LINEAR GUIDE SYSTEM

Abstract

The present invention relates to a linear guide system having: at least a first rail element and a second rail element, the first rail element and the second rail element being mounted linearly displaceably relative to each other in and counter to a extraction direction; an electric motor; an input shaft, the input shaft being operatively coupled to the electric motor such that the electric motor sets the input shaft in rotation during operation of the linear guide system; a linear drive, the linear drive having an output shaft, and the linear drive being designed such that a rotary movement of the output shaft effects a linear movement of the first and second rail elements relative to each other in or counter to the extraction direction; and a clutch, the clutch connecting the input shaft and the output shaft to each other such that the clutch transmits a torque from the input shaft to the output shaft, the clutch being a magnetic clutch. The magnetic clutch has a first and a second clutch element, the first clutch element being connected in a torque-resistant manner to the input shaft, and the second clutch element being connected in a torque-resistant manner to the output shaft.

Claims

1. A linear guide system, comprising: at least a first rail element and a second rail element, the first rail element and the second rail element) being mounted linearly displaceably relative to each other in and counter to a extraction direction, an electric motor, an input shaft, the input shaft being operatively coupled to the electric motor such that the electric motor sets the input shaft in rotation during operation of the linear guide system, a linear drive, the linear drive having an output shaft, and the linear drive being designed such that a rotary movement of the output shaft effects a linear movement of the first and second rail elements relative to each other in or counter to the extraction direction, and a clutch, the clutch connecting the input shaft and the output shaft to each other such that the clutch transmits a torque from the input shaft to the output shaft, wherein the clutch is a magnetic clutch having: a first clutch element, and a second clutch element, wherein the first clutch element is connected in a torque-resistant manner to the input shaft, and wherein the second clutch element is connected in a torque-resistant manner to the output shaft.

2. The linear guide system according to claim 1, at least the first clutch element or the second clutch element having a permanent magnet.

3. The linear guide system according to claim 1, the first clutch element and the second clutch element having a frictional fit with each other due to a magnetic force.

4. The linear guide system according to claim 1, the first clutch element having a first friction surface and the second clutch element having a second friction surface, the first friction surface preferably being perpendicular to the motor shaft and the second friction surface being perpendicular to the output shaft, and the first friction surface and the second friction surface being engaged with each other such that the torque is transmitted from the input shaft to the output shaft by a frictional fit between the first friction surface and the second friction surface.

5. The linear guide system (1) according to claim 1, only the first clutch element or only the second clutch element having a permanent magnet, the permanent magnet being arranged such that portions of the permanent magnet are enclosed ferromagnetic material of the first clutch element, and portions of the permanent magnet are enclosed in ferromagnetic material of the second clutch element.

6. The linear guide system (1) according to claim 1, the first clutch element having a first centering portion and the second clutch element having a second centering portion, the first and second centering portions being designed complementary to each other, and the first and second centering portions being designed such that they guide the first clutch element and the second clutch element in the radial direction relative to each other such that the first clutch element and the second clutch element have a common axis of rotation.

7. The linear guide system (1) according to claim 1, the first and second centering portions being designed to enable rotation of the first clutch element at a first angular speed and rotation of the second clutch element at a second angular speed, the first angular speed being different from the second angular speed.

8. The linear guide system according to claim 6, one of the first and second centering portions forming a centering bushing and the other of the first and second centering portions forming a centering pin, at least portions of the centering pin extending into the centering bushing.

9. The linear guide system (1) according to claim 1, the centering pin and the centering bushing forming a clearance fit in the radial direction.

10. The linear guide system according to claim 8, at least the centering bushing or the centering pin having a cross section, at least portions of which taper.

11. The linear guide system (1) according to claim 1, at least the first clutch element or the second clutch element being clamped onto the input shaft or the output shaft such that a torque through a frictional joint between the respective clutch element and the respective shaft is transmittable, a torque-resistant connection being formed between the respective clutch element and the respective shaft.

12. The linear guide system according to claim 1, at least the first clutch element or the second clutch element having an assembly sleeve extending in the axial direction, the input shaft or the output shaft extending into the assembly sleeve and the input shaft or the output shaft being connected to the assembly sleeve with at least a frictional fit, a positive fit, or a bonded fit.

13. The linear guide system according to claim 1, the input shaft or the output shaft in the assembled state having an interference in the radial direction opposite the respective assembly sleeve.

Description

[0044] Further advantages, features, and possible applications of the present invention will become apparent from the description of embodiments hereinafter and the associated figures. In the figures, like elements are identified using like reference numbers.

[0045] FIG. 1 is a schematic lateral view of a telescopic rail according to one embodiment of the present invention.

[0046] FIG. 2 is an enlarged cross-sectional view of an embodiment of the magnetic clutch of the telescopic rail shown in FIG. 1.

[0047] FIG. 3 is a partially exposed isometric view of the magnetic clutch shown in FIG. 2.

[0048] FIG. 4 is an enlarged cross-sectional view of another embodiment of the magnetic clutch of the telescopic rail shown in FIG. 1.

[0049] FIG. 5 is a partially exposed isometric view of the magnetic clutch shown in FIG. 4.

[0050] In the embodiment described in the following examples, the linear guide system is a telescopic rail 1, as shown in FIG. 1. The telescopic rail 1 shown in FIG. 1 is a detail having a first outer rail element 2 and a second inner rail element 3. The rail elements are conventional rail elements, each with a rail rear and two contact surfaces extending from the rail rear. Arranged between the contact surfaces of the two rail elements 2, 3, are rolling elements, which roll along the contact surfaces, so that friction is reduced when the two rail elements 2, 3 slide against each other.

[0051] In addition to the two rail elements 2, 3, the telescopic rail 1 has a linear drive in the form of a spindle drive 4, an electric motor 5, and a clutch 6.

[0052] The spindle drive 4 consists of a threaded spindle 7 as an output shaft in the context of the present application and a spindle nut rotatable relative to the threaded spindle 7 on the supported spindle nut. The spindle nut (not shown in FIG. 1) is connected to the inner rail element 3. The threaded spindle 7 is supported in a stationary but rotatable direction on the outer rail element 2 in the axial direction. Thus, rotary movement of the threaded spindle 7 effects linear movement of the spindle nut and thus the inner rail element 3.

[0053] The direction in which the second rail element 3 is pushed out of the first rail element 2 refers to the extension direction. This direction is provided with reference number 9 in FIG. 1. The extraction direction 9 coincides with the axis of rotation of the threaded spindle 7 and a motor shaft 8 of the electric motor 5. The extraction direction 9 is therefore also referred to as the axial direction. Directions perpendicular to and intersecting the axis of rotation of the threaded spindle 7 and the motor shaft 8 are referred to as radial directions.

[0054] The electric motor 5 has a motor shaft 8, which rotates during operation of the telescopic rail 1 driven by the electrodynamic forces of the motor. This motor shaft 8 forms the input shaft within the context of the present application. The torque generated by the electric motor 5 and introduced into the motor shaft 8 is transmitted from the motor shaft 8 to the threaded spindle 7 using the magnetic clutch 6.

[0055] The magnetic clutch 6 will now be described in more detail on the basis of two embodiments thereof. These two embodiments are shown enlarged in FIGS. 2 to 4. FIGS. 2 and 3 in this case show a first embodiment, and FIGS. 3 and 4 show a second embodiment. The illustrations are taken from the circle K shown in FIG. 1.

[0056] Each of the magnetic clutches 6 of the embodiments shown in FIGS. 2 to 4 has a respective first clutch element 11 and a second clutch element 12.

[0057] The first clutch element 11 is the clutch element on the motor shaft side. This first clutch element 11 is connected to the motor shaft 8 in a torque-resistant manner. In other words, a torque of the motor shaft 8 is introduced from the motor shaft 8 into the first clutch element 11 without slip and torque loss. The motor shaft 8 and the first clutch element 11 always rotate at the same angular velocity. The second clutch element 12 is in turn connected to the threaded spindle 7 in a torque-resistant manner, so that a torque transmitted to the second clutch element 12 is transmitted to the threaded spindle 7 in full and without slip. The threaded spindle 7 and the second clutch element 12 always rotate at the same angular velocity.

[0058] The clutch elements 11, 12 each have an assembly sleeve 13, 14 for the torque-resistant connections between the first clutch element 11 and the motor shaft 8 and between the second clutch element 12 and the threaded spindle 7. The assembly sleeves 13, 14 are hollow cylindrical so that the respective shaft 7, 8 is inserted into this sleeve 13, 14. After insertion, the sleeves 13, 14 are pressed inwardly in a linear direction such that the sleeves 13, 14 have a frictional and torque-resistant fit on the respective shaft 7, 8. In this way, a simple assembly of the two clutch elements 11, 12 on the respective shaft 7, 8 is ensured.

[0059] In the embodiment shown in FIGS. 2 and 3, the assembly sleeve 13 of the first clutch element 11 is designed as a blind bore with a sleeve base. In contrast, the assembly sleeve 14 of the second clutch element 12 has a through-passage that is easier to manufacture.

[0060] The two embodiments of the magnetic clutch 6 have in common that the two clutch elements 11, 12 have a frictional fit with each other in the axial direction. The force acting in the axial direction and producing the friction fit is a magnetic force from a permanent magnet 20. In the illustrated embodiment, each of the first motor-end clutch elements has a permanent magnet 20 that attracts the second spindle-end clutch element 12. Therefore, the first clutch element 11 is also referred to as a pot magnet, and the second clutch element 12 is referred to as a magnetic thrust ring.

[0061] Each of the two clutch elements 11, 12 has a friction surface. The first friction surface of the first clutch element 11 is provided with reference number 15 in the drawings. The second friction surface 16 of the second clutch element 12 is in flat contact with the first friction surface 15. Thus, the maximum torque transmitted from the first clutch element 11 to the second clutch element 12 without slippage of the clutch 6 is determined not only by the magnetic force of the permanent magnet 20, but also by the surface of the two friction surfaces 15, 16, their surface quality, (i.e., roughness), and the material of the friction surfaces.

[0062] The friction surfaces 15, 16 of the magnetic clutch 6 of the embodiment shown in FIGS. 2 and 3 are annular in shape. The permanent magnet 20 of the first clutch element 11 of the embodiment shown in FIGS. 2 and 3 is an annular magnet. This magnet 20 is glued into a canister 21 made of ferromagnetic steel. The canister 21 has a base 22 on its motor shaft-facing side and is open on the side facing the second clutch element 12. The sidewall 24 of the canister sits on the side facing the second clutch element 12 opposite a surface 23 of the magnet 20. As a result, only the end face of the side wall 24 projecting over the surface 23 of the magnet 20 has a frictional fit with the second clutch element 12. This end face of the side wall 24 of the canister 21 thus forms the first friction surface 15 of the first clutch element 11.

[0063] In contrast, the two friction surfaces 15, 16 in the embodiments shown in FIGS. 3 and 4 are circular surfaces. The surface 23 of the magnet 20 and the end face of the side wall of the canister are flush with the surface. The magnet 20 of the clutch 6 in FIGS. 3 and 4 is a circular disc magnet.

[0064] The embodiment shown in FIGS. 2 and 3 on the one hand and the embodiment shown in FIGS. 4 and 5 on the other hand also differ with respect to the centring of the two clutch elements 11, 12 with respect to each other.

[0065] Each of the clutch elements 11, 12 has a centring portion. In the embodiment shown in FIGS. 2 and 3, the first centring portion of the first clutch element 11 is a centring bushing 17, into which a centring pin 18 extends as a centring portion of the second clutch element 12. The centring bushing 17 is formed by cylindrical inner wall surfaces of the ring magnets 20, while the centring pin 18 has cylindrical outer wall surfaces. The outer wall surfaces of the centring pin 18 and the inner wall surfaces of the centring bushing 17 together form a clearance fit, so that the centring pin 18 is freely rotatable in the centring bushing 17, but a relative movement in the radial direction 10 is only possible within the limited clearance provided.

[0066] In the embodiment shown in FIGS. 4 and 5, the second, spindle-driven clutch element 12 is designed in a pot-shaped manner so that the hollow cylindrical wall 19 of the canister receives a centring portion of the cylindrical first clutch element 11 as a centring portion. The first clutch element 11 and the hollow cylindrical wall 19 of the canister of the second clutch element 12 again form a clearance fit to minimize the influence on the maximum torque transmitted from the first clutch element 11 to the second clutch element 12 without slippage. As can be seen from the illustration in FIG. 4, the canister of the second clutch element 12 has a cross section that tapers towards the threaded spindle 7. In this way, centring of the two clutch elements 11, 12 with respect to each other is facilitated when the two clutch elements 11, 12 move apart once in the axial direction.

[0067] For the purposes of original disclosure, it should be noted that all of the features as they become apparent to a skilled person based on the present description, the drawings, and the claims, even if they have been specifically described only in connection with specific other features, can be combined both individually and in any combination with other features or groups of features disclosed here, insofar as this has not been expressly excluded or technical circumstances make such combinations impossible or pointless. A comprehensive, explicit presentation of all conceivable combinations of features is omitted here solely for the sake of the brevity and legibility of the description.

[0068] Although the invention has been presented and described in detail in the drawings and the foregoing description, this representation and description is made merely by way of example and is not intended to limit the scope of protection as defined by the claims. The invention is not limited to the embodiments shown.

[0069] Modifications of the disclosed embodiments will be obvious to the skilled person based on the drawings, the description, and the appended claims. In the claims, the word has does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality. The mere fact that certain features are claimed in different claims does not preclude their combination. The reference numbers in the claims are not intended to limit the scope of protection.

LIST OF REFERENCE NUMBERS

[0070] 1 Telescopic rail [0071] 2 First rail element [0072] 3 Second rail element [0073] 4 Spindle drive [0074] 5 Electric motor [0075] 6 Clutch [0076] 7 Threaded spindle [0077] 8 Motor shaft [0078] 9 Axial direction [0079] 10 Radial direction [0080] 11 First clutch element [0081] 12 Second clutch element [0082] 13, 14 Assembly sleeve [0083] 15 First friction surface [0084] 16 Second friction surface [0085] 17 Centring bushing [0086] 18 Centring pin [0087] 19 Hollow cylindrical wall [0088] 20 Permanent magnet [0089] 21 Canister [0090] 22 Base [0091] 23 Surface of the magnet [0092] 24 Side wall of the canister