CN114135518A

CN114135518A - A centrifugal fresh water pump

Info

Publication number: CN114135518A
Application number: CN202111449684.XA
Authority: CN
Inventors: 甘杰瑞; 胡辛阳; 郑松; 罗钰铜; 张潮; 余长虹; 王勇; 徐茂
Original assignee: Chongqing Yuejin Machinery Co ltd
Current assignee: Chongqing Yuejin Machinery Co ltd
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2022-03-04

Abstract

The invention discloses a centrifugal fresh water pump, comprising a volute, an impeller, a water-cooled bearing, a water pump shaft, a driving gear and a water inlet end cover. By abandoning the traditional centrifugal fresh water pump, the present invention designs the bearing seat to install the conventional rolling bearing, utilizes the feature that the new rolling bearing can work in water, liquid nitrogen and other media, makes full use of the working feature of the impeller, and installs the new rolling bearing on both sides of the impeller, Reduce the number of parts and achieve the purpose of compact structure design.

Description

Centrifugal fresh water pump

Technical Field

The invention belongs to the technical field of water pumps, and particularly relates to a centrifugal fresh water pump structure.

Background

The diesel engine is provided with a centrifugal fresh water pump which is arranged on a front end cover of the diesel engine, a driving gear of the water pump and a flywheel of the diesel engine form a gear pair, and when the diesel engine rotates to work, torque input to the water pump is achieved through the gear pair to drive the water pump to work. The torque obtained by the driving gear is transmitted to the impeller of the water pump by the water pump shaft, and the impeller is driven to synchronously rotate and work with the water pump shaft and the driving gear. After the impeller rotates, the flow direction and pressure of the working medium filled into the water inlet are changed, the conveying function of the working medium is realized, and the conversion from mechanical energy to working medium pressure energy is completed. The water pump shaft is a bridge from the input of the torque of the driving gear to the energy conversion of the impeller, in the traditional design, two rolling bearings are designed to support and position the water pump shaft, the stable rotation work of the water pump shaft is guaranteed, and the driving gear and the impeller of the water pump are respectively arranged at two ends of the water pump shaft. The working medium of the two rolling bearings is lubricating oil, the working medium of the impeller is treated fresh water, and the two media cannot be mixed, so that a mechanical seal and a rotating shaft lip seal are designed between the bearings and the impeller and are respectively used for sealing the fresh water and the lubricating oil. This kind of traditional project organization, water pump length is than longer, and the structure is complicated, and is with high costs, when installing at diesel engine front end housing, seriously influences the whole outward appearance of diesel engine.

The traditional diesel engine machine is provided with a centrifugal fresh water pump, two rolling bearings or sliding bearings are mounted on a water pump shaft and then mounted in a bearing support together, a positioning structure of the water pump is completed jointly, the bearings are lubricated by inputting lubricating oil, and normal use of the water pump bearings is guaranteed.

Disclosure of Invention

In view of the defects of the method for designing the machine-mounted centrifugal fresh water pump in the traditional way, the invention provides the centrifugal fresh water pump for the diesel engine, and the water-cooled bearing is applied, and the impeller is adopted to replace a water pump shaft to provide supporting and positioning, so that the length of the water pump is greatly reduced, the number of parts and the cost are reduced, and the structural compactness design of the water pump is realized.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the invention provides a centrifugal fresh water pump with a diesel engine, which comprises a volute, an impeller, a water pump shaft, a driving gear and a water inlet end cover, wherein the impeller is arranged at one end of the water pump shaft and is positioned in the volute, the other end of the water pump shaft extends out of the volute, and the driving gear is arranged and used for forming a gear pair with a gear train of the diesel engine to drive the water pump to work. The water-cooled bearing is arranged in an inner hole of the inner cavity of the volute on one side of the impeller, a check ring is arranged at an orifice to axially limit the outer ring of the water-cooled bearing, and the end surface of the outer ring of the bearing abuts against the bottom surface of the inner hole; the water pump shaft is provided with a step excircle, a bearing inner ring of the water-cooled bearing is arranged on the step excircle and is abutted against the end face of the step, and the other end of the water-cooled bearing compresses the impeller through a locking nut and also compresses the bearing inner ring, so that a positioning structure of the water-cooled bearing in the inner cavity at one side of the impeller is formed.

Furthermore, the water-cooled bearing can be arranged in a step inner hole designed in the inner cavity of the water inlet end cover at one side of the impeller, and the end surface of the outer ring of the bearing is abutted against the bottom surface of the inner hole; the bearing inner ring is arranged on the outer circle of the step on the side, close to the water inlet end cover, of the impeller and is close to the end face of the step, and therefore a water-cooling bearing positioning structure of inner cavities on two sides of the impeller is formed.

According to the invention, the water-cooled bearing is selected according to the working characteristics of the water pump, when the water pump works, the impeller can generate radial force and axial force, the bearing for supporting and positioning needs to have the capability of bearing stress in two directions, and the water-cooled bearings of the deep groove ball bearing, the angular contact bearing and the self-aligning bearing all have the capability, so that the technical problem of stress of the impeller can be solved by selecting the water-cooled bearings of the types.

The working medium of the centrifugal fresh water pump of the diesel engine is treated fresh water, and when the water pump works, the inner cavities at two sides of the impeller belong to a high-pressure area, so that sufficient cooling, lubricating and flushing capabilities can be provided for the water-cooled bearing.

The method has the advantages that the water-cooled bearing is applied, the impeller is used as a supporting and positioning structure, the inner cavity space of the water-cooled bearing and the water pump is fully utilized, the structure of the diesel engine with the centrifugal fresh water pump is more compact, compared with the traditional design method, the method has the advantages of less parts and light weight, the material and production cost are reduced, meanwhile, the bearing is lubricated by water cooling instead of the traditional lubricating oil, the consumption and pollution of the lubricating oil can be effectively prevented, and the method meets the requirements of green economy.

Drawings

FIG. 1 is a schematic structural view of a water-cooled bearing;

FIG. 2 shows a positioning structure of a water-cooled bearing in the inner cavity of one side of the impeller;

FIG. 3 shows the overall structure of a water-cooled bearing designed in the inner cavity on one side of the impeller;

FIG. 4 shows positioning structures of water-cooled bearings arranged in inner cavities at two sides of the impeller;

FIG. 5 shows the overall structure of the water-cooled bearing designed in the inner cavity at both sides of the impeller.

In the figure, 1-impeller 2-volute 3-retainer ring 4-volute inner hole 5-water pump shaft step excircle 6-water pump shaft 7-water cooling bearing A8-water cooling bearing B9-impeller locking nut 10-mechanical seal 11-rotating shaft lip seal 12-driving gear 13-gear locking nut 14-positioning excircle 15-bolt hole 16-fault diagnosis hole 17-water inlet end cover 18-impeller one side step excircle 19-impeller other side step excircle.

Detailed Description

The invention is further illustrated by the following examples in conjunction with the accompanying drawings:

the core of the invention is to use a water-cooled bearing and use an impeller to replace a water pump shaft for supporting and positioning. Therefore, the water-cooled bearing of the deep groove ball bearing, the angular contact bearing or the self-aligning bearing type can be selected, the bearing structure is shown in figure 1 and comprises a bearing inner ring 71, a roller 72, a retainer 73 and a bearing outer ring 74, the inner ring and the outer ring are made of duplex stainless steel, the roller is made of ceramic, and the retainer is made of graphite or graphite soaked in metal, so that the water-cooled bearing is ensured to have the capabilities of self-lubrication and small friction heating, and the technical problem of insufficient lubricating property of a working medium is solved.

The present invention may have the following two configurations as shown in the embodiments.

Embodiment 1, impeller side inner chamber water-cooling bearing location structure, its structure is as shown in fig. 2 and 3.

As shown in fig. 2, the structure is that a water-cooled bearing A7 and a water-cooled bearing B are arranged on the same side of the impeller. An inner hole is designed in the inner cavity of the volute 2 on one side of the impeller 1, a check ring 3 is designed at an orifice, and the bearing outer ring 74 of the water-cooled bearing is axially limited; the bearing outer ring 74 is arranged in the inner hole, and the end surface of the bearing outer ring is close to the bottom surface of the inner hole; the water pump shaft is provided with a step excircle 5, a bearing inner ring 71 is arranged on the excircle and is abutted against the end face of the step, the other end of the bearing inner ring presses the impeller 1 through an impeller locking nut 9, and the bearing inner ring 71 is also pressed at the same time, so that a water-cooling bearing positioning structure of an inner cavity at one side of the impeller 1 is formed.

The general structure of the water pump is shown in fig. 3, a mechanical seal 10 and a rotary shaft lip seal 11 are sequentially designed at the other ends of the water-cooled bearings A and B to respectively seal a working medium and lubricating oil, and a fault diagnosis hole 16 is designed between the two sealing elements for judging the damage of the sealing elements. The farthest position is provided with a driving gear 12 of the water pump, and a gear train of the diesel engine and the driving gear of the water pump form a gear pair to drive the water pump to work. The water pump shell is provided with a positioning excircle 14 and a bolt hole 15, so that the matching and locking of the water pump and the diesel engine are ensured.

Embodiment 2, impeller both sides inner chamber water-cooling bearing location structure

As shown in fig. 4, this structure is such that water-cooled bearings A7 and B are provided on both sides of the impeller. Specifically, a step inner hole is designed in the inner cavity of a water inlet end cover 17 at one side of an impeller 1, a bearing outer ring is arranged in the inner hole, and the end surface of the bearing outer ring is abutted against the bottom surface of the inner hole; the impeller 1 is provided with a step outer circle 18 at one side, and a bearing inner ring is arranged on the outer circle and is abutted against the end face of the step. The inner cavity of the volute 2 at the other side of the impeller 1 is provided with a step inner hole, the outer ring of the bearing is arranged in the inner hole, and the end surface of the bearing is abutted against the bottom surface of the inner hole; the impeller 1 is designed with a step excircle 19 at the other side, and a bearing inner ring is arranged on the excircle and is abutted against the end face of the step.

The overall structure of the water pump is shown in fig. 5, a mechanical seal 10 and a rotary shaft lip seal 11 are sequentially designed on a water pump shaft 6 far away from an impeller to respectively seal a working medium and lubricating oil, and a fault diagnosis hole 16 is designed between two sealing elements and used for judging the damage of the sealing elements. The farthest position is provided with a driving gear 12 of the water pump, and a gear train of the diesel engine and the driving gear of the water pump form a gear pair to drive the water pump to work. The water pump shell is provided with a positioning excircle 14 and a bolt hole 15, so that the matching and locking of the water pump and the diesel engine are ensured.

Therefore, the novel rolling bearing is arranged on the two sides of the impeller by abandoning the structure that the conventional rolling bearing is arranged on the bearing seat of the traditional centrifugal fresh water pump, making full use of the working characteristics of the impeller due to the fact that the novel rolling bearing can work in the medium such as water, liquid nitrogen and the like, reducing the number of parts and achieving the purpose of compact structural design.

Claims

1. A centrifugal fresh water pump, comprising a volute, an impeller, a water pump shaft, a drive gear and a water inlet end cover, the impeller is mounted on one end of the water pump shaft and located in the volute, and the other end of the water pump shaft extends out of the volute , Install the drive gear, the drive gear is used to form a gear pair with the gear train of the diesel engine, and drive the water pump to work; it is characterized in that a group of water-cooled bearings are also provided; the water-cooled bearings are installed in the inner cavity of the volute on one side of the impeller. In the hole, the orifice is provided with a retaining ring to limit the axial position of the bearing outer ring of the water-cooled bearing, and the end face of the bearing outer ring is close to the bottom surface of the inner hole; Installed on the outer circle of the step and close to the end face of the step, the other end of the water-cooled bearing presses the impeller through the lock nut, and also presses the inner ring of the bearing, thus forming the water-cooled bearing positioning structure in the inner cavity of the impeller.

2 . The centrifugal fresh water pump according to claim 1 , wherein another group of water-cooled bearings is also provided, and this group of water-cooled bearings is installed in the stepped inner hole of the inner cavity design of the water inlet end cover on the other side of the impeller. 3 . The end face of the outer ring of the bearing is close to the bottom surface of the inner hole, and the inner ring of the bearing is installed on the outer circle of the step on the side of the impeller close to the water inlet end cover and close to the end face of the step, thus forming the water-cooled bearing positioning structure on both sides of the impeller .

3. The centrifugal fresh water pump according to claim 1 or 2, characterized in that, a mechanical seal and a rotary shaft lip seal are sequentially designed on the water pump shaft away from the impeller direction to seal the working medium and the lubricating oil respectively.

4. The centrifugal fresh water pump according to claim 3, characterized in that a fault diagnosis hole is provided on the volute, leading to between the two sealing elements of the mechanical seal and the lip seal of the rotating shaft, for identifying the sealing element of damage.

5 . The centrifugal fresh water pump according to claim 3 , wherein the water-cooled bearing is a deep groove ball bearing, an angular contact bearing or a self-aligning bearing. 6 .