Vacuum pump

Abstract

The vacuum pump (1) comprises a machine body (2) configured to generate and maintain a pressure differential and a motor device (3) operatively configured to generate a drive power for actuating the machine body (2). The vacuum pump (1) further comprises a base (4) provided with a partitioning bulkhead (5) adapted to separate the machine body (2) from the motor device (3) and configured as a separation wall between an atmospheric pressure environment and an operating environment. The vacuum pump (1) comprises a mechanical transmission device (6) interposed between the motor device (3) and the machine body (2) and comprising a drive shaft (7) passing through such partitioning bulkhead (5), wherein said drive shaft (7) extends integrally between a connection joint (8) arranged on the side of the partitioning bulkhead (5) facing the motor device (3) up to the machine body (2).

Description

[0001] This invention relates to vacuum pumps.

[0002] This invention belongs to the industrial field, and is particularly applicable to the methane gas supply chain.

[0003] As is well known, methane gas can be transported via methane tankers.

[0004] Specifically, methane gas is stored on methane tank trucks in a storage tank consisting of two concentric tanks (one of which is inside the other).

[0005] These tanks are separated by gaps that act as highly efficient isolation layers using vacuum and / or materials with insulating properties.

[0006] To create a vacuum in such a gap, a vacuum pump is typically used to remove the air present in the gap.

[0007] These vacuum pumps include a machine body and a motor device suitable for actuating the machine body. The machine body is provided with a stator and a rotor, which cooperate to generate a vacuum in the gap.

[0008] These vacuum pumps are known to be installed such that the main body of the machine is operably connected within a gap and is therefore arranged in a special space classified as a hazardous area, while the motor assembly is operably arranged in an adjacent space classified as a safe area.

[0009] For this purpose, the base on which the machine body and motor are fixed is equipped with a partition bulkhead, which is constructed as a metal partition wall that is seamlessly welded to the two spaces.

[0010] Structurally, the transmission device between the motor unit and the machine body passes through the partition and generally includes three drive shafts arranged in series and connected by a connection joint.

[0011] Specifically, the intermediate drive shaft, equipped with rigid ball bearings, is fixed to the partition via flanges.

[0012] In addition, a special double seal, such as an oil barrier, is typically installed on the intermediate drive shaft, and this seal has its own oil circulation loop, storage and expansion tank, and finned cooling pipes.

[0013] Although this solution has been improved, it has many drawbacks that make it perform poorly in use.

[0014] First, the structure is extremely complex, and therefore very expensive.

[0015] In fact, the presence of an intermediate drive shaft with specialized dual mechanical seals, bearings, flanges, and other mechanical components significantly increases the construction cost of vacuum pumps.

[0016] Furthermore, due to wear and damage, these components require additional costs for maintenance and / or replacement.

[0017] Another issue concerns the installation steps of the vacuum pump.

[0018] In particular, due to its repetitive nature, aligning the three drive shafts is a rather arduous process in terms of cost, time, and labor.

[0019] In fact, if the drive shaft is not properly aligned at the end of the installation, the operator will be forced to repeat the alignment process from scratch.

[0020] In view of the above, the technical objective of the present invention is to provide a vacuum pump that can eliminate the shortcomings that have just emerged.

[0021] The purpose of this invention is to provide a vacuum pump that is not too complex in structure and therefore not too expensive.

[0022] Another object of the present invention is to provide a vacuum pump that can be easily and quickly installed.

[0023] Another object of the present invention is to provide a vacuum pump that is durable and requires less maintenance.

[0024] Specific technical tasks and objectives are generally achieved by a vacuum pump that includes one or more technical features set forth in the appended claims. The dependent claims correspond to possible embodiments of the invention.

[0025] This description will be illustrated below with reference to the accompanying drawings, which are for illustrative purposes only and are therefore intended for non-limiting purposes, wherein:

[0026] - Figure 1 This is a schematic description of a vacuum pump according to the present invention;

[0027] - Figure 2 yes Figure 1 A schematic description of the cross-sectional details of the vacuum pump.

[0028] Referring to the accompanying drawings, reference numeral "1" generally indicates a vacuum pump according to the present invention.

[0029] This vacuum pump 1 is configured to generate and maintain a pressure difference between the operating environment and the atmospheric pressure environment.

[0030] Basically, the vacuum pump 1 includes a machine body 2, a motor unit 3, a base 4, a mechanical transmission device 6, and a sealing device 9.

[0031] The main body 2 of the machine is configured to generate and maintain a pressure differential and includes a stator and a rotor.

[0032] Specifically, the rotor is inserted into and engages with the stator to generate this pressure difference.

[0033] Structurally, according to a preferred embodiment, vacuum pump 1 is a rotary vane vacuum pump type.

[0034] Specifically, the rotor is inserted into the stator in an eccentric manner and includes movable blades whose sliding within the corresponding seats of the rotor is constrained.

[0035] The machine body 2 also includes a lubrication circuit, which preferably uses oil.

[0036] The main body 2 is actuated by a motor device 3, which is operably configured to generate driving power for actuating the main body 2.

[0037] According to a preferred, exemplary and non-limiting embodiment, the motor device 3 includes an electric motor.

[0038] The machine body 2 and the motor unit 3 are permanently constrained to the base 4, which is configured to be anchored to the mounting surface.

[0039] Structurally, the base 4 includes a partition 5, which is adapted to separate the machine body 2 from the motor unit 3 and is configured as a separation wall between the atmospheric pressure environment and the operating environment.

[0040] In other words, depending on the preferred application of the vacuum pump 1, the partition 5 is seamlessly welded to the metal partition wall between the atmospheric pressure environment and the operating environment.

[0041] Preferably, the motor unit 3 is arranged in an atmospheric pressure environment, while the machine body 2 is arranged in an operating environment.

[0042] This feature is particularly advantageous in the application of vacuum pump 1, where the operating environment is classified as a hazardous area where a potentially explosive atmosphere may form, while the atmospheric pressure environment is classified as a safe area.

[0043] In fact, due to this arrangement of the machine body 2 and the motor device 3, the operator can safely reach the motor device 3 and perform maintenance operations on it.

[0044] The mechanical transmission device 6 is located between the electric motor device 3 and the machine body 2, and includes a drive shaft 7 that passes through the partition 5 through an opening obtained on the partition 5.

[0045] According to one aspect of the invention, the drive shaft 7 extends integrally between the connecting joint 8 and the machine body 2, the connecting joint 8 being arranged on the side of the partition plate 5 facing the motor device 3.

[0046] Specifically, the connecting joint 8 is arranged to be reversibly connected to the motor assembly 3.

[0047] Preferably, this connecting joint 8 is a flexible connecting joint.

[0048] Advantageously, the structure of the vacuum pump 1 is greatly simplified by the presence of the drive shaft 7, which extends integrally between the connecting joint and the machine body 2 and passes through the partition 5, thereby reducing the construction cost.

[0049] According to another aspect of the invention, the drive shaft 7 can be manufactured as a single body together with the rotor of the machine body 2.

[0050] Furthermore, the drive shaft 7 can be installed without a connecting joint between the partition plate 5 and the machine body 2.

[0051] Advantageously, these features help to further reduce construction and installation costs.

[0052] In fact, eliminating the intermediate drive shaft and the connecting joint facilitates the installation steps of vacuum pump 1.

[0053] In addition, the mechanical components that mate with the intermediate drive shaft, especially the rigid ball bearings, have been eliminated, reducing costs and wear-related issues.

[0054] Furthermore, this structure advantageously allows for significantly faster disassembly of the vacuum pump 1 during maintenance and / or component replacement.

[0055] The sealing device 9, which functions between the partition 5 and the drive shaft 7, is configured to prevent fluid from passing between the atmospheric pressure environment and the operating environment.

[0056] According to another aspect of the invention, the sealing device 9 may be of the double mechanical seal type, which acts on the opposite faces of the partition 5.

[0057] According to the preferred embodiment illustrated by way of non-limiting example in the accompanying drawings, the sealing device 9 may be of the oil barrier type and includes an oil supply device 10 and a cooling device.

[0058] However, according to an alternative embodiment, the sealing device 9 can be a standard double mechanical seal device.

[0059] Furthermore, as can be seen in the accompanying drawings, the sealing device 9 can be stably constrained to the partition plate 5 by means of a flange.

[0060] According to another aspect, as can be seen in the accompanying drawings, the vacuum pump 1 may include a coupling lantern 11 operatively arranged near an opening obtained on the partition 5, wherein the coupling lantern 12 is concentric with the front cover of the machine body 2.

[0061] Advantageously, this feature allows the sealing device 9 to be precisely and quickly assembled into the mechanical transmission device 6.

[0062] Furthermore, advantageously, this feature allows

[0063] The connecting cover 11 may also have one or more openings, which are obtained near the machine body 2 and are configured to allow the interior portion of the connecting cover 11 to communicate with the operating environment in which the machine body 2 is inserted.

[0064] Advantageously, this feature allows any leakage from the machine body 2 to be discharged into the operating environment.

[0065] According to another aspect of the invention, the sealing device 9 may include an axial expansion compensator 12 adapted to absorb any displacement of the partition 5 during normal operation of the vacuum pump 1.

[0066] In particular, this axial expansion compensator 12 is operably located between the partition plate 5 and the flange.

[0067] Advantageously, the present invention achieves the proposed objectives and overcomes the prominent shortcomings of the prior art.

[0068] First, the structure of vacuum pump 1 is quite simple, so the cost is low.

[0069] This result is achieved through the presence of a drive shaft 7 that extends integrally between the connecting joint 8 and the machine body 2, wherein the resilient joint is arranged to be reversibly connected to the motor unit 3, and wherein the drive shaft 7 is made as a single unit together with the rotor, which allows the elimination of an intermediate drive shaft and the mechanical parts that cooperate with it, thereby greatly reducing costs.

[0070] Furthermore, the possibility of achieving this result by using a standard double mechanical seal device 9 further reduces costs.

[0071] Another objective is to provide a vacuum pump that can be installed easily and quickly.

[0072] For the same reason, the presence of the drive shaft 7, which extends integrally between the connector 8 and the machine body 2, and the presence of the connector 8, makes the installation process significantly faster and easier.

[0073] Another objective is to provide a vacuum pump 1 that is durable and requires minimal maintenance.

[0074] This result is achieved by significantly reducing the number of mechanical parts involved in transmitting driving power between the motor unit 3 and the machine body 2.

Claims

1. A vacuum pump (1) for generating and maintaining a pressure difference between an operating environment and an atmospheric pressure environment, comprising: The machine body (2) is configured to generate and maintain a pressure difference and includes a stator and a rotor, the rotor being inserted into and cooperating with the stator to generate the pressure difference; the machine body (2) also includes a lubrication circuit; A motor device (3) is operably configured to generate driving power for actuating the machine body (2); The base (4) provides a stable constraint to the machine body (2) and the motor unit (3), and the base is configured to be anchored to a mounting surface; the base (4) includes a partition (5) adapted to separate the machine body (2) from the motor unit (3) and configured to be applied as a separation wall between the atmospheric pressure environment and the operating environment, such that the motor unit (3) and the machine body (2) are operably arranged in the atmospheric pressure environment and the operating environment, respectively; A mechanical transmission device (6) is located between the motor device (3) and the machine body (2) and includes a drive shaft (7) that passes through the partition plate (5) through an opening obtained on the partition plate (5). A sealing device (9) that functions between the partition plate (5) and the drive shaft (7) and is configured to prevent fluid from passing between the atmospheric pressure environment and the operating environment; The drive shaft (7) extends integrally from the connecting joint (8) to the machine body (2), the connecting joint (8) is arranged on the side of the partition plate (5) facing the motor device (3), and the connecting joint (8) is arranged to be reversibly connected to the motor device (3). The characteristic feature is that the drive shaft (7) is formed as a single unit together with the rotor.

2. Vacuum pump (1) according to claim 1, wherein The drive shaft (7) has no connecting joint between the partition plate (5) and the machine body (2).

3. The vacuum pump (1) according to any one of the preceding claims, wherein, The sealing device (9) is of the double mechanical oil barrier type and operates on the opposite surface of the partition plate (5).

4. The vacuum pump (1) according to claim 3, wherein, The sealing device (9) is of the oil barrier type and includes an oil supply device (10) and a cooling device.

5. The vacuum pump (1) according to any one of claims 1, 2 and 4, wherein, The sealing device (9) is stably constrained to the partition plate (5) by a flange.

6. The vacuum pump (1) according to claim 5, comprising a connecting cover (11) operably arranged near the opening obtained on the partition plate (5); the connecting cover (11) being concentric with the front cover of the machine body (2).

7. The vacuum pump (1) according to claim 5, comprising an axial expansion compensator (12) operably disposed between the partition plate (5) and the flange.

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