Filling an armature chamber in an actuator

Abstract

An actuator for an assembly in a motor vehicle may have a moving armature in an armature chamber, where the actuator has a fluid path that is configured for fluid transfer between the armature chamber and a fluid reservoir in the assembly when the actuator is installed in an assembly, where the actuator is configured to fill the armature chamber with fluid, in particular oil, when the armature moves axially, thereby drawing fluid into the armature chamber when the actuator is operated in a fluid chamber, in particular an oil chamber.

Claims

1. An electromagnetic actuator for an assembly in a motor vehicle, the electromagnetic actuator comprising: a magnetic coil, which radially encompasses an interior chamber; a pole tube which extends into the interior chamber encompassed by the coil; a bearing; and a moving armature located at least partially in an armature chamber, wherein the armature comprises an armature rod, and the armature rod is supported by the bearing, wherein the actuator has a first fluid path that is configured for fluid transfer between the armature chamber and a fluid reservoir in an assembly when the actuator is installed in an assembly, wherein the actuator is configured to fill the armature chamber with fluid when the armature moves axially via drawing the fluid into the armature chamber when the actuator is operated in a fluid chamber, wherein the armature chamber has a first fluid reservoir and a second fluid reservoir, wherein the first and second fluid reservoirs are connected to a second fluid path in a choke for fluid transfer by a choke such that the armature chamber dampens movement, wherein the second fluid path in the choke has a lower flow resistance than the first fluid path when the actuator is in operation, wherein a gap is formed between the pole tube and the bearing that results in the first fluid path for filling the armature chamber with fluid, and wherein the fluid is oil.

2. The electromagnetic actuator of claim 1, wherein the fluid chamber is an oil chamber.

3. The electromagnetic actuator according to claim 1, wherein when the actuator is in operation, the fluid is not drainable from the armature chamber.

4. The electromagnetic actuator according to claim 1, wherein the second fluid path in the choke is formed by a hole or recess in a surface of the choke.

5. The electromagnetic actuator according to claim 1, wherein the first fluid path forms a labyrinth.

6. The electromagnetic actuator according to claim 1, wherein the actuator is configured to fill the armature chamber with the fluid in a filling sequence that comprises a predefined number of axial movements of the armature.

7. The electromagnetic actuator according to claim 1, wherein the first fluid path is configured to drain the armature chamber.

8. The electromagnetic actuator according to claim 1, further comprising: a housing; and a core, which extends into the interior chamber encompassed by the coil, and is axially opposite the pole tube, wherein the core and the pole tube form the armature chamber, and wherein the choke forms an armature cover.

9. An assembly for a motor vehicle, the assembly having the fluid chamber and the electromagnetic actuator according to claim 1 located in the fluid chamber.

Description

DESCRIPTION OF THE DRAWINGS

(1) The present invention shall be explained in greater detail below in reference to the exemplary embodiments illustrated schematically in the drawings. Therein:

(2) FIG. 1 shows a schematic cutaway view of an electromagnetic actuator according to one embodiment of the invention;

(3) FIG. 2 shows a detail of FIG. 1; and

(4) FIG. 3 shows a schematic block diagram of a method according to one embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

(5) The drawings should provide a better understanding of the embodiments of the invention. They illustrate embodiments with which the principles and concepts of the invention are explained in conjunction with the description. Other embodiments and many of the advantages can be derived from the drawings. The elements in the drawings are not necessarily drawn to scale.

(6) Elements, features and components in the drawings that are identical, functionally identical, and have the same functions all have the same reference symbols, unless otherwise specified.

(7) Aspects of the invention relating to oil are referred to as fluids below. It is to be understood that the selection of oil as a fluid is merely of an exemplary nature, and does not limit the scope of protection for this patent application.

(8) FIG. 1 shows a schematic cutaway view of an electromagnetic actuator 1 that has a magnetic coil 2, a pole tube 3, a core 4, a bearing 5, and an armature 10, all of which are enclosed in a housing 14.

(9) The magnetic coil 2 forms an interior chamber in the actuator with the housing 14, in which the pole tube 3 and the core 4 are located. The pole tube 3 and core 4 are axially opposite one another and delimit an armature chamber 6 that contains an armature 10. The armature 10 comprises a choke in the form of an armature cover 7 in FIG. 1, which is radially inside the pole tube 3 and the core 4. There is an armature rod 8 inside the armature cover 7, which is supported in a bearing 5. The bearing 5 forms a receiver for the armature rod 8 and lies on the pole tube 3 at a stop on the bearing 5 such that a gap 15 is formed between the bearing 5 and the pole tube 3, which serves as the oil path 11 and a drain for the armature chamber. The gap 15 has a labyrinth structure that prevents dirt or particles from entering the armature chamber 6.

(10) Oil flows between a first fluid reservoir 19 and second fluid reservoir 20 in the armature chamber when the armature cover 7 moves axially. Fluid passes from one fluid reservoir 19, 20 to the other fluid reservoir 20, 19 when the oil is conveyed through the fluid path in the form of a hole 9 in the armature cover 7 by the movement of the armature cover 7.

(11) A protective cover 13 is placed on the pole tube 3 and the bearing 5 at the bearing end of the armature chamber that prevents shavings from entering the armature chamber. A receiver 12 for a plug-in connector is also attached to the pole tube 3.

(12) The armature rod 8 is formed along a longitudinal axis of the actuator 1, and therefore also defines the axial direction of movement for the armature 10.

(13) Line 16 indicates the oil level in the transmission. This shows that the actuator 1 is entirely immersed in the transmission fluid. Gravity therefore prevents a draining of the actuator when it is in operation.

(14) FIG. 2 shows a detail of FIG. 1 in which the gap 15, or the oil path 11 between the pole tube 3 and the bearing 5 is illustrated. This shows how oil passes through the gap 15 into a chamber 18 in the armature cover 7 that the hole 9 opens into.

(15) FIG. 3 shows a schematic block diagram of a method for filling an electromagnetic actuator with oil. The method comprises steps S1 to S3. In the first step S1, the actuator is installed in an oil chamber in a transmission. In the next step S2, the oil chamber in the transmission is filled with oil. In the following step S3, a filling sequence comprising one or more axial movements of the armature is started, in order to fill the armature chamber with oil.

REFERENCE SYMBOLS

(16) 1 actuator 2 coil 3 pole tube 4 core 5 bearing 6 armature chamber 7 choke 8 armature rod 9 fluid path 10 armature 11 fluid path 12 receiver 13 protective cover 14 housing 15 gap 16 oil level 17 still area 18 chamber 19 first fluid reservoir 20 second fluid reservoir S1-S3 method steps