Drive Unit for Awnings and Roller Blinds

This invention relates to a drive unit for awnings and roller blinds and, in particular, a drive unit which is to be installed in a tubular shaft upon which an awning or the roller blind is to be wound.

In one drive unit of this type, the entire drive unit is comprised of the following individual elements which are arranged one after the other in the order indicated along a common axis: an output shaft; a reduction gear; an electric motor; a capacitor; a shut-off unit with contactor and setting means for setting the end positions of the roller blind or the awning cloth; and a coupling member adapted to transmit the torque from the reduction gear to the tubular shaft.

It is an object of the present invention to provide a drive unit which can have a shorter axial length than the aforesaid drive unit and is simpler to install and easier to service.

In accordance with the principles of the present invention, the above and other objectives are accomplished in a drive unit of the above type by arranging the reduction gear of the unit between the electric motor and the shut-off unit thereof, and by employing as the coupling member of the unit a hollow gear wheel which is adapted to support and be drivingly connectable to the tubular shaft concentrically surrounding the unit and which is in driving connection with the reduction gear. Additionally, the capacitor of the drive unit is advantageously fastened at the BS end bell of the electric motor, the latter end bell being at the end of the drive unit facing away from the shut-off unit.

With the drive unit designed as aforesaid, the output moment of the unit is at a considerably shorter distance from the mounting flange at the outer end of the tubular shaft. Also, the motor and the capacitor can be more easily removed from the unit for repair, as they are disposed at an outer end of the unit. The use of an additional drive with a separate drive shaft for the shut-off unit also is now unnecessary, as the shut-off unit and the reduction gear are axially arranged directly behind one another. Additionally, since the capacitor is bolted to the outer free end of the drive unit, its size can largely be chosen as desired without effecting the overall design of the shut-off unit.

Advantageously, a casing of the capacitor is likewise, fastened at the BS end bell of the motor and is provided with a support rim which projects radially beyond the BS end bell and the rest of the casing and is adapted to support the tubular shaft. The latter support rim prevents undesirable rubbing of the shaft on the other parts of the drive unit, in case the unit is not properly aligned with the shaft axis when inserted into the shaft. Also, advantageously, the hollow gear wheel is provided at its outer circumference and, in particular, at its end facing the outer end of the tubular shaft, with bosses and/or slots which are adapted to engage with corresponding slots and/or bosses on the tubular shaft. A tight fitting drive connection thus results when the drive unit is inserted into the tubular shaft, and simple driving of the tubular shaft directly at the outer mounting flange of the tubular shaft is possible without additional parts.

In the illustrative embodiment of the invention to be described herein, the drive unit comprises a two-stage planetary drive which follows the electric motor on the AS end bell side and which is itself followed by a spur gear drive. Furthermore, the entire gear housing portion of the unit is advantageously divided into first and second housing parts. The first housing part houses the spur gear drive, the shut-off unit with its integrated setting means and a reduction gear arranged between the shut-off unit and the spur gear drive. The second gear housing part, on the other hand, houses the planetary drive and the AS end bell of the electric motor to which it is integrated.

The unit is further simplified by the fact that the second gear housing part can be tightly clamped together with the lamination stack and the BS end bell of the motor by tie bolts which are screwed into the integrated AS end bell and can be tightened from the BS end bell side of the electric motor, which preferably has no housing. Thus, the above-mentioned components of the drive unit can be connected with each other in a simple manner from the BS end bell side. To further simplify the drive unit, the intermediary gears of the spur gear drive are mounted on hollow shafts through which screws for joining the two housing parts can be inserted and tightened from the outer end, facing the shut-off unit, of the drive unit.

The above and other features and aspects of the present invention will become more apparent upon reading the following detailed description in conjunction with accompanying drawings, in which:

FIG. 1 shows a partial cross-sectional view of a drive unit in accordance with the principles of the present invention;

FIG. 2 shows a cross section through the drive unit of FIG. 1 along the plane II--II; and

FIG. 3 shows in greater detail a portion of the section of FIG. 1.

FIG. 1 shows a drive unit in accordance with the principles of the present invention. As illustrated the unit is housed in a tubular shaft 1 into which it has been inserted through the right-hand outer end of the shaft. The drive unit comprises a number of components which are arranged one behind the other along a common axis and which are connected with each other. More specifically, going from left to right, the unit comprises the following elements:

a capacitor 10 with casing 8;

an electric motor 6 which has no housing and which includes a stator lamination stack 61, an AS end bell 62, a BS end bell 63 and a rotor 65;

a two-stage planetary drive 4;

a spur gear drive 5 which includes a hollow gear wheel 2 for transmitting torque to the surrounding tubular shaft 1;

a reduction gear 7;

a shut-off unit 3 which includes a setting means 31 which can be operated from outside of the right-hand outer end of the tubular shaft 1;

and a transparent cover 26.

As above-indicated, the entire drive unit is inserted into the tubular shaft 1 through its right-hand outer end. To facilitate proper alignment of the unit within the shaft, bosses 21 are provided at the right-hand outer end of the hollow gear wheel 2. These bosses engage with corresponding slots in the tubular shaft 1 so as to provide in a simple manner a contact surface and close-fitting drive for transmitting the torque from the electric motor 6, via the planetary drive 4, the spur gear drive 5 and the internally geared hollow wheel 2, to the shaft 1. As can be seen, the tubular shaft 1 is supported predominantly by the hollow gear wheel 2, but additional support is also provided by a support rim 81 extending from the mounting flange of the capacitor casing 8.

The rotor 65 of electric motor 6 is arranged on a shaft 64 and is provided with an intermediate shorting ring 66 and with a sliding-armature brake 9. The latter brake is integrated within the BS end bell 63. When the motor 6 is switched on the rotor 65 and its intermediate shorting ring 66 provide a large axial force for lifting the brake disc 91 of the sliding-armature brake 9 off the stationary counter brake lining 92, which is firmly connected with the BS end bell 63.

The gear housing portion of the drive unit is divided into two gear housing parts. A first gear housing part 11 houses the spur gear drive 5, the reduction gear 7, and the shut-off unit 3 with its integrated setting means 31. A second gear housing part 12, on the other hand, houses the planetary drive 4 with the integrated AS end bell 62 of the electric motor 6.

As may be seen from FIG. 1 and particularly from FIG. 2, in the present illustrative embodiment, the spur gear drive 5 acts on the internally-geared hollow wheel 2 via intermediate gears 53 to 55 having fixed bearing axes. The gears 53 to 55, in turn, are driven by a central gear 52 which is arranged on a central shaft 51, the latter shaft being aligned with the electric motor shaft 64 and the central shaft 41 of the planetary gear. The intermediate gears 53 to 55 are supported on hollow shafts through which screws 14 for bolting the two gear housing parts 11, 12 together are inserted and tightened from the outer end of the drive unit, which is facing the shut-off unit.

Advantageously, also arranged on the spur gear 5 between the intermediate gear bearings are spacers 15 whose securing pins 16 permit the mutual aligning of the two housing halves 11, 12. Spur gear drive 5 also includes at least one spacer 17 having an axial hole 18, through which an electrical line connection 19 is led from the electric motor 6 to the shut-off unit 3.

The connecting line 19 can be run through the housing parts 11, 12 without limiting the space provided for the planetary gear 4, by providing a longitudinal hole 20 in the outer wall of the second housing part 12 in the region of the planetary gear 4 which has a radially directed opening 27 at the BS end bell side of the housing part 12. Additionally by pressing an intermediate ring 22 with an inner bevel 23 onto the end of the second housing part 12 which faces the spur gear drive 5, the connecting line 19 upon passing from the longitudinal hole 20 will be deflected toward the further inwardly disposed longitudinal hole 18 in the spacer 17. Thus, as illustrated in FIG. 3, the connecting line 19 runs past the planetary gear 4 and is deflected by the bevel 23 so as to pass through the longitudinal hole 18 of the spacer 17, which is stationary within the spur gear drive 5. The longitudinal hole 19 can be formed by drilling into the drive housing part 12 from the spur gear side while the radial opening 27 can be formed by perforating the housing part.

As can be seen, the ring 22 also provides support for the hollow gear wheel 2. The latter wheel, in turn is sealed via sealing rings 24 and 25 against the housing parts 11 and 12.

To simplify the assembly of the individual components of the present drive unit, the first gear housing part 11 is, on the one hand screwed via the screws 14 to the second gear housing part 12 and is, on the other hand, advantageously firmly clamped by the tie bolts 13, which can be screwed into the integrated AS end bell 62 and can be tightened from the BS end bell side 63, with the lamination stack 61 and the BS end bell 63. Also advantageously, cover 26 is selected to be transparent so as to permit the shut-off unit to be observed and its setting checked without having to disassemble any of the parts of the drive unit.