Electromagnetically actuable brake device

Abstract

An electromagnetically actuable brake device includes: a coil shell, in particular of the solenoid, an armature disk, which is connected to the coil shell in a torque-proof yet displaceable manner, a sensor having a sensor housing, a spring part, and a screwed cable gland. The coil shell has a stepped through bore, the sensor housing of the sensor has a stepped configuration, the screwed cable gland is situated at an end of the bore, in particular is screwed into a threaded section of the bore, the spring part is situated in the bore between the screwed cable gland and the sensor housing, the spring part is braced on a step of the sensor housing on one side and on the screwed cable gland on the other, and the sensor housing is pressed against a step of the bore, in particular by the spring part.

Claims

1. A sensor system for an electromagnetically actuable brake device, comprising: a coil shell including a stepped through bore; a sensor including a stepped sensor housing; and a spring part arranged in the bore and pressing the sensor housing against a step of the stepped through bore.

2. The sensor system according to claim 1, wherein one side of the spring part is braced on a step of the sensor housing.

3. The sensor system according to claim 1, wherein the stepped through bore transitions at the step from a first diameter to a second diameter, the second diameter being smaller than the first diameter.

4. The sensor system according to claim 3, wherein the sensor housing includes a step, the sensor housing having a first diameter on a first side of the step of the sensor housing and a second diameter on second side, opposite the first side, of the step of the sensor housing.

5. The sensor system according to claim 4, wherein the first diameter of the sensor housing is smaller than the first diameter of the stepped through bore, and the second diameter of the sensor housing is smaller than the second diameter of the stepped through bore.

6. The sensor system according to claim 1, wherein a portion of the sensor housing having the first diameter is arranged in a portion of the stepped through bore having the first diameter, and wherein a portion of the sensor housing having the second diameter is arranged in a portion of the stepped through bore having the second diameter.

7. The sensor system according to claim 4, wherein the spring part presses the step of the sensor housing against the step of the stepped through bore.

8. The sensor system according to claim 1, wherein the sensor housing includes a first step and a second step, the spring part pressing the first step against the step of the stepped through bore and being braced against the second step of the sensor housing.

9. The sensor system according to claim 1, further comprising a screwed cable gland arranged at an end of the stepped through bore, the spring part being arranged between the screwed cable gland and the sensor housing.

10. The sensor system according to claim 1, wherein the sensor is arranged as an eddy-current sensor.

11. The sensor system according to claim 1, wherein the sensor is adapted to sense a distance between an armature disk of the brake device and the sensor.

12. The sensor system according to claim 9, wherein the screwed cable gland is screwed into a threaded section of the stepped through bore.

13. The sensor system according to claim 1, wherein the sensor and the stepped through bore are located at a greater radial distance from an axis of a shaft of the brake device to be braked than a coil of a solenoid of the brake device.

14. The sensor system according to claim 1, further comprising a cable centrically routed from the sensor through the spring part.

15. The sensor system according to claim 14, further comprising a screwed cable gland arranged at an end of the stepped through hole, the spring part being arranged between the screwed cable gland and the sensor housing, the cable being arranged centrically through the screwed cable gland.

16. The sensor system according to claim 1, wherein the sensor is adapted to monitor wear of a brake pad of the brake system by sensing an axial distance between an armature of the brake system and the coil shell.

17. The sensor system according to claim 1, wherein the spring part is arranged as a helical spring.

18. The sensor system according to claim 1, wherein the step is arranged at a first end of the stepped through bore.

19. The sensor system according to claim 18, further comprising a screwed cable gland arranged at a second end of the stepped through bore opposite the first end, the spring part being arranged between the screwed cable gland and the sensor housing.

20. The sensor system according to claim 9, wherein the screwed cable gland includes a hexagonal shoulder engaging against a surface of the coil shell.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a brake device according to an example embodiment of the present invention including a sensor for wear detection, in a sectional view.

(2) FIG. 2 shows the sensor with an associated mounting system in an oblique view.

(3) FIG. 3 shows an alternative brake device equipped with a sensor for wear detection, in a sectional view.

(4) FIG. 4 shows the sensor associated with FIG. 3 with an associated mounting system, in an oblique view.

DETAILED DESCRIPTION

(5) As illustrated in FIG. 1 and FIG. 2, an electromagnetically actuable brake according to an example embodiment of the present invention is depicted.

(6) A brake-pad carrier 11 is connected to a shaft to be braked in a torque-proof yet axially displaceable manner. The shaft is mounted inside a housing part that is connected to coil shell 3 of a solenoid in a torque-proof manner.

(7) Brake-pad carrier 11 has an internal tooth system which is in engagement with an external tooth system disposed on the shaft. The tooth system extends in the axial direction so that brake-pad carrier 11 is able to be axially displaced in relation to the shaft.

(8) A coil brace 6, in which an energizable coil 7 is situated, is accommodated in an annular groove of coil shell 3. The ring axis of the annular groove is aligned coaxially with respect to the shaft axis.

(9) Brake-pad carrier 11 is provided with brake pads 9 axially on both sides. An armature disk 8 is situated axially between brake-pad carrier 11 and coil shell 3. For example, armature disk 8 is made from a ferromagnetic material. Armature disk 8 is connected to coil shell 3 in a torque-proof yet axially displaceable manner with the aid of guide elements, the armature disk being guided by the guide elements during the displacement.

(10) Spring elements are situated between coil shell 3 and armature disk 8. An approach of armature disk 8 toward coil shell 3 can therefore only take place counter to the force generated by the spring elements.

(11) When coil 7 is energized, armature disk 8 is pulled toward coil shell 3 counter to the spring force generated by the spring elements.

(12) In the non-energized state of coil 7, the spring elements axially press armature disk 8 in the direction of brake-pad carrier 11, the latter being axially displaced in the process and pressed against a part 10, which has a brake surface and is firmly connected to coil shell 3.

(13) In other words, in the non-energized state of coil shell 7, armature disk 8 is pushed away from coil shell 3 up to an axial stop position. The stop position is a function of the thickness of the brake pads. Depending on the wear, the axial distance between armature 8 and coil shell 3 thus differs in the non-energized state.

(14) To monitor wear, a sensor is provided for sensing this distance.

(15) The sensor is arranged as an eddy-current sensor.

(16) The housing of the sensor has a stepped outer contour.

(17) A through bore, in which the sensor is accommodated, is situated in coil shell 3. The bore also has a stepped configuration and has a cross-section that tapers in the direction of the armature disk. Via a corresponding step, housing 1 of the sensor rests against the step of the bore and includes a step 20 on the side facing away from this step and/or on the side facing away from armature disk 8. This step 20 leads from a first diameter to a second diameter which is smaller than the first diameter. The axial end region tapering in this manner is disposed at the end of sensor housing 1 facing away from armature disk 8.

(18) Sensor housing 1 may be arranged as a rotating body.

(19) Sensor cable 5 is centrally routed out of sensor housing 1. A spring part 2, arranged as a spiral spring, is accommodated in the bore and braced on step 20 of sensor housing 1. The end of the bore that faces away from armature disk 8 is sealed with the aid of a screwed cable gland 4, which presses against the end of spring part 2 facing away from step 20. Screwed cable gland 4 is connected by screws to an internal threaded section of the bore, or stated another way, is screwed into the bore.

(20) The internal threaded section extends only across an end section of the bore and not across the entire bore. This end section of the bore is situated in the end region of the bore that faces away from armature disk 8.

(21) Screwed cable gland 4 may be formed of metal.

(22) In the same manner, sensor housing 1 and spring part 2 are made from metal.

(23) When screwing screwed cable gland 4 into the bore, spring part 2 is tensioned and thus presses against sensor housing 1. Because of the preloading created in this manner, the sensor housing 1 is pressed against the step of the bore.

(24) Cable 5 is axially routed through spring part 2 in a centered manner and is then centrically routed through a recess in screwed cable gland 4 in the axial direction.

(25) Screwed cable gland 4 has a hexagonal shoulder 21, which limits the screwing-in of screwed cable gland 4 and is furthermore suitable for the positive application of an open end wrench. This makes it easy to screw screwed cable gland 4 into the threaded section of the bore.

(26) In contrast to the exemplary embodiment according to FIGS. 1 and 2, in the exemplary embodiment according to FIGS. 3 and 4 a sleeve 30 for spacing spring part 2 apart from sensor housing 1 is placed inside the bore.

(27) In this way the sensor is able to be installed on a second brake situated at a greater distance, sleeve 30 bridging a first brake.

(28) As illustrated in FIGS. 3 and 4, a first and a second electromagnetically operable brake are provided in the double brake.

(29) The first brake is arranged according to FIG. 1. The second brake has a similar configuration; here, the part of the second brake having a counter-brake surface is not a coil shell or need not be a coil shell, but may exemplarily be arranged as a bearing shield of an electric motor.

(30) In this case, a second coil shell 36 is used as the particular part 10 that has a brake surface for brake-pad carrier 11 with brake pad 9. Second coil shell 36 is firmly connected to coil shell 3 of the first brake, in particular connected with the aid of screws.

(31) Another annular groove, its ring axis being aligned coaxially with the shaft axis, is also situated in second coil shell 36.

(32) Once again, a coil brace 34, which accommodates a second coil 35, is accommodated in the annular groove of second coil shell 36.

(33) A second brake-pad carrier 11 is connected to the shaft in a torque-proof yet axially displaceable manner; the shaft has an axially extending external tooth system for this purpose, which is in engagement with an internal tooth system of brake-pad carrier 11. An armature disk 33 is axially situated between the second brake-pad carrier and second coil shell 36 and connected to second coil shell 36 in a torque-proof yet axially displaceable manner with the aid of guide elements.

(34) Second spring elements are situated between second armature disk 33 and second coil shell 36 so that when second coil 35 is energized, armature disk 33 is pulled toward coil shell 36 counter to the spring force generated by the second spring elements. In the non-energized state of second coil 35, second armature disk 33 is axially pushed away from second coil shell 36 and onto the second brake-pad carrier with brake pads. The second brake-pad carrier in turn is axially pressed onto a part having a counter-brake surface, the part being situated on the side of the second brake-pad carrier axially facing away from armature disk 33.

(35) A sensor for wear detection of the brake pads of the second brake is in turn disposed in a bore that is situated in coil shell 36 in an axially uninterrupted manner and has a stepped configuration; the narrower and/or tapered section of the bore is situated on the side facing second armature disk 33, and the section having the larger cross-section is situated on the side facing second armature disk 33.

(36) The bore, so to speak, continues through armature disk 8 of the first brake and through coil shell 3 of the first brake. The bores in armature disk 8 and coil shell 3 have a coaxial alignment and are arranged using at least the same cross-section.

(37) Thus, sensor housing 1 is pressed against the step of the bore implemented in second coil shell 36, and a corresponding step of the sensor housing is placed against the step of the bore introduced into second coil shell 36, or in other words, is pressed against it.

(38) A spring part 2 is in turn pressing against step 20 of sensor housing I; however, at its axial end facing away from sensor housing 1, spring part 2 is braced on a sleeve 30, which is in turn braced at its axial end facing away from spring part 2 on screwed cable gland 4, which is screwed into coil shell 3 in the threaded section.

(39) This screwed cable gland is in turn resting against coil shell 3 via its shoulder 21.

(40) Sleeve 30 is hollow. Thus, cable 5 is centrically routed through spring part 2 and sleeve 30 so that it is likewise able to be centrically routed through the screwed cable gland and out of the interior space of the brake device in a sealed manner.

(41) The bore and sleeve 30 are situated at a radial distance from the shaft axis such that brake-pad carrier 11 together with brake pads 9 is radially situated within the bore and sleeve 30. The axial range covered by sleeve 30 covers the axial range covered by armature disk 8 and the axial range covered by brake-pad carrier 11 with brake pads 9, and it overlaps with the axial range covered by coil shell 3 and by second coil shell 36.

(42) Coil shell 3 and second coil shell 36 are connected with the aid of a cover 31, especially a rubber cover, so that the intermediate region situated axially between coil shell 3 and coil shell 36 is covered in the manner of a housing. Cover 31 has an annular design for this purpose and is placed in a nonpositive manner onto a subregion of the external surface of coil shell 3 and coil shell 36.

(43) Situated in the intermediate region are brake-pad carrier 11 together with brake pads 9 and armature disk 8. The region axially covered by cover 31 therefore covers the axial region covered by brake-pad carrier 11 together with brake pads 9 and the axial region covered by armature disk 8.

(44) In addition, when viewed from the direction of the shaft axis, cover 31 is situated radially outside brake-pad carrier 11 together with brake pads 9 and armature disk 8.

(45) Coil shell 36 and the part having the counter-brake surface are similarly connected with the aid of a cover 32, in particular a rubber cover, so that the second intermediate region that is situated axially between second coil shell 36 and the part having the counter-brake surface is covered in the manner of a housing. Cover 32 has an annular design for this purpose and is placed in a nonpositive manner on a subregion of the external surface of coil shell 36 and of the part having the counter-brake surface.

(46) Situated in the second intermediate region are the second brake-pad carrier together with the brake pads and second armature disk 33. As a result, the region axially covered by cover 32 covers the axial region covered by the second brake-pad carrier together with the brake pads and the axial region covered by armature disk 33.

(47) In addition, when viewed from the direction of the shaft axis, cover 32 is situated radially outside the second brake-pad carrier together with the brake pads and armature disk 33.

(48) Cover 31 may be arranged in the same manner as cover 32. As a result, only one type of cover needs to be stocked.

(49) Sleeve 30 is situated at a greater radial distance than coil 7, coil shell 6 and/or the annular groove in coil shell 3 and/or the annular groove in coil shell 36.

LIST OF REFERENCE NUMERALS

(50) 1 Sensor housing, stepped configuration 2 Spring part 3 Coil shell 4 Screwed cable gland 5 Cable 6 Coil brace 7 Coil, in particular brake coil 8 Armature disk 9 Brake pad 10 Part having the brake surface 11 Brake-pad carrier 20 Step 21 Shoulder 30 Sleeve 31 Cover, in particular rubber cover 32 Cover, in particular rubber cover 33 Further armature disk 34 Further coil brace 35 Further coil 36 Further coil shell