WO2024144468A1 - A service casing and extension seal configuration that facilitates the replacement of the rotor and stator in progressive cavity pumps - Google Patents

Abstract

The invention relates to the construction of a service casing that facilitates the maintenance or replacement of the rotor and stator used in progressive cavity pumps that can pump all liquids, liquid-solid or liquid-gas mixtures even if they have different density, concentration and viscosity values in different industries such as petroleum, food, waste water treatment.

Description

A SERVICE CASING AND EXTENSION SEAL CONFIGURATION THAT FACILITATES THE REPLACEMENT OF THE ROTOR AND STATOR IN PROGRESSIVE CAVITY PUMPS

Technical Field

The invention relates to the construction of a service casing for progressive cavity pumps for ease of maintenance and installation.

The invention, in particular; relates to a service casing configuration that facilitates the maintenance or replacement of the rotor and stator used in progressive cavity pumps that can pump all liquids, liquid-solid or liquid-gas mixtures even if they have different density, concentration and viscosity values in different industries such as petroleum, food, waste water treatment.

Prior Art

Today, pumps are used in various fields of industry to transfer difficult fluids from one place to another. For example, progressive cavity pumps (PCP) are preferred for the transfer of fluids such as chocolate or cream used in the food industry with low vibration without causing any change in the product structure.

In the progressive cavity pumps in the current technique, the steel rotor part rotates inside the stator part, which is generally made of rubber material, by constantly crushing it, so these parts wear out in a short time and need to be replaced. In order to remove these parts and replace them with new ones, the pump must be completely removed from the installation line to which it is connected and disassembled. These operations take a lot of time, require labor and require physical space in the working environment. This means long and laborious maintenance periods.

In the prior art, due to the nature of the pump, the rotor and stator elements wear out rapidly and need to be replaced. During the disassembly of the parts of the pump, it is very laborious and time consuming to completely disassemble and reassemble all parts. For this reason, there is a need for a development that will eliminate this disadvantage, facilitate maintenance and service work and eliminate time loss. As a result of the research on the subject in the literature, a document with publication number EP2944819B1 was found. The document relates to a progressive cavity pump comprising a rotor extending from a drive end to a free end along its longitudinal axis, a stator casing extending from a stator inlet opening to a stator outlet opening and having an internal volume formed to receive the rotor, a drive assembly (motor and reducer) with a drive shaft coupled to the rotor to transmit torque, a universal joint for transmitting torque between the drive shaft and the rotor, a pump casing assembly for inlet of the material and an outlet flange positioned behind the rotor in the direction of flow. The present technique does not include any enhancements to allow quick and easy disassembly and connection of the rotor and stator, facilitating maintenance and servicing.

Another document encountered on the subject is the document with the publication number US10648337B2. The document relates to a progressive cavity pump having at least one stator made of elastic material and a rotor rotatable or rotatably mounted in the stator, where the stator can be reliably reconnected, preferably even under higher loads. The present technique does not include any enhancements to allow quick and easy disassembly and connection of the rotor and stator, facilitating maintenance and servicing.

Consequently, due to the above-mentioned drawbacks and the fact that the existing solutions have room for improvement, it was deemed necessary to develop an improvement in the relevant technical area.

Purpose of the Invention

The invention is inspired by existing situations and aims to solve the above-mentioned problems.

The main purpose of the invention is to provide a service casing configuration that facilitates the maintenance or replacement of the rotor and stator used in progressive cavity pumps that can pump all liquids, liquid-solid or liquid-gas mixtures even if they have different density, concentration and viscosity values in different industries such as petroleum, food, wastewater treatment.

The other purpose of the invention is to enable the replacement of the rotor and stator group in a short time with the service casing placed between the pump casing and the stator group. In this way, a significant time and labor saving is achieved. Another purpose of the invention is to create a distance between the outlet flange and the pipeline by means of an extension seal, thus creating space for the outlet flange to move when the extension seal is removed. This space allows the outlet flange to be easily separated from the system.

In order to fulfill the above-mentioned purposes, the invention is a progressive cavity pump which is able to pump all liquids, liquid-solid or liquid-gas mixtures, even if they have different density, concentration and viscosity values, in different industries such as petroleum, food, wastewater treatment, comprising:

• A motor-reducer that provides the power the machine needs,

• A pump casing assembly, the part where the fluid enters the pump,

• A lantern casing connecting the motor-reducer and the pump casing assembly,

• A drive shaft that transmits the rotary motion received from the motorreducer,

• A cardan shaft that transmits the rotary motion received from the drive shaft,

• A rotor that rotates eccentrically with the drive from the cardan shaft and provides flow and pressure,

• Connection pins that connect both the drive shaft to cardan shaft and the cardan shaft to rotor,

• A stator whose internal geometry allows the rotor to rotate eccentrically,

• An outlet flange, the part where the fluid exits the pump and characterized by comprising;

• A service casing located between the stator group and the pump casing, which eliminates the need to dismantle the connections of the pump casing with both the installation fluid inlet flange and the lantern casing in case of pump maintenance, creates the necessary gap for the removal of the rotor connection pin connected to the cardan shaft, of the rotor and thus allows the rotor and stator to be replaced. The structural and characteristic features and all advantages of the invention will be more clearly understood with the following figures and the detailed description with references to these figures, and therefore the evaluation should be made by taking these figures and detailed description into consideration.

Figures to Help Understanding of the Invention

Figure 1 is a top perspective view of a progressive cavity pump.

Figure 2 is a close-up view of the pump casing, service casing and stator assembly.

Figure 3 is a side view of a progressive cavity pump.

Figure 4 shows general views of the service casing which is subject to the invention from the front and rear.

Figure 5 is a pre-assembly view of the service casing and extension seal, which is subject to the invention.

Figure 6 is a close-up view of the service casing which is subject to the invention as assembled.

Figure 7 is a cross-sectional view of all elements of the progressive cavity pump with service casing assembly.

Figure 8 is a detail view of service casing stator connection and pump casing connection.

Description of Part References

1. Progressive cavity pump

10. Motor-reducer

11. Reducer pin

12. Drive shaft

13. Cardan shaft

20. Lantern casing

30. Rotor

31. Rotor connection pin 40. Stator assembly

41. Stator

42. Stator assembly cover

43. Stator casing

50. Pump casing assembly

51. Pump casing

52. Service casing

53. Primary fastener

54. Secondary fastener

55. O-ring

60. Outlet flange

70. Extension seal

Detailed Description of the Invention

In this detailed description, preferred embodiments of the inventive progressive cavity pump (1) are described only for the purpose of a better understanding of the subject matter.

Since the progressive cavity pump (1) which is subject to the invention, can pump almost all liquids, liquid - solid, liquid - gas mixtures even if they have different density, concentration and viscosity values, it can be used in industries such as petroleum, food, waste water treatment. The progressive cavity pump (1), which has a wide range of applications, basically consists of a motor-reducer (10), drive shaft (12), cardan shaft (13), lantern casing (20), rotor (30), stator assembly (41), pump casing (51), service casing (52) and outlet flange (60).

The motor-reducer (10) in the progressive cavity pump (1 ) which is subject to the invention, provides the power required by the machine. The fluid enters the pump through the pump casing (51). The lantern casing (20) connects the motor-reducer (10) and the pump casing (51). There is a drive shaft (12) which transfers the rotary motion received from the reducer. The cardan shaft (13) provides the transmission of the rotational motion received from the drive shaft (12) to the rotor (30). The rotor (30) rotates eccentrically inside the stator (41 ), creating flow and pressure through the closed chambers it forms. The internal geometry of the stator (41) is suitable for the rotation of the rotor (30).

The reducer pin (11) in the pump subject to the invention is the element that transfers the rotational motion received from the reducer to the drive shaft (12). The rotor connection pins (31) connects the drive shaft (12) to the cardan shaft (13) and the cardan shaft (13) to the rotor (30).

The most important purpose of the progressive cavity pump (1 ) which is subject to the invention, is to be able to replace the rotor and stator of the pump casing (51) without disassembling both the installation fluid inlet flange and the lantern casing (20) connections when the pump is to be serviced. In order to realize this purpose, an additional part named as service casing (52) is added to the part named as pump casing (51). Thanks to the service casing (52), the need to dismantle the connections of the pump casing (51) and lantern casing (20) is eliminated in case of maintenance to the pump, and the space required for the removal of the rotor connection pin (31), which is connected to the cardan shaft (13) of the rotor (30), is opened and thus the rotor (30) and stator (41) can be replaced.

The service casing (52) is located between the stator assembly (40) and the pump casing

(51). There is a groove where the service casing (52) connects to the stator assembly (40), likewise there is a groove and at least one O-ring seat where it connects the pump casing (51). This groove ensures that the service casing (52) fits and centers the pump casing (51) and the stator assembly (40).

The service casing (52) is connected to the pump casing (51) with secondary fasteners (54) and the sealing between them is provided by sealing elements such as O-ring (55). The service casing (52) is connected to the stator assembly (40) with primary fasteners (53), preferably bolts. This is because studs are not used; however, if studs are used, the studs will ensure the connection with the output casing and compress the stator assembly (40).

The subject matter of the invention further comprises at least one stator assembly cover (42) at both ends of the stator (41) and the stator casing (43), which provides sealing and connection between the stator (41 ) and the output flange (60) and between the stator (41 ) and the service casing (52). However, one more part is required for the service casing

(52) to be used. This part is the extension seal (70). The extension seal (70) connects the outlet flange (60) to the pipeline, maintains the distance between the outlet flange (60) and the pipeline, and creates a space or gap through which the outlet flange (60) can move when removed. This gap is created by removing the extension seal (70) after the bolts of the outlet flange (60) have been removed. The outlet flange (60) is moved forward as far as the gap created, freeing it from the groove of the stator assembly cover (42), so that it can be separated from the system. After the outlet flange (60) is separated from the system, the stator assembly (40) can be removed by lifting up.

The steps of changing the rotor and stator in the progressive cavity pump which is subject to the invention, are as follows:

• Remove the installation line connection bolts on the outlet flange (60),

• Remove the extension seal (70),

• Unscrew the bolts at the leg of the outlet flange (60),

• Remove the primary fasteners (53) and secondary fasteners (54) connecting the stator assembly (40) to the output flange (60) and the service casing (52). (As mentioned before, these bolts can be replaced by studs),

• Move the outlet flange (60) forward and separate it from the system

• Lift and remove the stator assembly (40),

• Remove the leg connections of the service casing (52) and move it forward,

• Remove the rotor connection pin (31) connecting the cardan shaft (13) to the rotor (30),

• Install the new rotor (30) to the cardan shaft (13) and/or install the new stator (41 ) on the stator assembly (40). The pump assembly is completed by reassembling the other components.

Claims

1. A progressive cavity pump (1) which is able to pump all liquids, liquid-solid or liquid-gas mixtures even if they have different density, concentration and viscosity values in different industries such as petroleum, food, waste water treatment, comprising:

• A motor-reducer (10) that provides the power the machine needs,

• A pump casing (51), the part where the fluid enters the pump,

• A lantern casing (20) connecting the motor-reducer (10) and the pump casing (51),

• A drive shaft (12) that transmits the rotational motion received from the reducer,

• A cardan shaft (13) that transmits the rotational motion received from the drive shaft (12),

• An eccentrically rotating rotor (30) driven by a cardan shaft, generating flow and pressure,

• Rotor connection pin (31 ), which connects both the drive shaft (12) to cardan shaft (13) and the cardan shaft (13) to rotor (30),

• A stator (41) whose internal geometry allows the rotor (30) to rotate eccentrically and

• An outlet flange (60) where the fluid exits the pump, and characterized by comprising;

• A service casing (52) located between the stator assembly (40) and the pump casing (51), which eliminates the need to dismantle both the installation fluid inlet flange and the lantern casing (20) connections of the pump casing (51) in case of pump maintenance, creates the necessary gap for the removal of the rotor connection pin (31) connected to the cardan shaft (13) of the rotor (30), and thus enables the replacement of the rotor (30) and stator (41).

2. The progressive cavity pump (1) according to claim 1 , characterized by comprising a stator assembly cover (42) at both ends of the stator (41), which provides sealing and connection between the stator (41) and the outlet flange (60) and between the stator (41) and the service casing (52).

3. The progressive cavity pump (1) according to claim 1 , characterized by comprising an extension seal (70) that connects the outlet flange (60) to the pipeline, maintains the distance between the outlet flange (60) and the pipeline, and creates a space where the outlet flange (60) can move when removed.

4. The progressive cavity pump (1) according to claim 2, characterized by comprising a primary fastener (53) for connecting the service casing (52) and the stator assembly cover (42).

5. The progressive cavity pump (1) according to claim 1 , characterized by comprising a secondary fastener (54) for connecting the service casing (52) and the pump casing (51).

6. The progressive cavity pump (1) according to claim 1 , characterized by comprising at least one O-ring (55) for sealing between the service casing (52) and the pump casing (51).