Electromagnet and method of making the electromagnet

Abstract

An electromagnet and method for producing the electromagnet. The electromagnet is intended to maintain pretensioning force of fastening by a force acting on a yoke over intended operating time under changing operating temperatures. The yoke encloses an armature that is provided with a flange, which conducts magnetic flux from a housing to the armature, the housing being connected on the one hand to a flange of the yoke and on the other hand to a core flange in a material-bonding manner by welding. The electromagnet can be used for actuation of valves, couplings or other electromechanical adjusting elements.

Claims

1. A method for producing an electromagnet, that includes at least a magnetic coil wound onto a coil core, a housing, a pole core, an armature, an armature rod, and a yoke, wherein the coil core includes the yoke, the pole core, and a core flange, and wherein the yoke enclosing the armature is provided with a yoke flange, which conducts magnetic flux from the housing to the armature, comprising: overmolding the yoke, the yoke flange, the pole core and the core flange with a plastics compound for producing the coil core; winding the magnetic coil around the coil core; fitting the housing around a first outer-most surface of the yoke flange, the magnetic coil, and the second outer-most surface of the core flange; welding the housing to the first outer-most surface of the yoke flange and the second outer-most surface of the core flange to form a weld connection; fitting a sliding film into the yoke; fitting the armature rod and the armature into the yoke; welding an end plate onto the yoke or pressing the end plate into the yoke; and pressing a holder onto the yoke flange and the core flange to cause a flux of a majority of a force to pass from the holder to a transmission housing via the yoke flange, the housing, and the core flange.

2. The method of claim 1, further comprising fastening the electromagnet to a vehicle transmission housing by engaging and pressing the holder directly against the yoke flange to directly engage and press the core flange against the vehicle transmission housing.

3. The method of claim 1, further comprising: passing less than a majority of the flux of force through the plastics compound between the yoke and the pole core.

4. An electromagnet comprising: a housing; a coil core having a yoke, a pole core, and a core flange, the yoke, the pole core, and the core flange having a plastic overmold, the yoke and the pole core defining an axial intermediate space between the yoke and the pole core, the plastic overmold fills the axial intermediate space; a magnetic coil wound on the coil core; an armature; an armature rod extending from the armature; and a welded connection; a holder; wherein the yoke flange has an outer yoke surface configured to be directly engaged by the holder to cause a flux of a majority of a force to pass from the holder to a transmission housing via the yoke flange, the housing, and the core flange; wherein the yoke covers at least a portion of the armature and includes a yoke flange having a first outer radial surface, the yoke flange configured to conduct magnetic flux from the housing to the armature; wherein the core flange has a second outer radial surface; wherein the housing is connected to the first outer radial surface of the yoke flange and the second outer radial surface of the core flange by the welded connection; wherein the housing encloses the yoke flange and the core flange about the first outer radial surface and the second outer radial surface.

5. The electromagnet of claim 4, wherein the armature is mounted in the yoke by a sliding film.

6. The electromagnet of claim 4, wherein fastening of the electromagnet to a transmission housing is by the holder pressing onto the yoke flange and the core flange supporting the electromagnet on the transmission housing.

7. The electromagnet of claim 4, wherein the core flange has an outer core surface configured to directly engage a vehicle transmission housing; wherein the holder is configured to press against the outer yoke surface and press the outer core surface against the vehicle transmission housing.

8. The electromagnet of claim 4, wherein less than a majority of the flux of force is through the plastic overmold between the yoke and the pole core.

Description

DRAWINGS

(1) The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

(2) FIG. 1 shows the electromagnet according to the disclosure, and the fastening to the transmission housing.

(3) Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

(4) Example embodiments will now be described more fully with reference to the accompanying drawings.

(5) The electromagnet 1 according to FIG. 1 includes at least a magnetic coil 2 wound onto a coil core 6, a housing 3, a pole core 4, an armature 5, an armature rod 16 and a yoke 7.

(6) In this case, the coil core 6 includes the yoke 7, the pole core 4 and a core flange 14.

(7) The coil core 6 is produced by a joint encapsulation or overmolding of the yoke 7, the pole core 4 and the core flange 14 with a plastics compound 8.

(8) In this case, the axial intermediate space 10 between the yoke 7 and the pole core 4 is also filled with the plastics compound 8.

(9) The coil core 6 is produced with great accuracy in its inside diameter 11 bearing the armature 5.

(10) The yoke 7 enclosing the armature 5 is provided with a flange 15, which conducts the magnetic flux from the housing 3 to the armature 5.

(11) In this case, the housing 3 is connected on the one hand to the flange 15 of the yoke 7 and on the other hand to the core flange 14 in a material-bonding manner by welding.

(12) The fastening of the electromagnet 1 to a transmission housing 13, which is only partially shown, is performed by a likewise only partially shown holder 12 pressing onto the yoke flange 15 and the core flange 14 supporting the electromagnet 1 on the transmission housing 13.

(13) Advantageously, after assembly, the initial flux of force passes from the holder 12 to the transmission housing 13 predominantly over 50% via the yoke flange 15, the housing 3 and the core flange 14, because the stiffness of the flux-of-force path via the housing 3 is accordingly made greater than the stiffness of the flux-of-force path via the yoke 7, the pole core 4 and the plastics compound 8 between the yoke and the pole core, the plastics compound 8 referred to being responsible in particular for reducing the stiffness.

(14) After an operating time of for example 100 h, a still greater proportion of the flux of force passes via the yoke flange 15, the housing 3 and the core flange 14, because the plastics compound 8 gradually deforms plastically.

(15) Preferably, the housing 3 encloses the yoke flange 15 and the core flange 14 respectively on the outside.

(16) It is likewise preferable that the housing 3 is connected to the yoke flange 15 and the core flange 14 by laser welding.

(17) Advantageously, the armature 5 of the electromagnet is mounted in the yoke 7 by means of a sliding film 9.

LIST OF DESIGNATIONS

(18) 1. Electromagnet

(19) 2. Magnetic coil

(20) 3. Housing

(21) 4. Pole core

(22) 5. Armature

(23) 6. Coil core

(24) 7. Yoke

(25) 8. Plastics compound

(26) 9. Sliding film

(27) 10. Intermediate space

(28) 11. Inside diameter

(29) 12. Holder

(30) 13. Transmission housing

(31) 14. Core flange

(32) 15. Yoke flange

(33) 16. Armature rod

(34) 17. End plate

(35) The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.