Connecting structure of impeller and motor in centrifugal pump

Abstract

The utility model provides a connecting structure of an impeller and a motor in a centrifugal pump, and belongs to the technical field of water pumps. The problem that an existing centrifugal pump is short in service life is solved. The connecting structure of the impeller and the motor in the centrifugal pump comprises a pump shell arranged on the front side of the motor, the impeller and a transmission shaft are arranged in the pump shell, the impeller is fixed to the front end of the transmission shaft, the rear side of the pump shell is open, a mechanical seal is installed on the transmission shaft, a sealing cover for sealing the opening is fixed to the rear side of a pump cover, and a cavity is formed in the sealing cover; a first through hole and a second through hole are formed in the front side and the rear side of the sealing cover correspondingly and communicate with the cavity. The rear end of the transmission shaft sequentially penetrates through the first through hole and the cavity and extends into the second through hole. The front end of the motor spindle extends into the second through hole and is in matched connection with the transmission shaft through a flat key or a spline. Two ends of the mechanical seal respectively act on the front side of the sealing cover and the impeller; the transmission shaft is rotationally matched with the inner wall of the through hole II through a bearing. The service life of the centrifugal pump can be prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of water pumps and relates to a centrifugal pump, in particular to a connection structure between an impeller and a motor in a centrifugal pump. Background Art

[0002] A centrifugal pump is a pump that uses the centrifugal force generated by the rotation of the impeller to transport liquid.

[0003] Existing centrifugal pumps, such as a split pipeline centrifugal pump disclosed in the China Patent Library (application number: 201420044010.0), include a pump body, an impeller, a pump shaft, a motor, a machine seal, and a bearing. The motor is fixedly connected to the pump body by a connecting flange, and the connecting flange is sealed to the pump body. The machine seal and the bearing are installed between the pump shaft and the connecting flange. The lower end of the pump shaft is fixedly connected to the impeller through a blade cap. Mainly, a coupling is fixedly installed on the upper end of the pump shaft. The coupling is a cylindrical structure. The lower end surface of the cylinder is fixedly connected to the upper end of the pump shaft. A circular hole that movably cooperates with the motor shaft is formed in the center of the cylinder. A flat key is provided on the inner wall of the circular hole of the cylinder along the center line direction of the cylinder. The flat key cooperates with the keyway at the end of the motor shaft.

[0004] In the above centrifugal pump, the bearing is directly pressed on the connecting flange. When the centrifugal pump transports high-temperature fluid, the temperature of the fluid will be directly transferred to the bearing through the connecting flange, resulting in excessively high temperature at the bearing and untimely heat dissipation, which affects the life and working stability. Utility Model Content

[0005] The utility model aims to solve the above problems in the prior art and proposes a connection structure between an impeller and a motor in a centrifugal pump, and solves the technical problem of how to prolong the service life of the centrifugal pump.

[0006] The purpose of the utility model can be achieved through the following technical solutions: a connection structure between an impeller and a motor in a centrifugal pump, comprising a pump casing arranged at the front side of the motor, an impeller and a horizontally arranged transmission shaft are arranged in the pump casing, the impeller is fixed at the front end of the transmission shaft, the rear side of the pump casing is open, and a mechanical seal is installed on the transmission shaft, characterized in that a sealing cover is fixed to the rear side of the pump cover to close the above-mentioned opening, and the sealing cover has a cavity inside; a through hole 1 and a through hole 2 are respectively formed on the front and rear sides of the sealing cover, and the through hole 1, the through hole 2 and the transmission shaft are coaxially arranged, and the through hole 1 and the through hole 2 are both connected to the above-mentioned cavity; the rear end of the transmission shaft passes through the through hole 1 and the cavity in turn and extends into the through hole 2, and the front end of the motor main shaft extends into the through hole 2 and is connected to the transmission shaft through a flat key or a spline; the two ends of the mechanical seal act on the front side of the sealing cover and the impeller respectively; the transmission shaft rotates with the inner wall of the through hole 2 through a bearing.

[0007] The pump casing, pump chamber and bearing are respectively arranged on the front and rear sides of the sealing cover, and the pump casing, pump chamber and bearing are separated by a cavity formed inside the sealing cover. The cavity plays a good role in thermal insulation, thereby effectively reducing the heat transferred to the bearing when conveying high-temperature fluid. This can not only extend the life of the bearing, thereby extending the life of the centrifugal pump, but also improve the working stability of the centrifugal pump.

[0008] In the connection structure of the impeller and the motor in the centrifugal pump, the sealing cover is composed of a coaxially arranged front barrel and a rear barrel, the inner hole of the rear barrel is the through hole 2, the barrel mouth of the front barrel is arranged forward, and the through hole 1 is arranged on the barrel bottom of the front barrel, the cavity is formed between the front barrel and the rear barrel, and the front barrel closes the opening. The above design is adopted to facilitate the processing of the sealing cover.

[0009] In the connection structure of the impeller and the motor in the above-mentioned centrifugal pump, the front barrel body is inserted into the above-mentioned opening, and the outer wall of the front barrel body is in contact and sealed with the inner wall of the opening through a sealing ring to form a better sealing performance and ensure the stable operation of the centrifugal pump.

[0010] In the connection structure of the impeller and the motor in the above-mentioned centrifugal pump, the rear end of the front barrel body extends out of the pump casing, and an annular positioning seat is formed on the outer wall of the rear end of the front barrel body, and an annular flange is formed on the outer wall of the front end of the rear barrel body, the annular flange is fixedly connected to the pump casing, and the above-mentioned positioning seat is clamped and positioned between the annular flange and the pump casing, so that the positioning of the front barrel body and the overall positioning of the sealing cover are carried out simultaneously, so as to effectively reduce the assembly steps and facilitate installation.

[0011] In the connection structure between the impeller and the motor in the above-mentioned centrifugal pump, the annular flange is fixedly connected to the pump casing by a circle of screws.

[0012] In the connection structure of the impeller and the motor in the above centrifugal pump, a clearance hole for the screw to pass through is provided on the positioning seat, the shape and size of the clearance hole match the screw rod, the number of the clearance holes and the screw are the same and the positions correspond one to one. The clearance holes and the screw rod cooperate to further limit the front barrel in the circumferential direction, making the overall structure of the sealing cover more stable.

[0013] In the connection structure between the impeller and the motor in the above-mentioned centrifugal pump, a support cylinder extending backward is formed on the bottom of the front barrel body, the inner hole of the support cylinder is the above-mentioned through hole one, and the rear end of the mechanical seal extends into the through hole one and presses on the inner wall of the through hole one, which is beneficial to the installation and positioning of the mechanical seal.

[0014] In the connection structure between the impeller and the motor in the above-mentioned centrifugal pump, a circle of reinforcing ribs is formed between the outer wall of the support tube and the inner wall of the front barrel body to enhance the strength of the support tube to better support the mechanical seal.

[0015] In the connection structure of the impeller and the motor in the centrifugal pump, a heat dissipation port is vertically penetrated through the lower side of the second through hole, and the heat dissipation port is located at the rear side of the bearing. The design of the heat dissipation port is more conducive to the heat dissipation of the bearing.

[0016] Compared with the prior art, the connection structure between the impeller and the motor in the centrifugal pump has the following advantages:

[0017] 1. The pump housing, pump chamber and bearing are arranged on the front and rear sides of the sealing cover respectively, and the pump housing, pump chamber and bearing are separated by a cavity formed inside the sealing cover. The cavity plays a good role in heat preservation and heat insulation, thereby effectively reducing the heat transferred to the bearing when conveying high-temperature fluid. This can not only extend the life of the bearing, thereby extending the life of the centrifugal pump, but also improve the working stability of the centrifugal pump.

[0018] 2. The positioning seat is clamped and positioned between the annular flange and the pump housing, so that the front barrel body positioning and the sealing cover overall positioning are carried out simultaneously, so as to effectively reduce the assembly steps and facilitate installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the connection structure between the impeller and the motor in a centrifugal pump.

[0020] Figure 2 It is a three-dimensional schematic diagram of the sealing cover.

[0021] In the figure, 1, pump casing; 2, impeller; 3, transmission shaft; 4, mechanical seal; 5, sealing cover; 5a, cavity; 5b, through hole 1; 5c, through hole 2; 5d, front barrel; 5d1, positioning seat; 5d2, support cylinder; 5d3, reinforcing rib; 5e, rear barrel; 5e1, annular flange; 5e2, heat dissipation port; 6, bearing; 7, sealing ring; 8, screw; 9, motor. DETAILED DESCRIPTION

[0022] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0023] like Figure 1 As shown, the connection structure between the impeller and the motor in the centrifugal pump includes a pump housing 1 which is arranged at the front side of the motor 9 and has a pump cavity, and an impeller 2 and a transmission shaft 3 are arranged in the pump cavity.

[0024] Specifically, the rear side of the pump housing 1 is open, that is, the rear side of the pump chamber is open; the transmission shaft 3 is horizontally arranged, and the axis of the transmission shaft 3 extends forward and backward; the impeller 2 is fixed to the front end of the transmission shaft 3, and a mechanical seal 4 is installed in the middle of the transmission shaft 3, and the front end of the mechanical seal 4 is pressed on the impeller 2. Among them, the mechanical seal 4 is a prior art, and its structure and installation method are both existing, and will not be described in detail here.

[0025] like Figure 1 As shown, a sealing cover 5 is fixed to the rear side of the pump cover to close the above-mentioned opening, and the sealing cover 5 has a cavity 5a inside. The front and rear sides of the sealing cover 5 are respectively formed with a through hole 1 5b and a through hole 2 5c, and the through hole 1 5b, the through hole 2 5c and the transmission shaft 3 are coaxially arranged, and the through hole 1 5b and the through hole 2 5c are both connected to the above-mentioned cavity 5a. The rear end of the transmission shaft 3 passes through the through hole 1 5b and the cavity 5a in turn and extends into the through hole 2 5c, and the front end of the main shaft of the motor 9 extends into the through hole 2 5c and is connected to the transmission shaft 3 through a flat key or a spline. The rear end of the mechanical seal 4 is pressed on the front side of the sealing cover 5. The transmission shaft 3 is rotatably matched with the inner wall of the through hole 2 5c through the bearing 6.

[0026] The pump chamber of the pump casing 1 and the bearing 6 are respectively arranged on the front and rear sides of the sealing cover 5, and the pump chamber of the pump casing 1 and the bearing 6 are separated by a cavity 5a formed inside the sealing cover 5. The cavity 5a plays a good role in heat preservation and heat insulation, thereby effectively reducing the heat transferred to the bearing 6 when conveying high-temperature fluid. This can extend the life of the bearing 6, thereby extending the life of the centrifugal pump, and improve the working stability of the centrifugal pump.

[0027] In this embodiment,

[0028] The connection method between the transmission shaft 3 and the main shaft of the motor 9 is as follows: a flat key is set on the main shaft of the motor 9, and a keyway matching the flat key is axially opened on the rear end face of the transmission shaft 3, and the flat key and the keyway cooperate to achieve the matching of the main shaft of the motor 9 and the transmission shaft 3.

[0029] like Figure 1 and Figure 2 As shown, the structure of the sealing cover 5 is as follows: the sealing cover 5 is composed of a front barrel body 5d and a rear barrel body 5e arranged coaxially, wherein the inner hole of the rear barrel body 5e is the above-mentioned through hole 2 5c; the barrel mouth of the front barrel body 5d is arranged forward, and the through hole 1 5b is arranged on the barrel bottom of the front barrel body 5d; the cavity 5a is formed between the front barrel body 5d and the rear barrel body 5e, and the front barrel body 5d closes the above-mentioned opening, at this time, the rear end of the mechanical seal 4 is pressed on the front barrel body 5d. The above design is adopted to facilitate the processing of the sealing cover 5. Among them, the way in which the front barrel body 5d closes the above-mentioned opening is as follows: the front barrel body 5d is inserted into the above-mentioned opening, and the outer wall of the front barrel body 5d is in contact and sealed with the inner wall of the opening through the sealing ring 7 to form a better sealing performance to ensure the stable operation of the centrifugal pump.

[0030] The installation method of the front barrel body 5d and the rear barrel body 5e is as follows: the rear end of the front barrel body 5d extends out of the pump housing 1, and a ring-shaped positioning seat 5d1 is formed on the outer wall of the rear end of the front barrel body 5d, and a ring-shaped flange 5e1 is formed on the outer wall of the front end of the rear barrel body 5e. The ring-shaped flange 5e1 is fixedly connected to the pump housing 1, and the positioning seat 5d1 is clamped and positioned between the ring-shaped flange 5e1 and the pump housing 1, so that the positioning of the front barrel body 5d and the overall positioning of the sealing cover 5 are carried out simultaneously, so as to effectively reduce the assembly steps and facilitate installation. Further explanation, the ring-shaped flange 5e1 is fixedly connected to the pump housing 1 through a circle of screws 8, and the positioning seat 5d1 is provided with a clearance hole for the screw 8 to pass through. The shape and size of the clearance hole match the rod of the screw 8, and the number of the clearance holes and the screw 8 are the same and the position corresponds one by one. The clearance hole and the rod of the screw 8 cooperate to further limit the front barrel body 5d in the circumferential direction, so that the overall structure of the sealing cover 5 is more stable.

[0031] like Figure 1 As shown, a support cylinder 5d2 extending backward is formed on the bottom of the front barrel body 5d, and the inner hole of the support cylinder 5d2 is the above-mentioned through hole 1 5b. The rear end of the mechanical seal 4 extends into the through hole 1 5b and presses on the inner wall of the through hole 1 5b, which is conducive to the installation and positioning of the mechanical seal 4. Further explanation, a circle of reinforcing ribs 5d3 is formed between the outer wall of the support cylinder 5d2 and the inner wall of the front barrel body 5d to strengthen the strength of the support cylinder 5d2 to better support the mechanical seal 4.

[0032] In the actual product, a heat dissipation port 5e2 is vertically penetrated at the lower side of the through hole 2 5c, and the heat dissipation port 5e2 is located at the rear side of the bearing 6. The design of the heat dissipation port 5e2 is more conducive to the heat dissipation of the bearing 6. An annular flange is formed on the outer wall of the rear end of the rear cylinder 5e, and the rear cylinder 5e is connected to the motor 9 by the annular flange and bolts.

[0033] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A connection structure between an impeller and a motor in a centrifugal pump, comprising a pump casing (1) arranged in front of a motor (9), an impeller (2) and a horizontally arranged transmission shaft (3) arranged in the pump casing (1), the impeller (2) being fixed to the front end of the transmission shaft (3), the rear side of the pump casing (1) being open, and a mechanical seal (4) being installed on the transmission shaft (3), characterized in that: A sealing cover (5) is fixed to the rear side of the pump cover to close the above-mentioned opening, and the sealing cover (5) has a cavity (5a) inside; a through hole (5b) and a through hole (5c) are respectively formed on the front side and the rear side of the sealing cover (5); the through hole (5b), the through hole (5c) and the transmission shaft (3) are coaxially arranged, and the through hole (5b) and the through hole (5c) are both connected to the above-mentioned cavity (5a); the rear end of the transmission shaft (3) passes through the through hole (5b) and the cavity (5a) in sequence and extends into the through hole (5c); the front end of the main shaft of the motor (9) extends into the through hole (5c) and is connected to the transmission shaft (3) through a flat key or a spline; the two ends of the mechanical seal (4) act on the front side of the sealing cover (5) and the impeller (2) respectively; the transmission shaft (3) is rotatably matched with the inner wall of the through hole (5c) through a bearing (6).

2. The connection structure between the impeller and the motor in the centrifugal pump according to claim 1, characterized in that: The sealing cover (5) is composed of a front barrel body (5d) and a rear barrel body (5e) which are coaxially arranged. The inner hole of the rear barrel body (5e) is the second through hole (5c). The barrel mouth of the front barrel body (5d) is arranged to face forward, and the first through hole (5b) is arranged on the barrel bottom of the front barrel body (5d). The cavity (5a) is formed between the front barrel body (5d) and the rear barrel body (5e), ​​and the front barrel body (5d) closes the opening.

3. The connection structure between the impeller and the motor in the centrifugal pump according to claim 2, characterized in that: The front barrel body (5d) is inserted into the above-mentioned opening, and the outer wall of the front barrel body (5d) is in contact and sealed with the inner wall of the opening via a sealing ring (7).

4. The connection structure between the impeller and the motor in the centrifugal pump according to claim 3, characterized in that: The rear end of the front barrel body (5d) extends out of the pump casing (1), and an annular positioning seat (5d1) is formed on the outer wall of the rear end of the front barrel body (5d), and an annular flange (5e1) is formed on the outer wall of the front end of the rear barrel body (5e), ​​the annular flange (5e1) is fixedly connected to the pump casing (1), and the positioning seat (5d1) is clamped and positioned between the annular flange (5e1) and the pump casing (1).

5. The connection structure between the impeller and the motor in the centrifugal pump according to claim 4, characterized in that: The annular flange (5e1) is fixedly connected to the pump housing (1) by a circle of screws (8).

6. The connection structure between the impeller and the motor in the centrifugal pump according to claim 5, characterized in that: The positioning seat (5d1) is provided with a clearance hole for the screw (8) to pass through, the shape and size of the clearance hole match the rod of the screw (8), the number of the clearance holes and the screw (8) are the same and the positions correspond one to one.

7. The connection structure between the impeller and the motor in a centrifugal pump according to claim 2 or 3, characterized in that: A support cylinder (5d2) extending backward is formed on the bottom of the front barrel body (5d), the inner hole of the support cylinder (5d2) is the through hole 1 (5b) mentioned above, and the rear end of the mechanical seal (4) extends into the through hole 1 (5b) and presses on the inner wall of the through hole 1 (5b).

8. The connection structure between the impeller and the motor in a centrifugal pump according to claim 7, characterized in that: A circle of reinforcing ribs (5d3) is formed between the outer wall of the support tube (5d2) and the inner wall of the front barrel body (5d).

9. The connection structure between the impeller and the motor in a centrifugal pump according to claim 1, characterized in that: A heat dissipation port (5e2) vertically penetrates the lower side of the second through hole (5c), and the heat dissipation port (5e2) is located at the rear side of the bearing (6).

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