LINEAR DRIVE WITH CONTROL HOUSING

Description

[0001] The invention relates to a linear drive with a gear housing extending along a longitudinal axis, in which a spindle extending along the longitudinal axis is rotatably mounted with a worm gear connected thereto in a rotationally fixed manner, a spindle nut running on the spindle, which is adjustable on the spindle between a retracted retracted position and an extended extended position, wherein the spindle nut, in the retracted position, is arranged retracted in a stationary guide tube receiving the spindle nut in the region of a rear end of the guide tube and thus the lifting tube is retracted into the guide tube, wherein the spindle nut, in the extended position, is arranged at a front end of the guide tube and thus the lifting tube is extended out of the guide tube, a worm driven by an electric motor, which extends along a transverse axis extending transversely to the longitudinal axis,the worm gear meshes and wherein the electric motor is accommodated in a motor housing which is connected to the gear housing, and a control for the linear drive arranged in a control housing.,

[0002] The control housing contains circuit boards and other electronic components for controlling the motor to ensure the correct position of the lifting tube in relation to the stationary guide tube in order to drive a piece of furniture driven by the linear drive, such as an armchair or a hospital bed, to adjust the foot and headrest.

[0003] A generic linear drive is described, for example, in the published patent application US 2017324301 A1. Disadvantages of the state of the art

[0004] The control housing is mounted at various locations on the piece of furniture, often on the side of a hospital bed or underneath the bed base. To do this, the control housing must first be installed on the piece of furniture, bed, or similar, and then an electrical connection to the linear actuator must be established. This typically involves running a cable from the control housing to the linear actuator, particularly connecting it to the gear housing. This process of mounting the control housing is relatively time-consuming and therefore costly. Task / technical problem

[0005] Based on this prior art and the associated disadvantages, the invention is therefore based on the task / technical problem of at least partially avoiding these disadvantages and, in particular, of realizing an easy, quick and reliable assembly of the control housing. invention

[0006] This technical problem is already solved according to the invention by the features of independent claim 1. Advantageous, but thus not mandatory, further developments are recited in the dependent claims.

[0007] In the simplest embodiment, this object is thus achieved in that the control housing comprises a fastening system which, during mechanical fastening to the drive housing, simultaneously realizes the electrical and / or data connection with the drive housing in the installed position.

[0008] The control housing is preferably connected only to the gearbox housing, but can in principle also be connected to the motor housing or to the gearbox housing and the motor housing, i.e. the drive housing.

[0009] The fastening system is preferably designed such that only a translational movement of the control housing in relation to the gear housing is required during assembly, i.e. pushing or plugging the control housing with an insertion section into a receiving section of the complementary other joining partner or vice versa, in order to transfer the control housing into the desired end position in which the plug is not only mechanically fixed, but also the electronic and / or data connection is realized.

[0010] According to the invention, separate installation of the control housing on the piece of furniture is therefore no longer necessary, and there is no longer any need to lay a cable from the control housing to the linear drive, in particular the gear housing, and to connect it to it.

[0011] According to the invention, the mechanical connection or mechanical fastening is designed to be very robust, so that the mechanical connection only occurs in conjunction with the electrical connection.

[0012] Preferably, the connection technology is designed such that during the joining process, i.e., the plugging together process, a ground contact is established, preferably before further electrical contacting of the other contacts is made. This can be achieved, for example, by having the ground contact protrude from the other contacts. This can be achieved by providing an additional electrical ground contact during the mechanical contacting.

[0013] According to the invention, the control housing comprises a first and a second housing wall, which enclose a wall angle between them, which is preferably a right or acute angle. A plug-in system is formed between the first housing wall and the gear housing adjacent to it in the installed position, and a connector system is formed between the second housing wall and the gear housing wall adjacent to it. Only in the final installed position, i.e., when the control housing is fully inserted into the plug-in system, is the electrical and / or data connection established via the connector system.

[0014] This corner connection between the drive housing and the control housing provides a particularly robust fixation, which is therefore particularly stable against forces and thus very effectively prevents the control housing from breaking off accidentally.

[0015] Particularly preferably, the insertion system is designed as a linear guide system, which thus creates a positive connection between the joining partners such that only a translational relative movement between the gearbox housing and the control housing is possible. Embodiments provide for the design of the insertion system / linear guide system with a dovetail guide formed between the joining partners.

[0016] The connector system preferably comprises a plug on one joining partner and a complementary socket on the other joining partner, into which the plug is inserted in the end position after the translational movement has been carried out.

[0017] The connector system can further include a union nut, which, in the installed position after the connector engages the socket, is screwed over the connection point between the plug and socket to secure the two mating parts in the intended installation position and ensure good contact within the connector system. In abstract terms, this seals the connector system's connection point against the ingress of dust and / or moisture.

[0018] In a preferred embodiment, the connector system, or the plug or socket, is located very close to the circuit board, so that the contacts are close to the board, which increases the stability of the assembly and the applied pressure during linear displacement. The contacts are preferably designed to electrically connect the circuit boards to each other.

[0019] Preferably, the contacts themselves are firmly connected to the respective circuit board.

[0020] According to the invention, the connection comprises both the plug-in system and the plug-in system. This has the advantage of providing an improved and more robust connection for large and particularly heavy control enclosures.

[0021] The control housing is preferably secured to the drive, particularly preferably to the gear housing, using a connector union nut. However, this union nut is optional. It is therefore essential that the control housing is displaced relative to the drive housing, i.e., the housing of the linear actuator, during fixation in such a way that the two parts are mechanically inserted into the guide system in the installed position, and the connector system is mechanically and electrically connected.In the preferred embodiment, the two housing walls of the control housing are at a right angle to each other and engage the respective joining partners on the drive housing or gear housing, particularly preferably in the region of the receptacle for the hollow cylindrical gear housing on the drive housing, which is arranged in a region in which a right angle runs between the receiving region of the drive housing for the gear housing and the region extending at right angles thereto along the longitudinal axis for receiving the gear with the spindle and the worm wheel.

[0022] The connector system is preferably designed to provide the power supply separately from the data supply.

[0023] The plug preferably comprises a first power supply connector part and a second data supply connector part. The power supply connector part, in turn, has two sections, namely a section for the positive pole and a section for the negative pole, which correspond to corresponding sections within the socket. The data supply connector part implements the data supply for the signal line and for the sensors. A bus system is preferably used for data transmission.

[0024] In this respect, the controller, or rather the control board installed in the control housing, is fully bus-capable, particularly with a 2-wire differential bus. The drive sends or receives data for the lift tube control, speed control, and synchronous operation.

[0025] Preferably, both connector parts are IP-protected by tightening the union nut, meaning they are protected against water ingress. IP protection means that protection against dust and moisture is provided according to various requirements.

[0026] Preferably, the connector system is designed to be as flat as possible in order to ensure that the control housing fits as closely as possible to the gearbox housing and thus to prevent the penetration of objects that could cause the control housing to break off.

[0027] A further embodiment provides that linear guide means are also formed or only formed in the connector system, e.g. two projections which interact with complementary recesses on the other joining partner during joining, in order to thus ensure the correct positional alignment of the joining partners to one another in the installed position.

[0028] Further features and advantages of the present invention will become clear from the following description of preferred embodiments with reference to the accompanying drawings.

[0029] In this regard, directional terminology such as "top," "bottom," "front," "back," "fore," "rear," etc., is used with reference to the orientation of the described figure(s). Since components of embodiments can be positioned in a number of different orientations, the directional terminology is for illustrative purposes and is in no way limiting. It is understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description is not to be taken in a limiting sense.

[0030] In this description, the terms "connected," "attached," and "integrated" are used to describe both direct and indirect connections, direct or indirect attachments, and direct or indirect integration. In the figures, identical or similar elements are provided with identical reference symbols where appropriate. The illustrations in the figures are essentially to scale. However, to illustrate details, certain areas may be exaggerated in a manner that is recognizable to a person skilled in the art. Furthermore, the drawings may be simplified and may not include every detail that may be present in practice.

[0031] Unless otherwise stated, the indefinite article and the definite article do not refer solely to a single component, but should be understood as "at least one." The terminology includes the aforementioned words, variations thereof, and similar meanings. Furthermore, it should be understood that the terms "about," "substantially," and similar terms in connection with the dimensions and a characteristic of a component of the invention do not describe the described dimension and characteristic as a strict limit or parameter and do not preclude minor variations thereof that are functionally similar. At a minimum, descriptions containing numerical parameters also include variations of these parameters according to mathematical and manufacturing principles in the prior art, e.g., rounding, deviations, and other systematic errors, manufacturing tolerances, etc.

[0032] Finally, for reasons of clarity, where several identical components or elements are shown, only one of them is provided with a reference symbol. Identical reference numbers in the figures refer to identical components or features.

[0033] All features of the respective embodiments are also generally disclosed independently of one another within the scope of the invention.

[0034] They show: Figure 1: a plan view of a linear drive according to the invention; Figure 2: an enlarged view of the connection area between the control housing and the gear housing; and Figure 3: an enlarged isometric front view of the control board connector with the control housing removed.

[0035] The Figure 1shows a plan view of the linear drive according to the invention, comprising essentially a gear housing 2, a motor housing 4 accommodated therein, a guide tube 6 with a lifting tube 8 which is relatively movable in the longitudinal direction and a control housing 10 connected to the drive.

[0036] The guide tube 6 and the relatively movable stroke tube 8 define the longitudinal axis X of the linear drive. The motor housing 4 extends transversely to this longitudinal direction in a transverse direction Y.

[0037] The gear housing 2 is divided into two parts with a rear housing part 2a and a housing cover 2b connected to it, which are sealingly connected to one another at the joint.

[0038] The worm gear is housed within the gear housing 2 and is mounted non-rotatably on a spindle that drives a spindle nut, which in turn is connected to the rear end of the lifting tube 8, located in the guide tube 6. A front fork head 12 is mounted on the front end of the lifting tube 8. At the rear end of the gear housing 2, which is opposite the end that receives the guide tube 6, a rear fork head 14 is inserted into the gear housing 2. The fork heads 12, 14 can be connected to furniture axes in a known manner, so that the furniture or furniture components can be adjusted relative to one another. Such a linear drive or drive is particularly preferably used for adjusting the head and foot sections of hospital beds. Other areas of application include patient hoists, treatment couches, dentist's chairs, and the like.

[0039] The rear housing part 2a comprises a circular cylindrical receiving socket of corresponding size, into which a complementary hollow cylindrical socket of the motor housing 4 or alternatively of the gear housing 2 is inserted, which receives the electric motor rotatably along the rotor longitudinal axis extending transversely to the longitudinal direction.

[0040] A worm at the front end of the rotor shaft drives the worm wheel for the adjustment drive within the gear housing 2.

[0041] This electric motor is controlled via the control electronics housed in the control housing 10.

[0042] The control housing is also designed as a substantially rectangular plastic housing, which is greater in length than in width and height. The control housing 10 is essentially box-shaped, formed as a rectangular box with at least two housing walls 10a, 10b positioned at a housing angle of 90° to each other. A shorter end wall 10a is attached to the receiving section of the gear housing 2 for the guide tube 6, which extends along the longitudinal direction of the drive.Spaced-apart insertion legs of a linear guide / insertion system are formed on this receiving section, into which a corresponding insertion section on the housing end wall 10a of the control housing 20 can be inserted in the longitudinal direction, so that when inserted, the correct alignment of the control housing 10 in relation to the gear housing 2 is realized, thus only in the correct alignment is the pairing between the control housing 10 and the gear housing 2 possible.

[0043] The control housing 10 is pushed onto the gear housing 2 in the longitudinal direction thereof until the plug 18 of the plug system provided on the longitudinal wall 10b of the housing engages in the socket 2c formed at the corresponding point on the gear housing 2 and the union nut 16 can then be tightened in order to pull the control housing 10 into the final installation position against the gear housing 2 and to fix it in the installation position in such a way that the electrical and data connection between the control housing 10 and the gear housing 2 is realized at the same time.

[0044] Furthermore, the insertion system can be designed with at least one insertion leg and / or one insertion section in the manner of a dovetail guide.

[0045] The Figure 3The plug 18, shown enlarged, is inserted into the socket 2c. The plug 18 is arranged on a plug plate 22, which is arranged transversely extending on the control board 24 within the control housing 10.

[0046] The connector 18 basically comprises two separate connector parts, a first connector part for the power supply and a second connector part for the data supply.

[0047] Both plug parts can be designed as individual plugs or as a group of plugs. Furthermore, individual plugs can also have multiple plug contacts. Furthermore, a plug contact designed as a ground contact or as a shield contact has a longer contact that protrudes relative to the other contacts and, during the establishment of the electrical connection during mating, can be electrically connected as the first plug contact to the complementary plug contact of the other plug, thus protruding and thus forming the first contact.

[0048] The first plug part comprises a positive and a separate negative pole for electrical contact, which are each arranged in the rectangular plug extensions and each have an opening at one end for engagement with the complementary joining partner within the socket 2c of the gear housing 2.

[0049] To the side of this first connector part, the second connector part is designed to implement the data connection between the connector housing 10 and the gear housing 2, which in this case comprises a total of six separate connections in a 2 x 3 grid on a rectangular front surface.

[0050] Both plug parts are protected by the union nut 20 IP, so like the rest of the drive they are protected against water ingress. List of reference symbols

[0051] 2 Gearbox housing 2a Rear housing section 2b Housing cover 2c Bushing 4 Motor housing 6 Guide tube 8 Lifting tube 10 Control housing 10a Housing end wall 10b Housing longitudinal wall 12 Front clevis 14 Rear clevis 16 Linear guide 18 Connector 20 Union nut 22 Connector plate 24 Control board

Claims

1. Linear drive with a gear housing (2) extending along a longitudinal axis (X), in which a spindle extending along the longitudinal axis is rotatably mounted with a worm wheel connected to it in a rotationally fixed manner, with a spindle nut running on the spindle, which is adjustable on the spindle (4) between a retracted position and an extended extended position and which acts on a lifting tube, wherein the spindle nut in the retracted position is arranged retracted in a stationary guide tube (6) receiving the spindle nut in the region of a rear end of the guide tube (6) and thus the lifting tube (8) is retracted into the guide tube (6), wherein the spindle nut is arranged at a front end of the guide tube (6) in the extended position and thus the lifting tube (8) is extended out of the guide tube (6), with a worm driven by an electric motor extending along a transverse axis (Y) extending transversely to the longitudinal axis (X), and meshing with the worm wheel, and wherein the electric motor is accommodated in a motor housing (4) which is connected to the gear housing (2), and wherein the gear housing (2) and the motor housing form a drive housing and with a control system arranged in a control housing (10), CHARACTERIZED IN THAT a connection is formed between the control housing (10) and the drive housing, which is adapted to simultaneously realize an electrical connection when mechanically fastened to the drive housing, wherein the control housing (10) comprises a first and a second housing wall (10a, 10b) which enclose between them a housing angle which is preferably a right angle or an acute angle, in that an insertion system is formed between the first housing wall (10a) and the gear housing (2) adjoining the latter in the installed position, and in that a connector system is formed between the second housing wall (10b) and the gear housing (2) adjoining the latter and that the connection comprises the connector system and the insertion system.

2. Linear drive according to claim 1, CHARACTERIZED IN THAT the insertion system is designed as a linear guide system.

3. Linear drive according to claim 2, CHARACTERIZED IN THAT the connector system comprises a plug on one mating partner and a complementary socket on the other mating partner.

4. Linear drive according to claim 3, CHARACTERIZED IN THAT the connector system comprises a union nut (20).

5. Linear drive according to claim 3 or 4, CHARACTERIZED IN THAT the plug (18) is designed for the power supply and separately for the data supply.

6. Linear drive according to claim 5, CHARACTERIZED IN THAT the plug (18) comprises a first power supply connector part (plus / minus) and a second data supply connector part.

7. Linear drive according to one of claims 1 to 6, CHARACTERIZED IN THAT the insertion system comprises a dovetail guide.