JP6453070B2 - Dry vacuum pump and dry vacuum pump manufacturing method - Google Patents

Description

  The present invention relates to a dry vacuum pump provided with a heater for heating a pump casing that houses a pump rotor. The invention also relates to a method of manufacturing such a dry vacuum pump.

  The dry vacuum pump can control the pressure so that the pressure in the chamber becomes a predetermined value while discharging the gas in the chamber to create a vacuum, or discharging the process gas. Many process gases used for manufacturing semiconductor devices change from a gas state to a liquid or solid state depending on the gas temperature or saturated vapor pressure. In the prior art, solidification of the process gas is prevented by attaching a ribbon heater to the pump casing.

  However, the degree of adhesion of the ribbon heater attached to the pump casing is poor, and the heat transfer efficiency from the ribbon heater to the pump casing is low. For this reason, the supply electric power with respect to the required amount of heat becomes excessive. Furthermore, since the shape of the ribbon heater is standardized, it may not be possible to attach the ribbon heater to a part that needs to be heated. On the other hand, a part of the ribbon heater may be attached to a part that is not necessary. is there.

  A heater may be embedded in the pump casing instead of the ribbon heater. However, in order to embed the heater in the pump casing, the wall of the pump casing needs to be thick to some extent. For this reason, there may be a structural restriction that a heater cannot be embedded in a thin portion of the pump casing, and a necessary portion may not be heated sufficiently.

JP 2003-35290 A

  This invention is made | formed in view of the situation mentioned above, and aims at providing the dry vacuum pump which can fully heat the site | part which needs heating. Moreover, an object of this invention is to provide the manufacturing method of such a dry vacuum pump.

In order to achieve the above-described object, an aspect of the present invention includes a pump rotor for transferring a gas, a pump casing in which the pump rotor is disposed, and a thermal spray heating element formed on the inner surface of the pump casing. A dry vacuum pump characterized by comprising:

In a preferred aspect of the present invention, the thermal spray heating element has an insulating layer made of an insulating material sprayed on the inner surface of the pump casing and a conductive layer made of a conductive material sprayed on the insulating layer. It is characterized by.
In a preferred aspect of the present invention, the thermal spray heating element includes a first thermal spray heating element formed on the first part of the pump casing and a second thermal spray heat generation formed on the second part of the pump casing. The dry vacuum pump includes a first temperature sensor that measures the temperature of the first part, a second temperature sensor that measures the temperature of the second part, and the temperature of the first part. And a temperature control unit for separately controlling the amount of heat generated by the first thermal spray heating element and the second thermal spray heating element based on the measurement value of the second part and the temperature measurement value of the second part. And

In a preferred aspect of the present invention, a heat insulating material that covers the thermal spray heating element is further provided .
In a preferred aspect of the present invention, the dry vacuum pump further includes a gas inlet port and a gas outlet port connected to the pump casing, and at least one of the gas inlet port and the gas outlet port has a thermal spray heating element. Is formed.
In a preferred aspect of the present invention, a seal layer formed on the exposed surface of the thermal spray heating element is further provided.

Another aspect of the present invention is a method of manufacturing a dry vacuum pump, wherein a thermal spray heating element is formed on the inner surface of a pump casing by thermal spraying, and a pump rotor is disposed in the pump casing.
In a preferred aspect of the present invention, the step of forming the thermal spray heating element by spraying on the inner surface of the pump casing forms an insulating layer by spraying an insulating material on the inner surface of the pump casing , and the conductive material is insulated by the insulating material. It includes a step of forming a conductive layer by spraying on the layer.
In a preferred aspect of the present invention, the method further includes a step of forming a seal layer on the exposed surface of the thermal spray heating element.

  According to the present invention, the pump casing is heated by the thermal spray heating element. In this specification, the thermal spray heating element refers to an electric heater formed by spraying a material on a member to be heated. The thermal spray heating element formed by the thermal spraying technique adheres firmly on the pump casing. In addition, the thermal spray heating element can be formed in a desired size and a desired shape at a desired location. Therefore, the thermal spray heating element can sufficiently heat a desired portion of the pump casing, and can prevent the process gas from solidifying. In addition, by controlling the amount of heat generated by a plurality of thermal spray heating elements, it is possible to correct the thermal deformation of the pump casing, thereby stabilizing the pump performance or preventing contact failure between the pump casing and the pump rotor due to abnormal deformation. Is possible. As a result, pump performance can be improved.

It is side surface sectional drawing which shows the dry vacuum pump which concerns on one Embodiment of this invention. FIG. 2 is a top sectional view of the dry vacuum pump shown in FIG. 1. It is side surface sectional drawing which shows embodiment using a Roots type pump rotor as a pump rotor. FIG. 4 is a top sectional view of the dry vacuum pump shown in FIG. 3. It is a top view which shows a thermal spray heating element typically. It is the sectional view on the AA line of FIG. It is a top view which shows a thermal spray heating element typically. FIG. 8 is a cross-sectional view of the thermal spray heating element and the seal layer shown in FIG. 7. It is a schematic diagram which shows the ribbon heater currently used for the general dry vacuum pump. It is a schematic diagram which shows the thermal spraying heat generating body of this embodiment. It is an external view of the dry vacuum pump shown in FIG. It is an external view of the dry vacuum pump shown in FIG. It is the BB sectional view taken on the line of FIG. It is CC sectional view taken on the line of FIG. It is a figure which shows the example of installation of a temperature sensor. It is a figure which shows the other example of installation of a temperature sensor. It is a figure which shows the other example of installation of a temperature sensor. It is an external view of the dry vacuum pump which concerns on other embodiment. It is sectional drawing of the dry vacuum pump shown in FIG. It is side surface sectional drawing of the dry vacuum pump which concerns on other embodiment. It is upper surface sectional drawing of the dry vacuum pump shown in FIG. It is side surface sectional drawing of the dry vacuum pump which concerns on other embodiment. It is a side view of the dry vacuum pump concerning other embodiments.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing a dry vacuum pump according to an embodiment of the present invention, and FIG. 2 is a top sectional view of the dry vacuum pump shown in FIG. As shown in FIGS. 1 and 2, the dry vacuum pump includes two pump rotors 10 that transfer gas, a pump casing 1 in which these pump rotors 10 are disposed, and two pump rotors 10 that rotate two pump rotors 10. Two motors 14.

  The pump rotor 10 is fixed to two rotating shafts 15, and these rotating shafts 15 are rotatably supported by bearings 17 and 18. The two motors 14 are connected to one end of each rotating shaft 15. The motor 14 is configured to rotate the two pump rotors 10 synchronously in opposite directions. Two timing gears 20 are fixed to the other end of the rotating shaft 15. The timing gear 20 is provided to ensure the synchronous rotation of the two pump rotors 10 when the synchronous rotation of the two motors 14 is lost.

  The pump casing 1 includes a peripheral wall 2 surrounding the pump rotor 10 and two side walls 3 and 4 disposed on both sides of the pump rotor 10. The pump rotor 10 is disposed in a space formed by the peripheral wall 2 and the two side walls 3 and 4. A gas inlet port 5 for introducing gas into the pump casing 1 and a gas outlet port 6 for discharging gas from the pump casing 1 are connected to the pump casing 1. The suction side bearing 17 is arranged in a bearing casing 22 fixed to the side wall 3, and the motor 14 is arranged in a motor casing 19 fixed to the bearing casing 22, and the timing gear 20 and the discharge side are arranged. The bearing 18 is disposed in a gear casing 21 fixed to the side wall 4.

  In the present embodiment, a screw type pump rotor is used as the pump rotor 10. However, the present invention is not limited to screw type pump rotors, and other types of pump rotors may be used. For example, as shown in FIGS. 3 and 4, a roots type pump rotor may be used as the pump rotor 10. In the dry vacuum pump shown in FIG. 3 and FIG. 4, the same components are denoted by the same reference numerals, and redundant description thereof is omitted. The roots type pump rotor shown in FIGS. 3 and 4 is a multistage pump rotor, but may be a single stage pump rotor.

  The dry vacuum pump is operated as follows. When the motor 14 rotates the two pump rotors 10 in opposite directions, gas is introduced into the pump casing 1 through the gas inlet port 5. The gas is compressed while being transferred to the downstream side by the rotation of the pump rotor 10. The compressed gas is discharged to the outside of the pump casing 1 through the gas outlet port 6.

  Since the dry vacuum pump does not use lubricating oil in the gas flow path, it is widely used in the semiconductor device manufacturing process that requires a clean environment. For example, the gas inlet port 5 of the dry vacuum pump is connected to the process chamber of the CVD apparatus and sucks the process gas from the process chamber. Some process gases used in the manufacture of semiconductor devices solidify as temperature decreases. When the process gas is solidified in the pump casing 1 to form a precipitate, the precipitate inhibits the rotation of the pump rotor 10.

  Therefore, the dry vacuum pump includes thermal spraying heat generators 23, 24, and 25 for heating the pump casing 1. The thermal spray heating element is an electric heater formed by spraying a material on a member to be heated (pump casing 1 in the present embodiment). 5 is a plan view schematically showing the thermal spray heating element 23, and FIG. 6 is a cross-sectional view taken along the line AA of FIG. The thermal spray heating element 23 includes an insulating layer 27 formed on the pump casing 1, a conductive layer 28 formed on the insulating layer 27, and an electrode 29 connected to the conductive layer 28.

  The thermal spray heating element 23 is formed on the pump casing 1 as follows. First, an insulating material is sprayed on the surface of the pump casing 1 to form an insulating layer 27 on the pump casing 1. Next, a conductive material is sprayed on the insulating layer 27 to form a conductive layer 28 on the insulating layer 27. Finally, the electrode 29 is connected to the conductive layer 28. The other thermal spray heating elements 24 and 25 are also formed by the same process and have the same configuration. The step of forming the thermal spray heating element on the pump casing 1 may be performed before the pump rotor 10 is disposed in the pump casing 1 or may be performed after the pump rotor 10 is disposed in the pump casing 1. .

  In one example, aluminum oxide (alumina) is used as the insulating material constituting the insulating layer 27, and a metal such as copper is used as the conductive material constituting the conductive layer 28. When a current is supplied to the conductive layer 28 through the electrode 29, the conductive layer 28 generates heat. Since the thermal spray heating element is in close contact with the surface of the pump casing 1, there is an advantage that the heat transfer coefficient is high. Further, the thermal spray heating element can be formed thin. For example, it is possible to form a thermal spray heating element having a thickness of about 100 μm.

  Since the conductive layer 28 of the thermal spray heating element 23 is exposed to the atmosphere, the state of the conductive layer 28 such as oxidation changes due to contact with the atmosphere, causing a change in the conductive resistance value, a crack in the conductive path, and the like. there's a possibility that. Further, as will be described later, when the thermal spray heating element 23 is formed in the pump casing 1, the process gas passing through the pump casing 1 may cause reaction corrosion such as oxidation, which may deteriorate the performance of the conductive layer 28. There is sex.

  Therefore, as shown in FIGS. 7 and 8, a seal layer 30 covering the entire exposed surface of the thermal spray heating element 23 may be provided. The seal layer 30 is formed on the exposed surface of the thermal spray heating element 23, and is in close contact with the exposed surfaces of the conductive layer 28, the insulating layer 27, and the electrode 29. The configuration and formation process of the seal layer 30 are not particularly limited as long as the purpose of protecting the conductive layer 28 from the ambient atmosphere can be achieved. For example, the seal layer 30 may be formed by spraying the same material as the insulating layer 27 on the thermal spray heating element 23, or the seal layer 30 may be formed by applying a resin agent to the thermal spray heating element 23. . The other thermal spray heating elements 24 and 25 may be similarly covered with a seal layer.

  FIG. 9 is a schematic diagram showing a ribbon heater 33 used in a general dry vacuum pump, and FIG. 10 is a schematic diagram showing a thermal spray heating element 23 of the present embodiment. As shown in FIG. 9, a convex portion 31 such as a flange may be formed on the outer peripheral surface of the pump casing 1 for reasons of assembly of the dry vacuum pump. When the ribbon heater 33 is wound around the outer peripheral surface of the pump casing 1 having such a convex portion 31, a part of the ribbon heater 33 is separated from the pump casing 1, resulting in a low heat transfer rate.

  On the other hand, since the thermal spray heating element 23 is formed on the outer peripheral surface of the pump casing 1 by thermal spraying, as shown in FIG. It is possible to arrange in size. It is also possible to form a thermal spray heating element on the convex portion 31.

  As shown in FIGS. 1 to 4, in this embodiment, three thermal spray heating elements 23, 24, and 25 are formed on the pump casing 1. Specifically, the thermal spray heating element 23 is formed on the outer surface of the peripheral wall 2, the thermal spray heating element 24 is formed on the outer surface of the suction side wall 3, and the thermal spray heating element 25 is disposed on the discharge side. It is formed on the outer surface of the side wall 4.

  11 is an external view of the dry vacuum pump shown in FIG. 1, FIG. 12 is an external view of the dry vacuum pump shown in FIG. 2, and FIG. 13 is a sectional view taken along line BB in FIG. 14 is a cross-sectional view taken along the line CC of FIG. An electric wire 35 is connected to the electrode 29 of the thermal spray heating element 24. Similarly, an electric wire 35 is connected to the electrode 29 of the thermal spray heating element 25. The current flows to the thermal spray heating elements 24 and 25 through these electric wires 35, and the thermal spray heating elements 24 and 25 generate heat. Although not shown, an electric wire is also connected to the electrode 29 (see FIG. 5) of the thermal spray heating element 23, and current flows to the thermal spray heating element 23 through the electrical wire. The thermal spray heating element 23 covers the entire outer peripheral surface of the pump casing 1 (that is, the outer surface of the peripheral wall 2).

  As shown in FIG. 1, the thermal spray heating elements 23, 24, 25 are connected to the temperature control unit 40 via the electric wires (shown by dotted lines), and the amount of heat generated from the thermal spray heating elements 23, 24, 25 is the temperature. It is controlled by the control unit 40. The pump casing 1 is provided with temperature sensors 43, 44, 45 for measuring the temperatures of different parts of the pump casing 1. Specifically, the temperature sensor 43 is fixed to the peripheral wall 2 of the pump casing 1, the temperature sensor 44 is fixed to the suction side wall 3 of the pump casing 1, and the temperature sensor 45 is the discharge side of the pump casing 1. It is being fixed to the side wall 4 of this.

  The temperatures of the peripheral wall 2 and the side walls 3, 4 of the pump casing 1 are measured by these temperature sensors 43, 44, 45, and the measured temperature values are sent to the temperature control unit 40. The temperature control unit 40 separately controls the amount of heat generated by the thermal spray heating elements 23, 24, 25 based on the measured values of the temperature of the peripheral wall 2 and the side walls 3, 4 of the pump casing 1. More specifically, the temperature control unit 40 is configured to control the current flowing through the thermal spray heating elements 23, 24, 25 based on the measured values of the temperature of the peripheral wall 2 and the side walls 3, 4 of the pump casing 1. ing.

  In general, the temperature on the intake side of the pump casing 1 is lower than the temperature on the discharge side of the pump casing 1. This is because the gas temperature increases as the gas is compressed by the rotation of the pump rotor 10. Some process gases tend to solidify under low temperature conditions. Therefore, the process gas that solidifies in such a relatively low temperature condition is easily solidified on the intake side of the pump casing 1.

  According to this embodiment, not only the outer surface of the pump casing 1 is heated, but the side wall 3 on the intake side and the side wall 4 on the discharge side are heated separately. For example, the process gas can be prevented from solidifying on the intake side of the pump casing 1 by heating the side wall 3 on the intake side where the process gas is easily solidified. Furthermore, the temperature control unit 40 is sprayed so that the temperatures of the peripheral wall 2 and the side walls 3 and 4 of the pump casing 1 are kept at the same value based on the measured values of the temperature sent from the temperature sensors 43, 44 and 45. The amount of heat generated by the heating elements 23, 24, and 25 can also be controlled.

  In the dry vacuum pump, a minute gap is formed between the pump rotor 10 and the pump casing 1. If this gap becomes non-uniform due to thermal deformation of the pump casing 1, the pump performance deteriorates. Since the temperature control unit 40 can individually control the amount of heat generated from the thermal spray heating elements 23, 24, 25, it is possible to correct the thermal deformation of the pump casing 1 and stabilize the pump performance. Further, abnormal deformation of the pump casing 1 can prevent contact between the pump casing 1 and the pump rotor 10.

  FIGS. 15 to 17 are diagrams showing an installation example of the temperature sensor 43 for measuring the temperature of the peripheral wall 2 of the pump casing 1 heated by the thermal spray heating element 23. In the example shown in FIG. 15, the temperature sensor 43 is sandwiched between the outer surface of the peripheral wall 2 and the thermal spray heating element 23. In the example shown in FIG. 16, the temperature sensor 43 is embedded in the peripheral wall 2. In the example shown in FIG. 17, the temperature sensor 43 is disposed on the peripheral wall 2 adjacent to the thermal spray heating element 23. In any case, the temperature sensor 43 can measure the temperature of the peripheral wall 2 of the pump casing 1 heated by the thermal spray heating element 23. Temperature sensors 44 and 45 for measuring the temperature of the side walls 3 and 4 of the pump casing 1 are also installed as shown in FIGS.

  In the above embodiment, the three thermal spray heating elements 23, 24 and 25 are fixed to the pump casing 1, but four or more thermal spray heating elements may be provided in the pump casing 1. For example, a plurality of thermal spray heating elements may be provided on the peripheral wall 2 of the pump casing 1. A temperature sensor is preferably provided for each thermal spray heating element.

  18 is an external view of a dry vacuum pump according to another embodiment, and FIG. 19 is a cross-sectional view of the dry vacuum pump shown in FIG. In this embodiment, two thermal spray heating elements 23A and 23B are formed on the outer surface of the pump casing 1. More specifically, the first thermal spray heating element 23 </ b> A is formed on the intake side portion of the peripheral wall 2 of the pump casing 1, and the second thermal spray heating element 23 </ b> B is formed on the discharge side portion of the peripheral wall 2 of the pump casing 1. Yes. On the side walls 3 and 4 of the pump casing 1, thermal spray heating elements 24 and 25 are formed as in the above-described embodiment.

  Fixed to the pump casing 1 is a first temperature sensor 43A for measuring the temperature of the intake side portion heated by the first thermal spray heating element 23A. Further, a second temperature sensor 43B for measuring the temperature of the discharge side portion heated by the second spray heating element 23B is fixed to the pump casing 1. The temperatures of the intake side portion and the discharge side portion of the pump casing 1 are measured by these temperature sensors 43 </ b> A and 43 </ b> B, and the measured temperature values are sent to the temperature control unit 40. The temperature control unit 40 separately controls the amount of heat generated by the thermal spray heating elements 23A and 23B based on the measured values of the temperatures of the intake side portion and the discharge side portion of the pump casing 1. More specifically, the temperature control unit 40 is configured to control the current flowing through the thermal spray heating elements 23A and 23B based on the measured values of the temperature at the intake side portion and the discharge side portion of the pump casing 1. .

  According to the present embodiment, the intake side portion and the discharge side portion of the pump casing 1 are heated separately. For example, the process gas can be prevented from solidifying on the intake side of the pump casing 1 by heating the intake side portion where the process gas is easily solidified. Furthermore, the temperature control unit 40 is based on the temperature measurement values sent from the temperature sensors 43A and 43B so that the temperature of the intake side portion and the discharge side portion of the pump casing 1 is maintained at the same temperature. The amount of heat generated by 23A and 23B can also be controlled.

  Furthermore, in this embodiment, the thermal spray heating element 47 is also provided in the gas inlet port 5. The thermal spray heating element 47 is formed on the outer peripheral surface of the gas inlet port 5. A temperature sensor 48 is fixed to the gas inlet port 5, and the temperature of the gas inlet port 5 heated by the thermal spray heating element 47 is measured by the temperature sensor 48. The temperature measurement value is sent to the temperature control unit 40, and the temperature control unit 40 controls the amount of heat generated by the thermal spray heating element 47 based on the temperature measurement value of the gas inlet port 5.

  Since the process gas before being compressed passes through the gas inlet port 5, the gas inlet port 5 tends to have a low temperature. For this reason, the process gas is easily solidified in the gas inlet port 5. According to this embodiment, since the gas inlet port 5 is heated by the thermal spray heating element 47, the solidification of the process gas in the gas inlet port 5 can be prevented. Although not shown, a thermal spray heating element for heating the gas outlet port 6 and a temperature sensor for measuring the temperature of the gas outlet port 6 may be provided.

  20 is a side sectional view of a dry vacuum pump according to still another embodiment, and FIG. 21 is a top sectional view of the dry vacuum pump shown in FIG. As shown in FIGS. 20 and 21, the thermal spray heating elements 23, 24 and 25 are formed on the inner surface of the pump casing 1. More specifically, the thermal spray heating element 23 is formed on the inner surface of the peripheral wall 2 of the pump casing 1, and the thermal spray heating element 24 is formed on the inner surface of the side wall 3 on the suction side of the pump casing 1. Is formed on the inner surface of the side wall 4 on the discharge side of the pump casing 1. Similarly to the embodiment described above, temperature sensors 43, 44, 45 for measuring the temperature of the peripheral wall 2, the temperature of the suction side wall 3, and the temperature of the discharge side wall 4 are fixed to the pump casing 1. .

  Solidification of the process gas takes place inside the pump casing 1. According to this embodiment, since the inside of the pump casing 1 is preferentially heated, solidification of the process gas can be effectively prevented. In particular, the process gas flowing in the pump casing 1 comes into contact with the thermal spray heating elements 23, 24, 25 formed on the inner surface of the pump casing 1 and is directly heated by these thermal spray heating elements 23, 24, 25. Therefore, the thermal spray heating elements 23, 24, and 25 formed on the inner surface of the pump casing 1 can effectively prevent the process gas from solidifying.

  Since the thermal spray heating elements 23, 24, and 25 can be formed very thin, the thermal spray heating element can be disposed inside the pump casing 1 as shown in FIGS. 20 and 21. As in the embodiment shown in FIGS. 18 and 19, the first spraying heating element 23 </ b> A on the intake side and the second spraying heating element 23 </ b> B on the discharge side may be formed on the inner surface of the peripheral wall 2 of the pump casing 1. Also in this case, it is preferable that the temperature control unit 40 controls the first thermal spray heating element 23A and the second thermal spray heating element 23B separately.

  You may form a thermal spray heat generating body in both the outer surface of the pump casing 1, and an inner surface. For example, the embodiment shown in FIGS. 1 and 2 may be combined with the embodiment shown in FIGS. Alternatively, as shown in FIG. 22, the thermal spray heating element 23 may be formed on the outer surface of the peripheral wall 2 of the pump casing 1, and the thermal spray heating elements 24 and 25 may be formed on the inner surfaces of the side walls 2 and 3 of the pump casing 1. Good.

  FIG. 23 is a side view of a dry vacuum pump according to still another embodiment. The configuration of the present embodiment that is not specifically described is the same as that of the embodiment shown in FIGS. 1 and 2, and thus redundant description thereof is omitted. As shown in FIG. 23, the thermal spray heating element 23 formed on the peripheral wall 2 of the pump casing 1 is covered with a heat insulating material 51. The heat insulating material 51 can prevent radiation of heat generated from the thermal spray heating element 23. Therefore, the thermal spray heating element 23 can efficiently heat the pump casing 1 with less electric power.

  The embodiment described above is described for the purpose of enabling the person having ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Accordingly, the present invention is not limited to the described embodiments, but is to be construed in the widest scope according to the technical idea defined by the claims.

DESCRIPTION OF SYMBOLS 1 Pump casing 2 Perimeter wall 3, 4 Side wall 5 Gas inlet port 6 Gas outlet port 10 Pump rotor 14 Motor 15 Rotating shaft 17, 18 Bearing 19 Motor casing 20 Timing gear 21 Gear casing 22 Bearing casing 23, 23A, 23B, 24, 25 Thermal spray heating element 27 Insulating layer 28 Conductive layer 29 Electrode 30 Seal layer 35 Electric wire 40 Temperature control unit 43, 43A, 43B, 44, 45 Temperature sensor 51 Heat insulating material

Claims (9)

A pump rotor for transferring gas;
A pump casing in which the pump rotor is disposed;
A dry vacuum pump comprising a thermal spray heating element formed on the inner surface of the pump casing. 2. The thermal spray heating element includes an insulating layer made of an insulating material sprayed on an inner surface of the pump casing and a conductive layer made of a conductive material sprayed on the insulating layer. The dry vacuum pump described in 1. The thermal spray heating element includes a first thermal spray heating element formed on a first part of the pump casing, and a second thermal spray heating element formed on a second part of the pump casing,
The dry vacuum pump is
A first temperature sensor for measuring the temperature of the first part;
A second temperature sensor for measuring the temperature of the second part;
A temperature control unit for separately controlling the amount of heat generated by the first thermal spray heating element and the second thermal spray heating element based on the temperature measurement value of the first part and the temperature measurement value of the second part; The dry vacuum pump according to claim 1 or 2, further comprising:   The dry vacuum pump according to any one of claims 1 to 3, further comprising a heat insulating material that covers the thermal spray heating element. The dry vacuum pump further comprises a gas inlet port and a gas outlet port connected to the pump casing,
The dry vacuum pump according to any one of claims 1 to 4 , wherein a thermal spray heating element is formed in at least one of the gas inlet port and the gas outlet port. Dry vacuum pump according to any one of claims 1 to 5, further comprising a sealing layer formed on the exposed surface of the spray heating element. A thermal spray heating element is formed on the inner surface of the pump casing by thermal spraying,
A method of manufacturing a dry vacuum pump, wherein a pump rotor is disposed in the pump casing. The step of forming a thermal spray heating element by thermal spraying on the inner surface of the pump casing,
Forming an insulating layer by spraying an insulating material on the inner surface of the pump casing;
The method for manufacturing a dry vacuum pump according to claim 7 , further comprising forming a conductive layer by spraying a conductive material on the insulating layer. Method for producing a dry vacuum pump according to claim 7 or 8, further comprising the step of forming a sealing layer on the exposed surface of the spray heating element.

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