Linear movement device having a lubricant sensor

Abstract

The linear movement device (1) comprises a first device component (2) and a second device component (3), wherein the second device component (3) is supported on the first device component (2) via rolling bodies (4) such that the second device component (3) can be moved linearly relative to the first device component (2) along a linear movement direction (A), and the second device component comprises a circulating device (5), in which at least one of the rolling bodies (4) can be circulated at least during a relative movement between the second device component (3) and the first device component (2). In order to improve the wear resistance, the second device component (3) has an electro-based lubricant sensor (7) which is designed to detect information relating to the amount and / or composition of a lubricant in a detection part (9) in the circulating device (5) on the basis of an electrical property of the lubricant.

Description

[0001] Linear motion device with a lubricant sensor

[0002] Field of invention

[0003] The present invention relates to a linear motion device with a lubricant sensor.

[0004] Background of the invention

[0005] Linear motion devices are known in the prior art, comprising a first device component and a second device component, wherein the second device component is supported on the first device component by rolling elements, such that the second device component is movable linearly relative to the first device component along a linear motion direction. Such linear motion devices can, for example, be designed as a linear guide with a guide rail as the first device component and with a linear guide carriage or a linear guide slide as the second device component, wherein in this example the linear guide carriage or the linear guide slide is supported on the guide rail by rolling elements (usually in the form of balls or rollers), such that the linear guide carriage or the linear guide slide is movable along the guide rail.The linear guide slide can move via the rolling elements in a longitudinal direction relative to the guide rail. Alternatively, linear motion devices of the aforementioned type can also be designed as a threaded drive with a threaded spindle as the first device component and with a threaded nut as the second device component, wherein in this example the threaded nut is supported on the threaded spindle via rolling elements (for example in the form of balls) so that the threaded nut can move via the rolling elements in a longitudinal direction relative to the threaded spindle.

[0006] In the prior art, for example from DE 10 2018 204 852 A1, a linear guide carriage is known which is movable relative to a guide device. A plurality of rolling elements are located between the linear guide carriage and the guide device. To increase wear resistance and ensure smooth operation, a lubricant reservoir is also provided on the linear guide carriage. The fill level of this lubricant reservoir is monitored so that the lubricant can be replenished as needed.

[0007] With linear guide carriages of this type, the amount of lubricant present in the area of ​​the rolling elements is particularly critical. However, monitoring the lubricant level in the reservoir is insufficient and allows only limited conclusions about the amount of lubricant present in the area of ​​the rolling elements. Thus, wear can still occur in known linear guide carriages despite monitoring.

[0008] It is therefore an object of the present invention to provide a linear motion device with improved detection accuracy of a lubricant condition and improved wear resistance.

[0009] Summary of the invention

[0010] This problem is solved according to the invention by a linear motion device according to claim 1.

[0011] According to one aspect, a linear motion device is proposed, comprising a first device component and a second device component, wherein the second device component is supported on the first device component via rolling elements, such that the second device component is movable linearly relative to the first device component along a linear motion direction. The second device component comprises a recirculating device in which at least one of the rolling elements is circulatory, at least during a relative motion between the second device component and the first device component.

[0012] The second device component further includes an electrically based lubricant sensor, which is arranged to detect, based on an electrical property of a lubricant, information regarding a quantity and / or composition of the lubricant in a detection section in the circulating device.

[0013] According to this approach, the information regarding the quantity and / or composition of the lubricant is acquired within the circulating device, in which at least one rolling element can circulate. This allows the information to be acquired directly in the area of ​​the rolling elements. As a result, the detection accuracy of the lubricant condition, i.e., the quantity and / or composition, can be improved, enabling timely refilling, which in turn reduces the occurrence of wear phenomena such as pitting and / or galling of the rolling elements.

[0014] Because the lubricant sensor is electro-based, the measurement process can be particularly efficient and compact. In particular, expensive optical elements can be dispensed with.

[0015] In this disclosure, the detection section is a section along the longitudinal extent of the circulating device where the information is acquired. An electrically based lubricant sensor is a sensor that uses an electrical property of the lubricant to acquire the information. The property can be a material property of the lubricant. In particular, it can be electrical conductivity, resistivity, and / or relative permittivity. Furthermore, the electrically based lubricant sensor can have an electrical quantity, such as voltage and / or current, as the measurand on which it acquires the information. The electrically based lubricant sensor can have a detection circuit that connects the detection section in such a way that it represents an electrical circuit element, such as an electrical capacitor with an electrical capacitance or an ohmic resistance.

[0016] The information can be directly related to the quantity and / or composition of the lubricant. However, it can also be related to the quantity and / or composition, in particular an electrical quantity corresponding to the electrical circuit element in the detection circuit formed by the detection section, such as a capacitance value or an ohmic resistance value.

[0017] The detection section can be arranged at least partially, and in particular completely, in a linear section of the circulation device.

[0018] This aspect allows for a simple arrangement of the lubricant sensor and a simple design of the components, since the lubricant sensor can simply be positioned along the linear section. Furthermore, the detection accuracy can be improved due to less complex flow conditions compared to a curved section.

[0019] The rotating device can include a load-bearing section through which the at least one rolling element can be moved during a relative movement between the second device component and the first device component in such a way that the at least one rolling element is in contact with both a running surface formed on the first device component and a running surface formed on the second device component.The circulating device may also include a return mechanism extending between a first end of the load-bearing section of the circulating device and a second end of the load-bearing section of the circulating device. This return mechanism is designed to allow the return of at least one rolling element outside the load-bearing section of the circulating device between the first and second ends of the load-bearing section of the circulating device during relative movement between the second and first device components. Alternatively or additionally, the detection section may be arranged at least partially, and in particular completely, outside a load-bearing section of the circulating device. The detection section may, in particular, be arranged outside the load-bearing section of the circulating device within the return mechanism of the circulating device.

[0020] This also simplifies the arrangement of the lubricant sensor, as it does not need to be located in the load-bearing section, i.e., in an area of ​​the second device component facing the first device component. Furthermore, it ensures that lubricant is not displaced from the detection section by the acting loads and can therefore be reliably detected.

[0021] Furthermore, the circulation device can, at least in the detection section, comprise an electrically insulating material, in particular be formed from it.

[0022] This allows for further improvement in detection accuracy due to the electrical insulation. Electrical interference from an electrically conductive circulating device can also be avoided. An electrically insulating material can have a relative permittivity greater than 1. It can, for example, be a plastic, particularly a thermoplastic and / or thermoset. Furthermore, the detection section can extend over a large number of rolling elements. This improves detection accuracy because averaging can be performed across multiple rolling elements. Isolated lubricant accumulations or voids can thus be compensated for.

[0023] For example, the detection section can extend over a length of at least two, three, four or more diameters of the rolling elements.

[0024] The electro-based lubricant sensor can be arranged to capture the information capacitively.

[0025] Thus, the relative electrical permittivity of the lubricant can be used as an electrical property to acquire the information. In other words, an electrical capacitor with a specific capacitance can be created in the detection section. This allows for a relatively accurate measurement. The lubricant sensor can acquire at least the capacitance value, or it can use this value to directly determine information about the quantity and / or composition of the lubricant.

[0026] The electro-based lubricant sensor can include a detection circuit for acquiring information. This circuit has two opposing electrodes between which at least one rolling element, and in particular a plurality of rolling elements, is arranged. This allows for easy capacitance generation. Depending on the position of the rolling element during circulation in the detection section, one capacitance or two capacitances can be established, which the detection circuit can connect in series or, in particular, in parallel. One capacitance can be established when the rolling element contacts one of the electrodes. Conversely, two capacitances can be established, namely between each of the electrodes and the rolling element, when the rolling element does not contact either electrode. The detection circuit can therefore be designed to connect the electrodes in series or in parallel with each other, with the capacitances then being determined according to the rolling element position.

[0027] Within the scope of the invention, the detection circuit can therefore be designed such that, depending on the position of the rolling element in the detection section, a capacitance is established between the electrodes or a capacitance is established between the electrodes and the at least one rolling element.

[0028] In particular, at least one of the electrodes, and in particular both, may have an electrically insulating coating on a side facing the at least one rolling element.

[0029] This ensures reliable capacitance build-up. An electrically insulating coating can suppress ohmic contact between the at least one electrode and the at least one rolling element. This allows for more precise information acquisition, as ohmic influences can be suppressed. The electrically insulating coating can have a relative electrical permittivity greater than 1. It can be made of a plastic, in particular a thermoplastic and / or thermoset, and again, in particular, polyimides.

[0030] Alternatively or additionally, the electrodes can be positioned opposite each other in a direction intersecting the direction of gravity and / or parallel or perpendicular to an axis of rotation of at least one rolling element in the detection section.

[0031] This also prevents contact between at least one rolling element and the electrodes, as the rolling element is not pushed towards the electrodes by gravity. The arrangement parallel to the axis of rotation allows the rolling element to be reliably positioned between the electrodes. Furthermore, the lubricant can reliably fill the space between the electrodes and the rolling element.

[0032] At least one of the electrodes, and in particular both, can be glued to the circulation device. This can facilitate the attachment of the electrodes. An adhesive that attaches at least one electrode to the circulation device can also provide electrical insulation to the outside.

[0033] Furthermore, at least one of the electrodes, in particular both, can be arranged in such a way that it cannot be contacted with the at least one rolling element.

[0034] This also ensures reliable capacitance build-up. A resistive contact between the electrode(s) and the rolling element can be prevented. The arrangement is geometrically designed such that contact is impossible under normal operating conditions. For example, at least one of the electrodes can be positioned in a recess formed by an inner peripheral surface of the rotating device. Alternatively, the inner peripheral surface can be tapered or curved, and the electrode attached to it, in such a way that contact is impossible.

[0035] Alternatively or additionally, the rotating device in the detection section can have larger dimensions than the at least one rolling element, particularly in the direction of the rolling element's axis of rotation in the direction in which the electrodes face each other. This can also prevent ohmic contact.

[0036] The rotating device may have a guide section designed to guide at least one rolling element out of contact with the electrodes.

[0037] Furthermore, the electrically based lubricant sensor can have a detection circuit for capturing the information that electrically contacts at least one rolling element.

[0038] Accordingly, an electrical circuit can be conducted via at least one rolling element, reducing the number of components. Furthermore, electrical quantities such as voltage and / or current can be easily measured. In particular, in the detection circuit, which includes the electrodes, both cases of one or two capacitors can be implemented by electrically contacting the rolling element, depending on the position of the rolling element. The detection circuit can be designed so that the two capacitors or the two electrodes are connected in parallel or in series. If the two electrodes are connected in parallel, the circuit can be easily closed via the electrical contact with the rolling element.

[0039] The detection circuit may also include a resistance element connected in series with the two electrodes.

[0040] This prevents excessive current draw when charging the capacity(s). The electrically based lubricant sensor can be designed to capture information based on a charging and / or discharging time.

[0041] Thus, a capacity value can be determined based on the charging / discharging time. This allows for relatively simple implementation, requiring only the measurement of the time it takes for the capacity to be charged to or discharged from a predetermined voltage. The predetermined voltage can be the voltage of the capacity's time constant, i.e., 63.2% of the applied voltage or 63.2% of the capacity's initial voltage.

[0042] Alternatively or additionally, the electro-based lubricant sensor can be designed to acquire information based on sampling a charging and / or discharging curve. This allows a capacity value to be determined based on a sample of the charging and / or discharging curve. This enables high detection accuracy, as measurement errors are more easily detected. The voltage and time can be measured at intervals, particularly regular ones. The interval can be a few milliseconds, especially less than 10 milliseconds.

[0043] Furthermore, the linear guide carriage can include a DC voltage source arranged to supply the electro-based lubricant sensor with direct current.

[0044] This allows the lubricant sensor to be operated with direct current, which simplifies the configuration and acquisition of information.

[0045] Alternatively, the electrically based lubricant sensor can be designed to capture the information ohmically.

[0046] Information regarding the lubricant condition can also be reliably acquired based on this aspect. The configuration can be further simplified. For example, the lubricant sensor can have an electrical contact element in the detection section. The lubricant sensor can be designed to detect the number of contacts with the contact element, for example, within a predetermined time interval or across a predetermined number of rolling elements, and compare this number with a reference value. If the number of contacts is equal to or greater than the reference value, the lubricant sensor can detect that there is insufficient lubricant. Otherwise, it can detect that there is sufficient lubricant.

[0047] According to another aspect, the circulation device can be designed in multiple parts, at least in the detection section, and / or be formed by injection molding.

[0048] This allows for easy installation of the lubricant sensor. Furthermore, the second device component can include an energy harvester designed to supply electrical energy to the second device component based on the relative motion between the second and first device components. In particular, the second device component can be designed such that the electrical energy supplied by the energy harvester can be used to operate the electrically based lubricant sensor. Accordingly, the second device component can be used autonomously. The lubricant sensor can therefore be operated without requiring an external energy supply. The energy harvester can generate an alternating current, while the lubricant sensor can still be operated with direct current. For this purpose, an inverter can be provided between the energy harvester and the lubricant sensor.

[0049] Furthermore, the second device component can include an output unit capable of displaying the information. The output unit can be a wireless communication unit that transmits data related to the information, or a visual or acoustic output unit.

[0050] It should be noted that the lubricant sensor can also be implemented by physically separate units, whereby part of the lubricant sensor need not be located on the second device component. In particular, if the information is directly related to the quantity and / or composition of the lubricant, the lubricant sensor can include external devices that perform conversions of an electrical quantity such as capacitance into this information. A further aspect of the invention relates to a method for operating a linear guide carriage according to one of the aspects mentioned above. In this context, the functional features defined here can be operated according to their function. For example, during operation, the lubricant sensor can acquire information based on the charging / discharging time or by sampling the charging / discharging curve.

[0051] Brief description of the drawings

[0052] The above aspects are explained in more detail in the following description and with reference to the attached figures.

[0053] Fig. 1 shows a perspective view of a linear motion device designed as a linear guide. Fig. 2 shows a perspective view of a linear guide carriage of the linear guide in a state reversed compared to Fig. 1.

[0054] Fig. 3 shows the linear guide carriage according to Fig. 2, with one base body removed. Fig. 4 shows a longitudinal section through a circulation device.

[0055] Fig. 5A shows a cross-section through the linear guide carriage in a detection section, with a lubricant sensor arranged on the detection section according to a first embodiment.

[0056] Fig. 5B shows a cross-section through the linear guide carriage in a detection section, with a lubricant sensor arranged on the detection section according to a second embodiment.

[0057] Fig. 5C shows a cross-section through the linear guide carriage in a detection section, with a lubricant sensor arranged on the detection section according to a second embodiment.

[0058] Fig. 6 shows a circuit diagram for Fig. 5B.

[0059] Fig. 7A shows a perspective view of a linear motion device, which is designed as a threaded drive with a threaded spindle and a threaded nut.

[0060] Fig. 7B shows the screw drive according to Fig. 7A in a side view.

[0061] Fig. 7C shows the screw drive according to Fig. 7A in a side view as in Fig. 7B, wherein the threaded nut is shown in a longitudinal section and an arrangement of rolling elements designed as balls and an arrangement of a lubricant sensor and an energy harvester are visible.

[0062] Detailed description of exemplary embodiments

[0063] Fig. 1 shows a linear motion device 1, which in the present example is realized as a linear guide and comprises a first device component and a second device component, wherein the linear guide comprises a guide device 2 representing the first device component of the linear motion device 1 and a linear guide carriage 3 representing the second device component of the linear motion device 1.

[0064] In the following, the linear motion device 1 will also be referred to as "linear guide 1". The guide element 2 is designed here as a guide rail, which extends linearly in a guide direction A, represented in Fig. 1 by an arrow labeled "A". The guide element 2 includes a plurality of running surfaces 2a. Two outer running surfaces 2a are provided on one side in a lateral direction transverse to the guide direction A, while two further outer running surfaces 2a are provided on the other side. The running surfaces 2a are arranged essentially symmetrically with respect to a central plane of the guide element 2 along the guide direction A. Two running surfaces 2a on each side with respect to the central plane are arranged in a V-shape in the lateral direction in the top view along the guide direction A. The linear guide carriage 3 of the linear guide 1 shown in Fig. 1 is shown separately in Fig.Figure 2 shows the linear guide carriage 3 in an inverted state compared to Figure 1. As can be seen in Figures 1 and 2, the linear guide carriage 3, when assembled, essentially surrounds the guide assembly 2 in an inverted U-shape. Two inner running surfaces 3a are formed on each of the two legs of the U-shape. The running surfaces 3a are oriented opposite each other in the width direction, forming an insertion space into which the guide assembly 2 is inserted. The guide assembly 2 is inserted into the insertion space such that each running surface 2a interacts with a running surface 3a, with a plurality of rolling elements 4, as shown in Figure 4, arranged between them.

[0065] The linear guide carriage 3 can move linearly back and forth along the guide direction A relative to the guide device 2 via the rolling elements 4, the rolling elements moving between the running surface 3a and the running surface 2a. The rolling elements can comprise or be formed of an electrically conductive material, for example, steel.

[0066] Since the guide carriage 3 is arranged on the guide device 2 such that the guide carriage 3 is linearly movable in the guide direction A with respect to the guide device 2 by means of the rolling elements 4, the term "linear direction of movement A" is used in the following as an alternative to the term "guide direction A". The linear guide carriage 3 further comprises a circulation device 5 in which the plurality of rolling elements 4 can circulate, at least during the relative movement between the linear guide carriage 3 and the guide device 2.

[0067] The circular carriage 5 has a load-bearing section 5a, which contains the running surface 3a and has two opposing ends E1 and E2. In addition to the load-bearing section 5a, the circular carriage 5 comprises a return mechanism 6. The return mechanism 6 is continuous to both ends E1 and E2 of the load-bearing section 5a, in particular the running surface 3a, along the guide direction (linear direction of motion) A and comprises a return tube 6a that extends linearly and parallel to the running surface 3a along the guide direction (linear direction of motion) A. It should be noted that both the load-bearing section 5a and the return tube 6a of the linear guide carriage 3 are linear sections. In other words, the return tube 6a and the load-bearing section 5a define a substantially straight path for the rolling elements 4, in particular a centerline of the return tube 6a and the load-bearing section 5a.

[0068] The return tube 6a is shown, for example, in Figures 3 and 4. The return tube 6a is located further out in the lateral direction (on a side facing away from the guide device 2) with respect to the load-bearing section 5a, and is therefore spaced apart from it. Furthermore, the return device 6 comprises two curved sections 6b (see Figure 4) which connect the load-bearing section 5a and the return tube 6a on both sides in the guide direction (linear movement direction) A.

[0069] The curved sections 6b are convexly curved in a longitudinal section through the rotating device 5. The rotating device 5 is designed such that the axes of rotation of the rolling elements 4 are aligned parallel over the entire rotation. The entire rotating device 5 extends essentially parallel to the guide direction (linear motion direction) A.

[0070] As shown in Figures 1 and 2, the linear guide carriage 3 comprises a base body 31 and two end caps 32, which close off the base body 31 at both ends along the guide direction A. The end caps 32 can be designed to be attached to and removed from the base body 31, i.e., as separate elements. The base body 31 is not shown in Figure 3. As shown in Figure 4, the curved sections 6b are each provided in an end cap 32. The curved sections 6b can be tubular and / or provided as separate elements from the end cap.

[0071] The return tube 6a is provided as an element separate from the base body 31. The return tube 6a can be made of or formed from an electrically insulating material, for example, a plastic.

[0072] The return mechanism 6 enables the circulation of the rolling elements 4 from one of the ends E1 or E2 of the load-bearing section 5a in the guide direction A to the other end E1 or E2 of the load-bearing section 3a in the guide direction A. The return mechanism 6 is designed to guide the circulation and completely surrounds the rolling elements 4. The return mechanism 6 is designed to be fluid-tight, preventing lubricant from escaping. Furthermore, a space between the load-bearing section 5a (running surface 3a) and the corresponding running surface 2a of the guide mechanism 2 can be sealed. For this purpose, the linear guide carriage 3 can have a seal at each end of the load-bearing section 5a.

[0073] In Fig. 3, two return tubes 6a are shown on each side in the width direction, each corresponding to a running surface 3a of the linear guide carriage 3.

[0074] The rolling elements 4 can be, for example, cylindrical rollers or balls. Figure 4 shows, by way of example, rolling elements 4 designed as cylindrical rollers. However, the invention is also applicable to other types of rolling elements.

[0075] Figures 3 and 4 further illustrate the invention in detail. It should be noted that both figures are merely schematic views and do not necessarily correspond.

[0076] According to the invention, an electrically based lubricant sensor 7 is provided. The electrically based lubricant sensor 7 is arranged, in particular, to acquire information regarding the quantity and / or composition of lubricant in the circulating device 5. The lubricant sensor 7 is specifically designed such that the acquisition of this information takes place directly in the circulating device 5.

[0077] As shown in Fig. 4, the lubricant sensor 7 comprises two opposing electrodes 8, with the rolling elements 4 arranged between them and, in particular, spaced apart from each of the electrodes 8. The lubricant sensor 7 can be provided, at least partially, on an inner surface of the circulation device 5. In particular, as shown in Fig. 4, the two electrodes 8 can be arranged on an inner surface of the return tube 6. The electrodes 8 can be bonded in the return tube 6a.

[0078] The electrodes 8 are, for example, strip-shaped or plate-shaped elements.

[0079] Figure 4 further shows the axes of rotation 4a of the rolling elements 4. In the present example, the axes of rotation 4a of the rolling elements 4 are oriented perpendicular to the plane of the drawing. The electrodes 8 face each other perpendicular to the axes of rotation 4a, or are opposite each other in this direction. In this case, the direction in which the electrodes 8 face each other is also a direction intersecting the direction of gravity. If the rolling elements 4 are cylindrical rollers (as in the present example), the electrodes 8 can be arranged so that they face the respective end faces or the respective cylindrical surfaces of the rollers.

[0080] The longitudinal extent of the electrodes 8 defines a detection section 9 along the rotating device 5. The detection section 9 is the section in which an electrical interaction occurs to acquire the information. In the case of electrodes 8 of different lengths, the detection section is defined at least over a region where the electrodes 8 overlap. The electrodes 8 extend over a length corresponding to a plurality of rolling elements 4, in particular diameters thereof. Thus, the electrodes 8 can extend over at least four or five rolling elements 4.

[0081] The detection section 9 is located entirely within the linear section, namely the return tube 6a. In particular, the electrodes 8 are located entirely within the linear section.

[0082] Fig. 5A shows an exemplary arrangement of the electrodes 8 in cross-section with respect to the return tube 6a. In the representation according to Fig. 5A, the arrangement of the electrodes 8 relative to the rolling elements 4 corresponds to the arrangement shown in Fig. 4. In this example, the rolling elements 4 are designed as cylindrical rollers. The electrodes 8 are flat, plate-shaped elements arranged such that they extend parallel to the axes of rotation 4a of the rolling elements 4 (or along the outer surfaces of the respective cylindrical rollers). The dimension of the return tube 6a is larger than the diameter of the rolling elements 4 at least in one direction, particularly in the direction in which the electrodes 8 are opposite each other, and in a direction perpendicular to the axes of rotation 4a. Even though in Fig.Not shown in Fig. 5A, the circulation device 5, in particular the return tube 6a, can have a guide section that guides the rolling elements so that they do not contact the electrodes 8. For example, a V-shaped groove can be provided that prevents the rolling elements 4 from shifting towards the electrodes. In Fig. 5A, the electrodes 8 extend into recesses 61, which are each recessed by a right and left inner peripheral surface of the return tube 6a in a direction perpendicular to the direction in which the electrodes 8 are oriented.

[0083] Fig. 5B shows – as an alternative to the representation in Fig. 5A – an alternative arrangement of the electrodes 8 in the return tube 6a, in which the electrodes 8 are arranged in a recess 61 formed by the lower and upper inner peripheral surfaces of the return tube 6a, respectively. The recess is perpendicular to the direction in which the electrodes 8 face each other. The electrodes 8 are flat, plate-shaped elements arranged such that they extend perpendicular to the axes of rotation 4a of the rolling elements 4 (or parallel to the end faces of the respective cylindrical rollers) and are spaced apart from each other in the direction of the axes of rotation 4a of the rolling elements 4. This prevents contact between the rolling elements 4 and the electrodes 8.Alternatively, the inner peripheral surface of the recirculating device can also be curved, in particular more strongly curved than the rolling elements 4, such that contact between the electrodes 8 and the rolling elements 4 is not possible. Fig. 5C shows – as an alternative to the representations according to Figs. 5A and 5B – a further alternative arrangement of the electrodes 8 in the return tube 6a. In the representation according to Fig. 5C, it is assumed that the rolling elements 4 are designed as spheres. Accordingly, in the present example, the return tube 6a has an internal channel for receiving the rolling elements 4, which extends longitudinally along the return tube 6a and has a circular cross-section with an inner diameter that is larger than the diameter of the rolling elements 4. The return tube 6a according to Fig. 5C has two recessed recesses 61 in the channel intended for receiving the rolling elements 4, each of which serves to receive one of the electrodes 8.In the present example, the electrodes 8 are designed as elements extending longitudinally along the return tube 6a, which are curved in cross-section perpendicular to the longitudinal direction of the return tube 6a (for example, with a radius of curvature larger than the radius of the rolling elements 4). In this way, the shape of the electrodes 8 is adapted to the spherical shape of the rolling elements 4.

[0084] Furthermore, at least one or both of the electrodes 8 can have an electrically insulating coating, for example a polyimide film, on the side facing the rolling element 4.

[0085] Fig. 6 shows a circuit diagram for a possible detection circuit according to the invention, exemplified by the arrangement of electrodes 8 shown in Fig. 5B. A DC voltage source can be provided on the linear guide carriage 3. In the diagram of Fig. 6, the detection circuit of the lubricant sensor 7 is designed such that two capacitances are connected in series. In particular, the electrodes 8 are connected in series. According to the laws of electricity, the reciprocal of the total capacitance corresponds to the sum of the reciprocals of the individual capacitances. The voltage can be measured by a voltmeter of the detection circuit between the two electrodes, across the rolling element 4, or it can be measured between the rolling element 4 and each electrode 8. In the latter case, the voltmeter establishes an electrical contact with the rolling element.

[0086] However, it is also conceivable to connect the two capacitors in parallel. In particular, the two electrodes 8 can be connected in parallel. Then one pole of the DC voltage source can be electrically connected to both electrodes 8. The detection circuit can further be designed such that the other pole contacts at least one rolling element 4. In such a parallel connection, the capacitors add up to a total capacitor. The voltage can be measured by a voltmeter of the detection circuit between the two electrodes, across the rolling element 4, or can be measured between the rolling element 4 and each electrode. In any case where the detection circuit establishes electrical contact with the rolling elements, this occurs, in particular, in the direction of gravity, from above or below. Thus, for example, in Fig.6. The top or bottom surface of the inner peripheral area of ​​the return tube shall be provided with an electrically conductive material to which the voltmeter or DC voltage source is connected.

[0087] In the detection circuit, a resistor element R can also be connected in series with the electrodes 8. When the voltage U from the DC voltage source is applied, a current l flows during charging. c via this resistive element R, whereby the voltage Uc builds up at the capacitance.

[0088] In Figures 5A, 5B, and 6, the return pipe 6a is designed in multiple sections, with one division plane running parallel to the direction in which the electrodes 8 are opposite each other. This allows the electrodes 8 to be inserted easily. However, it is also possible to provide a division plane that runs perpendicular to the direction in which the electrodes 8 are opposite each other (Fig. 5C).

[0089] The linear guide carriage 3 also includes an energy harvester 10, as indicated in Fig. 3. The energy harvester 10 can provide electrical energy through interaction with at least one rolling element 4. In particular, kinetic and / or potential energy of the rolling elements 4 can be converted into electrical energy.

[0090] For example, the energy harvester 10 includes a piezoelectric device. The piezoelectric device can be configured such that an electrical voltage is generated when a force is applied to a deformation element. The deformation element can, in particular, deform elastically. Here, the deformation element can be a piezoelectric crystal. The piezoelectric device can be arranged such that it receives a gravitational force from at least one rolling element in an interaction section 11 of the circulating device 5, in particular the return tube 6a. The interaction section 11 is a section along the longitudinal direction of the circulating device 5 in which the interaction with the at least one rolling element 4 for energy generation takes place.

[0091] In Figure 3, the interaction section 11 is also located in the linear section (feedback tube 6a) next to the detection section 9. The energy harvester 10 (piezoelectric device) can be configured as a module. Here, the energy harvester 10 forms part of the feedback device 6, in particular an end section of the feedback tube 6a. Specifically, the piezoelectric device can come into direct contact with the at least one rolling element 4 and thus receive the force. In other words, the energy harvester 10 can completely surround the at least one rolling element 4, thereby forming part of the feedback device 6. The energy harvester 10 can be configured to generate alternating current.

[0092] The energy harvester 10 can be coupled to the DC voltage source, for example to store energy in it.

[0093] The linear guide carriage 3 can also have an inverter, which is provided, for example, between energy harvester 10 and DC voltage source.

[0094] The linear guide carriage 3 can further include an output unit configured to output at least the information detected by the lubricant sensor 7. The output unit can be a wireless communication unit capable of exchanging data with another wireless communication unit. The wireless communication unit can be arranged in an end cap 32.

[0095] It should be noted that the lubricant sensor 7 and / or the output unit can be powered at least indirectly, for example via the DC voltage source, by the electrical energy provided by the energy harvester 10.

[0096] The functions and effects of the invention will now be described.

[0097] According to the invention, the linear guide carriage 3 has an electrically based lubricant sensor 7 which, in the detection section 9 located in the circulation unit 5, acquires information regarding the lubricant condition. Thus, it is possible to detect the lubricant condition in the circulation unit 5, which has the load-bearing section 5a, and thereby prevent wear of the rolling elements 4 by enabling timely relubrication, for example, when the information indicates a lubricant quantity that is below a predetermined threshold.

[0098] The linear guide carriage 3 can have a lubricant reservoir from which lubricant can be supplied to the circulation device 5. The lubricant reservoir can be refillable. The information is acquired capacitively, which enables precise measurement. In particular, the dielectric properties of the lubricant can be used to infer its condition.

[0099] As mentioned above, the detection circuit can include a voltmeter to measure the voltage across the capacitor. Furthermore, the lubricant sensor can include an electronic controller powered either by the DC voltage source or by an internal power source. The controller can include a timer for measuring time. The controller can be configured as a combination of hardware and software, or as hardware only.

[0100] Thus, a capacitance value can be determined based on a charge / discharge time, specifically by measuring the time constant at which the capacitor's voltage is charged to 63.2% of the applied DC voltage or discharged to 63.2%. The capacitance value can then be calculated as the quotient of the measured time constant and the electrical resistance of the resistive element R. Alternatively, the capacitor's voltage and the corresponding time can be measured at intervals. Then, using a mapping method, such as the least squares method, the capacitance value can be determined that exhibits a charging curve most closely matching the measured values.

[0101] In both methods, a capacitance value is determined that can be compared to a reference capacitance. The reference capacitance can be determined in advance for a given lubricant, for example, via simulation and / or analytically, based on the parameters of the circulating device, such as electrode spacing, electrode and rolling element materials, distance between electrodes and rolling elements, electrode length, relative electrical permittivity of the lubricant, and the applied voltage of the DC power supply.

[0102] The lubricant sensor can have a non-transient storage unit in which the reference capacity is stored. If the measured capacity is equal to or greater than the reference capacity, the lubricant sensor can interpret this as information indicating that sufficient lubricant is present in the circulating system. Otherwise, insufficient lubricant is present.

[0103] Based on the parameters mentioned above and a model stored in the memory unit, the lubricant sensor can also record a numerical value as information about the amount of lubricant present in the circulating device.

[0104] It should be noted that the lubricant sensor need not be a single physical unit. For example, the controller and / or the storage unit can also be spatially separated from the detection circuitry. The communication unit can then, for example, send data from the section of the lubricant sensor provided on the linear guide carriage to the controller. In this context, the invention is therefore also directed to a linear guide carriage system that includes the linear guide carriage, wherein part of the lubricant sensor is provided outside the linear guide carriage. Variations on the above details are now described.

[0105] The detection section and / or the interaction section can be located in a curved section of the circulation device. Alternatively, the detection section and / or the interaction section can be located in the load-bearing section.

[0106] Alternatively and / or additionally to the DC voltage source, an AC voltage source can be provided on the linear guide carriage. However, the information can still be acquired capacitively.

[0107] Instead of being piezoelectric, the energy harvester can also be inductively designed. It can have an induction device.The induction device can, for example, comprise: a permanent magnet for generating a static magnetic field in the interaction section, which at least one rolling element 4 must successively traverse during operation when circulating in the circulation device, wherein the rolling elements 4 are made of a magnetically permeable material, for example steel, such that the rolling elements are suitable to influence the magnetic field depending on the position of the rolling elements 4 in the interaction section; and at least one induction coil with at least one coil turn, wherein the at least one induction coil is arranged in a stationary position relative to the device for generating a static magnetic field such that, due to a change in the position of the rolling elements 4 during circulation of the rolling elements 4 through the interaction section 9, it experiences a change in magnetic flux, which induces an electrical voltage in the at least one coil turn.

[0108] Furthermore, the lubricant sensor can also acquire the information resistively. For example, a contact element can be provided in the circulating device that can make resistive contact with the rolling elements. A detection circuit of the lubricant sensor can then count the number of contacts and compare them with a reference value.

[0109] The return tube does not need to be provided as a separate element. For example, the return device can be formed directly from the base body.

[0110] The invention is suitable not only for a linear guide carriage for a linear guide device, but also for threaded nuts for threaded drives.

[0111] Figures 7A-7C show a linear motion device 100, which in the present example is implemented as a threaded drive and comprises a first device component and a second device component, wherein the threaded drive includes a threaded spindle 102 representing the first device component of the linear motion device 100 and a threaded nut 103 representing the second device component of the linear motion device 100. Hereinafter, the linear motion device 100 will also be referred to as the "threaded drive 100".

[0112] As can be seen from Figs. 7A-7C, the threaded spindle 102 has a linearly extending longitudinal axis LA and extends linearly along this longitudinal axis LA. The threaded nut 103 comprises a base body 131, which extends annularly around the threaded spindle 102 and accordingly has a substantially cylindrical cavity, which is bounded radially to the longitudinal axis LA of the threaded spindle 102 by an inner wall 131a, such that the inner wall 131a extends annularly around the longitudinal axis LA of the threaded spindle 102 at a distance from the outer periphery of the threaded spindle 102.

[0113] As indicated in Fig. 7C, the threaded nut 103 is supported on the outer periphery of the threaded spindle 102 by a plurality of rolling elements 104, which in the present example are designed as balls, such that the threaded nut 103 moves linearly relative to the threaded spindle 102 in the direction of the longitudinal axis LA of the threaded spindle 102 when the threaded spindle 102 performs a relative movement relative to the threaded nut 103 which corresponds to a rotation of the threaded spindle 102 relative to the threaded nut 103 about the longitudinal axis LA of the threaded spindle 102. In other words, in the present example, it is assumed that the threaded nut 103 can be moved linearly in a linear direction A parallel to the longitudinal axis LA of the threaded spindle 102 when the threaded spindle 102 is rotated relative to the threaded nut 103 about the longitudinal axis LA of the threaded spindle 102 (this linear direction A is represented in Fig. 7A-7C by an arrow labeled “A”).

[0114] To enable the aforementioned relative movement of the threaded nut 103 relative to the threaded spindle 102 by means of the rolling elements 104, the threaded spindle 102 has an (external) thread on its outer periphery, which is designed as a groove 102a extending spirally around the longitudinal axis LA of the threaded spindle 102. As indicated in Fig. 7C, the groove 102a has a cross-sectional profile shaped such that the rolling elements 104 (designed as balls in this example) can roll in the longitudinal direction of the groove 102a and thereby move relative to the threaded spindle 102 on a spiral path around the longitudinal axis LA of the threaded spindle 102. The groove 102a therefore forms a “running surface” for the rolling elements 104 on the outer periphery of the threaded spindle 102, on which “running surface” the rolling elements 104 can move by rolling when the threaded spindle 102 is rotated about the longitudinal axis LA of the threaded spindle 102.The groove 102a will therefore also be referred to as the "running surface 102a" of the threaded spindle 102 for the rolling elements 104. In order to enable the aforementioned relative movement of the threaded nut 103 relative to the threaded spindle 102 by means of the rolling elements 104, the threaded nut 103 has an (internal) thread on its inner wall 131a, which is designed as a groove 103a extending spirally around the longitudinal axis LA of the threaded spindle 102. As indicated in Fig. 80, the groove 103a has a cross-sectional profile which is shaped such that the rolling elements 104 can roll in the longitudinal direction of the groove 103a and thereby move relative to the threaded nut 103 on a spiral path around the longitudinal axis LA of the threaded spindle 102.The groove 103a therefore forms a “running surface” for the rolling elements 104 on the inner wall 131a of the threaded nut 103, on which running surface the rolling elements 104 can move by rolling when the threaded spindle 102 is rotated about the longitudinal axis LA of the threaded spindle 102.

[0115] In order to enable the aforementioned relative movement of the threaded nut 103 relative to the threaded spindle 102 by means of the rolling elements 104, the groove 102a of the threaded spindle 102 and the groove 103a of the threaded nut 103 are designed to correspond to each other such that those rolling elements 104, by means of which the threaded nut 103 is supported on the threaded spindle 102, are arranged on the one hand in a section of the groove 102a of the threaded spindle 102 and are in rolling contact with the threaded spindle 102 in this section of the groove 102a and are arranged on the other hand in a section of the groove 103a of the threaded nut 103 and are in rolling contact with the threaded nut 103 in this section of the groove 103a.

[0116] In order to enable the aforementioned relative movement of the threaded nut 103 relative to the threaded spindle 102 by means of the rolling elements 104, the threaded nut 103 additionally has a recirculation device 105, which together with the groove (or the running surface) 102a of the threaded spindle 102 defines a “closed path” (hereinafter also “recirculation path”) for the rolling elements 104, along which closed path (recirculation path) the rolling elements 104 can circulate endlessly in an arrangement in which the individual rolling elements 104 are each arranged in a row one behind the other, when the threaded nut 103 is moved relative to the threaded spindle 102 in the linear direction of movement A.

[0117] The rotating device 105 comprises, on the one hand, a first section of the groove 103a in which those rolling elements 104 are arranged in a row which are in rolling contact with both the threaded nut 103 and the threaded spindle 102. This first section of the groove 103a, in which those rolling elements 104 are arranged in a row which are in rolling contact with both the threaded nut 103 and the threaded spindle 102, shall in the following also be referred to as the "running surface 103a" of the threaded nut 103 for the rolling elements 104.

[0118] As indicated in Fig. 70, the running surface 103a of the threaded nut 103 for the rolling elements 104 extends in the longitudinal direction of the longitudinal axis LA of the threaded spindle 102 over a finite length between two opposite ends E1 and E2 of the running surface 103a (the respective ends E1 and E2 are marked in Fig. 70 by arrows labelled “E1” and “E2” respectively).

[0119] The recirculating device 105 has a load-bearing section 105a, which contains the running surface 103a and extends between the two ends E1 and E2 of the running surface 103a. As can be seen from Fig. 70, the recirculating device 105 comprises – in addition to the aforementioned running surface 103a of the threaded nut 103 – a return device 106. The return device 106 comprises a section of the recirculating path for the rolling elements 104, which connects one end E1 of the running surface 103a of the threaded nut 103 with the other end E2 of the running surface 103a of the threaded nut 103. In this way, the return device 106 is designed so that, during the aforementioned relative movement of the threaded nut 103 relative to the threaded spindle 102, those rolling elements 104 which leave the running surface 103a of the threaded nut 103 at one end (e.g., at end E1) during the circulation of the rolling elements 104 along the circulation path, are returned to the other end (e.g.,to the end E2) of the running surface 103a of the threaded nut 103.

[0120] As can be seen from Fig. 7C, the return device 106 in the present example comprises a section 106a, which is designed as a through channel for rolling elements 104 extending through the base body 131 along the longitudinal axis LA of the threaded spindle 102. Furthermore, in the present example, the recirculation device 106 has two sections 106b, each comprising a section of the circulation path of the rolling elements 104, wherein one of the sections 106b comprises a section of the circulation path of the rolling elements 104 which connects the end E1 of the running surface 103a of the threaded nut 103 with an end (close to the end E1 of the running surface 103a) of the section 106a of the recirculation device 106, and wherein the other of the sections 106b comprises a section of the circulation path of the rolling elements 104 which connects the end E2 of the running surface 103a of the threaded nut 103 with the other end (close to the end E2 of the running surface 103a) of the section 106a of the recirculation device 106.

[0121] As indicated in Fig. 70, in the present example the sections 106b of the return device 106 can be realized in separate components 107, which components 107 are formed separately from the base body 131 and are to be mounted on the base body 131 in order to provide, on the one hand, the aforementioned connection between the section 106a of the return device 106 and the end E1 of the running surface 103a of the threaded nut 103 and, on the other hand, the aforementioned connection between the section 106a of the return device 106 and the end E2 of the running surface 103a of the threaded nut 103.

[0122] As indicated in Fig. 70, the section 106a of the feedback device 106 (optionally) can extend such that the section 106a provides a linearly extending section of the circulation path of the rolling elements 104, so that in this case the section 106a would be designed as a “linear section” of the feedback device 106.

[0123] In contrast, sections 106b of the return device 106 each provide a section of the circulation path of the rolling elements 104 extending along a curved line and therefore each form a “curved section” of the return device 106 (Fig. 7C).

[0124] As indicated in Fig. 7C, the threaded nut 103 of the linear motion device (the threaded drive) 100 can be equipped with an energy harvester 10 and an electrically based lubricant sensor 7 (which can be supplied with electrical energy by means of the energy harvester 10) in an analogous manner to the linear guide carriage 3 of the linear motion device (linear guide) 1 described above.

[0125] The energy harvester 10 can provide electrical energy through interaction with at least one rolling element 104. In particular, kinetic and / or potential energy of the rolling elements 104 can be converted into electrical energy.

[0126] Analogous to the linear motion device 1 shown in Figures 3 and 4, the energy harvester 10 of the linear motion device 100 can have a piezoelectric device (not shown in Figures 7A-7C). In the case of the linear motion device 100, the piezoelectric device can be configured such that an electrical voltage is provided when a force is applied to a deformation element. The deformation element can deform elastically. Here, the deformation element can be a Piezo-Krista II. The piezoelectric device can be arranged such that it receives a force from at least one rolling element 104 in an interaction section 11 of the feedback device 106.

[0127] In Fig. 7C, the interaction section 11 is shown. In this example, the interaction section 11 extends along a section of section 106a of the feedback device 106. The interaction section 11 is, in this example, a section along the extension direction of the feedback device 106 in which the rolling elements 104 interact with the energy harvester 10. The energy harvester 10 (piezoelectric device) is designed here as a module. The energy harvester 10 forms part of the feedback device 106. In particular, the piezoelectric device can come into direct contact with the at least one rolling element 104 and thus receive the force. In other words, the energy harvester 10 can completely surround the at least one rolling element 104, thereby forming part of the feedback device 106.

[0128] Analogous to the linear motion device 1 shown in Figs. 1-4, the energy harvester 10 of the linear motion device 100 can (alternatively or additionally to a piezoelectric device mentioned above) include an induction device (not shown in Figs. 7A-7C).

[0129] In this case, the induction device can, for example, comprise: a permanent magnet for generating a static magnetic field in the interaction section 11, which at least one rolling element 104 must successively traverse during operation when circulating in the circulation device, wherein the rolling elements 104 are made of a magnetically permeable material, for example steel, so that the rolling elements are suitable to influence the magnetic field depending on the position of the rolling elements 104 in the interaction section 11;and at least one induction coil with at least one coil turn, wherein the at least one induction coil is arranged in a stationary position relative to the device for generating a static magnetic field such that, due to a change in the position of the rolling elements 104 during a circulation of the rolling elements 4 through the interaction section 11, it experiences a change in magnetic flux which induces an electrical voltage in the at least one coil turn.

[0130] The energy harvester 10 of the linear motion device 100, in particular the induction unit, can also be designed as a module. Here too, the induction unit forms part of the feedback device 106, with the induction unit simultaneously guiding the rolling elements 104.

[0131] Figure 7C further shows an electrically based lubricant sensor 7, which is attached as a module to the feedback device 106, in particular to section 106a of the feedback device 106. The lubricant sensor 7 is provided on an outer peripheral surface of the feedback device 106 and can (analogous to the lubricant sensor 7 of the linear guide carriage 3 of the linear motion device 1 shown in Figures 3 and 4) be designed to acquire information regarding a quantity and / or composition of the lubricant in a detection section 9 in the circulation device 105 based on an electrical property of a lubricant.

[0132] The lubricant sensor 7 can accordingly comprise two opposing electrodes 8, with the rolling elements 104 located between them. A lubricant in the feedback device 106 thus serves as a dielectric, which allows the determination of the quantity and / or composition of the lubricant. The electrodes extend along a detection section 9 of the feedback device 106, the length of which corresponds to the length of the electrodes 8.

[0133] The base body 131 of the threaded nut 103 is generally made of an (electrically conductive) metal (for example, steel). Therefore, in the arrangement of the lubricant sensor 7 shown in Fig. 7C, the electrodes 8 should be electrically insulated from the base body 131 to ensure reliable operation of the lubricant sensor 7.

[0134] To achieve electrical insulation of the electrodes 8 from the base body 131, it is alternatively possible to design section 106a of the recirculation device 106, or a part thereof (e.g., the detection section 9 of the circulation device 105), as a tube made of an electrically insulating material. This tube is inserted into a passage for the rolling elements 104 extending through the base body 131, such that the rolling elements 104 must pass through the tube when circulating through the circulation device 105. In this case, the two electrodes 8 could be implemented in the aforementioned tube. For this purpose, it is possible, for example, to design the tube like the recirculation tube 6a shown in Fig. 5C and to provide it with an arrangement of electrodes 8 as shown in Fig. 50.

[0135] In Fig. 7C, the detection section 9 and the interaction section 11 are both provided in section 106a of the feedback device 106, with the detection section 9 and the interaction section 11 arranged one behind the other in the linear direction of movement A. The detection section 9 is thus offset relative to the interaction section 11 in the direction of the longitudinal extent of section 106a of the feedback device 106.

[0136] It should be noted that the energy harvester 10 can be connected to the lubricant sensor 7 via electrical lines (to supply the lubricant sensor 7 with electrical energy).

[0137] Alternatively, the energy harvester 10 and / or the lubricant sensor 7 of the linear motion device 100 can also be arranged on the threaded nut 103 such that the interaction section 11 of the energy harvester 10 and / or the detection section 9 of the lubricant sensor 7 are placed in one of the (curved) sections 106b of the feedback device 106.

[0138] The return device 106 can alternatively be designed as a separate component, separate or separable from the base body 131, which encloses a section of the circulation path for the rolling elements 104, connecting one end E1 of the running surface 103a of the threaded nut 103 with the other end E2 of the running surface 103a of the threaded nut 103. Such a component can, for example, be tubular or composed of several tubular sections.

[0139] The threaded nut 103 of the linear motion device (the threaded drive) 100 can—similar to the guide carriage 3 of the linear motion device 1 shown in Figs. 1-4—have an output unit (not shown in Figs. 7A-7C, functionally corresponding to the communication unit 14) configured to output at least the information detected by the lubricant sensor 7. The output unit can be a wireless communication unit capable of exchanging data with another wireless communication unit. The lubricant sensor 7 and / or the output unit can be powered, at least indirectly, for example via the DC voltage source, by the electrical energy provided by the energy harvester 10. Such an output unit can, for example, be attached to the base body 131.

Claims

26 Patent claims:

1. Linear motion device (1, 100) comprising a first device component (2, 102) and a second device component (3, 103), wherein the second device component (3, 103) is supported on the first device component (2, 102) via rolling elements (4, 104) such that the second device component (3, 103) is linearly movable relative to the first device component (2, 102) along a linear motion direction (A), wherein the second device component (3, 103) comprises: - a rotating device (5, 105) in which at least one of the rolling elements (4, 104) is circulatory at least during a relative movement between the second device component (3, 103) and the first device component (2, 102), characterized by - an electrically based lubricant sensor (7) which is arranged to detect, on the basis of an electrical property of a lubricant, information regarding a quantity and / or composition of the lubricant in a detection section (9) in the circulation device (5, 105).

2. Linear motion device (1, 100) according to claim 1, wherein the detection section (9) is arranged at least partially, in particular completely, in a linear section (6a, 106a) of the circulation device (5, 105).

3. Linear motion device (1, 100) according to claim 1 or 2, wherein the rotating device (5, 105) comprises a load-bearing section (5a, 105a) through which the at least one rolling element (4, 104) is movable during a relative movement between the second device component (3, 103) and the first device component (2, 102) such that the at least one rolling element (4, 104) is in contact with both a running surface (2a, 102a) formed on the first device component (2, 102) and a running surface (3a, 103a) formed on the second device component (3, 103a), wherein the rotating device (5, 105) comprises a return device (6, 106) which extends between a first end (E1) of the load-bearing section (5a, 105a) of the rotating device (5, 105) and a second end (E2) of the load-bearing section (5a, 105a) of the rotating device (5, 105) and is equipped, in the event of a relative movement between the second device component (3, 103) and the first device component (2, 102), to return the at least one rolling element (4, 104) outside the load-bearing section (5a, 105a) of the rotating device (5, 105) between the first end (E1) of the load-bearing section (5a, 105a) of the rotating device (5, 105) and the second end (E2) of the load-bearing section (5a, 105a) of the rotating device. (5, 105) to enable, wherein the detection section (9) is arranged outside the load-bearing section (5a, 105a) of the circulation device (5, 105) in the return device (6) of the circulation device (5, 105).

4. Linear motion device (1, 100) according to at least one of the preceding claims, wherein the circulation device (5, 105) comprises, at least in the detection section (9), an electrically insulating material, in particular is formed thereof.

5. Linear motion device (1, 100) according to at least one of the preceding claims, wherein the detection section (9) extends over a plurality of rolling elements (4, 104).

6. Linear motion device (1, 100) according to at least one of the preceding claims, wherein the electro-based lubricant sensor (7) is arranged to capacitively capture the information.

7. Linear motion device (1, 100) according to claim 6, wherein The electro-based lubricant sensor (7) has a detection circuit for recording the information, which has two opposing electrodes (8) between which at least one rolling element (4, 104), in particular a plurality thereof, is arranged.

8. Linear motion device (1, 100) according to claim 7, wherein at least one of the electrodes (8), in particular both, has an electrically insulating coating on a side facing the at least one rolling element (4, 104).

9. Linear motion device (1, 100) according to claim 7 or 8, wherein the electrodes (8) are positioned opposite each other in a direction intersecting the direction of gravity and / or parallel or perpendicular to an axis of rotation (4a) of the at least one rolling element (4, 104) in the detection section (9).

10. Linear motion device (1 , 100) according to at least one of claims 7 to 9, wherein at least one of the electrodes (8), in particular both, are glued to the rotating device (5, 105).

11. Linear motion device (1, 100) according to at least one of claims 6 to 10, wherein at least one of the electrodes (8), in particular both, is arranged in such a way that it cannot be contacted with the at least one rolling element (4).

12. Linear motion device (1, 100) according to one of claims 6 to 11, wherein the electro-based lubricant sensor has a detection circuit for capturing the information that contacts the at least one rolling element (4).

13. Linear motion device (1, 100) according to at least one of claims 6 to 12, wherein the electro-based lubricant sensor (7) is designed to capture information based on a charging and / or discharging time.

14. Linear motion device (1, 100) according to at least one of claims 6 to 12, wherein 29 The electro-based lubricant sensor (7) is designed to capture information based on a sampling of a charging and / or discharging curve.

15. Linear motion device (1, 100) according to at least one of the preceding claims, further comprising an energy harvester (10) which is configured to provide electrical energy to the second device component (3, 103) due to the relative motion between the second device component (3, 103) and the first device component (2, 102), and in particular the second device component (3, 103) is configured such that the electrical energy provided by the energy harvester (10) can be used to operate the electro-based lubricant sensor (7).

16. Linear motion device (1) according to one of claims 1-15, designed as a linear guide with a guide rail as the first device component (2) and with a linear guide carriage or linear guide slide as the second device component (3).

17. Linear motion device (100) according to one of claims 1-15, designed as a threaded drive with a threaded spindle as the first device component (102) and with a threaded nut as the second device component (103).

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