Vacuum pump

Abstract

A vacuum pump comprises a rotating element, a sensor attached to the rotating element and configured to measure a physical property of the rotating element, a transmitter located on the rotating element and having a communicative link with the sensor, and a receiver located in a non-rotating area of ​​the vacuum pump. At least one non-rotating element of the vacuum pump is arranged between the transmitter and receiver. The transmitter is configured to wirelessly transmit measurement data from the sensor to the receiver.

Description

[0001] The invention relates to a vacuum pump with a sensor which is arranged on a rotating element of the vacuum pump and is configured to measure a physical property of the rotating element, and to a method for operating such a vacuum pump.

[0002] For the reliable operation of a vacuum pump, it may be necessary to measure certain physical properties of its components. Examples of such properties include the temperature or rotational speed of the pump's rotor. Measuring these properties is essential for optimizing the vacuum pump's performance and ensuring the required operational reliability over the long term.

[0003] Non-contact measurement methods are frequently used to measure the physical or chemical properties of rapidly rotating vacuum pump components. For example, a pyrometer with thermal or photoelectric detectors can be used to measure the temperature of a rotor shaft. Alternatively, power characteristic curves can be used to indirectly measure the rotor temperature of the vacuum pump, where the rotor temperature is correlated with a specific power input of the vacuum pump. Furthermore, magnetic-inductive measurement methods can be used for the indirect measurement of the rotor temperature.

[0004] These non-contact measurement methods for certain physical or chemical properties of vacuum pump components therefore usually require certain assumptions, for example, regarding the temporal constancy of known measurement parameters. Furthermore, the known non-contact measurement methods usually require specific calibration of the vacuum pump before it can be delivered, which can involve considerable costs. In addition, the known non-contact measurement methods can be surface-sensitive, and their reliability can depend on the specific operating conditions or the current load case of the vacuum pump.

[0005] As an alternative to the aforementioned indirect, non-contact measurement methods, it was recently proposed to attach an RFID transponder to the rotor of a vacuum pump, which communicates with a corresponding sensor for measuring the rotor's temperature or rotational speed. Furthermore, this measurement method provides for the RFID transponder to communicate with a corresponding RFID reader in order to wirelessly transmit the sensor's measurement data.

[0006] However, with such a vacuum pump, the RFID reader must be mounted in close proximity to, or within range of, the RFID transponder, for example, on the stator of the vacuum pump. Therefore, the RFID reader includes, for instance, a non-rotating receiver board located near the corresponding RFID transponder board on the vacuum pump's rotor. This receiver board on the stator of the vacuum pump, however, incurs additional costs and must also be connected to another board or control unit of the vacuum pump via a suitable cable. This results in additional installation effort and further costs.

[0007] One object of the invention is to create a vacuum pump and a method for operating such a pump, with which a contactless measurement of a given property of a rotating component of the vacuum pump is possible in a simple and reliable manner.

[0008] This problem is solved by a vacuum pump and a method with the features of the independent claims. Advantageous embodiments of the invention are specified in the dependent claims, the description, and the drawings.

[0009] The vacuum pump according to the invention comprises a rotating element, a sensor attached to the rotating element and configured to measure a physical property of the rotating element, a transmitter unit arranged on the rotating element and having a communicative link with the sensor, and a receiver unit located in a non-rotating area of ​​the vacuum pump. At least one non-rotating element of the vacuum pump is arranged between the transmitter unit and the receiver unit. The transmitter unit is configured to wirelessly transmit measurement data from the sensor to the receiver unit.

[0010] The vacuum pump could, for example, be a turbomolecular pump, and the rotating element could, for example, be a rotor of such a turbomolecular pump. The sensor could be, for example, a temperature sensor attached to a rotor of such a turbomolecular pump, or another sensor such as a gyroscope or a strain gauge. Because the sensor is attached directly to the rotating element, a direct measurement of the rotating element's physical properties is possible.

[0011] Since at least one non-rotating element, such as the stator of a turbomolecular pump, is positioned between the transmitter and receiver units, the receiver unit does not need to be located in close proximity to the transmitter unit for wireless data transmission. Unlike an RFID reader, for example, the receiver unit does not require a receiver board located near a corresponding RFID transponder board on the vacuum pump rotor. This reduces the assembly effort for the vacuum pump. Furthermore, it eliminates the costs associated with wiring a receiver board for an RFID reader.

[0012] According to one embodiment, the vacuum pump includes control electronics into which the receiver unit is integrated. Such integration reduces the overall space required for the electrical and electronic components of the vacuum pump.

[0013] Furthermore, a frequency range for transmitting the sensor's measurement data from the transmitting unit to the receiving unit can be selected depending on one or more materials of the at least one non-rotating element located between the transmitting unit and the receiving unit. In other words, the frequency for transmitting the measurement data can be adapted to the material or materials of the at least one non-rotating element of the vacuum pump between the transmitting unit and the receiving unit. Such a selection of the frequency range ensures that a communicative link can be established between the transmitting unit and the receiving unit despite the presence of the at least one non-rotating element.

[0014] Furthermore, the transmitting and receiving units can be configured to use a low-frequency technology for transmitting the sensor's measurement data from the transmitting unit to the receiving unit. Examples of such low-frequency technologies include Bluetooth Low Energy (BLE) or Long Range (LoRa), as well as protocols based on them, such as Mioty. These technologies are characterized by low energy consumption, robustness, and inexpensive hardware.

[0015] According to a further embodiment, the rotating element can be configured to supply the sensor with energy through its rotation. The sensor's energy supply can be inductive, in particular. Since the sensor can thus be mounted on the rotating element autonomously with respect to its energy supply, no mechanisms for transferring or storing energy to or on the rotating element are required. Rather, the energy to supply the sensor can be generated by the rotation of the rotating element when it is needed.

[0016] Furthermore, at least one magnet can be arranged in the non-rotating area of ​​the vacuum pump. The rotating element can have an inductor located within the magnet's effective range. The inductor can be coupled to the sensor to supply it with energy.

[0017] The inductor can be, for example, a conductor or a coil that, when the rotating element turns, interacts with the magnet located in the non-rotating area, thereby generating an induced voltage for the sensor. Through this interaction of the inductor with the magnet, the rotation of the element within the vacuum pump can thus be used to power the sensor.

[0018] The inductor can be integrated into the sensor and / or integrated into a circuit board with the sensor, or even form a single circuit board with it. This allows for a compact design of the inductor-sensor combination. Alternatively, the inductor and the sensor can be spaced apart and mounted on the rotating element. This allows, for example, the sensor and inductor to be positioned in areas with different temperatures, which can be particularly useful if the sensor is designed to measure relatively high temperatures at which the inductor should not be operated.

[0019] Furthermore, the transmitter and the inductor, preferably together with the sensor, can extend along the rotating element in a circumferential direction over a limited angular range. In other words, in this embodiment, the transmitter and the inductor can be designed without rotating components extending over the entire circumference of the rotating element, as is the case, for example, with transmitter elements of an RFID transponder on the rotor of a vacuum pump. The limited angular range can, for example, be less than 90° or, preferably, less than 45°.

[0020] Although an energy storage device on the rotating element of the vacuum pump is generally not required, an intermediate storage device, such as a rechargeable battery, can nevertheless be arranged on the rotating element. The energy generated by induction can be absorbed by the intermediate storage device on the rotating element of the vacuum pump and made available again later.

[0021] The intermediate storage can be particularly advantageous in the embodiment described above, where the inductance extends only over a limited angular range of the rotor. In such cases, a sufficient energy supply to the sensor may only be ensured for a brief moment while the inductance sweeps across the magnet. The intermediate storage can, in this case, enable a continuous energy supply to the sensor.

[0022] The sensor, transmitter, and inductor can also be integrated into a single circuit board. Such a circuit board enables a particularly compact design for a measuring unit comprising the sensor, transmitter, and power supply inductor.

[0023] Furthermore, any imbalance in the rotating element that might be caused by such a circuit board can be compensated for by milling a groove in the rotating element. This groove can be designed so that the rotating element is balanced after the circuit board, along with the sensor, transmitter, and inductor, is attached. Conversely, the circuit board can act as a counterweight, compensating for any minor imbalance introduced by the milling. Thus, the milling can prevent any imbalance in the rotating element despite the circuit board's installation.

[0024] The sensor can also be configured as a temperature sensor. Alternatively or additionally, the sensor can be a speed sensor.

[0025] A further aspect of the invention is a method for measuring a physical property of a rotating element of a vacuum pump. According to the method, measurement data of the physical property of the rotating element are acquired by means of a sensor attached to the rotating element. The measurement data are wirelessly transmitted by means of a transmitter unit, which is arranged on the rotating element and has a communicative link with the sensor, to a receiver unit located in a non-rotating area of ​​the vacuum pump. At least one non-rotating element of the vacuum pump is arranged between the transmitter unit and the receiver unit.

[0026] The method is therefore intended for use in the operation of the vacuum pump described above, in order to measure the physical properties of the rotating element during this operation, for example, the temperature of a rotor of the vacuum pump. Consequently, the preceding statements regarding the vacuum pump apply accordingly to the method, and this applies in particular with regard to the advantages and preferred embodiments. Furthermore, it is understood that all features mentioned herein are combinable with one another, unless explicitly stated otherwise.

[0027] According to one embodiment of the method, the vacuum pump further comprises at least one magnet located in the non-rotating section of the vacuum pump. The rotating element of the vacuum pump may also include an inductor located within the effective range of the magnet. According to the method, the sensor can also be energized by the inductor during rotation of the rotating element. Consequently, during operation of the vacuum pump, it may not be necessary to supply the sensor on the rotating element with energy from an external source or to provide an energy storage device, such as a battery, on the rotating element.

[0028] The invention is described below by way of example with reference to advantageous embodiments and the accompanying figures. These show, schematically: Fig. 1 shows a sectional view of a vacuum pump according to the invention with a sensor on a rotating element and with a transmitter and receiver unit for transmitting the sensor's measurement data, and Fig. 2 shows a side view of the rotating element of the vacuum pump. Fig. 1 with a milling groove for arranging a circuit board.

[0029] Fig. 1 Figure 1 schematically shows a vacuum pump 100 in a sectional view. The vacuum pump 100 comprises a rotating element, or rotor, 110, and a non-rotating section 120 that surrounds the rotor 110. The non-rotating section 120 comprises a stator 122 of the vacuum pump 100, which surrounds the rotor 110, and a housing 124 of the vacuum pump 100, which encloses the stator 122.

[0030] The vacuum pump 100 can, for example, be configured as a turbomolecular pump. In this case, the rotor 110 comprises a plurality of rotor disks, while the stator 122 comprises a plurality of stator disks. Rotor disks and stator disks are oriented axially perpendicular to the plane of the drawing. Fig. 1 alternately arranged one above the other. A gap 112 between rotor 110 and stator 122 of the vacuum pump 100 is shown only for illustrative purposes, to show rotor 110 and stator 120 in the representation of Fig. 1 to be able to distinguish them. In a turbomolecular pump, however, there is indeed a gap 112 between the rotor disks and the stator disks, which extends mainly in a radial direction, i.e., from a central axis or axis of rotation of the rotor 110 outwards. In the top view, i.e., from the perspective of Fig. 1, the rotor disks of rotor 110 and the stator disks of stator 122 in a turbomolecular pump would consequently overlap in such a way that no gap 112 would be visible.

[0031] A circuit board 130 is arranged on the rotating element or rotor 110. This circuit board includes a sensor 132, which is thus also arranged on the rotating element or rotor 110 of the vacuum pump 100. The sensor 132 is designed to measure a physical property of the rotor 110. In the present embodiment, the sensor 132 is a temperature sensor that detects the temperature of the rotating element or rotor 110.

[0032] The circuit board 130 on the rotor 110 also includes a transmitter unit 134, which is thus also arranged on the rotating element or rotor 110 and furthermore has a communicative connection with the sensor 132, as indicated by the connecting line between the sensor 132 and the transmitter unit 134.

[0033] Furthermore, the circuit board 130 includes an inductor 136 in the form of a coil. The inductor 136 is coupled to the sensor 132, as indicated by the connecting line between them. The inductor 136 is intended to supply the sensor 132 with energy, as explained in more detail below.

[0034] The circuit board 130 with the sensor 132, the transmitter unit 134 and the inductor 136 extends only over a limited angular range 138 of the rotor 110, as illustrated by the double arrow and the dashed lines. The transmitter unit 134 therefore does not require any rotating components such as conductor tracks or coils around the rotor 110.

[0035] In the non-rotating area 120, i.e., for example, in the area of ​​the housing 124 of the vacuum pump 100, there is also a magnet 140 which interacts with the inductor 136 on the rotor 110. Conversely, the inductor 136 is located within the effective range of the magnet 140.

[0036] When the vacuum pump 100 is in operation and the rotor 110 is rotating, the rotation of the rotor 110 causes the magnet 140 to induce a voltage in the inductor 136. Through coupling with the sensor 132, the inductor 136 supplies the sensor 132 with energy due to the induced voltage.

[0037] During operation of the vacuum pump 100, no external or internal power source, such as a battery, is required to activate or operate the temperature sensor 132. This also applies to the power supply of the transmitter unit 134, which is likewise provided with the voltage induced in the inductor 136. The sensor 132, the transmitter unit 134, and the inductor 136 thus form a self-contained unit on the circuit board 130 with regard to their power supply.

[0038] The vacuum pump 100 further comprises control electronics 150, which are shown schematically outside the housing 124 of the vacuum pump 100. However, the control electronics 150 of the vacuum pump 100 can alternatively be arranged inside the housing 124 of the vacuum pump 100. A receiver unit 160 is integrated into the control electronics 150 and is thus located together with the control electronics 150 in the non-rotating area 120 of the vacuum pump 100.

[0039] Through the communicative connection between the sensor 132 and the transmitter unit 134, the transmitter unit 134 is able to receive measurement data from the sensor 132, such as temperature values ​​from the sensor 132.

[0040] Between the transmitting unit 134 and the receiving unit 160, as shown in Fig. 1 It can be seen that at least one non-rotating element of the vacuum pump 100, i.e., the stator 122 and possibly additional sections of the housing 124 or similar, are involved. As indicated by the wave symbols 162, the transmitter unit 134 is able to wirelessly transmit the measurement data of the sensor 132 to the receiver unit 160, despite the elements 122 and 124 located between the transmitter unit 134 and the receiver unit 160. The measurement data of the sensor 132 can thus be used directly by the control electronics 150 of the vacuum pump 100 to control the vacuum pump 100.

[0041] To enable the transmitter 134 to transmit the measurement data from the sensor 132 to the receiver 160 despite the non-rotating elements 122, 124 between the transmitter 134 and the receiver 160, the transmitter 134 and receiver 160 use a low-frequency technology for transmitting the sensor's measurement data. Examples of such low-frequency technologies are Bluetooth Low Energy (BLE) or Long Range (LoRa), as well as protocols based on them, such as Mioty. These technologies are characterized by low energy consumption, robustness, and inexpensive hardware.

[0042] A specific frequency range for transmitting the measurement data from sensor 132 from transmitter 134 to receiver 160 is selected based on one or more materials of the at least one non-rotating element 122, 124 located between transmitter 134 and receiver 160. The frequency for transmitting the measurement data is thus adapted to the material or materials of the at least one non-rotating element 122, 124 of the vacuum pump 100 located between transmitter 134 and receiver 160. This selection of the frequency range ensures that a communicative connection between transmitter 134 and receiver 160 can be established despite the presence of the at least one non-rotating element 122, 124.

[0043] Fig. 2Figure 1 shows a side sectional view of rotor 110. Rotor 110 has a milled recess 170 in which circuit board 130 is located. The milled recess 170 on rotor 110 compensates for any potential imbalance that would otherwise be caused by the circuit board 130. The milled recess 170 is thus designed such that, after the circuit board 130 is attached, the rotor 110 is balanced with the sensor 132, the transmitter unit 134, and the inductor 136. Conversely, the circuit board 130 can be considered a balancing weight, which compensates for any slight imbalance caused by the milled recess 170. Therefore, despite the attachment of the circuit board 130 to rotor 110, the milled recess 170 prevents any imbalance in the rotor 110. Reference symbol list

[0044] 100 Vacuum pump 110 Rotating element or rotor 112 Gap between rotor and stator 120 Non-rotating area 122 Stator 124 Housing 130 Circuit board 132 Sensor 134 Transmitter unit 136 Inductor 138 Angle range 140 Magnet 150 Control electronics 160 Receiver unit 162 Wave symbol 170 Milling

Claims

1. Vacuum pump (100) comprising: a rotating element (110), a sensor (132) attached to the rotating element (110) and configured to measure a physical property of the rotating element (110), a transmitter unit (134) arranged on the rotating element (110) and having a communicative connection with the sensor (132), and a receiver unit (160) located in a non-rotating area (120) of the vacuum pump (100), wherein at least one non-rotating element (122, 124) is arranged between the transmitter unit (134) and the receiver unit (160), and wherein the transmitter unit (134) is configured to wirelessly transmit measurement data from the sensor (132) to the receiver unit (160).

2. Vacuum pump (100) according to claim 1, further comprising control electronics (150) in which the receiving unit (160) is integrated.

3. Vacuum pump (100) according to claim 1 or 2, wherein a frequency range for the transmission of the measurement data of the sensor (132) from the transmitting unit (134) to the receiving unit (160) is selected depending on one or more materials of the at least one non-rotating element (122, 124) which is arranged between the transmitting unit (134) and the receiving unit (160).

4. Vacuum pump (100) according to one of the preceding claims, wherein the transmitting unit (134) and the receiving unit (160) are configured to use a low-frequency technology for transmitting the measurement data of the sensor (132) from the transmitting unit (134) to the receiving unit (160).

5. Vacuum pump (100) according to one of the preceding claims, wherein the rotating element (110) is configured to supply the sensor (132) with energy by its rotation.

6. Vacuum pump (100) according to claim 5, wherein the energy supply of the sensor (132) is inductive.

7. Vacuum pump (100) according to claim 6, wherein at least one magnet (140) is arranged in the non-rotating area (120) of the vacuum pump (100), the rotating element (110) has an inductance (136) which is arranged in an effective area of ​​the magnet (140), and the inductance (136) is coupled to the sensor (132) to supply energy to the sensor (132).

8. Vacuum pump (100) according to claim 7, wherein the inductance (136) is integrated into the sensor (132) and / or is integrated with the sensor (132) into a circuit board (130).

9. Vacuum pump (100) according to claim 7, wherein the inductor (136) and the sensor (132) are arranged spaced apart from each other on the rotating element (110).

10. Vacuum pump (100) according to one of claims 7 to 9, wherein the transmitter unit (134) and the inductor (136), preferably together with the sensor (132), extend on the rotating element (110) in a circumferential direction of the rotating element (110) over a limited angular range (138).

11. Vacuum pump (100) according to claim 10, wherein the sensor (132), the transmitter unit (134) and the inductor (136) are integrated into a circuit board (130).

12. Vacuum pump (100) according to claim 11, wherein an imbalance of the rotating element (110) caused by the circuit board (130) is compensated by a milling (170) on the rotating element (110).

13. Vacuum pump (100) according to one of the preceding claims, wherein the sensor (132) is designed as a temperature sensor.

14. Method for measuring a physical property of a rotating element (110) of a vacuum pump (100), the method comprising: acquiring measurement data of the physical property of the rotating element (110) by means of a sensor (132) attached to the rotating element (110), and wirelessly transmitting the measurement data to a receiving unit (160) located in a non-rotating area (120) of the vacuum pump (100) by means of a transmitting unit (134) arranged on the rotating element (110) and having a communicative link with the sensor (132), wherein at least one non-rotating element (122, 124) of the vacuum pump (100) is arranged between the transmitting unit (134) and the receiving unit (160).

15. Method according to claim 14, wherein the vacuum pump (100) further comprises at least one magnet (140) which is mounted in the non-rotating region (120), and the rotating element (110) has an inductance (136) which is arranged in an effective area of ​​the magnet (140), and the sensor (132) is supplied with energy by means of the inductance (136) during a rotation of the rotating element (110).

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