Actuator for a vehicle transfer case

Abstract

Actuator (1) for controlling a motor vehicle transfer case, comprising a commutator motor (2) consisting of a pot-shaped housing (4) made of magnetically conductive material, to the inner circumference of which permanent magnets (44) are attached, a wound, iron-grooved rotor (40), the winding (42) of which is supplied with current via carbon brushes (50) and a commutator (43) mounted on a rotor shaft (41) and electrically connected to the winding (42), the rotor (5) being mounted in a first bearing (7) arranged in the base of the housing (4), and a brake (10) which prevents unwanted adjustment of the actuator by torques acting back from the drive output, characterized by the combination of the following features: a) A plastic housing part (6) made of injection-moldable material and provided with axially parallel ribs (37) is attached to the housing (4), in which the brake (10) is arranged, b) the plastic housing part (6) is mechanically connected to a brush bridge (23) and an eccentrically arranged connector, c) A light alloy cover (9) is attached to the plastic housing part (6) with a seal (31) in between, the cover having a passage (33) for the motor shaft (41) and a connection area for connection to a transfer case housing, d) that the plastic housing part provides receptacles (36) which are aligned parallel to screw receptacles (17b) and to the motor axis and extend from the mounting flange (3) of the housing (4) to the light alloy cover (9). e) the rotor (5) is mounted in a second bearing (8) which is received in a stator part (14) of the brake (10). f) that the brush bridge (23) and the brake (10) are arranged at least partially within the space enclosed by the plastic housing part (6).

Description

[0001] The invention relates to an actuator (1) with a commutator motor (2) comprising a pot-shaped housing (4) made of magnetically conductive material, to the inner circumference of which permanent magnets (44) are attached, a wound, iron-grooved rotor (40) whose winding (42) is supplied with current via carbon brushes (50) and a commutator (43) attached to a rotor shaft (41) and electrically connected to the winding (42), which rotor (5) is mounted in a first bearing (7) arranged in the base of the housing (4) and a brake which prevents unwanted adjustment of the actuator by torques acting from the drive output.

[0002] From EP 1 320 176 A2 a generic actuator with a commutator motor and a brake (10) is known.

[0003] DE 203 18 344 U1 discloses a motor housing for an electric motor and / or its accessories, consisting of one or more identical housing elements that can be joined together and which can be closed and / or connected to each other by flange elements, wherein at least four bores for the insertion of fastening means are provided on the end face, which define a rectangle with sides a and b of different lengths, wherein a housing element and a flange element can be joined together alternately in any number, and the adjacent housing elements are each arranged rotated by 90 degrees relative to each other.

[0004] DE 20 2005 004 435 U1 relates to an electric drive with components that are connected to each other via at least one snap connection with a deflectable locking device that is arranged projecting from an outer area of ​​the electric motor, geared motor or steep drive.

[0005] DE 295 06 768 U1 describes a drive unit for a forklift truck, with a DC motor, a brake attached to the housing of the DC motor with a brake rotor arranged in a brake housing, which is coupled to the shaft of the DC motor, wherein the brake rotor is designed as a fan wheel, the brake housing has an intake opening and a discharge opening which is connected to the interior of the motor housing and the motor housing has an exhaust opening.

[0006] EP 0 384 948 B1 shows a cylinder for a piston-cylinder assembly with a tubular cylinder housing made of plastic-containing material, in which a bore opening for the slidable reception of a piston is formed, and whose wall is connected to at least one stiffening element arranged outside the bore opening in the circumferential area thereof, wherein the stiffening element is designed as a stiffening rod or bar which extends parallel to the longitudinal direction of the bore opening along it and is held in a recess in the wall of the cylinder housing.

[0007] DE 42 09 586 A1 discloses a throttling device for power control of an internal combustion engine with a throttle housing, an actuable throttle element, an actuator and a throttle element stop connected to the throttle element, wherein the throttle element is mounted in the throttle housing and is adjustable by the actuator and the pivoting movement of the throttle element is limited by a counter-stop by means of which a stop position of the throttle element can be determined, wherein when the throttle element stop is against the counter-stop the throttle element assumes its stop position, wherein the counter-stop is connected to the actuator and the stop position of the throttle element can be changed by adjusting the actuator relative to the throttle housing.

[0008] DE 39 13 176 A1 describes a working method for the axial and radial fixing of a rolling bearing inserted into the bearing housing, wherein the accessible outer ring of the rolling bearing is fixed by features formed without machining from the material of the bearing housing and acting on its end face, wherein a barrier made of deformed bearing housing material, which at least partially surrounds the end face of the outer ring of the rolling bearing from the outside, serves as the sole fixing means for the rolling bearing.

[0009] In demanding applications, the housing sections for mounting a brake are made of die-cast aluminum or zinc parts. Manufacturing lightweight metal housings requires a number of complex production processes. These processes include post-treatment procedures such as deburring, sandblasting, tempering, machining, threading, and surface treatments to improve corrosion resistance. Furthermore, lightweight metal components have disadvantages in terms of storage, transport, and assembly. Tool life is relatively short, and the integration of additional components is very limited. To reduce the fuel consumption of motor vehicles, it is also necessary to provide actuators with the lowest possible weight.

[0010] The object of the present invention is therefore to design a generic actuator in such a way that it can be manufactured economically, has the lowest possible weight and can be adapted to different stability requirements using simple means.

[0011] This problem is solved according to the invention by the characterizing feature of claim 1. The plastic components provide an actuator whose housing exhibits high rigidity, strength, temperature resistance, good surface quality, in particular corrosion resistance, high creep resistance, high dimensional stability, and low distortion, while its manufacture is very economical and a high degree of functional integration is possible. The weight is approximately 50% to 75% less than that of light metal housings (depending on the material). The reinforcing ribs stiffen the housing and also act as cooling fins. To allow the plastic housing to be adapted to different strength requirements, receptacles are provided in the housing for inserting reinforcing rods as needed (application-specific).Because the plastic housing part rests against the mounting flange of the housing, the drive can absorb higher forces than with an intermediate layer of a seal.

[0012] Further developments of the invention are described in the dependent claims. Assembly is simplified by the fact that the brush bridge is arranged between the housing and the plastic housing part, and that the brush bridge and the connector are integral.

[0013] A particularly high proportion of plastic in the overall drive housing is achieved by shifting the connection plane between the motor housing pot and the plastic housing part into the area of ​​the commutator; this allows the housing sections not required for the magnetic circuit, which include the commutator, the brush bridge and also the brake, to be manufactured from the easily injection-moldable and lightweight plastic material.

[0014] An improvement in the stability of the actuator during operation is achieved by providing the mounting flange (3), the plastic housing part (6), and the light alloy cover (9) with additional recesses (16a, 16b, 16c) for bolting the actuator (1) to a distribution gearbox housing. These recesses can be further reinforced with sleeves, if necessary, to withstand compressive forces. The same effect is achieved by rods that can be installed in correspondingly shaped receptacles arranged parallel to the additional recesses (16b). Both reinforcement measures can be used alternatively or in combination.

[0015] Advantages in the assembly of the light alloy cover result from recesses (18) in the plastic housing part, into which the mounting projections (40) of the light alloy cover (9) can engage; these projections act similarly to an assembly aid and allow the light alloy cover to accommodate an internal thread. However, for reasons of material savings and easier post-processing of the light alloy cover by turning, one variant provides for the thread to be located in the plastic housing part, thus eliminating the need for the mounting projections (40).

[0016] For reasons of space optimization, part reduction and easier assembly, it is provided that an output-side motor bearing (8) is mounted in the stator part (14) of an electromagnet (12), wherein the stator part (14) consists of a sintered magnetically conductive material.

[0017] A simple connection option is provided by orbital riveting of the bearing to the stator part (14) on the stator part of the brake.

[0018] The connection area of ​​the light alloy cover receives an interface or adapter function through a projection (19) which is provided on its outer circumference with an annular groove (20) in which a sealing ring (32) is inserted, the projection being centered in a distribution gearbox housing.

[0019] The plastic housing part is made of fiber-reinforced plastic material, e.g., glass fiber reinforced.

[0020] Exemplary embodiments of the invention are explained in more detail below with reference to the drawing. The drawing shows: Fig. 1 a three-dimensional view of a first embodiment of an actuator, Fig. 2a A first view of a plastic housing part of the actuator, Fig. 2b a second view of the plastic housing part, Fig. 3a A first view of a light alloy cover of the actuator, Fig. 3b a second view of the light alloy lid, Fig. 4 a sectional view of the actuator, Fig. 5 an exploded view of a second embodiment of the actuator, Fig. 6a a first view of a plastic housing part of the second embodiment, Fig. 6b a second view of the plastic housing part with sleeves before assembly, Fig. 6c a third view of the plastic housing part with mounted sleeves, Fig. 6c a fourth view of the plastic housing part with rods before assembly, Fig. 7 a fifth view of the plastic housing part, Fig. 8 a light alloy lid of the second embodiment, Fig. 9 a first three-dimensional view of the actuator of the second embodiment, Fig. 10 a second three-dimensional view of the actuator and Fig. 11 a partial sectional view of the actuator of the second embodiment.

[0021] Fig. Figure 1 shows a three-dimensional view of a first embodiment of an actuator 1 according to the invention, comprising a housing 4 of a commutator motor 2, a brush bridge 23 with a connector 24, a plastic housing part 6, and a light metal cover 9. The housing 4 has a mounting flange 3 with screw recesses that correspond to screw recesses in the plastic housing part 6 and the light metal cover 9. The housing 4 is screwed into the light metal cover by means of mounting screws 25, thereby firmly connecting the housing 4, the brush bridge 23 arranged between the housing 4 and the plastic housing part 6, the plastic housing part 6, and the light metal cover 9. The brush bridge 23 is additionally fastened to the plastic housing part 6 by screws 27.The mounting flange 3, the plastic housing part 6, and the light alloy cover 9 each have corresponding recesses 16a that allow the actuator 1 to be mounted. The plastic housing part has recesses 18 into which mounting projections 40 of the light alloy cover engage, with the screws 25 being screwed into the mounting projections.

[0022] Fig. Figure 2a shows a first view of the plastic housing part 6 of the first embodiment of the actuator, with the recesses 18, the screw receptacles 17b, the additional recesses 16b and a plug support 45 for the plug of the brush bridge.

[0023] Fig. Figure 2b shows a second view of the plastic housing part 6 of the first embodiment of the actuator, with the connector support 45, the screw receptacles 17b, the recesses 18, the additional recesses 16b and a projection 51 with an annular groove 52 for a ring seal. The projection 52 serves as a centering element for the motor housing pot.

[0024] The Fig. 3a and Fig. Figure 3b shows a view of the light-alloy cover 9 of the first embodiment of the actuator, with the mounting projections 40, the screw receptacles 17c, the additional recesses 16c, a passage 33 for a motor shaft, and a projection 19 with an annular groove 20 for a ring seal. The light-alloy cover is made of aluminum; however, zinc is also suitable.

[0025] Fig. Figure 4 shows a sectional view of the first embodiment of the actuator 1, comprising the commutator motor 2, the pot-shaped housing 4 (stator) made of magnetically conductive material, a rotor 5, a shaft 41, a slotted laminated core 53, and a winding 42 connected to a commutator 43. The stator of the commutator motor includes permanent magnets 44 arranged in the pot-shaped housing. The rotor 5 is supported on one side by a first bearing 7, which is received in the pot-shaped housing 4, and on the other side by a second bearing 8, which is received in a stator part 14 of a brake 10. The brake 10 comprises an electromagnet 12, with a magnetic coil 13 which is housed in the stator part 14, a spring ring and a brake disc 11 and is housed in the plastic housing part 6, as is the brush bridge 23, with carbon brushes 50, the plug 24, plug contacts 21 and a coil connection 22 for the magnetic coil 13.A ring seal 29 is inserted in the annular groove 52 of the extension 51, which conforms to the inner circumference of the housing 4. A seal 30 is arranged between the brush bridge 23 and the plastic housing part 6. A seal 31 is arranged between the plastic housing part 6 and the light alloy cover 9. A ring seal 32 is inserted in the annular groove 20 on the extension 19 of the light alloy cover 9. The extension 19 serves as an adapter piece to a housing of an automotive transfer case. The brake 10 serves to brake the shaft 41 of the non-self-locking actuator when de-energized, in order to prevent unintentional adjustment due to external torques. This does not necessarily have to be an electromagnetic brake. Wedge clamp brakes could also be used.

[0026] Fig. Figure 5 shows an exploded view of a second embodiment of the invention, comprising a pot-shaped housing 4, permanent magnets 44, a mounting flange 3 with screw receptacles 17a and additional recesses 16a, mounting screws 25, a rotor 5 with a commutator 43 and a shaft 41, an annular seal 29, a brush bridge 23 with connector 24, a seal 30 adapted to the shape of the brush bridge 23, mounting screws 26 for attaching the brush bridge to a plastic housing part 6, which includes a connector support 45, screw receptacles 17b, additional recesses 16b, receptacles 36 for rods 35 and ribs 37, a brake 10 with a stator part 14, mounting screws 27 for attaching the stator part 14, a magnetic coil 13, a spring washer 34, a brake disc 11, a magnetically conductive magnetic disc 54, and a thrust washer 55 with anti-rotation devices 56, 57,The assembly consists of a drive lug 58, which is positively secured against rotation in the plastic housing part 6, a drive lug 58 having a polygon 59 corresponding to a polygonal recess 60 in the brake disc 11 and which is mounted on the shaft 41, a seal 31, a light alloy cover 9 with mounting recesses 17c, additional recesses 16c, a shaft passage 33, a seal 32, and mounting screws 28 for attaching the light alloy cover 9 to the plastic housing part 6. The drive lug 58 is made of a sintered material. A copper-beryllium washer 61 is arranged between the drive lug 58 and the thrust washer 55 to reduce friction. The spring washer 34 is manufactured by folding a stamped sheet metal strip. The magnetic disc 54, the brake disc 11, and the thrust washer 55 each have a coding opening 62, which facilitates their easier and correct positioning during installation. The mounting flange 3,The plastic housing part 6 and the light alloy housing cover each have three screw receptacles (17a, 17b, 17c) located outside an area defined by the outer diameter of the motor housing. The electrical connection between the solenoid coil 13 and the connector 24 is established via guide plates and plug contacts. Bearings 7 and 8 are ball bearings. Bearing 7 in the motor housing is designed as a floating bearing, and bearing 8 in the magnet stator 14 is designed as a fixed bearing.

[0027] In the Fig. Figures 6a to 6d each show a view of the plastic housing part 6 of the second embodiment of the actuator in different assembly states. The plastic housing part 6 has in all Fig. 6a to 6d screw receptacles 17b and additional fastening recesses 16b, reinforcing ribs 37 on the outer circumference, a sealing edge 49, screw-in recesses 46 and rod receptacles 36. In Fig. 6b shows sleeves 48 before assembly, which are inserted into the additional recesses 16b. Fig. Figure 6c shows the 48 sleeves in their assembled state. Fig. Figure 6d shows the plastic housing part 6 with rods 35 in a pre-assembly position before assembly into the receptacles 36. The sleeves and the rods are preferably made of metal and serve as spacer sleeves or spacer rods.

[0028] Fig. Figure 7 shows another view of the plastic housing part of the second embodiment of the actuator with screw-in recesses 47 for fastening the stator part 14 of the brake 10.

[0029] Fig. Figure 8 shows a view of a light alloy cover of the second embodiment of the actuator, with screw receptacles 17c, additional recesses 16c and a shaft passage 33.

[0030] The Fig. 9 and Fig. Figures 10 each show a three-dimensional view of the second embodiment of the actuator with the housing 4, the plastic housing part 6, with the ribs 37 and the plug support 45, the brush bridge with the plug 24 and plug contacts 21, which is fastened to the plastic housing part 6 with a screw 26.

[0031] Fig. Figure 11 is a partial sectional view of the second embodiment, with the housing 4, the rotor 5, the commutator 43, the permanent magnets 44, the bearings 7 and 8, the brush bridge 23 with the brushes 50, the plastic housing part 6, the light alloy cover 9 with the projection 19, the annular groove 20 and the ring seal 32 inserted therein, the motor shaft 41, the brake 10, with the stator part 14, the spring ring 15, the brake disc 11 and the thrust washers 54, 55. Reference symbol list 1 actuator 2 Commutator motor 3 Mounting flange 4 pot-shaped housings 5 Rotor 6 plastic housing parts 7 first camp 8 second camp 9 light alloy lids 10 Brake 11 Brake disc 12 Electromagnet 13 Magnetic coil 14 Stator part of the brake 15 spring washers 16a Additional recess in the mounting flange 16b additional recess in the plastic housing part 16c additional recess in the light alloy lid 17a Screw receptacle in housing 17b Screw receptacle in the plastic housing part 17c Screw receptacle in the light alloy lid 18 recess 19 Approach 20 Ring groove 21 Plug contact 22 Coil connection 23 Brush bridge 24 plugs 25 screws 26 screw 27 screw 28 screw 29 Seal 30 Seal 31 Seal 32 Seal 33rd round 34 spring washer 35 bars 36 Recording (for staff) 37th rib 38 first camp 39 second camp 40 Mounting projection 41 wave 42 windings 43 Commutator 44 permanent magnet 45 Plug support 46 Screw-in recess (for screw 26) 47 Screw-in recess (for screw 27) 48 Sleeve 49 Sealing edge 50 brushes 51 Approach to the plastic housing part 52 Ring groove on the plastic housing part 53 sheet metal package 54 Thrust washer 55 Thrust washer 56 Anti-rotation device 57 Anti-rotation device 58 drivers 59 Polygonal 60 multi-sided recess 61 disc 62 coding breakthroughs 63 Guide plate

Claims

[1] Actuator (1) for controlling a motor vehicle transfer case, comprising a commutator motor (2) consisting of a pot-shaped housing (4) made of magnetically conductive material, to the inner circumference of which permanent magnets (44) are attached, a wound, iron-grooved rotor (40), the winding (42) of which is supplied with current via carbon brushes (50) and a commutator (43) mounted on a rotor shaft (41) and electrically connected to the winding (42), the rotor (5) being mounted in a first bearing (7) arranged in the base of the housing (4) and a brake (10) which prevents unwanted adjustment of the actuator by torques acting back from the drive output, characterized by the combination of the following features: a) A plastic housing part (6) made of injection-moldable material and provided with axially parallel ribs (37) is attached to the housing (4), in which the brake (10) is arranged, b) the plastic housing part (6) is mechanically connected to a brush bridge (23) and an eccentrically arranged connector, c) A light alloy cover (9) is attached to the plastic housing part (6) with a seal (31) in between, the cover having a passage (33) for the motor shaft (41) and a connection area for connection to a transfer case housing, d) that the plastic housing part provides receptacles (36) which are aligned parallel to screw receptacles (17b) and to the motor axis and extend from the mounting flange (3) of the housing (4) to the light alloy cover (9). e) the rotor (5) is mounted in a second bearing (8) which is received in a stator part (14) of the brake (10). f) that the brush bridge (23) and the brake (10) are arranged at least partially within the space enclosed by the plastic housing part (6). [2] Actuator according to claim 1, characterized by, that the brush bridge (23) is arranged between the housing (4) and the plastic housing part (6) with seals (29, 30) in between and the brush bridge (23) is integral with the eccentrically arranged connector (24). [3] Actuator according to claim 1 or 2, characterized by , that the commutator (43) and the brush bridge (23) are arranged at least partially outside the space enclosed by the cup-shaped housing (4). [4] Actuator according to claim 1, 2 or 3, characterized by , that the mounting flange (3), the plastic housing part (6) and the light alloy cover (9) have additional recesses (16a, 16b, 16c) which serve for screwing the actuator (1) to a distribution gearbox housing. [5] Actuator according to claim 4, characterized by , that sleeves are inserted into the additional recesses (16b). [6] Actuator according to claim 1, characterized by, that rods (35) are built into the receptacles. [7] Actuator according to at least one of the preceding claims, characterized by , that the plastic housing part (6) has recesses (18) for mounting projections (40) of the light alloy cover (9). [8] Actuator according to at least one of the preceding claims, characterized by , that an output-side motor bearing (8) is mounted in the stator part (14) of an electromagnet (12), wherein the stator part (14) consists of a sintered magnetically conductive material. [9] Actuator according to claim 1, characterized by , that the motor bearing (8) is attached to the stator part (14) by means of wobble rivets. [10] Actuator according to at least one of the preceding claims, characterized by, that the connection area includes a projection (19) which is provided on its outer circumference with an annular groove (20) in which a sealing ring (32) is inserted, wherein the projection (19) is centered in a distribution gearbox housing.

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