Mechanical water pump and assembling method thereof

Abstract

The invention provides a mechanical water pump and an assembling method thereof.The mechanical water pump comprises a pump body, a pump cover, a driving shaft, a bearing, an impeller and a water seal, the water seal comprises a water seal moving ring body and a water seal static ring body, the upper end face of the pump body is a pump cover combination face, a stepped shaft hole is formed in the pump body, and three annular stepped faces are arranged in the pump body around the stepped shaft hole; an impeller working height measuring surface, a moving ring press-fitting positioning surface and a static ring limiting surface are sequentially arranged from top to bottom; the pump cover junction surface, the impeller working height measuring surface, the moving ring press-fitting positioning surface and the static ring limiting surface are all finish machining surfaces and are parallel to one another; the static ring limiting surface is used for axially limiting the water seal static ring body; a gap is reserved between the upper end face of the water seal static ring body and the lower end face of the water seal moving ring body, the upper end face of the water seal moving ring body and the lower end face of the impeller are in contact fit, and a gap is reserved between the lower end face of the impeller and the working height measuring face of the impeller, so that the working height of the water seal and the working height of the impeller meet requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the cooling system of automobile engine, specifically relates to a mechanical water pump and an assembling method thereof. BACKGROUND

[0002] With the continuous development and upgrading of diesel engine technology, the requirements for reliability and installation structure of diesel engine are also increasing at present. On the basis of ensuring the reliability requirement, the cooling water pump assembled on the engine also requires compact structure and small size. At this time, the key parts such as water seal and impeller need to be connected by interference fit to realize torque transmission, and the interference fit torque transmission method puts higher requirements on the machining precision of parts. The existing water pump usually includes a pump body, a driving shaft, a bearing, an impeller and a water seal, wherein the driving shaft and the bearing are respectively interference fit and pressed into the pump body, and then the water seal static ring body, the water seal dynamic ring body and the impeller are respectively pressed in the area where the cooling liquid flows through the water pump. In addition to ensuring the working height H of the water seal and the working height L of the impeller after pressing the above-mentioned parts, the lower end surface of the impeller and the upper end surface of the water seal dynamic ring body also need to be ensured to be in close contact, so that the impeller, the driving shaft and the water seal dynamic ring body form a whole rotation, and the relative rotation of the water seal dynamic ring body is avoided, and the reliability is improved. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a mechanical water pump and an assembling method thereof, which can ensure that the lower end surface of the impeller and the upper end surface of the water seal dynamic ring body are in close contact, and the working height of the water seal and the working height of the impeller meet the requirements.

[0004] In order to solve the above technical problems, the present application adopts the following technical scheme: a mechanical water pump, comprising a pump body, a pump cover, a driving shaft, a bearing, an impeller and a water seal, the water seal comprising a water seal dynamic ring body and a water seal static ring body, the upper end surface of the pump body being a pump cover joint surface, the pump body being provided with a stepped shaft hole, and three annular stepped surfaces being provided around the stepped shaft hole in the pump body, from top to bottom being an impeller working height measuring surface, a dynamic ring pressing and assembling positioning surface and a static ring limiting surface; the pump cover joint surface, the impeller working height measuring surface, the dynamic ring pressing and assembling positioning surface and the static ring limiting surface are all precision machined surfaces and are parallel to each other; the static ring limiting surface is used for axially limiting the water seal static ring body; the lower end surface of the water seal static ring body is in contact with the static ring limiting surface, a gap is left between the upper end surface of the water seal static ring body and the lower end surface of the water seal dynamic ring body, the upper end surface of the water seal dynamic ring body is in contact with the lower end surface of the impeller, and a gap is left between the lower end surface of the impeller and the impeller working height measuring surface.

[0005] The present application relates to an assembling method of a mechanical water pump, comprising the following steps:

[0006] S1 The pump cover joint surface on the pump body is finished as the impeller press-fitting positioning surface, and the impeller working height measuring surface, the dynamic ring press-fitting positioning surface, and the static ring limiting surface are finished with the pump cover joint surface as the reference;

[0007] S2 The driving shaft and the bearing are installed into the stepped shaft hole of the pump body;

[0008] S3 The water seal static ring body is press-fitted into the stepped shaft hole of the pump body in an interference fit, the lower end surface of the water seal static ring body is in contact with the static ring limiting surface, and the inner hole of the water seal static ring body is in clearance fit with the driving shaft;

[0009] S4 The water seal dynamic ring body is press-fitted onto the driving shaft through the shaft hole in an interference fit, and a gap is left between the end surface of the water seal dynamic ring body and the upper end surface of the water seal static ring body;

[0010] S5 The impeller is press-fitted onto the driving shaft through the shaft hole in an interference fit, when the impeller is pressed down to the lower end surface in contact with the water seal dynamic ring body, the impeller is further pressed down, the lower end surface of the impeller transmits the force to the water seal dynamic ring body, and the water seal dynamic ring body is further moved down by a certain distance, so that the gap between the lower end surface of the water seal dynamic ring body and the upper end surface of the water seal static ring body is reduced, and a gap is left between the lower end surface of the impeller and the impeller working height measuring surface.

[0011] Preferably, in step S4, the water seal dynamic ring body is press-fitted onto the driving shaft through the shaft hole in an interference fit, and a gap of 0.4-0.5 mm is left between the end surface of the water seal dynamic ring body and the upper end surface of the water seal static ring body; in step S5, when the impeller drives the water seal dynamic ring body to further move down by a certain distance, the gap between the lower end surface of the water seal dynamic ring body and the upper end surface of the water seal static ring body is reduced to 0.2-0.3 mm.

[0012] Further, in step S4, the press-fitting of the water seal dynamic ring body is completed by a press-fitting sleeve, the press-fitting sleeve is provided with a longitudinal stepped through hole connected by an upper small hole section and a lower large hole section, a step surface is formed at the connection of the small hole section and the large hole section, the small hole section is in clearance fit with the driving shaft, the large hole section is in clearance fit with the water seal dynamic ring body, the depth of the large hole section is greater than the height of the water seal dynamic ring body, the press-fitting sleeve drives the water seal dynamic ring body to move from top to bottom until the lower end surface of the press-fitting sleeve is in contact with the dynamic ring press-fitting positioning surface, and a gap of 0.4-0.5 mm is left between the lower end surface of the water seal dynamic ring body and the upper end surface of the water seal static ring body.

[0013] Furthermore, in step S5, the impeller is pressed by an impeller pressing device, which is composed of a positioning disc and a pressing shaft. The positioning disc has an axial hole, and the pressing shaft includes a lower cylinder and an upper limiting boss. The lower end face of the cylinder is provided with a blind hole, the diameter of the cylinder is smaller than the aperture of the positioning disc axial hole, the diameter of the limiting boss is larger than the aperture of the positioning disc axial hole, and the aperture of the blind hole is larger than the diameter of the driving shaft; the lower surface of the positioning disc is provided with a positioning structure that cooperates with the pump body to ensure that the axial hole of the positioning disc and the driving shaft are located on the same axial center line On the upper part, the cylinder of the pressure shaft and the axial hole of the positioning disc are matched with a small gap, and the pressure shaft can move up and down relative to the positioning disc. Under the action of external force, the lower end face of the pressure shaft contacts the upper end face of the impeller, thereby pushing the impeller to move downward along the active shaft. When the impeller is pressed down until its lower end face contacts the water seal dynamic ring body, it continues to be pressed downward. The lower end face of the impeller will transmit the force to the water seal dynamic ring body, and drive the water seal dynamic ring body to continue to move down a certain distance until the limiting boss of the pressure shaft contacts the positioning disc. At this time, there is a gap of 0.2~0.3mm between the lower end face of the water pump dynamic ring body and the upper end face of the water seal static ring body.

[0014] The beneficial effects of the present invention are as follows: since the lower end face of the water seal static ring body is in contact with the static ring limit surface, a gap is left between the upper end face of the water seal static ring body and the lower end face of the water seal dynamic ring body, the upper end face of the water seal dynamic ring body is in contact with the lower end face of the impeller, and a gap is left between the lower end face of the impeller and the impeller working height measuring surface, so that the water seal working height H and the impeller working height L can be guaranteed, and the lower end face of the impeller can be ensured to fit the upper end face of the water seal dynamic ring body, so that the three parts of the impeller, the driving shaft and the water seal dynamic ring body can rotate as a whole, avoiding relative rotation of the water seal dynamic ring body and improving reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the overall structure of the water pump in an embodiment of the present invention;

[0016] Figure 2 Schematic diagram of a partial cross-sectional structure of a pump body in an embodiment of the present invention;

[0017] Figure 3 Schematic diagram of the structure of the water pump when press-fitting the water seal dynamic ring body in an embodiment of the present invention;

[0018] Figure 4 Schematic diagram of the structure of the press-fit sleeve in an embodiment of the present invention;

[0019] Figure 5 Schematic diagram of the structure of the water pump when the impeller is press-fitted in an embodiment of the present invention;

[0020] Figure 6 Schematic diagram of the structure of the impeller press-fitting device in an embodiment of the present invention;

[0021] Reference signs are:

[0022] 1, pump body; 2, water seal; 2.1, water seal moving ring body; 2.2, water seal static ring body; 3, driving shaft; 4, impeller; 5, bearing; 6, pump cover; 7, fastening bolt; 8, press fitting sleeve; 9, impeller press fitting device; 9.1, press shaft; 9.2, positioning disc; A, pump cover joint surface; B, impeller working height measuring surface, C, moving ring press fitting positioning surface, D, static ring limiting surface. DETAILED DESCRIPTION

[0023] For the convenience of those skilled in the art, the present application will be further described below in conjunction with the embodiments and the accompanying drawings, and the content mentioned in the embodiments is not a limitation of the present application.

[0024] It should be pointed out in advance that in the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0025] As shown in Figure 1 , 2 A mechanical water pump, comprising a pump body 1, a pump cover 6, a driving shaft 3, a bearing 5, an impeller 4 and a water seal 2, the water seal 2 comprising a water seal moving ring body 2.1 and a water seal static ring body 2.2, the upper end surface of the pump body 1 being a pump cover joint surface A, the pump body 1 being provided with a stepped shaft hole, and three annular stepped surfaces being provided around the stepped shaft hole in the pump body 1, from top to bottom being an impeller working height measuring surface B, a moving ring press fitting positioning surface C and a static ring limiting surface D; the pump cover joint surface A, the impeller working height measuring surface B, the moving ring press fitting positioning surface C and the static ring limiting surface D are all finish machining surfaces and are parallel to each other; the static ring limiting surface D is used for axially limiting the water seal static ring body 2.2; the lower end surface of the water seal static ring body 2.2 is in contact with the static ring limiting surface D, a gap is left between the upper end surface of the water seal static ring body 2.2 and the lower end surface of the water seal moving ring body 2.1, the upper end surface of the water seal moving ring body 2.1 is in contact with the lower end surface of the impeller 4, and a gap is left between the lower end surface of the impeller 4 and the impeller working height measuring surface B.

[0026] The assembly method of the above-mentioned mechanical water pump comprises the following steps:

[0027] S1, finish machining the pump cover joint surface A on the pump body 1, taking it as the impeller press fitting positioning surface, and then finish machining the impeller working height measuring surface B, the moving ring press fitting positioning surface C and the static ring limiting surface D with the pump cover joint surface A as the reference;

[0028] S2 install the driving shaft 3 and the bearing 5 into the stepped shaft hole of the pump body 1;

[0029] S3 press the water seal static ring body 2.2 into the stepped shaft hole of the pump body 1 in an interference fit, the lower end surface of the water seal static ring body 2.2 is in contact with the static ring limiting surface D, and the inner hole of the water seal static ring body 2.2 is in clearance fit with the driving shaft 3;

[0030] S4 the water seal dynamic ring body 2.1 is pressed onto the driving shaft 3 through its shaft hole in an interference fit, and a gap of 0.4-0.5mm is left between the end surface of the water seal dynamic ring body 2.1 and the upper end surface of the water seal static ring body 2.2;

[0031] S5 the impeller 4 is pressed onto the driving shaft 3 through its shaft hole in an interference fit, when the impeller 4 is pressed down to the point where its lower end surface is in contact with the water seal dynamic ring body 2.1, further pressing down is needed, the lower end surface of the impeller 4 will transmit the force to the water seal dynamic ring body 2.1 and drive the water seal dynamic ring body 2.1 to move down a certain distance, so that the gap between the lower end surface of the water seal dynamic ring body 2.1 and the upper end surface of the water seal static ring body 2.2 is reduced by 0.2-0.3mm, at this time, a gap is left between the lower end surface of the impeller 4 and the impeller working height measuring surface B.

[0032] As shown in Figure 3 , 4 , in step S4, the pressing of the water seal dynamic ring body 2.1 is completed through a pressing sleeve 8, the pressing sleeve 8 is provided with a longitudinal stepped through hole, the stepped through hole is connected by an upper small hole section and a lower large hole section, a step surface is formed at the connection between the small hole section and the large hole section, the small hole section is in clearance fit with the driving shaft 3, the large hole section is in clearance fit with the water seal dynamic ring body 2.1, the depth of the large hole section is greater than the height of the water seal dynamic ring body 2.1, the pressing sleeve 8 drives the water seal dynamic ring body 2.1 to move from top to bottom until the lower end surface of the pressing sleeve 8 is in contact with the dynamic ring pressing positioning surface C, at this time, a gap of 0.4-0.5mm is left between the lower end surface of the water pump dynamic ring body and the upper end surface of the water seal static ring body 2.2.

[0033] As shown in Figure 5 , 6As shown, in step S5, the pressing of the impeller 4 is completed by an impeller pressing device 9, which is combined by a positioning disc 9.2 and a pressing shaft 9.1, the positioning disc 9.2 is provided with a shaft hole, the pressing shaft 9.1 includes a lower cylinder and an upper limiting boss, the lower end surface of the cylinder is provided with a blind hole, the diameter of the cylinder is smaller than the hole diameter of the shaft hole of the positioning disc 9.2, the diameter of the limiting boss is larger than the hole diameter of the shaft hole of the positioning disc 9.2, and the hole diameter of the blind hole is larger than the diameter of the driving shaft 3; the lower surface of the positioning disc 9.2 is provided with a positioning structure matched with the pump body 1, so as to ensure that the shaft hole of the positioning disc 9.2 is located on the same axial line as the driving shaft 3, the cylinder of the pressing shaft 9.1 is in small gap fit with the shaft hole of the positioning disc 9.2, the pressing shaft 9.1 can move up and down relative to the positioning disc 9.2, under the action of external force, the lower end surface of the pressing shaft 9.1 is in contact with the upper end surface of the impeller 4, and then the impeller 4 is pushed to move downward along the driving shaft 3, when the impeller 4 is pressed to the lower end surface in contact with the water seal dynamic ring body 2.1, the impeller 4 is continuously pressed downward, the lower end surface of the impeller 4 transmits the force to the water seal dynamic ring body 2.1, and drives the water seal dynamic ring body 2.1 to move downward by a certain distance, until the limiting boss of the pressing shaft 9.1 is in contact with the positioning disc 9.2, at this time, the gap between the lower end surface of the water pump dynamic ring body and the upper end surface of the water seal static ring body 2.2 is 0.2-0.3mm.

[0034] Due to the contact and cooperation between the lower end surface of the water seal static ring body 2.2 and the static ring limiting surface D, the gap between the upper end surface of the water seal static ring body 2.2 and the lower end surface of the water seal dynamic ring body 2.1, and the contact and cooperation between the upper end surface of the water seal dynamic ring body 2.1 and the lower end surface of the impeller 4, the gap between the lower end surface of the impeller 4 and the impeller working height measuring surface B, so as to ensure the working height H of the water seal 2 and the working height L of the impeller 4, and ensure the fit between the lower end surface of the impeller 4 and the upper end surface of the water seal dynamic ring body 2.1, so that the impeller 4, the driving shaft 3 and the water seal dynamic ring body 2.1 form a whole rotation, avoid the relative rotation of the water seal dynamic ring body 2.1, and improve the reliability.

[0035] The above embodiment is the preferred implementation scheme of the present application, in addition to this, the present application can also be realized in other ways, any obvious replacement without departing from the technical scheme concept of the present application is within the protection scope of the present application.

[0036] In order for those skilled in the art to more conveniently understand the improvements of the present application over the prior art, some drawings and descriptions of the present application have been simplified, and some other elements have been omitted in the present application file for the sake of clarity, those skilled in the art should realize that these omitted elements can also constitute the content of the present application.

Claims

1. A mechanical water pump, comprising a pump body (1), a pump cover (6), a driving shaft (3), a bearing (5), an impeller (4), and a water seal (2), wherein the water seal (2) comprises a water seal dynamic ring body (2.1) and a water seal static ring body (2.2), and the upper end surface of the pump body (1) is a pump cover joint surface (A), characterized in that: The pump body (1) is provided with a stepped shaft hole, and three annular stepped surfaces are provided around the stepped shaft hole in the pump body (1), which are, from top to bottom, an impeller working height measuring surface (B), a dynamic ring press-fitting positioning surface (C), and a static ring limiting surface (D); the pump cover joint surface (A), the impeller working height measuring surface (B), the dynamic ring press-fitting positioning surface (C), and the static ring limiting surface (D) are all precision-machined surfaces and are parallel to each other; the static ring limiting surface (D) is used to axially limit the water seal static ring body (2.2); the lower end surface of the water seal static ring body (2.2) contacts and cooperates with the static ring limiting surface (D), and a gap is left between the upper end surface of the water seal static ring body (2.2) and the lower end surface of the water seal dynamic ring body (2.1); the upper end surface of the water seal dynamic ring body (2.1) contacts and cooperates with the lower end surface of the impeller (4), and a gap is left between the lower end surface of the impeller (4) and the impeller working height measuring surface (B).

2. A method for assembling a mechanical water pump according to claim 1, characterized in that: The following steps are involved: S1: Fine-machine the pump cover joint surface (A) on the pump body (1) and use it as the impeller (4) press-fit positioning surface. Then, based on the pump cover joint surface (A), fine-machine the impeller working height measurement surface (B), the dynamic ring press-fit positioning surface (C), and the static ring limit surface (D). S2 Install the driving shaft (3) and bearing (5) into the stepped shaft hole of the pump body (1); S3 Press the water seal static ring body (2.2) into the stepped shaft hole of the pump body (1) in an interference fit manner, with the lower end surface of the water seal static ring body (2.2) in contact with the static ring limit surface (D), and the inner hole of the water seal static ring body (2.2) and the driving shaft (3) in a clearance fit; The S4 water seal dynamic ring body (2.1) is press-fitted onto the driving shaft (3) through its shaft hole in an interference fit manner, and a gap is left between the end face of the water seal dynamic ring body (2.1) and the upper end face of the water seal static ring body (2.2); The S5 impeller (4) is press-fitted onto the driving shaft (3) through its shaft hole in an interference fit manner. When the impeller (4) is pressed down until its lower end surface contacts the water seal dynamic ring body (2.1), it is pressed further downward. The lower end surface of the impeller (4) transmits the force to the water seal dynamic ring body (2.1), and drives the water seal dynamic ring body (2.1) to continue to move downward a certain distance, so that the gap between the lower end surface of the water seal dynamic ring body (2.1) and the upper end surface of the water seal static ring body (2.2) is reduced. At this time, a gap is left between the lower end surface of the impeller (4) and the impeller working height measurement surface (B).

3. The assembly method of the mechanical water pump according to claim 2, characterized in that: In step S4, the water seal dynamic ring body (2.1) is press-fitted onto the driving shaft (3) through its axial hole in an interference fit manner, and a gap of 0.4-0.5 mm is left between the end face of the water seal dynamic ring body (2.1) and the upper end face of the water seal static ring body (2.2); in step S5, when the impeller (4) drives the water seal dynamic ring body (2.1) to continue to move downward a certain distance, the gap between the lower end face of the water seal dynamic ring body (2.1) and the upper end face of the water seal static ring body (2.2) is reduced to 0.2-0.3 mm.

4. The assembly method of the mechanical water pump according to claim 3, characterized in that: In step S4, the press-fitting of the water seal dynamic ring body (2.1) is completed by a press-fitting sleeve (8), wherein the press-fitting sleeve (8) is provided with a longitudinal stepped through hole, wherein the stepped through hole is formed by connecting an upper small hole section and a lower large hole section, wherein a step surface is formed at the connection between the small hole section and the large hole section, wherein the small hole section is clearance-matched with the driving shaft (3), and the large hole section is clearance-matched with the water seal dynamic ring body (2.1), and the depth of the large hole section is greater than the height of the water seal dynamic ring body (2.1), and the press-fitting sleeve (8) pushes the water seal dynamic ring body (2.1) to move from top to bottom until the lower end face of the press-fitting sleeve (8) contacts the dynamic ring press-fitting positioning surface (C), and at this time, a gap of 0.4-0.5 mm is left between the lower end face of the water pump dynamic ring body and the upper end face of the water seal static ring body (2.2).

5. The assembly method of the mechanical water pump according to claim 2 or 3, characterized in that: In step S5, the impeller (4) is pressed and installed by an impeller pressing device (9), which is composed of a positioning disc (9.2) and a pressing shaft (9.1), wherein the positioning disc (9.2) has an axial hole, and the pressing shaft (9.1) includes a lower cylinder and an upper limiting boss, and a blind hole is provided on the lower end face of the cylinder, wherein the diameter of the cylinder is smaller than the aperture of the axial hole of the positioning disc (9.2), the diameter of the limiting boss is larger than the aperture of the axial hole of the positioning disc (9.2), and the aperture of the blind hole is larger than the diameter of the driving shaft (3); the lower surface of the positioning disc (9.2) is provided with a positioning structure that matches the pump body (1), ensuring that the axial hole of the positioning disc (9.2) and the driving shaft (3) are located on the same axis, and the pressing shaft (9.1) The cylindrical body and the axial hole of the positioning disc (9.2) are matched with each other with a small gap, and the pressure shaft (9.1) can move up and down relative to the positioning disc (9.2). Under the action of external force, the lower end face of the pressure shaft (9.1) contacts the upper end face of the impeller (4), thereby pushing the impeller (4) to move downward along the driving shaft (3). When the impeller (4) is pressed down until its lower end face contacts the water seal dynamic ring body (2.1), it continues to be pressed downward. The lower end face of the impeller (4) will transmit the force to the water seal dynamic ring body (2.1), and drive the water seal dynamic ring body (2.1) to continue to move downward a certain distance until the limiting boss of the pressure shaft (9.1) contacts the positioning disc (9.2). At this time, a gap of 0.2~0.3mm is left between the lower end face of the water pump dynamic ring body and the upper end face of the water seal static ring body (2.2).

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