Multifunctional pump

Abstract

The utility model relates to the technical field of pumps, in particular to a multifunctional pump. Comprising a driving device; the driving device is connected with an output shaft, the other end of the output shaft is connected with a connecting shaft, the connecting shaft is located in the shaft transmission mechanism, and the other end of the connecting shaft is connected with a rotating mechanism. A shaft hole is formed in the end, close to the output shaft, of the connecting shaft, a slotted hole is formed in the inner wall of the shaft hole, a protruding edge matched with the slotted hole is arranged at the end, close to the connecting shaft, of the output shaft, the output shaft is inserted into the shaft hole of the connecting shaft, and the protruding edge abuts against the interior of the slotted hole. By arranging the output shaft and the connecting shaft, the output shaft and the connecting shaft are connected in an inserted mode, when the impeller works, absorbs water and slightly moves, only the connecting shaft is driven to slightly move together, the output shaft cannot move, the axial force of the output shaft can be only transferred to the shaft hole and the groove hole and cannot be transferred to the motor, the load and stress of the motor are reduced, and the service life of the motor is prolonged. The energy consumption can be reduced; and the service life of the motor can be prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of pumps, in particular to a multifunctional pump. Background Art

[0002] A pump is a machine that transports fluids or increases the pressure of fluids. It transfers the mechanical energy of the prime mover or other external energy to the liquid, increasing the energy of the liquid. Pumps are mainly used to transport liquids such as water, oil, acid-base solutions, emulsions, suspension emulsions, and liquid metals, and can also transport liquid-gas mixtures and liquids containing suspended solids. Pumps can generally be divided into three categories according to the working principle: positive displacement pumps, dynamic pumps, and other types of pumps. In addition to classification by working principle, they can also be classified and named by other methods. For example, according to the driving method, they can be divided into electric pumps and water turbine pumps, etc.; according to the structure, they can be divided into single-stage pumps and multi-stage pumps; according to the use, they can be divided into boiler feed pumps and metering pumps, etc.; according to the nature of the transported liquid, they can be divided into water pumps, oil pumps, and mud pumps, etc. According to the presence or absence of a shaft structure, they can be divided into linear pumps and traditional pumps. A water pump can only transport logistics with fluid as the medium and cannot transport solids.

[0003] Currently, the pump structure generally includes a motor, an output shaft, a shaft transmission mechanism, and an impeller. In the prior art, the motor is connected to the output shaft, and the other end of the output shaft is directly connected to the shaft transmission mechanism. However, the shaft transmission mechanism is generally composed of a single-layer oil seal and a single-layer mechanical seal, resulting in poor sealing performance of the shaft transmission mechanism. Liquids are likely to flow through the output shaft into the motor, causing damage to the motor, or splashing outside the shaft transmission mechanism; based on this, we propose a multifunctional pump. Content of the Utility Model

[0004] Aiming at the deficiencies of the prior art, the utility model provides a multifunctional pump. After improvement, this pump can effectively solve the problems raised in the above background art.

[0005] The technical solution of the utility model is as follows:

[0006] A multifunctional pump includes a driving device, an output shaft, a connecting shaft, a shaft transmission mechanism, and a rotating mechanism;

[0007] The driving device is connected to an output shaft, the other end of the output shaft is connected to a connecting shaft, the connecting shaft is located inside the shaft transmission mechanism, and the other end of the connecting shaft is connected to a rotating mechanism;

[0008] A shaft hole is provided at one end of the connecting shaft close to the output shaft, a slot hole is provided on the inner wall of the shaft hole, a convex rib adapted to the slot hole is provided at one end of the output shaft close to the connecting shaft, the output shaft is inserted into the shaft hole of the connecting shaft, and the convex rib abuts against the inside of the slot hole.

[0009] Furthermore, the shaft drive mechanism includes a housing, and several layers of oil chambers, mechanical oil seals, and skeleton oil seals are arranged inside the housing. The several layers of oil chambers are arranged alternately or sequentially with the mechanical oil seals and the skeleton oil seals. The connecting shaft communicates with the several layers of oil chambers, the mechanical oil seals, and the skeleton oil seals respectively. An alloy sleeve is installed at one end of the connecting shaft close to the rotating mechanism, and a bearing is installed on the outer side of the connecting shaft at the shaft hole. Both the alloy sleeve and the bearing are located inside the housing.

[0010] Furthermore, the mechanical oil seal, the skeleton oil seal, and the several layers of oil chambers are arranged between the alloy sleeve and the bearing.

[0011] Furthermore, a spare chamber is also arranged inside the housing. The spare chamber is arranged between the mechanical oil seal and the skeleton oil seal. One end of the spare chamber communicates with the connecting shaft, and the other end of the spare chamber communicates with the outside. A notch is arranged at the other end of the spare chamber, and an installation pipe is installed on the notch. One of a lubricating oil layer, a cooling layer, or a heating layer can be arranged inside the spare chamber.

[0012] Furthermore, the lubricating oil layer is a grease layer; the cooling layer is a coolant layer or a cooling oil layer; the heating layer is a hot liquid layer or a hot oil layer.

[0013] Furthermore, the mechanical oil seal is fixedly connected to the connecting shaft, and the skeleton oil seal, the alloy sleeve, and the bearing are respectively in transmission connection with the connecting shaft.

[0014] Furthermore, the driving device used is a motor, the rotating mechanism used is an impeller, and the impeller is detachably connected to the connecting shaft.

[0015] Furthermore, the multi-functional pump further includes a pump housing. The open end of the housing is detachably connected to the pump housing. The impeller is located inside the pump housing. One end of the pump housing is provided with a water inlet, and the other end is provided with a water outlet.

[0016] Furthermore, the output shaft can be connected to the connecting shaft through a coupling or the output shaft and the connecting shaft are of an integrally formed structure.

[0017] Furthermore, the multi-functional pump further includes an outer cylinder. The shaft drive mechanism is located inside the outer cylinder, and a cooling and heating pipe is fixedly installed on the outer wall of the outer cylinder.

[0018] Furthermore, an electric heating pipe is installed inside the spare chamber.

[0019] The beneficial effects of the present utility model are as follows:

[0020] 1. Compared with the prior art, the utility model is provided with an output shaft and a connecting shaft. The connecting shaft is provided with a shaft hole and a slot hole, and the output shaft is provided with convex ribs. The output shaft and the connecting shaft are inserted. When the impeller works and absorbs water and moves slightly, it will only drive the connecting shaft to move slightly together, and will not cause the output shaft to move, so that the axial force will only be transferred to the shaft hole and the slot hole, rather than to the motor, reducing the load and stress on the motor, thereby being able to reduce energy consumption and improve the service life of the motor;

[0021] 2. By arranging several layers of oil cavities, mechanical oil seals, skeleton oil seals, alloy sleeves and bearings inside the housing, the several layers of oil cavities, mechanical oil seals and skeleton oil seals can achieve multi-point support for the connecting shaft, so that the connecting shaft will not move and is more stable during operation. Moreover, the several layers of oil cavities, mechanical oil seals, skeleton oil seals and alloy sleeves achieve the function of multi-point sealing, and the sealing effect is excellent, which can effectively prevent liquid from flowing through the connecting shaft into the motor or splashing out of the connecting shaft;

[0022] 3. By providing a spare cavity, when an electric heating tube is installed inside the spare cavity, the cavity can be heated, and then the butter inside the other several layers of oil cavities can be heated, which can weaken the aging speed of the mechanical seal. Similarly, when hot water or hot oil is added to the spare cavity, the butter inside the other several layers of oil cavities can also be heated; when cold water or cold oil is injected into the spare cavity, the butter inside the other several layers of oil cavities can also be cooled, which can weaken the aging speed of the mechanical seal; in addition, the spare cavity can also be used as an oil cavity, and butter can be injected to lubricate the mechanical oil seal and the skeleton oil seal. Moreover, the spare cavity is communicated with the connecting shaft, and the spare cavity can also achieve the function of draining water, effectively preventing liquid from flowing through the spare cavity to the next layer of oil seal or mechanical seal, achieving an excellent sealing and waterproof effect; the application of the connection structure between the output shaft and the connecting shaft, the multi-layer sealing structure, and the spare cavity and other structures makes the utility model have various functional effects and strong practicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of the shaft transmission mechanism of the utility model;

[0024] Figure 2 It is a schematic structural diagram of another side of the shaft transmission mechanism of the utility model;

[0025] Figure 3 It is a sectional view of the utility model;

[0026] Figure 4 It is a sectional view of the shaft transmission mechanism of the utility model;

[0027] Figure 5 It is a sectional view of the utility model after connecting the outer cylinder.

[0028] In the figure, 1 is a driving device; 2 is an output shaft; 3 is a connecting shaft; 4 is a shaft transmission mechanism; 5 is a rotating mechanism; 6 is a shaft hole; 7 is a slot hole; 8 is a convex rib; 9 is a housing; 10 is an oil chamber; 11 is a mechanical oil seal; 12 is a skeleton oil seal; 13 is an alloy sleeve; 14 is a bearing; 15 is a spare chamber; 16 is an installation pipe; 17 is a pump casing; 18 is a water inlet; 19 is a water outlet; 20 is an outer cylinder; 21 is a cooling and heating pipe. Detailed implementation mode

[0029] The following further describes the detailed implementation mode of the present utility model in conjunction with the accompanying drawings:

[0030] As Figures 1-5 shown,

[0031] A multifunctional pump includes a driving device 1, an output shaft 2, a connecting shaft 3, a shaft transmission mechanism 4 and a rotating mechanism 5; the driving device 1 is connected to the output shaft 2, the other end of the output shaft 2 is connected to the connecting shaft 3, the connecting shaft 3 is located inside the shaft transmission mechanism 4, and the other end of the connecting shaft 3 is connected to the rotating mechanism 5; a shaft hole 6 is provided at one end of the connecting shaft 3 close to the output shaft 2, a slot hole 7 is provided on the inner wall of the shaft hole 6, and a convex rib 8 adapted to the slot hole 7 is provided at one end of the output shaft 2 close to the connecting shaft 3. The output shaft 2 is inserted into the shaft hole 6 of the connecting shaft 3, and the convex rib 8 abuts against the inside of the slot hole 7 in the horizontal direction. In other words, the convex rib 8 and the slot hole 7 can move in the vertical direction; in this embodiment, when the rotating mechanism 5 works and absorbs water with a slight displacement, only the connecting shaft 3 will be driven to move slightly together (the connecting shaft 3 is limited by the rotating mechanism 5 and the alloy sleeve 13 and can only move slightly), and the output shaft 2 will not move, so that the axial force will only be transferred to the shaft hole 6 and the slot hole 7, rather than to the driving device 1, thereby reducing the load and stress on the driving device 1.

[0032] As a preferred embodiment, the shaft drive mechanism 4 includes a housing 9. Inside the housing 9, there are several layers of oil chambers 10 (the inside of the oil chambers 10 is mainly filled with grease to form a grease layer for lubricating the mechanical oil seal 11 and the skeleton oil seal 12, and having a sealing effect of blocking liquids), a mechanical oil seal 11 and a skeleton oil seal 12. The several layers of oil chambers 10 are arranged alternately or sequentially with the mechanical oil seal 11 and the skeleton oil seal 12. The connecting shaft 3 communicates with the several layers of oil chambers 10, the mechanical oil seal 11 and the skeleton oil seal 12 respectively. At one end of the connecting shaft 3 close to the rotating mechanism 5, an alloy sleeve 13 is installed. On the outer side of the connecting shaft 3 at the shaft hole 6, a bearing 14 is installed. Both the alloy sleeve 13 and the bearing 14 are inside the housing 9. It can be understood that the several layers of oil chambers 10, the mechanical oil seal 11 and the skeleton oil seal 12 can achieve multi-point support of the connecting shaft 3, so that the connecting shaft 3 will not move and is more stable during operation. Moreover, the several layers of oil chambers 10, the mechanical oil seal 11, the skeleton oil seal 12 and the alloy sleeve 13 achieve the function of multi-point sealing, and the sealing effect is excellent, which can effectively prevent the liquid from flowing to the motor through the connecting shaft 3 or splashing out of the connecting shaft 3.

[0033] It is worth mentioning that the mechanical oil seal 11 and the skeleton oil seal 12 can also be set to several. According to actual application requirements, multiple mechanical oil seals 11 and skeleton oil seals 12 can be set, and they are arranged alternately or sequentially with the several layers of oil chambers 10.

[0034] As a preferred embodiment, the mechanical oil seal 11, the skeleton oil seal 12 and the several layers of oil chambers 10 are arranged between the alloy sleeve 13 and the bearing 14. It can be understood that the purpose of this design is that the alloy sleeve 13 first comes into contact with water instead of the mechanical oil seal 11 or the skeleton oil seal 12. In the structure of a traditional pump, the mechanical oil seal 11 or the skeleton oil seal 12 is arranged close to the impeller end, and water and dirt in the dirty water easily enter the inside of the mechanical oil seal 11 or the skeleton oil seal 12, which easily causes damage to the mechanical oil seal 11 or the skeleton oil seal 12. However, in this application, the alloy sleeve 13 is used for the first-stage seal, which can block more than 95% of the water and dirt in the dirty water, thereby effectively protecting the mechanical oil seal 11 or the skeleton oil seal 12. Moreover, the alloy sleeve 13 is made of alloy, which can extend its service life.

[0035] As a preferred embodiment, a spare cavity 15 is further provided inside the housing 9. The spare cavity 15 is arranged between the mechanical oil seal 11 and the skeleton oil seal 12, and can also be arranged between other two layers of oil seals or mechanical seals. One end of the spare cavity 15 is communicated with the connecting shaft 3, and the other end of the spare cavity 15 is communicated with the outside. A notch is provided at the other end of the spare cavity 15, and an installation pipe 16 is installed on the notch. One of a lubricating oil layer, a cooling layer or a heating layer can be arranged inside the spare cavity 15. By providing the spare cavity 15, when hot water or hot oil is added to the spare cavity 15, the grease inside the other multiple oil cavities 10 can be heated; when cold water or cold oil is injected into the spare cavity 15, the grease inside the other multiple oil cavities 10 can be cooled, and both can weaken the aging speed of the mechanical seal. In addition, the spare cavity 15 can also be used as an oil cavity 10, and grease can be injected to lubricate the mechanical oil seal 11 and the skeleton oil seal 12. Moreover, the spare cavity 15 is communicated with the connecting shaft 3, and the spare cavity 15 can also realize the function of draining water, effectively preventing liquid from flowing through the spare cavity 15 to the next layer of oil seal or mechanical seal, achieving an excellent sealing and waterproof effect.

[0036] In addition, during the drainage process, the liquid flowing on the connecting shaft 3 will enter the spare cavity 15 and then be discharged through the installation pipe 16. The installation pipe 16 can be connected to a liquid storage tank through a pipeline so that the liquid can flow back again.

[0037] More specifically, the connecting shaft 3 is sequentially connected to the alloy sleeve 13, the oil cavity 10, the mechanical oil seal 11, the spare cavity 15, the skeleton oil seal 12, the oil cavity 10 and the bearing 14. However, due to the fact that the oil cavity 10 is provided in several layers and the mechanical oil seal 11 and the skeleton oil seal 12 can be provided in multiple numbers, the oil cavity 10, the mechanical oil seal 11, the spare cavity 15 and the skeleton oil seal 12 inside the shaft transmission mechanism 4 can be increased or decreased according to actual situations, and their positions can be adjusted at the same time.

[0038] As a preferred embodiment, the lubricating oil layer is a grease layer; the cooling layer is a coolant layer or a cooling oil layer; the heating layer is a hot liquid layer or a hot oil layer. It can be understood that the grease layer has the functions of sealing and lubricating. By setting the grease layer, the function of the spare cavity 15 can be the same as that of the oil cavity 10. In addition, the spare cavity 15 can also be used for temperature adjustment inside the shaft transmission mechanism 4, mainly for heating or cooling the grease inside other oil cavities 10, thereby weakening the aging speed of the mechanical seal. Moreover, the heating medium can be liquid water or oil, or other substances that can be heated or cooled. The installation pipe 16 can be connected to an external heating and cooling circulation system, and then form a connection with the spare cavity 15.

[0039] As a preferred embodiment, the mechanical oil seal 11 is fixedly connected to the connecting shaft 3, and the skeleton oil seal 12, the alloy sleeve 13, and the bearing 14 are respectively in transmission connection with the connecting shaft 3. It can be understood that the alloy sleeve 13 and the bearing 14 are first fixedly connected to the outer shell 9 and then in transmission connection with the connecting shaft 3, while the mechanical oil seal 11 rotates together with the connecting shaft 3. The gaps between the alloy sleeve 13 and the connecting shaft 3 and between the bearing 14 and the connecting shaft 3 are very small (within 50 microns), which can effectively seal.

[0040] As another preferred embodiment, the main function of the bearing 14 is to support and drive the connecting shaft 3. Therefore, the bearing 14 can be disassembled, and another alloy sleeve 13 can be installed below the connecting shaft 3 at the shaft hole 6. In this way, not only can the supporting effect be strengthened, but also the cost can be reduced because the diameter at the shaft hole 6 of the connecting shaft 3 will be larger than that of other parts, and using the alloy sleeve 13 can save materials.

[0041] As a preferred embodiment, the driving device 1 uses an electric motor, the rotating mechanism 5 uses an impeller, and the impeller is detachably connected to the connecting shaft 3. It can be understood that when disassembling, the electric motor and the output shaft 2 can be first removed from the connecting shaft 3, and then the pump casing 17 is opened, and the screws on the impeller and the connecting shaft 3 are removed, and then the connecting shaft 3 can be removed, which is convenient for future maintenance.

[0042] As a preferred embodiment, the multi-functional pump further includes a pump casing 17. The open end of the outer shell 9 is detachably connected to the pump casing 17. The impeller is located inside the pump casing 17. One end of the pump casing 17 is provided with a water inlet 18, and the other end is provided with a water outlet 19. The water inlet 18 and the water outlet 19 are communicated. The pump casing 17 and the outer shell 9 can be installed by bolts, which is convenient for disassembling the pump casing 17. Secondly, driven by the impeller, water can enter through the water inlet 18 and be discharged through the water outlet 19.

[0043] As another preferred embodiment, the outer shell 9 can be divided into multiple connecting shells. The alloy sleeve 13, the oil chamber 10, the mechanical oil seal 11, the spare chamber 15, the skeleton oil seal 12, the oil chamber 10, and the bearing 14 can all be separately provided with connecting shells. Each connecting shell is provided with a suitable connecting groove and step, so that each layer structure can be detachably connected in a laminated manner, and thus each part of the shaft transmission mechanism 4 can be made detachable, which is more convenient for future maintenance work. At the same time, a sealing ring can be installed at the connection between adjacent connecting shells to enhance its sealing effect.

[0044] As a preferred embodiment, the output shaft 2 can be connected to the connecting shaft 3 through a coupling or the output shaft 2 and the connecting shaft 3 are of an integrally formed structure. It can be understood that in addition to the way of inserting the output shaft 2 and the connecting shaft 3, the above two ways can also be adopted in this application.

[0045] As a preferred embodiment, the multi-functional pump further includes an outer cylinder 20. The shaft transmission mechanism 4 is located inside the outer cylinder 20, and a cooling and heating pipe 21 is fixedly installed on the outer wall of the outer cylinder 20. It can be understood that by providing the outer cylinder 20, the housing 9 forms an inner cylinder structure. The structure of the inner cylinder and the outer cylinder 20 is convenient for installing the shaft transmission mechanism 4. Moreover, a cooling and heating pipe 21 is also provided on the outer wall of the outer cylinder 20 and installed in a threaded winding manner to increase the external heating or cooling function. Multiple ways can be realized: First, the internal heating and cooling method; second, the external heating and cooling method; third, the combined internal and external heating and cooling method, making its function powerful.

[0046] As a preferred embodiment, an electric heating pipe is installed inside the spare cavity 15. It can be understood that in addition to using the heating and cooling medium, the electric heating pipe can also be used to meet the needs of different users.

[0047] In this application, during operation, the motor is started to drive the output shaft 2 and the connecting shaft 3 to rotate, and then drive the impeller to rotate to realize the pumping work of the pump. During operation, water will flow along the connecting shaft 3. Since the shaft transmission mechanism 4 is provided with a multi-layer sealing structure, the alloy sleeve 13 structure at the first place can block 95% of the dirty water, and the subsequent multi-layer oil seals and multiple mechanical seals make it extremely difficult for water to penetrate, thereby effectively protecting the motor and preventing water leakage and splashing. Moreover, a spare cavity 15 is also provided, which can have a drainage function. Once water enters the spare cavity 15, it will also be effectively discharged in the spare cavity 15 to ensure absolute safety. In addition, the multi-functional pump of this application can be used in various different environments such as in water or not in water, and the use effect is good.

[0048] It should be pointed out that the main problems in the prior art are as follows: When the pump is working, the impeller will have a slight displacement in the water absorption state, causing the output shaft to move outwards, pulling the motor, resulting in the motor having a load and being stressed, which will increase the power of the motor and thus increase energy consumption. Moreover, if this continues for a long time, the service life of the motor will be reduced.

[0049] Therefore, after the improvement of the present application, by providing an output shaft 2 and a connecting shaft 3, the output shaft 2 and the connecting shaft 3 are inserted. When the impeller works to absorb water and moves slightly, only the connecting shaft 3 will be driven to move slightly together, and the output shaft 2 will not move, so that the axial force will only be transferred to the shaft hole 6 and the slot hole 7, rather than to the motor, reducing the load and stress on the motor, and thus being able to reduce energy consumption and improve the service life of the motor.

[0050] The above embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A multifunctional pump, comprising a driving device, an output shaft, a connecting shaft, a shaft transmission mechanism and a rotating mechanism; characterized in that: The driving device is connected to an output shaft, the other end of the output shaft is connected to a connecting shaft, the connecting shaft is located inside the shaft transmission mechanism, and the other end of the connecting shaft is connected to a rotating mechanism; The shaft transmission mechanism includes a shell, and several layers of oil chambers, mechanical oil seals and skeleton oil seals are arranged inside the shell. The several layers of oil chambers and mechanical oil seals and skeleton oil seals are arranged alternately or sequentially. The connecting shaft is respectively connected to the several layers of oil chambers, mechanical oil seals and skeleton oil seals. An alloy sleeve is installed at one end of the connecting shaft close to the rotating mechanism. A bearing is installed on the outer side of the connecting shaft located at the shaft hole, and the alloy sleeve and the bearing are both located inside the shell.

2. A multifunctional pump according to claim 1, characterized in that: The mechanical oil seal, the skeleton oil seal and the plurality of layers of the oil chambers are arranged between the alloy sleeve and the bearing.

3. A multifunctional pump according to claim 2, characterized in that: A spare chamber is also provided inside the shell, and the spare chamber is provided between the mechanical oil seal and the skeleton oil seal. One end of the spare chamber is connected to the connecting shaft, and the other end of the spare chamber is connected to the outside. A notch is provided at the other end of the spare chamber, and a mounting tube is installed on the notch. A lubricating oil layer, a cooling layer or a heating layer can be provided inside the spare chamber.

4. A multifunctional pump according to claim 3, characterized in that: The lubricating oil layer is a butter layer; the cooling layer is a cooling liquid layer or a cooling oil layer; and the heating layer is a hot liquid layer or a hot oil layer.

5. A multifunctional pump according to claim 4, characterized in that: The mechanical oil seal is fixedly connected to the connecting shaft, and the skeleton oil seal, the alloy sleeve and the bearing are respectively drivingly connected to the connecting shaft.

6. A multifunctional pump according to claim 5, characterized in that: The driving device adopts a motor, the rotating mechanism adopts an impeller, and the impeller is detachably connected to the connecting shaft.

7. A multifunctional pump according to claim 6, characterized in that: The multifunctional pump further comprises a pump casing, the open end of the outer casing is detachably connected to the pump casing, the impeller is located inside the pump casing, one end of the pump casing is provided with a water inlet, and the other end is provided with a water outlet.

8. A multifunctional pump according to claim 7, characterized in that: The output shaft can be connected to the connecting shaft via a coupling, or the output shaft and the connecting shaft can be an integrally formed structure.

9. A multifunctional pump according to claim 8, characterized in that: The multifunctional pump further comprises an outer cylinder, the shaft transmission mechanism is located inside the outer cylinder, and a cooling and heating pipe is fixedly mounted on the outer wall of the outer cylinder.

10. A multifunctional pump according to claim 9, characterized in that: An electric heating tube is installed inside the standby cavity.

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