vacuum pump

Abstract

The present invention provides a vacuum pump and a method for operating such a vacuum pump, which allows for reliable, non-contact measurement of predetermined physical or chemical properties of the vacuum pump's components without cumbersome calibration. [Solution] The vacuum pump 100 includes a sensor 134 positioned on a first component 110 and configured to measure the physical properties of the first component, a RIFD transponder 130 attached to the first component and communicating with the sensor, and an RFID reader 140 attached to a second component 120 of the vacuum pump at a distance such that the RFID reader 140 and the RFID transponder are communicating with the RIFD transponder.

Description

Technical Field

[0001] The present invention relates to a vacuum pump having a sensor arranged in a component of the vacuum pump and configured to measure a physical property of the component, and a method of operating such a vacuum pump.

Background Art

[0002] During operation of a vacuum pump, it is necessary to detect certain physical properties of the components of the vacuum pump. Examples of such properties are the temperature of the rotor of the vacuum pump or the rotational speed of the vacuum pump. For example, detection of such properties is essential in order to continuously achieve the necessary operating safety or operating stability of the vacuum pump while achieving the highest possible performance.

[0003] In order to be able to measure the physical or chemical properties of the components of a vacuum pump that rotate at high speed, such as the physical or chemical properties of a rotor shaft, a non-contact measurement method is often used. To measure the temperature of the rotor shaft, for example, a pyrometer having a thermal detector or a photoelectric detector can be used. However, in order to determine the temperature of the rotor shaft in a reliable manner, it is necessary to accurately know the emissivity of the measurement surface on the rotor shaft detected by the pyrometer. Furthermore, generally, such measurement parameters as the emissivity of the measurement surface are presumed not to change during operation of the vacuum pump. However, this presumption is not always accurate under certain operating conditions of the vacuum pump. For example, depending on the properties of the gas to be pumped, coating of the surface of the vacuum pump that changes the emissivity of the measurement surface can occur.

[0004] Alternatively, an electric power characteristic curve may be used to indirectly measure the temperature of the vacuum pump rotor, where the rotor temperature is assigned to a predetermined power consumption of the vacuum pump. Furthermore, a magnetic induction measurement method may be used to indirectly measure the rotor temperature.

[0005] Therefore, known non-contact measurement methods for specific physical or chemical properties of vacuum pump components often require specific estimations regarding the time constants of the known measurement parameters, as mentioned above. Furthermore, known non-contact measurement methods often require specific calibration of the vacuum pump before it can be shipped, which can incur considerable costs. Moreover, known non-contact measurement methods may be surface-sensitive, and their reliability may depend on the operating conditions or current load of the vacuum pump at any given time. [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide a vacuum pump and a method for operating such a vacuum pump that allows for reliable, non-contact measurement of predetermined physical or chemical properties of the components of the vacuum pump without cumbersome calibration. [Means for solving the problem]

[0007] This problem is solved by a vacuum pump and method having the features of the independent claim. Advantageous variations of the present invention are described in the dependent claims, specification and drawings.

[0008] The vacuum pump includes a sensor located on a first component of the vacuum pump and configured to measure the physical properties of the first component, and an RFID transponder attached to the first component and communicated with the sensor. The RFID transponder is a device having a transmitter and a receiver for identification, and the device operates in the radio frequency range (RFID, Radio Frequency Identification). The vacuum pump further includes an RFID reader, which is attached to a second component of the vacuum pump, separate from the first component, at a distance from the RIFD transponder such that the RFID reader and the RFID transponder are communicated with each other.

[0009] The vacuum pump may be, for example, a turbomolecular pump, and the first component may be, for example, the rotor of such a turbomolecular pump. Moreover, the first component may be another component of the vacuum pump that does not rotate and is difficult to access. The sensor may be, for example, a temperature sensor attached to the rotor of the turbomolecular pump, or other sensors such as a gyroscope or strain gauge.

[0010] An RFID transponder and an RFID reader form an RFID system, which, on the one hand, performs the identification of the RFID transponder. This identification is performed, for example, by storing a unique identifier in the RFID transponder's microchip, which is then queried by an RFID reader query signal after the RFID transponder is so-called activated, and transmitted to the RFID reader. This identification ensures that the RFID reader is connected to the desired RFID transponder and not to any other device.

[0011] RFID transponders and sensors do not require their own energy storage devices, such as batteries. Instead, energy can be supplied to the RFID transponders and sensors by electromagnetic waves emitted by the RFID reader. The RFID reader's transmission signal, such as the aforementioned query signal or another signal, can be received and rectified by the RFID transponder, and the rectified signal thus supplies energy to the RFID transponder and sensors.

[0012] Both the RFID transponder and the sensor are attached to a first component, such as the rotor of a turbomolecular pump, and are communicated together so that sensor measurements representing the physical properties of the first component can be transmitted from the sensor to the RFID transponder, and from the RFID transponder to the RFID reader, which is also communicated together with the RFID transponder. The RFID reader may be configured to evaluate the detected sensor measurements and further transmit corresponding information, such as the temperature of the vacuum pump rotor, to the vacuum pump's control unit.

[0013] Therefore, the use of RFID transponders and RFID readers enables the wireless transmission or detection of physical properties of the first component, such as measured temperatures of the rotor of a turbomolecular pump. Such wireless detection of sensor measurements requires little effort, for example, because individual calibration of the entire system before shipping a vacuum pump is unnecessary.

[0014] Furthermore, additional assumptions regarding specific characteristics of the first component, such as the emissivity of the measurement surface during high-temperature measurements, are unnecessary. Instead, the sensor can be pre-calibrated and placed on the first component of the vacuum pump to perform direct measurements of the physical properties of the first component without further assumptions. This enables accurate identification of the physical properties of the first component.

[0015] The distance between the RFID reader and the RFID transponder is advantageously selected so that the electrical oscillation circuit of the RFID transponder matches the resonant frequency of RFID communication between the RFID reader and the RFID transponder. If the distance between the RFID transponder and the RFID reader is too large or the geometry changes, communication between them may no longer be possible in some cases.

[0016] According to one embodiment, an RFID transponder and an RFID reader are arranged adjacent to each other in the internal space of a vacuum pump. The internal space is located within the housing of the vacuum pump and more preferably includes the evacuated area of ​​the vacuum pump. Thus, the RFID reader may be connected to one or more vacuum feedthroughs. The vacuum feedthroughs enable, for example, communication between the RFID reader and the control equipment of the vacuum pump and the transmission of measurements to the RFID reader. The arrangement of the RFID transponder and RFID reader in the internal space of the vacuum pump allows for the direct detection of measurements of the physical properties of the first component when the first component is located in the internal space of the vacuum pump and, in some cases, cannot be accessed from the outside, i.e., from outside the housing of the vacuum pump.

[0017] The sensor can be integrated into the RFID transponder. Such a combination of sensor and RFID transponder requires minimal structural space, thereby allowing for flexible placement of the RFID transponder with the integrated sensor in the first component.

[0018] Alternatively, the sensor and RFID transponder may be positioned spaced apart from each other within the first component. When the sensor detects the temperature of the first component, for example, the temperature of the rotor of a vacuum pump, the temperature of the first component at the desired installation location of the sensor may be too high to activate the RFID transponder. If the sensor is attached to the rotor of, for example, a turbomolecular pump, temperatures exceeding 85°C may occur at certain points on the rotor, in which case the RFID transponder incorporating the sensor cannot operate. In such cases, only the sensor can be installed at the desired installation location, while the RFID transponder can be installed in a location where temperatures too high for operation are not expected. When the sensor and RFID transponder are positioned spaced apart from each other within the first component, they can communicate with each other wirelessly or via cable.

[0019] The RFID transponder may further be configured as a printed circuit board (PCB board) with the first component embedded within it. In such embodiments, the RFID transponder component can be incorporated into the material of the printed circuit board, thereby protecting it from high centrifugal forces, for example, when the first component is the rotor of a vacuum pump. In such forms, the RFID transponder component may first be mounted onto the printed circuit board by a standardized manufacturing method, and subsequently reinforced with a suitable filler material, for example, a two-component epoxide-based material. This provides additional protection for the component against the resulting centrifugal forces.

[0020] A shield may be placed between the RFID transponder and the first component. Such a shield may include, for example, a ferrite layer. The shield can prevent electromagnetic loss in the material of the first component. If a shield is not desired between the RFID transponder and the first component, an alternative may be provided where the RFID transponder is at a sufficient distance, for example, at least 2 to 3 mm from the metal surface within the vacuum pump in the axial direction along the rotor shaft of the vacuum pump.

[0021] The first component may include a rotating element of a vacuum pump to which an RFID transponder and sensor are attached, while the second component may include a non-rotating element of a vacuum pump to which an RFID reader is attached. The rotating element may be, for example, the rotor of a turbomolecular pump, while the non-rotating element may be the stator of such a turbomolecular pump. Thus, by using an RFID transponder and RFID reader to transmit sensor measurements, direct and low-cost detection of physical properties of the rotating element or rotor becomes possible without additional effort and guesswork.

[0022] When incorporating an RFID transponder into a rotating element or rotor, the RFID transponder may be positioned as close as possible to the axis of rotation of the rotating element, thereby minimizing the centrifugal force acting on the RFID transponder. Additionally, the RFID transponder may have a reinforcing part, whereby the RFID transponder is additionally protected from the action of centrifugal force.

[0023] The RFID transponder and sensor elements or components may further be arranged on the rotating element or rotor such that the imbalances of the rotating element are compensated for each other. In other words, the RFID transponder and sensor elements may be distributed over the first component such that the imbalance of the rotating element or rotor is minimized and ideally equal to zero. Such an arrangement prevents interference based on imbalance during the operation of the vacuum pump.

[0024] The RFID transponder may further be inserted into the rotating element by means of a threaded portion. This enables easy replacement of the RFID transponder.

[0025] The RFID reader may have built-in electronic components. This results in a compact configuration of the RFID reader. With the built-in electronic components, the RFID reader can further output already evaluated data.

[0026] Alternatively or additionally, at least one electronic component assigned to the RFID reader may be incorporated into the control device of the vacuum pump. This results in a simple configuration of the RFID reader. However, in this case, an electrical connection between the electronic component and the RFID reader, for example by means of a coaxial cable, is required.

[0027] The RFID transponder and / or the RFID reader may further be configured to transmit the measurement signal of the sensor from the RFID transponder to the RFID reader by means of load modulation. Such load modulation includes turning on and off the load resistances of the RFID transponder and / or the RFID reader in order to achieve amplitude modulation.

[0028] By means of load modulation or switching of the load resistance, a modulation signal can be generated at a sub-carrier frequency, i.e., a frequency outside the frequency band usually set for RFID communication. The RFID reader may have a band-pass filter for such a sub-carrier frequency at which the RFID transponder transmits the measurement signal of the sensor, for example, by means of amplitude modulation or load modulation. Such a band-pass filter ensures that the desired measurement signal is received by the RFID reader and that interference signals are not received.

[0029] Furthermore, the RFID reader and the RFID transponder may each have an antenna, which may be formed concentrically circularly or may have a half-shell shape. Such an antenna shape can ensure reliable data transmission between the RFID transponder and the RFID reader even when a first component having the RFID transponder rotates at high speed relative to a second component having the RFID reader.

[0030] A further subject of the present invention is a method for measuring the physical properties of a first component in a vacuum pump. The vacuum pump has a sensor, which is attached to the first component. According to this method, an RFID reader attached to a second component of the vacuum pump, different from the first component, transmits a signal to an RFID transponder attached to the first component and communicated with the sensor. The signal from the RFID reader is received by the RFID transponder, which in turn supplies power to the RFID transponder and the sensor. The sensor detects at least one measurement of the physical properties of the first component and transmits it from the sensor to the RFID transponder. Subsequently, at least one measurement is transmitted from the RFID transponder to the RFID reader by load modulation in the RFID transponder and / or RFID reader. The RFID reader can then evaluate the measurement.

[0031] Therefore, this method is configured to measure the physical properties of the first component, such as the temperature of the vacuum pump rotor, during operation for the operation of the aforementioned vacuum pump. Accordingly, the above description of the vacuum pump applies to this method accordingly, and this is especially true with respect to the effects and preferred embodiments. Furthermore, naturally, all features mentioned herein are combinable with respect to each other unless otherwise explicitly stated.

[0032] The present invention will be described below with reference to the accompanying drawings, based on exemplary advantageous embodiments. [Brief explanation of the drawing]

[0033] [Figure 1] A cross-sectional view shows a part of the vacuum pump according to the present invention, in which an RFID transponder and an RFID reader are arranged. [Figure 2] Figure 1 shows a perspective view of the arrangement. [Figure 3] Figures 1 and 2 show two configurations of RFID transponders and RFID reader antennas. [Figure 4] A cross-sectional view shows another part of the vacuum pump according to the present invention, in which an RFID transponder and an RFID reader are arranged. [Figure 5] A cross-sectional view shows a further part of the vacuum pump according to the present invention, which includes an RFID transponder and an RFID reader. [Modes for carrying out the invention]

[0034] Figure 1 schematically shows a portion of a vacuum pump 100 configured as a turbomolecular pump. The turbomolecular pump 100 includes a rotor 110 having a rotor shaft 112 and a plurality of rotor blades. One of the rotor blades, 114, is shown in Figure 1 in the region of a labyrinth seal 116.

[0035] Furthermore, the turbomolecular pump 110 includes a stator 120. However, of the stator 120, only the labyrinth hub 122 is shown in Figure 1. The upper side of the labyrinth hub 122 and the lower side of the illustrated rotor blades 114 work together to form a labyrinth seal 116.

[0036] During operation of the turbomolecular pump 100, the rotor 110 rotates at an extremely high speed relative to the stator 120, for example, at a rotational speed of tens of thousands of revolutions per minute. Therefore, the rotor hub 112 and the rotor blades 114 belong to the rotating components of the vacuum pump or turbomolecular pump 100, while the stator 120, which has a labyrinth hub 122, belongs to the non-rotating components of the turbomolecular pump 100.

[0037] During operation of the turbomolecular pump 100, it is necessary to detect or measure the physical or chemical properties of the components of the turbomolecular pump 100, for example, in order to ensure sustained operational stability. These properties include, for example, the temperature of the rotor 110.

[0038] To detect or measure the temperature of the rotor 110, the turbomolecular pump 110 includes an RFID transponder 130. The RFID transponder 130 is attached to the rotor blades 114 by a screw fastening 132. The RFID transponder 130 is also referred to as an RFID tag. A temperature sensor 134 is incorporated into the RFID transponder 130. A corresponding component for the RFID transponder forms an RFID reader 140, which is attached to the labyrinth hub 122 of the stator 120, for example, by screw fastening or adhesive.

[0039] The RFID transponder 130 and the RFID reader 140 work together to form an RFID system, that is, an identification system that operates in the radio frequency range (RFID: Radio Frequency Identification). The RFID transponder 130 has a microchip, and a unique identifier is stored in the microchip. Furthermore, the RFID transponder 130 is a passive device that does not include an energy storage device such as a battery. That is, the temperature sensor 134 also does not have its own energy source. Instead, energy is supplied to the RFID transponder 130 and the temperature sensor 134 by the RFID reader 140, that is, by the electromagnetic waves emitted by the RFID reader 140.

[0040] More specifically, the RFID reader 140 transmits a query signal to the RFID transponder 130 via an antenna, which will be described in more detail later. The query signal is received by the antenna of the RFID transponder 130 and used, on the one hand, to activate or "activate" the RFID transponder 130. Furthermore, the query signal and / or other signals from the RFID reader 140 are converted by the rectifier of the RFID transponder 130 into signals for supplying energy to both the RFID transponder 130 and the integrated temperature sensor 134.

[0041] Furthermore, the query signal from the RFID reader 140 is read by the electronic components of the RFID transponder 130, and in response to this signal, a signal containing the unique identifier of the RFID transponder 130 is transmitted back to the RFID reader 140. This ensures accurate communication between the RFID transponder 130 and the RFID reader 140, and that the RFID reader 140 does not receive signals or interference signals from other devices.

[0042] The microchip of the RFID transponder 130 detects the measurement or data from the integrated temperature sensor 134. In addition to the temperature sensor 134, the RFID transponder 130 includes a microcontroller and a voltage regulator in its microchip, the voltage regulator being mounted on a common board 300 (see Figure 3) or integrated into the board 300 together with the antenna 310.

[0043] The measured value or data detected by the temperature sensor 134 is transmitted to the RFID reader 140 via amplitude modulation of the electromagnetic field radiated from the RFID transponder 130. Amplitude modulation is performed, for example, by turning a load resistor on and off, and this is also called load modulation. At a frequency of, for example, 13.56 MHz used for RFID communication, connecting an additional load resistor generates a signal at a different frequency, i.e., a so-called subcarrier frequency. These subcarrier frequencies are used for data transmission between the RFID transponder 130 and the RFID reader 140.

[0044] The RFID reader 140 includes a bandpass filter for the subcarrier frequency. Demodulation of the signal received by the RFID reader 140 generates a signal or data that can be identified and interpreted as measurement data from the temperature sensor 134 by the electronic components of the RFID reader 140. Therefore, in this embodiment, an evaluation electronic component for the measurement data from the temperature sensor 134 is incorporated into the RFID reader 140.

[0045] More specifically, the RFID reader 140 includes, in addition to the antenna for transmitting and receiving the aforementioned signals, a high-frequency reader chip, a microcontroller, and a tuning circuit, the tuning circuit including, for example, a coil and a digitally tunable capacitor. The electronic components of the RFID reader 140 are used to control the transmission output of the RFID reader 140's antenna and to decode the modulated electromagnetic field, thereby interpreting the signal transmitted from the RFID transponder 130 as data from the temperature sensor 134.

[0046] The electronic components of the RFID reader 140 are further connected to the drive electronic components of the vacuum pump 100, which are not shown, so that the drive electronic components of the vacuum pump 100 can access the RFID reader 140 or the data provided by the RFID reader 140. For such communication between the drive electronic components of the vacuum pump and the RFID reader 140, for example, a known software protocol is used.

[0047] The RFID transponder 130 is positioned within range of the RFID reader 140, thereby ensuring radio energy transfer and data communication between the RFID transponder 130 and the RFID reader 140. The distance between the antennas of the RFID transponder 130 and the RFID reader 140 is typically in the range of a few millimeters. In the form of the antenna 310 of the RFID transponder 130 (see Figure 3), a pump-specific adaptation of the electrical oscillator circuit of the RFID transponder 130 to the resonant frequency of RFID communication is required. In other words, such an electrical oscillator circuit of the RFID transponder 130 is calibrated taking into account a predetermined distance between the RFID transponder 130 and the RFID reader 140 or between their antennas.

[0048] The antennas of the RFID transponder 130 and RFID reader 140 should also have a sufficient axial distance, i.e., along the rotor axis 112, i.e., vertical in Figure 1, from the surface of other metal parts or components of the vacuum pump 110, thereby preventing electromagnetic losses in the materials of these components. Such a sufficient axial distance is, for example, 2 mm to 3 mm. If the distance between the antennas of the RFID transponder 130 and RFID reader 140 is less than such a distance from the metal components of the vacuum pump 100, appropriate shielding, for example, by a ferrite layer (not shown), will be necessary.

[0049] Since the temperature sensor 134 is integrated into the RFID transponder 130, no further components are needed to measure the temperature of the rotor 110, namely additional components for the RFID transponder 130 and RFID reader 140. During operation of the turbomolecular pump 100, high centrifugal force is generated based on the high rotational speed of the rotor 110, so the transponder 130 is positioned as close as possible to the rotation axis of the rotor shaft 112 (see also Figure 2), that is, as close as possible to the inner diameter region of the rotor blades 114 in the radial direction.

[0050] Additionally, to protect the transponder 130, including the integrated temperature sensor 134, from the centrifugal force generated during the operation of the turbomolecular pump 100, the RFID transponder 130, including the antenna 310 and the temperature sensor 134, is configured as an embedded printed circuit board 300 or an embedded PCB board (see also Figures 2 and 3). In this case, the components of the RFID transponder 130, including the antenna and the temperature sensor 134, are surrounded by the material of the substrate 300, thereby protecting these components, including the antenna 310 and the temperature sensor 134, from large centrifugal forces.

[0051] The components of the RFID transponder 130 are mounted on a PCB board, for example, by a standardized manufacturing method, and reinforced with a suitable filler material based on a two-component epoxide, thereby achieving additional protection against centrifugal forces generated by such reinforcement with the filler material. Furthermore, advantageously, a board substrate and / or antenna substrate having a yield point of appropriate height with corresponding temperature stability at a given temperature and rotational speed of the rotor 110 of the turbomolecular pump 100 is used.

[0052] The temperature sensor 134 is configured as a digital temperature sensor, in which case the thermal coupling between the temperature sensor 134 and the rotor shaft 112 can be optimized, for example, by "thermal pads" (i.e., by brazed contacts for thermal coupling). In such optimization, the copper lines on the printed circuit board 300 of the RFID transponder 130 are guided to positions that have direct contact, for example, with a metal mounting surface, or indirect contact, with the mounting surface of the screw heads when the RFID transponder's circuit board is screwed to the material of the rotor shaft 112.

[0053] In addition to such a configuration having an already incorporated temperature sensor 134, the temperature sensor 134 can also be realized in the form of temperature-sensing properties of the antenna 310 of the RFID transponder 130. Alternatively or additionally, further electronic elements of the RFID transponder 130 may also have properties that depend on detectable temperature, thereby allowing the temperature of the RFID transponder 130, and by extension the rotor 110, to be determined based on the detected properties.

[0054] In another embodiment not shown, the temperature sensor 134 may be located outside the RFID transponder 130. The temperature sensor 134 may be located, for example, in a position where the temperature of the rotor 110 of the turbomolecular pump 100 is expected to exceed 85°C during operation of the turbomolecular pump 100. In such a case, the electronic components of the RFID transponder 130 should be located in a position on the rotor 110 where the temperature is always below 85°C.

[0055] The electronic components of the RFID reader 140 are connected via signal lines (not shown) to the drive electronic components or control electronic components (not shown) of the turbomolecular pump 100 through the vacuum feedthrough of the turbomolecular pump 100. As previously mentioned, the evaluation electronic components for the measurement data of the temperature sensor 134 are incorporated into the RFID reader 140 in this embodiment. Alternatively, the evaluation electronic components for the data that the RFID reader 140 receives from the RFID transponder 130 may be incorporated into the drive electronic components of the turbomolecular pump 100 or into a separate module outside the turbomolecular pump 100.

[0056] Furthermore, the entire electronic components of the RFID reader 140, i.e., all components other than the evaluation components, may be incorporated into the controller of the turbomolecular pump 100 and, consequently, may be located away from the antenna of the RFID reader 140. In such a case, the antenna of the RFID reader 140 is connected to the electronic components incorporated into the controller of the turbomolecular pump 100 via a coaxial cable. However, the length of such a coaxial cable should be kept as small as possible, and the isolation of the shield of such a coaxial cable to form a vacuum feedthrough may result in energy loss.

[0057] Therefore, in the embodiment shown in Figure 1, the electronic components of the RFID reader 140 are located on a common substrate together with the antenna of the RFID reader 140, within the internal space of the turbomolecular pump 100, i.e., within the vacuum region of the turbomolecular pump 100. Thus, a coaxial cable is not required in this embodiment. The electronic components of the RFID reader 140 are controlled via a digital interface, such as I2C or SPI, and the necessary signal lines are connected to the controller of the turbomolecular pump 100 via a vacuum feedthrough.

[0058] For communication between the RFID transponder 130 and the RFID reader 140, components of the RFID transponder 130 and RFID reader 140, such as the oscillator circuit, are adapted to the frequency for communication between the RFID transponder 130 and the RFID reader 140. Such a frequency for RFID communication is, for example, between 10 MHz and 15 MHz. Alternatively, a frequency range between 800 MHz and 900 MHz or between 2 GHz and 5 GHz (as a UHF system) may be used, for example, for the use of the RFID transponder 130 at high temperatures.

[0059] During operation of the turbomolecular pump 100, the RFID reader 140 supplies energy to the RFID transponder 130, which incorporates the temperature sensor 134, at predetermined time intervals, for example, at predetermined short time intervals per second. Within such time intervals, one or more measurements from the temperature sensor 134, i.e., measurements of the rotor 110, are transmitted from the RFID transponder 130 to the RFID reader 140 by the aforementioned load modulation and evaluated by the integrated electronics of the RFID reader 140.

[0060] Figure 2 is shown as a cross-sectional view of Figure 1 and shows two perspective views of a portion of the vacuum pump or turbomolecular pump 100 according to the present invention, including the region of the labyrinth seal 116. Figure 2A shows a view of the rotor blades 114 and labyrinth hub 122 from below, while Figure 2B shows a view of the rotor blades 114 and labyrinth hub 122 from above.

[0061] To enable recognition, the substrate 300 of the RFID transponder 130 (see also Figure 3) and the substrate of the RFID reader 140 are formed in an annular shape such that each substrate surrounds the rotor shaft 112. Both the substrates of the RFID transponder 130 and the RFID reader 140 surround the rotor shaft 112 within the labyrinth seal 116 such that the distance of each substrate to the rotation axis of the rotor shaft 112 is minimized. This also minimizes the centrifugal force acting on the components or elements of the RFID transponder 130 during the operation of the turbomolecular pump 100 when the RFID transponder 130 rotates together with the rotor 110 of the turbomolecular pump 100.

[0062] Elements or components on the substrate 300 of the RFID transponder 130, together with the screw fasteners 132, may cause additional unbalance of the rotor 110. To minimize such additional unbalance, the elements or components of the RFID transponder 130, including the screw fasteners 132, are distributed around the perimeter of the substrate of the RFID transponder 130 such that the sum of the individual unbalance vectors of the RFID transponder 130 components, including the screw fasteners 132, and the antenna is minimized in terms of value, ideally being a zero vector. In other words, the components or components of the RFID transponder 130, including the antenna and the screw fasteners 132, can be arranged or distributed around the perimeter of the substrate 300 of the RFID transponder 130 such that the individual unbalances of these components or components compensate for each other.

[0063] Figure 3 shows top views of each embodiment of the substrate 300 (see Figures 1 and 2) of the RFID transponder 130, each having the antenna 310 of the respective embodiment. Figure 3A shows a first embodiment of the antenna 310, in which the individual windings of the conductor path 320 extend concentrically and circularly on the substrate. Starting from the outer winding, the diameter of the conductor path 320 decreases each time it circles the circular substrate 300, down to the innermost winding. In contrast, Figure 3B shows a second embodiment of the antenna 310 in which the conductor path 320 is arranged in a half-shell configuration.

[0064] The concentric arrangement of the conductor path 320 in Figure 3A allows for a larger antenna shape compared to the half-shell arrangement of the conductor path 320 in Figure 3B. However, in the first embodiment of Figure 3A, the maximum value of the electromagnetic field radiated by the antenna 310 is at the center of the antenna, i.e., in the region of the rotation axis of the rotor shaft 112 (see Figures 1 and 2). In contrast, in the half-shell shape of the conductor path 320 in Figure 3B, the electromagnetic field is generated coaxially around the rotor shaft 112. As a result, the second embodiment of Figure 3B is less susceptible to interference during RFID communication between the RFID transponder 130 and the RFID reader 140.

[0065] Figure 4 shows an alternative embodiment of the arrangement of the RFID transponder 130 on the rotor 110 of the turbomolecular pump 100 and the RFID reader 140 on the stator 120 of the turbomolecular pump 100, specifically in the area of ​​the magnetic bearing 400. The magnetic bearing 400 is configured as a permanent bearing and includes two stacks of permanent magnets 410, one of which is located on the rotor shaft 112 and the other on a pin of the high-vacuum star-shaped member 420 of the stator 120.

[0066] The RFID transponder 130 is also configured as a substrate, with its components embedded in the substrate. Furthermore, since the RFID transponder 130 or its substrate is arranged concentrically with respect to the rotation axis of the rotor shaft 112, the rotation axis of the rotor shaft 112 forms the central axis or axis of symmetry with respect to the RFID transponder 130. This is also true for the RFID reader 140; therefore, the components of the RFID reader 140 are similarly embedded in a substrate, and the RFID reader 140 is similarly arranged symmetrically with respect to the rotation axis of the rotor shaft 112. Thus, the rotation axis of the rotor shaft 112 forms the common central axis or axis of symmetry for both the RFID transponder and the RFID reader 140.

[0067] Furthermore, the above description of the features of the substrates of the RFID transponder 130 and RFID reader 140 also applies mutatis mutandis to the embodiment shown in Figure 4. Features include, in particular, shielding of the RFID transponder 130 as may be necessary, reinforcement of the RFID transponder 130 with injectable material, wiring including vacuum feedthrough to the RFID reader 140, embodiments of the two antennas shown in Figure 3, and periodic energy transfer and data transmission between the RFID transponder 130 and the RFID reader 140.

[0068] Figure 5 shows another embodiment of the vacuum pump or turbomolecular pump 100 according to the present invention, in which the RFID communication between the RFID transponder 130 and the RFID reader 140 is set in a different region of the rotor shaft 112 than in the embodiments of Figures 1 to 4. In the embodiment of Figure 5, the RFID transponder and RFID reader are located in the region of the drive motor of the vacuum pump, i.e., in the axial region of the Holbeck pump stage 500 of the vacuum pump 100 along the rotor shaft 112, on the side of the rotor shaft 112 beyond or below the projection 510. More specifically, the RFID transponder and RFID reader are located in the region of the drive magnet 520 of the rotor shaft 112 or in the region of the balance ring 530 of the rotor shaft 112.

[0069] For clarity, the RFID transponder 130 and RFID reader 140 are not explicitly shown in Figure 5. However, the arrangement of the RFID transponder 130 and RFID reader 140 is essentially the same as that shown in Figure 4, except that the RFID transponder 130 and RFID reader 140 are arranged on the axially extending planes of the rotor shaft 112 or the corresponding elements of the drive motor stator (not shown), rather than on the radially extending planes as shown in Figure 4. Furthermore, the above description regarding the RFID transponder 130 and RFID reader 140 also applies mutatis mutandis to the embodiment in Figure 5.

[0070] In addition to the temperature sensor 134 (see Figure 1), the RFID transponder 130 may include further sensors or be communicated with such sensors on the rotor shaft 112. Examples of such sensors are gyroscopes or strain gauges.

[0071] Furthermore, if deposits are expected on the components of the turbomolecular pump 100 based on the vacuum process or the use of the turbomolecular pump 100, a combination of an RFID transponder 130 and an RFID reader 140 can be used to determine, for example, the coating thickness on the rotor shaft 112. The deposits may be caused, for example, by the reactive gas pumped by the turbomolecular pump 100. From a predetermined coating thickness or limit thickness, such deposits will have an undesirable effect on the operation of the turbomolecular pump 100.

[0072] The power radiated from the RFID reader 140, which is necessary for RFID communication, serves as a measure of the coating of the RFID transponder 130 and the antenna of the RFID reader 140, which is made of metal or semiconductor material. The coating thickness based on deposits on the turbomolecular pump 100, i.e., the rotor shaft 112, can be estimated by detecting the power radiated from the RFID reader 140 as a function of time, i.e., at regular time intervals.

[0073] In other words, the power of the RFID reader 140 required to establish RFID communication provides information about the RFID transponder 130, the antenna of the RFID reader 140, and consequently, the thickness of the deposit already present on the rotor shaft 112. Alternatively, only changes in the deposit thickness based on changes in the power required for RFID communication may be detected and monitored at predetermined time intervals. [Explanation of Symbols]

[0074] 100 Vacuum pump or turbomolecular pump 110 Rotor 112 Rotor Shaft 114 Control surfaces in the labyrinth seal region 116 Labyrinth Seal 120 stator 122 Labyrinth Hub 130 RFID transponders 132 Screw fastening part 134 Temperature Sensor 140 RFID readers 300 RFID transponder substrates 310 RFID transponder antenna 320 Antenna Conductor Path 400 Magnetic Bearing 410 Permanent Magnet 420 High Vacuum Star-Shaped Components 500 Holbeck pump stage 510 Protrusion of the rotor shaft 520 drive magnets 530 Balance Ring

Claims

1. A vacuum pump (100), A sensor (134) is positioned in the first component (110) of the vacuum pump (100) and is configured to measure the physical properties of the first component (110), A RIFD transponder (130) is attached to the first component (110) and is in communication with the sensor (134), An RFID reader (140) is attached to a second component (120) of a vacuum pump (100) at a distance such that the RFID reader (140) and the RFID transponder (130) are connected for communication. A vacuum pump (100) including the vacuum pump.

2. The vacuum pump (100) according to claim 1, wherein the FID transponder (130) and the RFID reader (140) are arranged adjacent to each other in the internal space of the vacuum pump (100).

3. The vacuum pump (100) according to claim 1 or 2, wherein the sensor (134) is incorporated into the RFID transponder (130).

4. The vacuum pump (100) according to claim 1 or 2, wherein the sensor (134) and the RFID transponder (130) are arranged spaced apart from each other.

5. The vacuum pump (100) according to any one of claims 1 to 4, wherein the RFID transponder (130) is formed as a printed circuit board (300) embedded in the first component (110).

6. A vacuum pump (100) according to any one of claims 1 to 5, wherein a shield is disposed between the RFID transponder (130) and the first component (110).

7. The first component (110) includes a rotating element of a vacuum pump (100) to which an RFID transponder (130) and a sensor (134) are attached. The vacuum pump (100) according to any one of claims 1 to 6, wherein the second component (120) includes a non-rotating element of the vacuum pump (100) to which an RFID reader (140) is attached.

8. The RFID transponder (130) is a vacuum pump (100) according to claim 7, having a reinforcing portion.

9. The vacuum pump (100) according to claim 7 or 8, wherein the elements of the RFID transponder (130) and the elements of the sensor (134) are arranged on the rotating element (110) such that the imbalance of the rotating element (110) is compensated for by each other.

10. The vacuum pump (100) according to any one of claims 7 to 9, wherein the RFID transponder (130) is inserted into the rotating element (110) by a screw fastening portion.

11. The RFID reader (140) is a vacuum pump (100) according to any one of claims 1 to 10, having integrated electronics.

12. The vacuum pump (100) according to any one of claims 1 to 11, wherein at least one electronic component assigned to the RFID reader (140) is incorporated into the control device of the vacuum pump (100).

13. The vacuum pump (100) according to any one of claims 1 to 12, wherein the RFID transponder (130) and / or RFID reader (140) are configured to transmit the measurement signal of the sensor (134) from the RFID transponder (130) to the RFID reader (140) by load modulation.

14. The vacuum pump (100) according to claim 13, wherein the RFID reader (140) has a bandpass filter for the subcarrier frequency through which the RFID transponder (130) transmits the measurement signal of the sensor (134).

15. A method for measuring the physical properties of a first component (110) in a vacuum pump (100), wherein the vacuum pump (100) has a sensor (134), the sensor (134) is attached to the first component (110), and the method includes the following: An RFID reader (140) attached to a second component (120) of the vacuum pump (100), which is different from the first component (110), transmits a signal to an RFID transponder (130), and the RFID transponder (130) is attached to the first component (110) and is in communication with a sensor (134). The RFID reader (140) receives the signal from the RFID transponder (130), thereby supplying energy to the RFID transponder (130) and the sensor (134). At least one measurement value of the physical characteristics of the first component (110) is detected by the sensor (134) and transmitted from the sensor (134) to the RFID transponder (130). A method for transmitting at least one measurement value from an RFID transponder (130) to an RFID reader (140) by load modulation of the RFID transponder (130) and / or the RFID reader (140).

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