GB2035713A - Electro-motive multiple-drive unit - Google Patents

Abstract

In a drive unit having at least two parallel drive shafts (10, 11, 12) and a corresponding number of magnet systems (16, 17, 18) whose pole axes are parallel and spaced apart adjacent to one another, the two segments (29, 30) supporting one pair of magnets (23, 24) are interconnected by flat side walls (36, 37) to form a one-piece pole housing, which forms the magnet flux return path; and the segments (27, 28) of an adjacent magnet system are arranged on the first pole housing, such that one of its flat walls (36) interconnects the second pair of segments in a magnetically conductive manner and forms part of the magnetic flux return path of the second magnet system. This construction is compact and is for use as an adjusting drive in vehicles e.g. to adjust a seat. <IMAGE>

Description

SPECIFICATION Electro-motive drive unit The present invention relates to an electro-motive drive unit particularly for use as an adjusting drive in motor vehicles, e.g. as a drive unit for the adjustment of windows or sliding roofs. Such a drive unit also is preferred for use in the adjustment of seats in motor vehicles, the seat being adjustable in the prescribed manner by several mutually independent drive shafts. Thus, for example, one of the drive shafts is for vertical adjustment of the seat, the other is for adjustment of the seat in the longitudinal direction of the vehicle, and a third is for adjustment of the angle of slope of the back of the seat.

A drive unit of this kind must have adequate drive moment and must be of as compact and flat a construction as possible in order to accommodate it in the usually very narrow spaces available in the motor vehicle.

In a known drive unit of this kind, the individual flux return yokes of the magnet system are integrated in a common pole housing of one-piece construction which encloses all the magnet systems and the armatures rotating therein. It is very expensive to manufacture a pole housing of this type. In addition to this, a drive unit of this kind has a number of drive shafts which differs according to the purpose for which the drive unit is used, so that a special pole housing has to be manufactured for every kind of drive unit having two, three or more drive shafts. When one type of drive unit is manufactured in small numbers, such as, for example, a drive unit having three drive shafts, the cost of producing the particular pole housing required increases the total costs of manufacturing a drive unit to an unjustifiable extent.

There.is provided by the present invention an electro-motive drive unit having at least two parallel drive shafts and armatures thereon, and two-pole magnets systems, which are associated with the armatures and each of which has two diametrically oppositely located poles which are secured to a respective shell-shaped segment forming a part of the magnet flux return path, wherein the axes of the poles of the magnet systems are spaced apart adjacent to one another and extend substantially parallel to one another, the two segments of at least one magnet system are interconnected by way of diametrically oppositely located flat walls aligned substantially parallel to the pole axes to form a one-piece pole housing forming the magnetic flux return path, and the segments of at least one further magnet system are arranged on the pole housing of the other magnet system such that one of the flat wails of the said other magnet system is a component part, connecting the segments in a magnetically conductive manner, of the magnetic flux return path of the further magnet system.

In contrast to the known drive unit the electromotive drive unit in accordance with the invention has the advantage that the costs of manufacturing the known drive unit. This is achieved, particularly by virtue of the fact that the drive unit in accordance with the invention has individual pole houses which, together with the armature located therein, form a complete individual motor. Individual motors of this kind can be assembled to form a drive unit having two, three or more drive shafts according to the customer's requirements. The respective individual motors form a complete, conventional drive having a drive shaft and can also be used individually, that is to say, detached from the drive unit.Individual motors of this kind have many possibilities of use, so that they can be manufactured in large numbers, thus reducing the total costs of manufacturing an individual motor of this kind. Since the drive unit is composed of a plurality of standardized individual motors of this kind, it follows that the costs of manufacturing the unit are substantially reduced by the lower costs of manufacturing the individual parts which are used. Only a small number of parts, which are necessary to assemble a drive unit having the desired number of drive shafts, has to be additionally manufactured. The cost of manufacturing these individual parts represents only a small proportion of the total costs of the drive unit.

Despite this advantageous construction of the drive unit from standardized individual motors which are inexpensive to manufacture, the entire drive unit remains compact and space-saving. By virtue of the measures in accordance with the invention, the volume of the drive unit is smaller than the total of the volumes of the individual motors which are combined to form the drive unit.

One embodiment of the invention is particularly advantageous. In this embodiment, two complete individual motors each having a complete pole housing are combined with a third standardized armature of an individual motor to form a drive unit having three drive shafts. The only additional components required are two shell-shaped segments which are arranged between the two pole housings and both of which carry diametrically oppositely located poles. A drive of this kind is extremely compact and space-saving and can be assembled with a very small number of additional components from standardized individual motors.

It is also advantageous to provide common bearing covers which are arranged on and cover the end faces of the armatures and the magnet systems, and have reception members for the drive shafts, with the segments and the flat walls being held between the bearing covers.

This results in a simpler construction of the drive unit which can be simply and rapidly assembled from prefabricated parts. This means that the costs of assembly are extremely low, thus resulting in an additional reduction in the costs of manufacturing the drive unit.

The invention will be further described in the following specification with reference to embodiments illustrated in the accompanying drawings, in which. Figure 1 is a perspective illustration of a drive unit, Figure 2 is an elevation of the end face of the drive unit viewed in the direction of the arrow A of Figure 1, a front bearing cover having been removed, Figure 3 is a view of the inside of a rear bearing cover of the drive unit of Figures 1 and 2, Figure 4 is a portion of a plan view of a drive unit in accordance with a second embodiment.

The electro-motive drive unit illustrated in the Figures 1 to 3 is used particularly as an adjusting drive in motor vehicles, preferably for the adjustment of seats, and has three independently rotating drive shafts 10,11, arranged parallel to one another. A respective armature 13, 14, 15 is arranged on each of the drive shafts (Figure 2).The armatures 13,14,15 have two-pole magnet systems 16,17,18 which, in the present instance, are in the form of permanent magnet systems. Each magnet system 16,17,18 has two diametrically oppositeiy located poles 19,20 and 21,22 and 23,24 respectively, all these poles being in the form of permanent magnet segments.The poles 19 to 24 are secured to respective shell-shaped segments 25-30 which constitute parts of the magnetic flux return path in a respective one of the magnet systems 16 to 18.

The magnet systems 16 to 18 and the armatures 13 to 15 rotating therein are arranged adjacent to one another, the drive shafts 10 to 12 lying within a common plane. The axes, the so-called pole axes 31, 32,33 of the individual magnet systems 16, 17, 18 respectively extend through the diametrically oppositely located poles 19, 20 and 21, 22 and 23,24 of the individual magnet systems respectively and are spaced apart and extend substantially parallel to one another.

The segments 25, 26 and 29, 30 of the two outer magnet systems 16 and 18 respectively are integrally interconnected by way of diametrically oppositely located flat walls 34,35 and 36,37 respectively which are aligned substantially parallel to the pole axes 31 and 33 respectively. The flat walls 34, 35 and 36, 37 are combined with the segments 25, 26 and 29,30 respectively to form one-piece pole housings 38 and 39 respectively which form the magnetic flux return paths of the magnet systems 16 and 18 respectively.

The segments 27 and 28 of the magnet system 17 arranged centrally between the two outer magnet systems 16 and 18 are arranged between the two pole housings 38 and 39 and abut thereagainst at both sides. The respective adjacent flat walls 35, 36 of the pole housings 38 and 39 respectively form, together with the segments 27 and 28, the magnetic flux return path of the central magnet system 17, that is to say, the magnetic flux return path of the central magnet system 17 is only completed by the two adjacent flat walls 35 and 36, so that the central magnet system 17 is only capable of functioning with the inclusion of these two flat walls 35 and 36.

The end faces of the armatures 13 to 15 and of the magnet systems 16 to 18 are commonly covered by bearing covers 40 and 41 respectively. Each bearing cover 40 and 41 has reception members for the drive shafts 10 to 12. Only the reception members 42 to 44 in the rear bearing cover 41 are shown in the drawings. Similar reception members are provided in the front bearing cover 40. Preferably, the reception members 42 to 44 are in the form of journal bearings.

The segments 27 and 28, and the segments 25,26 and 29,30 combined with the flat walls 34 to 37 to form the pole housings 38 and 39, are held between the front bearing cover 40 and the rear bearing cover 41. The bearing covers 40 and 41 have the segments 25 to 30 and the flat walls 34 to 37, and locating elements 45 to 48 by means of which the pole housings 38 and 39, formed by the flat walls 34 to 37 and the segments 25, 26 and 29, 30 respectively, are fixed in their mutual spatial correlation. The locating elements 45 to 48 are arranged on the mutually facing insides of the locating covers 40 and 41. Of the two bearing covers, only the inside 57 of the rear bearing cover 41 is illustrated in Figure 3 of the drawings. The locating elements 45 to 48 on the inside of the rear bearing cover are in the form of grooves 49 to 52.The flanks of the grooves abut, preferably in the inter-locking manner, against the segments 25 to 30 and against the end regions of pole housings 38 and 39 formed by the said segments together with the flat walls 34 to 37, the grooves thus securing the segments 25 to 30 and the flat walls 34 to 37 against radial or transverse diaplacement. The grooves 49 and 51 are in the form of full annular grooves which are engaged by the end faces of the two pole housings 38 and 39 in an inter-locking manner. The grooves 50 and 52 are of arcuate configuration to match the segments 27 and 28. The end faces of the two said segments 27 and 28 extend into the grooves 50 and 52. Grooves of similar construction to the grooves 49 and 52 are located on the inside of the front bearing cover 40 and receive the other end regions of the segments 25 to 30 and of the flat walls 34 to 37.Instead of being in the form of grooves 49 to 52, the locating elements 45 to 48 can be in the form of ribs projecting from the insides 57 of the two bearing covers 41 and 40.

The two bearing covers 40 and 41 are clamped to one another by means of clamping elements 53 to 56 which are aligned substantially axially. In the present instance, the clamping elements are in the form of screw-threaded bolts which are inserted through the two bearing covers 40 and 41 and are clamped on the outsides of the bearing covers by means of nuts.

The drive unit of Figure 4 (only a portion of which is shown) differs from the drive unit of Figures 1 and 3 only by virtue of the different manner of securing the bearing covers 40 and 41, the segments 25 to 39 and the flat walls 34 to 37. Therefore, the same components are provided with the same reference numerals in Figure 4.

Figure 4 shows a portion of the rear bearing cover 41 and a portion of the pole housing 39 of the magnet system 18 located on the extreme left hand side. The end face of the pole housing 39 is secured to the bearing cover 41. Forthis purpose, the bearing cover 41 has an opening 58, and the end face of the pole housing 39 incorporates a fastening element which projects therefrom and which, in the present instance, is a tab 59. The tab 59 extends through the opening 58 and is secured to the outside 60 of the rear bearing cover 41, preferably by bending-over, or peening over. In a similar manner (not illustrated), the pole housing 38 of the right hand magnet system 16 and the segments 27 and 28 of the central magnet system 17 are connected to the rear bending cover 41. The pole housings 38 and 39 and the segments 27 and 28 are connected to the front bearing cover 40 in the same manner. With this type of fastening, the clamping elements 53 and 56 are omitted. The locating elements 45 to 48 on the insides 57 of the two bearing covers 41 and 40 are also superfiuous, since the openings 58 and the tabs 59 secure the said members in addition to locating them. In the case of the pole housings 38 and 39, the tabs 59 can be arranged on the segments 25, 26 and 29, 30 respectively as well as on the flat walls 34 to 37.

Claims (13)

1. An electro-motive drive unit having at least two parallel drive shafts and armatures arranged thereon, and two-pole magnets systems, which are associated with the armatures and each of which has two diametrically oppositely located poles which are secured to a respective shell-shaped segment forming a part of the magnet flux return path, wherein the axes of the poles of the magnet systems are spaced apart adjacent to one another and extend substantially parallel to one another, the two segments of at least one magnet system are interconnected by way of diametrically oppositely located flat walls aligned substantially parallel to the pole axes to form a one-piece pole housing forming the magnetic flux return path, and the segments of at least one further magnet system are arranged on the pole housing of the other magnet system such that one of the flat walls of the said other magnet system is a component part, connecting the segments in a magnetically conductive manner, ofthe magnetic flux return path of the further magnet system.

2. A drive unit as claimed in claim 1,wherein three drive shafts having armatures and three associated magnet systems are provided, the two outer magnet systems are in the form of magnet systems having a one-piece pole housing and the segments of the centrally disposed magnet system are arranged between the pole housings such that the segments and the respective adjacent flat walls of the two pole housings together form the magnetic flux return path of the centrally disposed magnet system.

3. A drive unit as claimed in claim 1 or 2, wherein respective common bearing covers are arranged on, and cover, the end faces of the armatures and the magnet systems and have reception members for the drive shafts, and the segments and flat walls are held between the bearing covers.

4. A drive unit as claimed in claim 3, wherein the bearing covers, the segments and the flat walls have locating elements which fix them in their mutual spatial correlation.

5. A drive unit as claimed in claim 4, wherein the locating elements are in the form of grooves or ribs which are disposed in or on the mutually facing insides of the bearing covers and whose flanks abut against the end regions of the segments and/or flat walls and secure the said segments and/or flat walls against radial displacement.

6. A drive unit as claimed in claim 5, wherein said flanks abut against said end regions in an interlocking manner.

7. A drive unit as claimed in any of the claims 3 to 6, wherein the two bearing covers are clamped to one another by means of substantially axially aligned clamping elements.

8. A drive unit as claimed in claim 7, wherein the clamping elements comprise screw-theaded bolts.

9. A drive unit as claimed in any of the claims 3 to 6, wherein the end faces of the segments and/or flat walls are secured to the bearing covers.

10. A drive unit as claimed claim 9, wherein the bearing covers have openings and fastening elements have tabs disposed on the end faces of the segments and/or flat walls to project therefrom and extend through the openings and are locked, on the outside of the bearing covers.

11. A drive unit as claimed in claim 10, wherein the tabs are locked by being bent or peened over.

12. A drive unit according to any of the preceding claims, wherein the magnet systems comprise permanent magnets.

13. An electro-motive drive unit substantially as hereinbefore described with reference to Figures 1 to 3 orto Figure 4 of the accompanying drawings.