dry vacuum pump

Abstract

The present invention relates to a dry vacuum pump, comprising: a drive unit (1) including a drive shaft (3) with at least one drive wheel (4) attached to one end of the drive shaft (3), the at least one drive wheel being used to drive at least one belt (5); at least two parallel rotors (7, 8), each rotor including a rotor shaft (9, 10) provided with rotor elements (11, 12), the shaft (9, 10) being rotatable by the belt (5), and having a toothed wheel (13, 14) provided at one axial end of the shaft; the pump is characterized in that the drive wheel (4) and the belt (5) are smooth; each shaft (9, 10) of the rotors (7, 8) includes at least one smooth section (16, 17) for engaging with the belt (5); and the toothed wheels (13, 14) of the shafts (9, 10) of the rotors (7, 8) are sized and arranged to mesh with each other.

Description

Technical Field

[0001] This invention relates to a dry vacuum pump, such as a dry compression vacuum pump used in so-called dust-free rooms or cleanrooms. More specifically, this invention relates to a dry vacuum pump including a belt drive. More specifically, this invention relates to a dry vacuum pump, such as a positive displacement dry vacuum pump, particularly in the form of a Roots pump, which includes a drive unit that ensures optimal synchronization of rotor rotation without the need for lubricating fluid. Background Technology

[0002] Dry vacuum pumps, such as Roots pumps, are well known in the art. Such pumps typically comprise two rotor elements placed in the pumping chamber, which are designed as lobe rotor elements in Roots pumps. Each rotor element is supported by a rotor shaft, which is driven to rotate by a drive unit.

[0003] In most pumps known in the prior art, the drive unit consists of two toothed gears, each mounted on a rotor shaft and meshing with each other. One of the two shafts is driven to rotate by a motor, such as an electric motor, which drives the second rotor shaft via the toothed gears.

[0004] A drive mechanism that includes toothed gears to transmit the driving torque of one rotor shaft to another has the following advantages: Using such gears automatically synchronizes the rotation of the two rotor shafts. To achieve an efficient compression process and good output, it is necessary to reduce the spacing between rotor elements, which requires very precise synchronization. Furthermore, whether intentional or due to malfunction, the toothed gear acts as a "landing gear" when the pump stops, preventing damage to the rotor elements.

[0005] The drawback of this device is that the permanent contact between the toothed gears, necessary for the transmission of driving torque, requires lubrication. In fact, without lubrication, the toothed gears will wear rapidly, leading to a lack of synchronization in the rotor shaft, decreased pump efficiency, and ultimately damage to rotor components. Unfortunately, in many applications, the use of lubricating fluids is undesirable because it can contaminate the evacuated vacuum chamber. This is a recurring problem in the semiconductor industry, for example, where such contamination is completely incompatible with the manufacturing processes employed.

[0006] European patent application EP1054160A1 discloses another method for synchronizing the rotor shafts of a vacuum pump. This relates to a dry screw pump whose rotor shafts are each driven by a separate electric motor, the angular position of which is determined by a rotary transformer. The motors of the rotor shafts are electronically synchronized based on the rotary transformer signal. While this method can effectively synchronize the rotor shafts, it requires two independent motors and an electronic system, which is disadvantageous in many applications.

[0007] International patent application WO 2018 / 224409 A1 proposes using a toothed belt to drive the rotor shaft of a dry screw pump, with the toothed belt itself being driven by toothed pulleys of a drive unit. The advantage of this is that it eliminates the mutual interference between the toothed pulleys mounted on the rotor shaft. If there is no contact between the toothed pulleys, lubrication is no longer required.

[0008] However, this type of drive, using a toothed belt, has a major drawback: it does not allow for sufficient synchronization of the rotor shaft rotation. To prevent damage to the rotor elements due to rotor shaft asynchrony, this international application proposes using rotor elements with larger clearances. Unfortunately, this means that without providing longer rotor elements and more compression vessels, pumps using this type of drive cannot achieve the same compression ratio as conventional pumps.

[0009] Therefore, the object of the present invention is to provide a dry vacuum pump whose drive unit does not require lubrication while ensuring full synchronization of the rotor shaft, so that the device can be used in conventional dry vacuum pumps such as Roots pumps. Summary of the Invention

[0010] The main objective of this invention is to propose a dry vacuum pump with a rotor drive mechanism that is more efficient than existing pumps.

[0011] According to the invention, these objectives are achieved through the subject matter of the independent claims. More specific aspects of the invention are described in the dependent claims and the specification.

[0012] More specifically, the object of the present invention is achieved by a dry vacuum pump, the dry vacuum pump comprising:

[0013] - A drive device, the drive device including a drive shaft, at least one drive wheel fixed at one end of the drive shaft, the at least one drive wheel being configured to rotate at least one belt;

[0014] - At least two parallel rotors, each rotor having a rotor shaft provided with rotor elements, the rotor shaft being rotatably driven by a belt, and equipped with a toothed pulley at one of the axial ends of the rotor shaft;

[0015] The pump is characterized by:

[0016] The drive wheel and the belt are smooth;

[0017] Each rotor shaft includes at least one smooth section arranged to engage with the belt; and

[0018] The toothed gears on the rotor shaft are sized and arranged to mesh with each other.

[0019] The belt drive and the automatic synchronization of the rotor due to the toothed pulleys make it possible to provide minimal clearance between rotor elements, which guarantees maximum pump efficiency, particularly its compression ratio, without having to modify the pump's rotor, rotor elements, and / or stator. In other words, the drive unit of the present invention can be integrated into existing pumps without modifying the rotor elements and stator, without sacrificing efficiency.

[0020] In fact, the toothed pulleys on the rotor shaft automatically synchronize the rotation of the rotor shaft. In cases where the rotor shafts are out of sync, such as due to belt slippage, the toothed pulleys make it possible to automatically resynchronize the rotor shafts. Since the toothed pulleys only bear the load when resynchronization is required, there is no need to lubricate these pulleys. When the two shafts are synchronized, although the toothed pulleys mesh with each other, they do not bear the load, thus avoiding wear and tear on the toothed pulleys. In fact, compared to pumps of known prior art, the rotational torque is transmitted by the belt rather than by the toothed pulleys.

[0021] Furthermore, for example, in the event of a belt breakage, the gears formed by the toothed pulleys on the rotor shaft keep both shafts rotating as a whole. The toothed pulleys thus act as a "landing gear" or safety gear. In the event of a belt failure, the toothed pulleys reduce the pump's speed until it stops, without the rotor coming into contact with the belt and thus preventing damage.

[0022] Because of the pump according to the invention, it is possible to eliminate the need for lubrication while ensuring optimal synchronization of the rotor shaft. Finally, the pump according to the invention prevents damage to the rotor components even in the event of a sudden stop in the pump drive, such as in the event of belt breakage or power failure. It is important to note that the pump according to the invention can include any type of motor for driving the drive wheel. For example, the motor can be electric or thermal.

[0023] In a preferred embodiment of the invention, the toothed gears are arranged such that the teeth of the respective toothed gears bear load only when the rotor shaft is driven asynchronously. This ensures minimal wear on the toothed gears, thereby extending the service life of the drive unit.

[0024] In another preferred embodiment of the invention, the angular clearance of the toothed gear is smaller than the angular clearance of the rotor elements. This makes it possible to ensure that the toothed gear bears the load before the rotor elements come into contact with each other, thereby ensuring that the rotor elements are not damaged even in the event of a sudden pump stop.

[0025] In a preferred embodiment of the invention, a smooth section of each rotor shaft is located at one end of the shaft. This makes it possible to easily separate the compression zone and the drive zone, in which the fluid to be discharged is efficiently transported and compressed by rotor elements supported by the rotor shaft, and the drive zone includes the drive mechanism for the rotor shaft, particularly the smooth section of each rotor shaft and the belt. This makes it possible to prevent the compression zone from being contaminated by the drive zone.

[0026] In another preferred embodiment of the invention, the diameter of the smooth section on each rotor shaft is smaller than the diameter of the toothed wheel.

[0027] In a preferred embodiment of the invention, the two toothed gears have the same diameter, and the two smooth sections have the same diameter. This allows for synchronized rotation of the rotor shaft. In fact, by providing the same diameter, it is easier to ensure that the rotor shaft rotates at the same speed.

[0028] In another preferred embodiment of the invention, the belt partially wraps around one segment of the smooth section and is pushed downward by the other segment. This makes it possible to easily drive the two rotor shafts to rotate in opposite directions. Since dry vacuum pumps known in the art, such as screw pumps, roots pumps, or claw pumps, typically employ rotor shafts that will predictably rotate in opposite directions, the drive mechanism of the pump according to the invention can be adapted to drive pumps known in the art.

[0029] In another preferred embodiment of the invention, the smooth section of the toothed pulley and the rotor shaft is located at the same axial end of the shaft. This makes it possible to provide a simple belt geometry, thereby preventing energy loss and the risk of belt breakage.

[0030] In another preferred embodiment of the invention, each smooth segment is located on the circumferential surface of the disc-shaped component. This makes it possible to increase the contact area between the belt and the rotor shaft, thereby optimizing the belt's drive of the rotor shaft. Furthermore, it reduces the risk of belt slippage relative to the smooth segments, which makes it possible to reduce the risk of rotor shaft asynchrony.

[0031] In a preferred embodiment of the invention, the disc-shaped component and the drive wheel are substantially in the same plane. This makes it possible to provide a belt that is itself in the same plane, which reduces the risk of belt breakage.

[0032] In another preferred embodiment of the invention, the points projected from the rotation axis of the rotor shaft and the rotation axis of the drive shaft are aligned on a plane perpendicular to the rotation axis. Because of this, the pressure of the belt on the smooth section of the rotor shaft is equal, making it possible to ensure optimal drive synchronization.

[0033] In another preferred embodiment of the invention, the distance between the drive shaft and the rotor shaft closest to it is adjustable. This allows for adjustment of the drive belt tension and optimization of the rotor shaft drive. By adjusting the belt tension, it is possible to minimize the risk of rotor shaft desynchronization, thereby preventing the toothed pulleys from contacting each other in an attempt to re-establish synchronization.

[0034] In another preferred embodiment of the invention, the dry vacuum pump is a dry vacuum pump in which the rotor elements are in the form of mutually cooperating teeth.

[0035] In a preferred embodiment of the invention, the vacuum pump is a Roots pump, a screw pump, or a claw pump.

[0036] In another preferred embodiment of the invention, the vacuum pump is single-stage or multi-stage.

[0037] Finally, in another preferred embodiment of the invention, the drive device includes a drive shaft with at least one drive wheel fixed at one end of the drive shaft, the at least one drive wheel being configured to drive two belts. Attached Figure Description

[0038] Other advantages and features of the present invention will be described in detail below in the description given with reference to the accompanying drawings, which schematically illustrate the invention.

[0039] - Figure 1 A perspective top view of a dry vacuum pump according to a first preferred embodiment of the present invention, wherein the dry vacuum pump is a dry Roots pump.

[0040] - Figure 2 : Figure 1 Part of a vacuum pump;

[0041] - Figure 3 : Figure 1 It is part of a vacuum pump, in which the pump casing is hidden;

[0042] - Figure 4 : Figures 1 to 3 Front view of a vacuum pump;

[0043] - Figure 5 : A top perspective view of a dry vacuum pump according to a second preferred embodiment of the present invention, wherein the dry vacuum pump is a dry Roots pump;

[0044] - Figure 6 : Figure 5 Front view of a vacuum pump;

[0045] - Figure 7 : Figure 5 A top view of the vacuum pump; and

[0046] - Figure 8 Vacuum pump edge Figure 7 The front view of the cross section of plane AA. Detailed Implementation

[0047] The dry vacuum pump according to the invention is a component comprising a drive unit 1, the drive unit 1 comprising a motor 2 (typically electric) that rotatably drives a drive shaft 3, at least one drive wheel 4 being fixed at the front end of the drive shaft 3, the drive wheel being configured to rotate at least one belt 5.

[0048] According to a first preferred embodiment of the invention, it is here in the form of a dry Roots pump and Figure 1 The dry vacuum pump shown in the figure is a component including a drive unit 1, which includes a motor 2 (usually electric) that rotatably drives a drive shaft 3, at the front end of which a drive wheel 4 is fixed, the drive wheel being configured to rotate a belt 5.

[0049] Fixed to the drive unit 1 is a housing comprising a lower part 6 and an upper part (not shown), within which at least two rotors 7, 8 are rotatably mounted. Each rotor 7, 8 includes a rotor shaft 9, 10, which is provided with rotor elements, here in the form of protruding teeth 11, 12, and is intended to be rotated by a belt 5. Each rotor shaft 9, 10 is equipped with a toothed pulley 13, 14 at one end of its axial end, preferably on the front side.

[0050] As in Figure 2 As can be seen more clearly, the rotation axes of the rotor shafts 9 and 10 of the two rotors 7 and 8 are parallel to each other and are generally also parallel to the rotation axis of the drive shaft 3.

[0051] Teeth 11 and 12 are typically identical, and the distance between the rotation axes of the rotor shafts 9 and 10 of rotors 7 and 8 is chosen such that these teeth 11 and 12 can interact to generate positive displacement and compress the fluid to be discharged, as is well known to those skilled in the art. Since rotors 7 and 8 are configured to rotate in opposite directions, their teeth 11 and 12 are rotated at an angle of 90° relative to the other (see reference). Figure 3 ).

[0052] An inlet port (not shown) for a fluid such as air is provided at the rear of the housing, and an outlet port (not shown) for the fluid is provided at the front. Therefore, the rotation of the protrusions 11 and 12 results in the circulation and compression of the fluid.

[0053] According to the present invention, the belt 5 is smooth, just like the drive wheel 4, which means that the drive wheel 4 has a smooth axial circumferential surface 15.

[0054] The smooth drive wheel 4 is designed to cooperate with the belt 5 attached to it, and because of this, the drive wheel 4 can be operated by the rotation of the shaft 3 of the motor 2.

[0055] Since the belt 5 is also configured to act on the rotor shafts 9 and 10 of the rotors 7 and 8 to make them rotate, these rotor shafts 9 and 10 have axially smooth circumferential surfaces to receive the belt 5 and allow the belt to attach. Therefore, these smooth sections 16 and 17 are located at the front ends of the shafts 9 and 10 of the rotors 7 and 8.

[0056] Especially Figure 4 As can be seen, the belt 5 forms a loop from the drive wheel 4 to the first rotor shaft, which is the rotor shaft 9 furthest from the drive wheel 4. Therefore, the belt 5 abuts against the smooth axial circumferential surface 15 of the drive wheel 4 and the smooth section 16 of the rotor shaft 9, and it is taut between the rotor shaft 9 and the drive wheel 4.

[0057] However, in order to simultaneously drive the second rotor shaft 10 located between the first rotor shaft 9 and the drive wheel 4, the belt 5 must contact and adhere to the smooth section 17 of the second rotor shaft 10. This is achieved by deforming the path of the belt 5; if there were only one shaft, the path of the belt 5 would be trapezoidal. Therefore, the path of the belt 5 is bent by forcing the belt 5 to pass under the smooth section 17 of the second rotor shaft 10.

[0058] Therefore, the belt 5 partially surrounds the wheel 4 of the drive unit 1 and the smooth section 16 of the first rotor shaft 9, and the belt is pressed downward by the smooth section 17 of the second rotor shaft 10.

[0059] Preferably, the projections of the rotation axes of the rotor shafts 9 and 10 from rotors 7 and 8 and the rotation axis of the drive shaft 3 are aligned on a plane perpendicular to the rotation axes, such as... Figure 4 As shown in the image.

[0060] The length of the belt 5 and / or the distance between the drive unit 1 and the housing are selected such that the belt 5 is kept sufficiently taut to perform its function of rotatably driving the first rotor shaft 9 and the second rotor shaft 10 of the rotors 7 and 8.

[0061] Advantageously, it is foreseeable that the distance between the drive unit 1 (or drive shaft 3) and the housing (or the second rotor shaft 10 of rotor 8) is adjustable, which makes it possible to use a belt of variable length and adjust the tension of belt 5 in an optimal manner.

[0062] To facilitate their rotational drive, the rotor shafts 9 and 10 of rotors 7 and 8 preferably each include disc-shaped components 19 and 20 with increased diameters. The axial circumferential surfaces of these disc-shaped components 19 and 20 are smooth, thus forming smooth sections 16 and 17 of the rotor shafts 9 and 10. Preferably, these disc-shaped components are pulleys. The disc-shaped components 19 and 20 and the drive wheel 4 are generally in the same plane to allow for effective engagement with the belt 5. Their axial thickness is typically at least equal to the thickness of the belt 5.

[0063] According to the invention, the toothed gears 13 and 14, preferably carried by the rotor shafts 9 and 10 at their front ends, are sized to mesh with each other and are located in the same plane. Therefore, taking into account the size of the teeth, the sum of the radii of these toothed gears 13 and 14 is approximately equal to the distance between the two rotation axes of the rotor shafts 9 and 10 of the rotors 7 and 8.

[0064] It is worth noting that, according to the present invention, the toothed gears 13 and 14 are sized such that the teeth of these gears only bear load when the rotation of the rotor shafts 9 and 10 is asynchronous. At other times, the toothed gears 13 and 14 mesh well with each other, but their teeth do not bear load. In fact, unlike known prior art pumps, the gears formed by the toothed gears 13 and 14 do not have the function of transmitting torque from one rotor shaft to another. The toothed gears 13 and 14 only have the function of automatically synchronizing the rotation of the rotor shafts 9 and 10. Therefore, lubrication of the toothed gears 13 and 14 is not required, and the entire pump drive unit can operate without lubricating fluid.

[0065] Compared to the gaps present in existing pumps equipped with toothed belts, ensuring optimal synchronization of rotor shafts 9 and 10, and therefore rotors 7 and 8, makes it possible to anticipate a reduction in the gaps between rotor elements 11 and 12 and between the pump housing, and more specifically, a reduction in the gaps between the pump stator sections. This reduction in the gaps between rotor elements 11 and 12 ultimately makes it possible to achieve less leakage in the compression chamber caused by the rotation of rotor elements 11 and 12, and therefore a greater compression ratio for the same pump size.

[0066] Furthermore, in the event of belt 5 breaking or pump stopping, the gears formed by toothed pulleys 13 and 14 act as "landing gears," preventing damage to the teeth 11 and 12 by preventing them from rubbing against each other. In fact, toothed pulleys 13 and 14 allow the synchronous rotors 7 and 8 to stop without being damaged.

[0067] Preferably, the diameter of the smooth sections 16 and 17 of the rotor shafts 9 and 10 of rotors 7 and 8 is smaller than the diameter of the toothed gears 13 and 14 carried by these shafts 9 and 10.

[0068] The toothed wheels 13 and 14 usually have the same diameter, and the two smooth sections 16 and 17, whether or not they are located on the disc-shaped parts 19 and 20, usually also have the same diameter.

[0069] According to a second preferred embodiment of the present invention, in Figure 5 A dry vacuum pump, represented in the form of a dry Roots pump, is a component including a drive unit 1, which includes a motor 2 (usually electric) that rotatably drives a drive shaft 3, at least one drive wheel 4 fixed at the front end of the drive shaft 3, the at least one drive wheel 4 being configured to rotate two belts 5a, 5b.

[0070] According to this implementation, the two belts 5a and 5b are smooth, just like the drive wheel 4, which means that the drive wheel 4 has a smooth axial circumferential surface 15.

[0071] The smooth drive wheel 4 is designed to engage with two belts 5a, 5b attached thereto in parallel, and as a result, the drive wheel 4 can be rotated by the rotation of the shaft 3 of the motor 2. In this embodiment, the smooth drive wheel 4 has a release groove that defines two smooth areas for axially receiving and retaining each of the two belts 5a, 5b.

[0072] According to one variant, the drive unit 1 includes a drive shaft 3 with two drive wheels 4 fixed at the front end of the drive shaft 3, the drive wheels 4 being configured to rotate two belts 5a, 5b.

[0073] Since the two belts 5a and 5b are also configured to act on the rotor shafts 9 and 10 of the rotors 7 and 8 to rotate them, these rotor shafts 9 and 10 have axially smooth circumferential surfaces to receive and attach the two belts 5a and 5b in parallel. Therefore, these smooth sections 16 and 17 are located at the front ends of the shafts 9 and 10 of the rotors 7 and 8 and include a release groove that defines two smooth sections for each rotor shaft 9 and 10 for axially receiving and retaining each of the two belts 5a and 5b.

[0074] Especially Figure 5 As can be seen, the two belts 5a and 5b each form a parallel loop from the drive wheel 4 to the first rotor shaft, which is the rotor shaft 9 furthest from the drive wheel 4. Therefore, the two belts 5a and 5b each abut against the smooth axial circumferential surface 15 of the drive wheel 4 and the smooth section 16 of the rotor shaft 9, and they are taut between the rotor shaft 9 and the drive wheel 4.

[0075] However, in order to simultaneously drive the second rotor shaft 10 located between the first rotor shaft 9 and the drive wheel 4, the two belts 5a and 5b must contact and be attached parallel to the smooth section 17 of the second rotor shaft 10. This is achieved by deforming the paths of the two belts 5a and 5b; if there were only one shaft, the paths of the two belts would be trapezoidal. Therefore, the paths of the two belts 5a and 5b are bent by forcing them to pass under the smooth section 17 of the second rotor shaft 10 (see reference). Figure 5 and Figure 6 ).

[0076] Therefore, belts 5a and 5b partially surround the wheel 4 of the drive unit 1 and the smooth section 16 of the first rotor shaft 9, and they are pressed downward by the smooth section 17 of the second rotor shaft 10 (see reference). Figure 6 ).

[0077] To facilitate their rotational drive, the rotor shafts 9 and 10 of rotors 7 and 8 preferably each include disc-shaped components 19 and 20 that increase their diameter. The axial circumferential surfaces of these disc-shaped components 19 and 20 are smooth and include a release groove defining two smooth areas designed to axially receive and retain each of the two belts 5a and 5b. The disc-shaped components 19 and 20 then constitute the smooth sections 16 and 17 of the rotor shafts 9 and 10 under consideration (see reference). Figure 7 ).

[0078] According to one variant, the rotor shafts 9 and 10 of rotors 7 and 8 each include two disc-shaped components 19 and 20.

[0079] The disc-shaped components 19 and 20 and the drive wheel 4 are generally in the same plane to allow for effective engagement with the two belts 5a and 5b. Their axial thickness is typically at least equal to the thickness of the two belts 5a and 5b (reference). Figure 7 ).

[0080] exist Figure 6 and Figure 8 In the illustrated embodiment, the disc-shaped components 19 and 20 include bearings 21a and 21b, such as sealed bearings, ball bearings, or deep groove ball bearings.

[0081] Typically, the risk of belt slippage is a function of torque and the angle between the belt and the disc-shaped component. Advantageously, according to a second preferred embodiment of the invention, each of the two belts 5a, 5b has an independent risk of slippage, thereby potentially reducing the resynchronization of the toothed pulleys. Therefore, by compensating for the slippage risk of the two belts 5a, 5b, it becomes possible to reduce and limit the risks of asynchrony and wear of the toothed pulleys.

[0082] It is evident that many variations of this invention can be implemented. Although two non-limiting embodiments have been described by way of example, it is well understood that it is impossible to exhaustively identify all possible variations. Of course, it is possible to replace the described device with an equivalent device without departing from the scope of the invention. All these modifications constitute part of the common sense of those skilled in the art of vacuum pumps. In particular, those skilled in the art will readily recognize that the belt drive device of this invention can be used in any positive displacement pump driven by the rotation of two rotors, such as a screw pump or a claw pump, whether they are lubricated or dry, and whether they are single-stage or multi-stage.

Claims

1. A dry vacuum pump, comprising: - A drive device (1), the drive device including a drive shaft (3), at least one drive wheel (4) fixed at one end of the drive shaft (3), the at least one drive wheel being configured to rotate at least one belt (5); - At least two parallel rotors (7, 8), each rotor having a rotor shaft (9, 10) provided with rotor elements (11, 12), the rotor shaft (9, 10) being rotatably driven by a belt (5), and equipped with a toothed pulley (13, 14) at one of the axial ends of the rotor shaft; Its features are, The drive wheel (4) and the belt (5) are smooth; Each rotor shaft (9, 10) of the rotors (7, 8) includes at least one smooth section (16, 17) arranged to engage with the belt (5); and The toothed gears (13, 14) of the rotor shafts (9, 10) of the rotors (7, 8) are sized and arranged to mesh with each other. The toothed gears (13, 14) are arranged such that the teeth of the corresponding toothed gear bear the load only when the rotor shaft (9, 10) is driven asynchronously.

2. The dry vacuum pump according to claim 1, wherein, The angular clearance of the toothed gears (13, 14) is smaller than the angular clearance of the rotor elements (11, 12).

3. The dry vacuum pump according to claim 1 or 2, wherein, The smooth section (16, 17) of each rotor shaft (9, 10) of the rotor (7, 8) is located at one end of the rotor shaft (9, 10).

4. The dry vacuum pump according to claim 1 or 2, wherein, On each rotor shaft (9, 10) of the rotors (7, 8), the diameter of the smooth section (16, 17) is smaller than the diameter of the toothed wheel (13, 14).

5. The dry vacuum pump according to claim 1 or 2, wherein, The two toothed wheels (13, 14) have the same diameter, and the two smooth sections (16, 17) have the same diameter.

6. The dry vacuum pump according to claim 1 or 2, wherein, The belt (5) partially surrounds one segment of the smooth sections (16, 17) and is pushed down by the other segment.

7. The dry vacuum pump according to claim 1 or 2, wherein, The smooth sections (16, 17) of the toothed gears (13, 14) and the rotor shafts (9, 10) of the rotors (7, 8) are located at the same axial end of the rotor shafts (9, 10).

8. The dry vacuum pump according to claim 1 or 2, wherein, Each smooth segment (16, 17) is located on the circumferential surface of the disc-shaped component (19, 20).

9. The dry vacuum pump according to claim 8, wherein the disc-shaped components (19, 20) and the drive wheel (4) are substantially in the same plane.

10. The dry vacuum pump according to claim 1 or 2, wherein, The points of the projections of the rotation axes of the rotor shafts (9, 10) from the rotors (7, 8) and the rotation axis of the drive shaft (3) are aligned on a plane perpendicular to the rotation axes.

11. The dry vacuum pump according to claim 1 or 2, wherein, The distance between the drive shaft (3) and the rotor shaft closest to the drive shaft is adjustable.

12. The dry vacuum pump according to claim 1 or 2, wherein, The pump is a dry vacuum pump in which the rotor elements (11, 12) are in the form of mutually cooperating teeth.

13. The dry vacuum pump according to claim 1 or 2, wherein, The vacuum pump is a Roots pump, screw pump, or claw pump.

14. The dry vacuum pump according to claim 1 or 2, wherein, The vacuum pump may be single-stage or multi-stage.

15. The dry vacuum pump according to claim 1 or 2, wherein, The drive device (1) includes a drive shaft (3), at least one drive wheel (4) is fixed at one end of the drive shaft (3), and the at least one drive wheel (4) is configured to drive two belts.

Images