows a cross-sectional view of a housing part with an electrical conductor fed through and sealed with a sealing body;

[0038] FIG. 3 shows a schematic cross-sectional view of an electrical conductor with a sealing body;

[0039] FIG. 4 shows a schematic sectional view of an electrical conductor with a sealing body and a housing part during the injection molding process of the housing part;

[0040] FIG. 5 shows a further schematic sectional view of an electrical conductor with a sealing body and a housing part after the injection molding process of the housing part;

[0041] FIG. 6 shows a view of a housing part with a fed-through electrical conductor, which is sealed with a sealing body; and

[0042] FIG. 7 shows four different shapes of the sealing body.

[0043] FIG. 1 shows a schematic view of a detail of an electrical conductor 10, which is passed through a housing part 12. The electrical conductor 10 is, for example, a conductor rail made of copper or another metal, and the housing part 12 in this advantageous embodiment example is made of plastic, which in particular can be a thermoplastic. A sealing body 11 is provided, which surrounds the electrical conductor 10 in a first sealing section 13. The first sealing section 13 therefore surrounds the electrical conductor 10 in its cross-section, which may be round or, as in this embodiment, see FIG. 6, rectangular with rounded edges.

[0044] The electrical conductor 10 also comprises two circumferential sealing sections, a third sealing section 14 and a fourth sealing section 15 to the housing part 12, which, as can be seen in the illustration of FIG. 1, adjoin the first sealing section 13 on the right and left, or axially. Furthermore, a second sealing section 16 is present between the housing part 12 and the sealing body 11, so that the electrical conductor 10 is sealed in a permeation-tight manner with respect to the housing part 12 via the first and second sealing sections 13, 16. The third and fourth sealing sections 14, 15 are in contact with the electrical conductor 10, which also achieves a sealing effect, but which are not provided for a permeation-tight seal due to the material combination in this example with copper and high-melting thermoplastic for conductor 10 and housing part 12. Among other things, sufficient sealing pressure is not provided for this purpose in the third and fourth sealing sections. Accordingly, it is possible that the third and fourth sealing sections are not sealed, for example, against creeping oil.

[0045] For sealing against creeping oil, the sealing body 11 is provided, which is formed of an elastic material, for example an elastomer, which is tight against permeation of oil. In this embodiment, the elastic material is a foamed elastomer which comprises closed pores 18 as hollow chambers 17 distributed in the material in order to exhibit a corresponding permeation tightness despite its property as an elastomer foam. The elastic material of the sealing body 11 preferably comprises a lower modulus of elasticity than the housing part 12. In particular, the modulus of elasticity of the sealing body 11 may be lower if the elastic material is an elastomeric foam.

[0046] The sealing body 11 is annular and its inner surface, i.e. the radially inward facing surface, is in contact with the electrical conductor 10. The contact is preferably a sealing pressure. The axial and radially outward-facing surfaces are enclosed by the housing part 12 with the second sealing section 16, as can be seen in the sectional views of FIGS. 1 and 2, so that the sealing body 12 is completely enclosed.

[0047] The sealing body 11 is compressible due to its pores 18 in the elastomeric foam, so that it can be inserted in a compressed state between the conductor 10 and the housing part 12 by being completely enclosed or also encased. This means that the sealing body 11 would occupy a larger volume at ambient pressure outside the space between conductor 10 and housing part 12. The compression provides a sealing pressure at the first and second sealing sections 13, 16, which provides a good seal that is tight against creep of oil.

[0048] In possible embodiments, the sealing body 11 may further comprise a substance-to-substance bond to the electrical conductor 10, which may be achieved, for example, by an appropriate pretreatment of the surface of the electrical conductor 10, such as roughening and application of adhesion promoters, and overmolding of the sealing body 11. A material bond may further improve the sealing, wherein the pretreatment may require additional effort. The substance-to-substance bond may also further increase the fixation of the sealing body 11 to the electrical conductor 10 during manufacture of the housing part 12.

[0049] In FIGS. 3, 4 and 5, various steps of a method for manufacturing a corresponding electrical conductor 10 with a housing part 12 arranged thereon, which are sealed against each other by means of a sealing body 11, are shown schematically.

[0050] FIG. 3 shows a section of the electrical conductor 10 provided, which has been partially overmolded with an elastomer foam in a first injection molding operation. The elastomer foam is an elastic material, for example rubber, which has been foamed. The corresponding pores 18 in the elastic material are shown schematically as circles. The sealing body 11 surrounds the electrical conductor 10 and rests against it at the first sealing section 13. The elastic material of the sealing body 11 preferably cross-links during the manufacturing process during the first molding.

[0051] The next step is illustrated in FIG. 4, in which the electrical conductor 10 with the molded-on sealing body 11 was partially overmolded in a second molding by means of an injection molding process. The second molding is used to produce the housing part 12, which is made of a thermoplastic material. The housing part 12 abuts the electrical conductor 10 with the third and fourth sealing sections 14, 15 and the sealing body 11 with the second sealing section 16. Due to the casting pressure, which is symbolized by arrows in FIG. 4, the sealing body 11 is compressed during the second molding. The compression of the sealing body 11 is illustrated by the reduced pores 18 in the form of smaller circles.

[0052] After cooling, if necessary, after curing of the housing part 12 produced during the second molding, the housing part 12 solidifies and shrinks due to cooling to ambient temperature. The sealing body 11, which was also heated during the manufacture of the housing part 12, also shrinks, wherein the coefficient of thermal expansion of the elastic material of the sealing body 11 is generally greater than that of the housing part 12.

[0053] However, gap formation, particularly at the second sealing section 16, can be prevented by compression of the elastomeric foam, as illustrated in FIG. 5. The compression of the sealing body 11, which is readily compressible due to the pores 18 or hollow chambers 17, results in a contact pressure corresponding to the symbolic arrows in FIG. 4 on the second sealing section 16 and also on the first sealing section 13. In this way, different coefficients of thermal expansion and shrinkages can be compensated for, so that gap formations can be avoided and at the same time sufficient sealing, for example against air, in particular against creeping oil, can be achieved.

[0054] FIG. 6 shows an embodiment of a finished electrical conductor 10 on which a housing part 12 is arranged, which can be mounted, for example, on a housing of an electric motor. The sealing body 11 is well protected against harmful influences and also mechanical loads between the housing part 12 and the electrical conductor 10, so that the sealing body 11 is not visible in the illustration in FIG. 6.

[0055] In FIG. 7, various possible shapes of the sealing body 11 are shown, which deviate from the shape of FIG. 1 with two radially circumferential sealing beads. For example, FIG. 7a shows a detail of an embodiment with three radially circumferential sealing beads. In the embodiment of FIG. 7b, the shape of the sealing body 11 comprises a rectangular cross-section in which the axial extension is more than twice the radial material thickness. Deviating from this, the sealing body 11 in the embodiment of FIG. 7c also comprises a rectangular cross-section, wherein the axial extension and the material thickness are substantially the same. FIG. 7d shows a further embodiment in which two sealing bodies 11, corresponding to the embodiment of FIG. 7c, are arranged axially spaced apart on the electrical conductor 10. The shape design of the housing part 12 is in each case adapted to the shape design of the sealing body 11, or can be produced accordingly by the shape design of the sealing body 11 during manufacture.

EMBODIMENTS

[0056] Embodiment 1. Electrical conductor (10) for conducting electrical current through a housing, wherein [0057] a sealing body (11) of an elastic material is arranged on the electrical conductor (10), wherein [0058] the sealing body (11) encloses the electrical conductor (10) in a first sealing section (13) radially surrounding the electrical conductor (10), wherein [0059] a housing part (12) is arranged on the electrical conductor (10), characterized in that [0060] the housing part (12) radially encloses at least a part of the surface of the sealing body (11), which is not in contact with the electrical conductor (10) in the first sealing section (13), in a second sealing section (16), wherein [0061] the elastic material of the sealing body (11) comprises at least one hollow chamber (17) and/or is an elastomer foam.

[0062] Embodiment 2. Electrical conductor (10) according to embodiment 1, characterized in that the elastic material is an elastomer foam with closed pores (18).

[0063] Embodiment 3. Electrical conductor (10) according to embodiment 1 or 2, characterized in that

[0064] the housing part (12) encloses the electrical conductor (10) in a third and/or fourth sealing section (14, 15) radially surrounding the electrical conductor (10).

[0065] Embodiment 4. Electrical conductor (10) according to embodiment 3, characterized in that

[0066] the third and/or fourth sealing section (14, 15) in each case axially adjoins the first sealing section (13) on the electrical conductor (10).

[0067] Embodiment 5. Electrical conductor (10) according to any one of the preceding embodiments, characterized in that the material of the housing part (12) is a plastic, preferably a thermoplastic.

[0068] Embodiment 6. Electrical conductor (10) according to any one of the preceding embodiments, in that the material of the housing part (12) comprises a higher modulus of elasticity than the elastic material of the sealing body (11).

[0069] Embodiment 7. Electrical conductor (10) according to any one of the preceding embodiments, characterized in that the electrical conductor (10) comprises a rounded contour at least in the first sealing section (13).

[0070] Embodiment 8. Electrical conductor (10) according to any one of the preceding embodiments, characterized in that

[0071] the electrical conductor (10) and the sealing body (11) comprise a substance-to-substance bond.

[0072] Embodiment 9. Method for manufacturing an electrical conductor (10) according to any one of the preceding embodiments, characterized by the following steps: [0073] providing an electrical conductor (10); [0074] first molding, in particular injection molding, of a sealing body (11) to the first sealing section (13) radially surrounding the electrical conductor (10) which encloses the electrical conductor (10), wherein the sealing body (11) is formed of an elastic material with at least one hollow chamber and/or of an elastomer foam; [0075] second molding, in particular injection molding, of the housing part (12) enclosing the sealing body (11) at the second sealing section (16).

[0076] Embodiment 10. Method according to embodiment 9, characterized in that during the second molding, in particular injection molding, the sealing body (11) is compressed under the molding pressure of the second molding of the housing part (12).

[0077] Embodiment 11. Method according to embodiment 10, characterized in that the volume of the sealing body (11) is reduced to at least 97% during the second molding, in particular injection molding.

[0078] Embodiment 12. Method according to any one of embodiments 9 to 11, characterized in that during the second molding, in particular injection molding, of the housing part (12), the electrical conductor (10) is enclosed by the housing part (12) in the third and fourth sections (14, 15).

[0079] Embodiment 13. Method according to any one of embodiments 9 to 12, characterized in that during the first molding, in particular injection molding, the elastic material is crosslinked to form the sealing body.