1. Field of Invention
This invention relates to a shade arrangement for a motor vehicle with a drive unit which has a roller tube for taking up a length of shade material, a roller shaft and an electric motor for driving the roller tube around the roller shaft, and planetary gearing. In particular, the present invention relates to such a shade arrangement in which the electric motor has a stator and an armature, the stator being connected to the roller tube such that, when the roller tube turns, the stator turns with it, and the armature being supported such that it turns relative to the vehicle body when the roller tube turns.
2. Description of Related Art
Electric motors for driving shade arrangements or window roller blinds which generally drive a roller shaft via gearing are known from various documents. German Patent Application DE 30 24 358 A1 describes a tube motor with a planetary gearing for driving a roller blind. In operation, the stator of the tube motor remains stationary and the turning armature drives a driving disk which turns the roller shaft of the roller blind in turn. In German Patent Application DE 35 39 513 A1, a tube motor with a planetary gearing drives the roller shaft of a vehicle window shade, the shade being inserted in a sleeve which likewise holds a step-down gearing. Here, only the armature of the motor is turned. German Patent Application DE 102 14 434 A1, conversely, discloses a tube motor for driving roller blinds, awnings, shades and gates in which the housing of the tube motor, for driving, is turned together with a roller shaft onto which, for example, a web of fabric can be taken up, against a stationary end cap. The use of certain gearing and other details on the electric motor are not shown here. The indicated shade arrangements have the disadvantage that, on the one hand, they require a comparatively large installation space for use in a motor vehicle, and on the other hand, due to their large number of components, they are relatively expensive and time-consuming to produce or install in a vehicle.
Thus, a primary object of this invention is to devise a shade arrangement for motor vehicles of the initially mentioned type in which both an economical design with as few components as possible and which requires only a small installation space can be achieved.
This object is achieved by shade arrangements described herein below. In a shade arrangement according to the invention the roller tube for taking up the length of shade material has an inside surface that is made as a ring gear of a planetary gearing by which a roller shaft is driven by an electric motor. By making the inside surface of the roller tube a ring gear of the planetary gearing, thus, the planet wheels of the planetary gearing run on the cylindrical inner surface of the roller tube which preferably have corresponding teeth or grooves along the lengthwise direction of the roller tube. Furthermore, making the cross section of the roller tube as a ring gear has the great advantage that an additional ring gear need not be installed into the roller tube and supported, by which considerable space is saved. Also, by eliminating an additional ring gear, production is simplified, and thus, also more economical.
In a preferred embodiment of this invention, the sun wheel of the planetary gearing is driven by the electric motor and output driving of the planetary gearing takes place via a planet carrier. In another preferred embodiment of this invention, the planetary gearing is made in several stages, i.e., several planetary gears are connected in succession. In such a multistage arrangement, preferably, the planet carrier of a preceding gear stage is connected to the sun wheel of a following gear stage. Output driving from the entire gear arrangement takes place via the planet carrier. When using such multistage gearing, preferably, the inner surface of the roller tube is used for all planetary stages as a common ring gear. In this connection, in turn, the inner surface of the ring gear is structured, at least in the region of the different gear stages along the roller tube, such that the roller tube has a cross section which corresponds to that of the ring gear.
In a shade arrangement according to another aspect of the invention, the electric motor itself comprises a stator (often also called a “frame” or “exciter”) and an armature (i.e., a “rotor” or “inductor”), the stator being connected to the roller tube such that when the roller tube turns, the stator turns with it. In preferred embodiments of this invention, the stator can have permanent magnets which are preferably cemented to the roller tube. The armature of the electric motor is supported such that it turns relative to the vehicle body when the roller tube turns. Since both the stator and also the armature of the electric motor move relative to the vehicle body when the roller tube is moved, the electric motor of the invention has sliding contacts by means of which it is connected to the voltage source of the vehicle. In an especially preferred version of this invention, the sliding contacts of the electric motor contain a body-mounted brush system which connects the voltage source of the vehicle to a commutator of the armature of the electric motor. Here, it is especially advantageous if the brush system of the electric motor, which is generally necessary for an electric motor with a current-carrying armature, is also used to form the sliding contact of the electric motor which turns at the same time as the roller tube towards the body.
In accordance with another feature of the shade arrangement of the invention, the electric motor for driving the roller tube around the roller shaft is connected to the roller tube by the stator such that the stator turns at the same time with the roller tube when the latter turns and the armature of the electric motor is also supported here such that it turns when the roller tube is turned relative to the vehicle body. According to the invention, the electric motor is connected by means of flexible cables to the voltage source of the vehicle, the length and flexibility of the cables being selected such that even for the maximum rotary path of the electric motor, the connection to the voltage source is preserved. This means that, when the shade of the shade arrangement is unwound by turning the electric motor, its cable is turned, their material properties being selected such that they cannot tear or be damaged even at the maximum withdrawal path of the length of shade. Preferably, the housing contains the stator of the electric motor within which, in turn, the armature is pivotally supported, and preferably, is electrically connected to the flexible cables via a corresponding brush system.
In accordance with another feature of the shade arrangement of the invention, the drive unit has a roller tube for taking up the shade and an electric motor for driving the roller tube, and in the drive line of the roller tube, there is a slip clutch which is used to prevent overloading of the drive line by, for example, the slip clutch being able to slip when the shade arrangement is blocked.
In a preferred embodiment of the invention, the slip clutch has two clutch disks which are in contact with one another and which are pretensioned against one another. Preferably, the electric motor is supported against one of the two clutch disks and the other clutch disk is connected to the vehicle body. In other embodiments of this invention, the clutch disks are arranged such that they can be turned relative to one another once a a predetermined torque is applied.
Alternative embodiments of the invention which can be implemented are explained below.
In preferred embodiments of the aforementioned invention, the roller tube is made in several parts and has partial tubes which, together with the round housing of the electric motor, form the roller tube. Preferably, the partial tubes can be slipped onto the electric motor so that the surface of the partial tubes together with the surface of the round housing of the electric motor forms a roller surface for the shade. However, alternatively, the roller tube can also be made in one piece and the electric motor can be inserted into the roller tube. Both in these described embodiments of one-piece and in multi-piece roller tubes, an especially space saving design can be achieved by installation of the electric motor in the roller tube. In especially preferred embodiments with a one-piece roller tube, the roller tube itself can form the housing of the electric motor. Since, in this connection, a complete electric motor is not inserted into the roller tube, but only the electric motor without the housing, the space requirement can thus be further reduced.
Preferably, all of these embodiments can have an end cap on one side of the roller tube, the end cap, in turn, containing an inner part which is pivotally supported relative to the roller tube and is connected to the vehicle body on its side facing away from the roller tube. The part of the end cap which is permanently connected to the roller tube can have a cylindrical section onto which the roller tube is slipped, and furthermore a conical cable drum for taking up the cable which pulls out the length of shade.
In other preferred versions, the roller shaft which is driven by the electric motor, on the side of the roller tube which faces away from the end cap, projects out of the roller tube and is supported on the body. Thus, the roller tube has a body-mounted bearing on both sides (roller shaft, on the one hand, and end cap, on the other) around which it turns when the shade is being rolled up or unrolled. One preferred version of the invention is achieved by the sliding contacts being housed within the end cap in versions with sliding contacts, by which in turn the required installation space is reduced. A shade arrangement according to the invention can also have at least one sensor, preferably a Hall sensor, which is made such that it can determine the rotational position of the roller tube.
In embodiments of the invention with a slip clutch, the provision of a rotational position sensor is preferably assigned to the roller tube, but in embodiments without a slip clutch, the sensor is advantageously assigned to the armature of the electric motor. Together with corresponding read-out electronics, the signals of the sensors can be used, for example, to fix the rotary path of the roller tube, and thus, the extension length of the shade. As a result, pre-selected extension lengths of the shade can be automatically obtained. This sensor can also be housed within the end cap in embodiments with an end cap.
The invention is explained by way of example below using the drawings.
Driving of the planetary gearing 16 by the electric motor 12 takes place via a sun wheel which cannot be seen here. The output driving from the planetary gearing 16 takes place via the last of the three planet carriers which is permanently connected to the motor-side clutch disk 24b. In accordance with the invention, all planet wheels 18 run in a ring gear which is formed by the inner surface of the roller tube 10. Therefore, roller tube 10 has corresponding teeth on its inner surface (not shown in the figure) which extend at least over the region of the roller tube which is in the path of the planet wheels 18 around the axis of rotation of the roller shaft 14. The teeth are made such that a transverse cross section through the roller tube 10 in the plane of the planetary wheels 18 yields a ring gear.
Therefore, in operation of the shade arrangement, when the shade which has been wound at least partially on roller tube 10 is extended or retracted, the electric motor 12 turns at its motor rpm. This motor rpm is converted by the planetary gearing 16 into the desired rpm of the roller tube 10, the planetary gearing being supported indirectly via the roller shaft 14 on the body of the vehicle. Thus, both the housing 38 of the electric motor 12 and also the armature of the electric motor (not shown here), which motor drives the planetary gear 16, turn relative to the vehicle body. To supply electric current to the rotating electric motor 12, the motor is connected to a voltage source in the vehicle by the cables 28. The cables 28 are chosen with respect to their flexibility and length such that rotation of the electric motor 12 around the body-mounted roller shaft 14 from the initial position with the shade taken completely up to an end position with the shade completely unwound is possible without the cables 28 themselves or the electrical connection from the motor to the battery being interrupted. The cables 28 are routed for this purpose through an end cap 30 which has a cylindrical part 48 with which it is slipped onto the roller tube 10. The end cap 30 has an inner part 32 which is pivotally mounted in it and which is connected to the vehicle body via a journal 34. Furthermore, the end cap 30 has a cone-shaped cable drum 46 onto which a cable which draws the shade can be taken up or slides it on in a compressively stiff design of the cable; see, e.g., commonly-owned, co-pending U.S. patent application Ser. No. 11/576,092.
An alternative embodiment of the roller tube is shown in
Number | Date | Country | Kind |
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10 2004 047 393.5 | Sep 2004 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/DE05/01689 | 9/23/2005 | WO | 00 | 1/8/2008 |