CN215171670U

CN215171670U - Electromagnetic clutch and water pump assembly

Info

Publication number: CN215171670U
Application number: CN202120502712.9U
Authority: CN
Inventors: 徐时聪; 张翼鹏; 樊美刚
Original assignee: Zhejiang Nessral Machinery Co ltd
Current assignee: Zhejiang Nessral Machinery Co ltd
Priority date: 2021-03-09
Filing date: 2021-03-09
Publication date: 2021-12-14
Anticipated expiration: 2031-03-09

Abstract

The utility model provides a lose electromagnetic clutch and water pump assembly belongs to mechanical technical field. The electromagnetic clutch solves the problems that the axial length in the existing electromagnetic clutch structure is too long and the like. This electromagnetic clutch loses, which comprises a rotating shaft, the belt pulley, coil iron core subassembly, the heat dissipation dish and have set gradually the coupling piece along the axial, friction disc and limiting plate, be provided with the elastic drive spare between belt pulley and the coupling piece, the elastic drive spare effect makes coupling piece and limiting plate centre gripping friction disc between the two on the coupling piece when coil iron core subassembly loses electricity, heat dissipation dish fixed connection is in the pivot, the outer edge of heat dissipation dish has to the convex collar of belt pulley on, the collar is located the periphery side of limiting plate, be fixed with the permanent magnet on the collar, be fixed with the response dish that corresponds with the collar on the outer edge of belt pulley, rotating gap has between response dish and the permanent magnet, and can produce magnetic induction between response dish and the permanent magnet. The electromagnetic clutch can shorten the axial length.

Description

Electromagnetic clutch and water pump assembly

Technical Field

The utility model belongs to the technical field of machinery, a lose electromagnetic clutch and water pump assembly is related to.

Background

When the engine operates, the cooling liquid needs to be circularly operated to dissipate heat, and the cooling liquid is conveyed by the water pump to circularly flow. When the temperature of the engine rises, the rotating speed of the water pump is increased, so that the cooling liquid is subjected to large circulation; when the temperature of the engine is low, the rotation speed of the water pump is reduced, and the coolant is circulated for a short time. In order to control the rotation of the water pump, it is common to arrange an electromagnetic clutch in the water pump, the electromagnetic clutch is connected with a controller, the controller is provided with a temperature sensor for detecting the temperature of the engine, the temperature sensor sends the detected temperature to the controller, the controller controls the electromagnetic clutch to act according to the received temperature information, the belt pulley drives the water pump rotating shaft to rotate at a high speed when the electromagnetic clutch is powered on, and the belt pulley does not drive the water pump rotating shaft to rotate or drives the water pump rotating shaft to rotate at a low speed when the electromagnetic clutch is powered off. When the water pump electromagnetic clutch with the structure is used, when the electromagnetic clutch breaks down or power failure occurs, the rotating shaft of the water pump cannot rotate, so that the engine cannot be cooled, and the engine is easily caused to be continuously in a high-temperature working state or even burnt out.

Chinese patent literature discloses a electromagnetic clutch assembly [ application number: cn201920818059. x; publication No.: 210050219U ], which comprises a rotating shaft, a belt pulley, a coil iron core assembly and a coupling piece, the coupling piece is attracted with the belt pulley through the coil iron core assembly after the power-on, fixedly connected with limiting plate on the belt pulley, the coupling piece is located between the belt pulley and the limiting plate and can axially move, the circumference is fixed with a friction plate in the rotating shaft, the friction plate is located between the coupling piece and the limiting plate and can axially slide, an elastic driving piece is arranged between the belt pulley and the coupling piece, when the coil iron core assembly loses power, the elastic driving piece acts on the coupling piece to enable the coupling piece and the limiting plate to clamp the friction plate between the coupling piece and the limiting plate.

The belt pulley passes through the rotation axis connection of drive mechanism with the engine, and the rotation axis of engine rotates and drives the belt pulley and rotate, thereby limiting plate fixed connection rotates along with the belt pulley on the belt pulley, and one of pivot is served and is connected with the water pump impeller. When the coil core assembly loses power, the coupling piece is not attracted to the belt pulley, and under the action of the elastic driving piece, the coupling piece and the limiting plate clamp the friction plate between the coupling piece and the limiting plate, so that the coupling piece, the friction plate and the limiting plate are overlapped and reach a fixed state, the belt pulley drives the rotating shaft to rotate through the friction plate and reach synchronous rotation, and the high-speed rotation of the water pump is realized. When the coil iron core assembly is electrified, the coil iron core assembly generates magnetic force to enable the coupling piece to be close to the belt pulley and to be attracted to the belt pulley, the coupling piece, the friction piece and the limiting plate are loosened, the friction piece is not fixed with the limiting plate any more, the rotation of the belt pulley cannot be transmitted to the rotating shaft, the rotating shaft does not rotate synchronously with the belt pulley, and the water pump does not rotate at a high speed any more. Therefore, when the electromagnetic clutch fails or power failure occurs, the rotating shaft of the water pump is in a high-speed rotating state, and the engine can be cooled, so that the engine is in a low-temperature working state and cannot be burnt out.

In the embodiments of the above patent documents, a heat dissipation plate fixed on the pulley and a magnet attachment plate fixed on the rotating shaft are also disclosed, and the limiting plate, the magnet attachment plate and the heat dissipation plate are sequentially arranged along the axial direction, so that the axial length of the whole electric-shock-free clutch is too long, which is not beneficial to the installation of the whole water pump in the engine compartment.

Disclosure of Invention

The utility model aims at the above-mentioned problem that prior art exists, provide a lose electromagnetic clutch and water pump assembly, the technical problem of solution is how to shorten the axial length of losing the electromagnetic clutch structure.

The purpose of the utility model can be realized by the following technical proposal:

a power-off electromagnetic clutch comprises a rotating shaft, a belt pulley, a coil iron core assembly and a heat dissipation disc, wherein an installation cavity is arranged between the belt pulley and the heat dissipation disc, a coupling sheet, a friction sheet and a limiting plate are sequentially arranged in the installation cavity along the axial direction, the coupling sheet is circumferentially fixed on the belt pulley and can axially move, the coupling sheet can be attracted with the belt pulley through the coil iron core assembly after being electrified, the friction sheet is circumferentially fixed on the rotating shaft and can axially move, the limiting plate is fixedly connected on the belt pulley, an elastic driving piece is arranged between the belt pulley and the coupling sheet, when the coil iron core assembly is powered off, the elastic driving piece acts on the coupling sheet to enable the coupling sheet and the limiting plate to clamp the friction sheet between the coupling sheet and the belt pulley, and is characterized in that the heat dissipation disc is fixedly connected on the rotating shaft, and the outer edge of the heat dissipation disc is provided with a mounting ring protruding towards the belt pulley, the utility model discloses a belt pulley, including the mounting ring, the mounting ring is located the periphery side of limiting plate, be fixed with on the mounting ring along circumference evenly distributed's several permanent magnet, be fixed with the response dish that corresponds with the mounting ring on the outer edge of belt pulley, rotating clearance has between response dish and the permanent magnet, and can produce magnetic induction between response dish and the permanent magnet.

The rotating shaft penetrates through a shell of the water pump assembly, a heat dissipation disc is fixed at one end of the rotating shaft, and an impeller is fixed at the other end of the rotating shaft. When the coil core assembly loses power, the coupling piece is not attracted to the belt pulley, the coupling piece and the limiting plate clamp the friction plate between the coupling piece and the limiting plate under the action of the elastic driving piece, and the belt pulley drives the rotating shaft to rotate through the friction plate and achieves synchronous rotation, so that the high-speed rotation of the water pump is realized. When the coil iron core assembly is powered on, the coupling piece is attracted and fixed on the belt pulley, the friction plate, the coupling piece and the limiting plate are kept in a relaxed state, the belt pulley cannot drive the rotating shaft to rotate synchronously through the coupling piece, the friction plate and the limiting plate when rotating, but the induction disc is fixed on the belt pulley and rotates synchronously with the belt pulley, the permanent magnet on the induction disc and the heat dissipation disc which can generate magnetic induction enables the belt pulley to drive the rotating shaft to rotate in a differential mode, and the rotating shaft rotates at a low speed.

The response dish is fixed on the outer edge of belt pulley, and heat dissipation dish snap-on has cancelled the original magnet that loses among the electromagnetic clutch and has attached the board, has cancelled the axial space that is taken up by magnet attached board between limiting plate and heat dissipation dish and the clearance between magnet attached board and the heat dissipation dish promptly, and the collar of fixing the permanent magnet simultaneously is located the periphery side of limiting plate, has cancelled the axial space that the permanent magnet took up between limiting plate and heat dissipation dish promptly to can shorten the axial length who loses the electromagnetic clutch. Therefore, the electromagnetic clutch can shorten the axial length, has a more compact structure and is beneficial to the installation of a water pump assembly in an engine compartment.

Simultaneously, the induction disc has lighter weight compared with the heat dissipation disc, the induction disc is fixed on the belt pulley, and the heat dissipation disc is fixed on the rotating shaft, so that the load of the belt pulley can be reduced, and the energy consumption of the belt pulley during rotation is reduced.

In foretell lose electromagnetic clutch, the belt pulley has seted up the mounting hole along the axial on the terminal surface of heat dissipation dish, the elastic drive spare is installed in the mounting hole, the belt pulley has seted up on the terminal surface of heat dissipation dish dorsad and has been the annular mounting groove, coil iron core subassembly is installed in the mounting groove, the mounting hole is located between the hole of mounting groove and belt pulley.

Set up the mounting hole between the hole of mounting groove and belt pulley, avoided the radial position that the mounting hole took when locating the outer edge of belt pulley department, and this loses the electromagnetic clutch and induces the dish and fix the outer edge department at the belt pulley, can reduce the radial dimension of response dish like this, prevent to lose electromagnetic clutch's radial dimension too big to be favorable to the installation of water pump assembly in the engine compartment.

In addition, in the conventional electromagnetic clutch, the outer diameter of the belt pulley is designed according to the requirement of the transmission torque of the belt pulley, and the overall dimension of the coil core assembly is designed according to the requirement of magnetic attraction, so that the mounting hole is greatly limited when being arranged at the outer edge of the belt pulley due to the structures of the belt pulley and the coil core assembly, the mounting hole cannot be arranged between the wheel groove and the mounting groove of the belt pulley, the axial length of the belt pulley needs to be prolonged to meet the requirement of the arrangement of the mounting hole, and the axial length of the belt pulley is overlong; this lose electromagnetic clutch mounting hole is located between the hole of mounting groove and belt pulley, does not receive the influence of belt pulley external diameter size and coil iron core subassembly overall dimension, just so can shorten the axial dimensions of belt pulley among the current lose electromagnetic clutch to make the axial length of losing electromagnetic clutch shorten, make the structure of losing electromagnetic clutch compacter, be favorable to the installation of water pump assembly in the engine compartment.

In the electromagnetic clutch, the outer edge of the induction disc is bent towards the heat dissipation disc to form a blocking edge, and the blocking edge axially extends to the outer peripheral side of the mounting ring. The blocking edge has a protection effect, so that external pollutants are reduced from entering a rotating gap and a mounting cavity, and the use stability of the electromagnetic clutch is guaranteed.

In the electromagnetic clutch, the belt pulley is provided with a clamping groove, and the inner edge of the induction disc is embedded into the clamping groove and fixed. The clamping groove has a positioning effect, so that the induction disc is fixed and stable on the belt pulley.

In the electromagnetic clutch, the installation ring is internally embedded with an annular iron plate, the end face of the installation ring facing the induction disc is provided with fixing holes, the fixing holes penetrate through the iron plate, the fixing holes are provided with a plurality of permanent magnets in one-to-one correspondence, and the permanent magnets are embedded into the fixing holes and adsorbed on the iron plate. The iron plate is arranged to enable the permanent magnets to be stably fixed in an adsorption mode, and has a magnetic conduction function to enable a magnetic field formed by the permanent magnets to be stable, and stable induction magnetic force is formed between the induction disc and the permanent magnets to enable the electromagnetic loss clutch to work stably.

The utility model provides a water pump assembly, includes casing and impeller, its characterized in that, water pump assembly still include as above lose electromagnetic clutch, the belt pulley passes through the main bearing suit on the casing, coil iron core subassembly fixed connection is on the casing, the rotatable wearing of pivot is established in the casing, impeller fixed connection is in the pivot.

Because the response dish is fixed on the outer edge of belt pulley, and heat dissipation dish snap-on has been cancelled original magnet among the electromagnetic clutch that loses attaches the board, has promptly cancelled the axial space that is occupied by magnet between limiting plate and heat dissipation dish and the clearance between magnet attaches the board and the heat dissipation dish, and the collar of fixing the permanent magnet simultaneously is located the periphery side of limiting plate, has promptly cancelled the axial space that the permanent magnet occupied between limiting plate and heat dissipation dish to can shorten the axial length of losing the electromagnetic clutch. Therefore, the electromagnetic clutch in the water pump assembly can shorten the axial length, so that the structure is more compact, and the installation of the water pump assembly in an engine compartment is facilitated.

In foretell water pump assembly, be provided with the installation department on the casing, the main bearing suit is on the installation department, be provided with on the outer peripheral face of installation department and keep off shoulder and retaining ring, the inner circle centre gripping of main bearing is fixed and is kept off between shoulder and the retaining ring, be provided with rand and convex shoulder on the hole wall of belt pulley hole, the outer lane centre gripping of main bearing is fixed between rand and convex shoulder. The two ends of the main bearing are positioned, so that the belt pulley is firmly installed.

In the water pump assembly, the casing is provided with a through hole, the rotating shaft penetrates through the through hole, one end of the rotating shaft extends out of the casing and is fixedly connected with the impeller, the other end of the rotating shaft extends out of the casing and is fixedly connected with a shaft sleeve, one end of the shaft sleeve is provided with a reinforcing ring inserted into the through hole, the outer peripheral surface of the shaft sleeve is provided with a convex connecting ring, the friction plate is connected to the connecting ring through a spline structure, and the heat dissipation disc is attached to the end surface of the connecting ring and is fixed through a bolt.

The strengthening ring can increase the structural strength of axle sleeve, makes axle sleeve stable in structure. The axial length of the rotating shaft can be shortened by inserting the reinforcing ring into the through hole, and the axial length of the electromagnetic clutch can be shortened by enabling the heat dissipation disc to be attached to the end face of the connecting ring, so that the electromagnetic clutch is compact in structure, and the water pump assembly is favorably mounted in an engine room.

Compared with the prior art, the utility model has the advantages of it is following:

the induction disc is fixed on the outer edge of the belt pulley, the mounting ring for fixing the permanent magnet is positioned on the outer peripheral side of the limiting disc, the axial length of the electromagnetic clutch is shortened, the structure of the electromagnetic clutch is compact, and the water pump assembly is favorably mounted in an engine room. The mounting hole of installation elastic drive spare is located between the hole of mounting groove and belt pulley, avoids the belt pulley axial length extension that the mounting hole arouses, and the beaded finish of axle sleeve inserts the perforation of casing, and the heat dissipation dish pastes and leans on the terminal surface of axle sleeve go-between, all makes and loses electromagnetic clutch compact structure.

Drawings

FIG. 1 is a cross-sectional view of the present water pump assembly;

fig. 2 is an enlarged view at a in fig. 1.

In the figure, 1, a housing; 1a, an installation part; 1a1, shoulder; 1a2, retaining ring; 1b, punching; 2. an impeller; 3. water sealing; 4. a rotating shaft; 5. a belt pulley; 5a, mounting holes; 5b, mounting grooves; 5c, a clamping groove; 5d, a clamping ring; 5e, shoulder; 6. a coil core assembly; 7. a heat dissipation plate; 7a, a mounting ring; 7b, iron plate; 7c, fixing holes; 7d, a permanent magnet; 8. a coupling piece; 9. a friction plate; 10. a limiting plate; 11. an elastic driving member; 12. an induction disc; 12a, a blocking edge; 13. a rotational clearance; 14. a shaft sleeve; 14a, a reinforcing ring; 14b, a connecting ring; 15. a bolt; 16. a mounting cavity; 17. and a main bearing.

Detailed Description

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

Example one

As shown in fig. 1 and 2, a water pump assembly includes a housing 1, an impeller 2, and a loss electromagnetic clutch, wherein the loss electromagnetic clutch includes a rotating shaft 4, a belt pulley 5, a coil core assembly 6, and a heat dissipation disc 7. The casing 1 is provided with a through hole 1b, the rotating shaft 4 is rotatably arranged in the through hole 1b in a penetrating mode, the rotating shaft 4 is provided with a shaft connecting bearing, and the shaft connecting bearing is arranged in the through hole 1b to enable the rotating shaft 4 to stably rotate. The left end of the rotating shaft 4 extends out of the shell 1 and then is connected with the impeller 2, a water seal 3 is further fixed on the left end of the rotating shaft 4, and the water seal 3 is located between the impeller 2 and the shaft connecting bearing. The belt pulley 5 is sleeved on the housing 1 through a main bearing 17, a mounting part 1a is arranged at the right end of the housing 1, and the main bearing 17 is sleeved on the mounting part 1a and fixed. A retaining shoulder 1a1 and a retaining ring 1a2 are respectively arranged on the outer peripheral surface of the mounting part 1a from left to right, the retaining shoulder 1a1 is integrally arranged on the mounting part 1a, the retaining ring 1a2 is clamped on the mounting part 1a, and the inner ring of the main bearing 17 is clamped and fixed between the retaining shoulder 1a1 and the retaining ring 1a 2. A collar 5d and a shoulder 5e are respectively arranged on the hole wall surface of the inner hole of the belt pulley 5 from left to right, the collar 5d is clamped on the hole wall surface of the inner hole of the belt pulley 5, the shoulder 5e is integrally arranged on the hole wall surface of the inner hole of the belt pulley 5, and the outer ring of the main bearing 17 is clamped and fixed between the collar 5d and the shoulder 5 e.

The right end of the rotating shaft 4 extends out of the shell 1 and is fixedly connected with a heat dissipation disc 7, and the heat dissipation disc 7 is positioned on the right side of the belt pulley 5. An installation cavity 16 is formed between the belt pulley 5 and the heat dissipation disc 7, and a coupling sheet 8, a friction sheet 9 and a limiting plate 10 are sequentially arranged in the installation cavity 16 from left to right along the axial direction. Coupling piece 8 circumference is fixed on belt pulley 5 and can axial displacement, and coupling piece 8 can be through the actuation of coil iron core subassembly 6 and belt pulley 5 after the circular telegram, and 9 circumference of friction disc are fixed on pivot 4 and can axial displacement, and limiting plate 10 fixed connection is on belt pulley 5. An elastic driving part 11 is arranged between the belt pulley 5 and the coupling sheet 8, and when the coil core assembly 6 is de-energized, the elastic driving part 11 acts on the coupling sheet 8 to enable the coupling sheet 8 and the limiting plate 10 to clamp the friction plate 9 between the coupling sheet 8 and the limiting plate 10. A sleeve 14 is fixedly connected to the right end of the rotating shaft 4, a reinforcing ring 14a inserted into the through hole 1b is provided at the left end of the sleeve 14, a protruding connecting ring 14b is provided on the outer circumferential surface of the sleeve 14, and the friction plate 9 is connected to the connecting ring 14b through a spline structure. The connection structure among the pulley 5, the coupling plate 8, the friction plate 9, the limit plate 10 and the bushing 14 can refer to patent document No. cn201920818059. x. The inner edge of the heat dissipation disc 7 abuts on the right end face of the connection ring 14b and is fixed by the bolt 15.

Belt pulley 5 has been seted up on the terminal surface of heat dissipation dish 7 dorsad and has been annular mounting groove 5b, and coil iron core subassembly 6 is installed in mounting groove 5b, is fixed with the mounting panel on the coil iron core subassembly 6, and mounting panel fixed connection is on casing 1. The end surface of the belt pulley 5 facing the heat dissipation disc 7 is provided with a mounting hole 5a along the axial direction, and the mounting hole 5a is positioned between the mounting groove 5b and the inner hole of the belt pulley 5. The elastic driving member 11 is installed in the installation hole 5a, and the elastic driving member 11 includes a compression spring. The mounting holes 5a are provided with a plurality of mounting holes which are evenly distributed along the circumferential direction, and each mounting hole 5a is provided with an elastic driving piece 11.

The outer edge of the heat dissipation plate 7 is provided with a mounting ring 7a protruding toward the pulley 5, and the mounting ring 7a is positioned on the outer peripheral side of the stopper plate 10. A plurality of permanent magnets 7d which are uniformly distributed along the circumferential direction are fixed on the mounting ring 7a, an induction disc 12 corresponding to the mounting ring 7a is fixed on the outer edge of the belt pulley 5, a rotating gap 13 is arranged between the induction disc 12 and the permanent magnets 7d, and magnetic induction can be generated between the induction disc 12 and the permanent magnets 7 d. The outer edge of the belt pulley 5 is provided with an annular clamping groove 5c, and the inner edge of the induction disc 12 is embedded into the clamping groove 5c and fixed. The outer edge of the induction disc 12 is bent towards the heat dissipation disc 7 to form a blocking edge 12a, and the blocking edge 12a axially extends to the outer periphery side of the mounting ring 7 a. The annular iron plate 7b is embedded in the mounting ring 7a, fixing holes 7c are formed in the end face, facing the induction disc 12, of the mounting ring 7a, the fixing holes 7c penetrate through the iron plate 7b, the fixing holes 7c are in one-to-one correspondence with the permanent magnets 7d, and the permanent magnets 7d are embedded into the fixing holes 7c and adsorbed on the iron plate 7 b.

When the coil core assembly 6 loses power, the coupling sheet 8 is not attracted to the belt pulley 5, under the action of the elastic driving piece 11, the coupling sheet 8 and the limiting plate 10 clamp the friction sheet 9 between the coupling sheet and the limiting plate, and the belt pulley 5 drives the rotating shaft 4 to rotate through the friction sheet 9 and achieve synchronous rotation, so that the high-speed rotation of the water pump is realized. When 6 circular telegrams of coil iron core group spare, 8 actuation of coupling piece are fixed on belt pulley 5, friction disc 9, keep the state of relaxing between coupling piece 8 and the limiting plate 10, can not drive pivot 4 and rotate through coupling piece 8, friction disc 9 and limiting plate 10 when belt pulley 5 rotates, because response dish 12 is fixed on belt pulley 5, response dish 12 and belt pulley 5 synchronous rotation, make belt pulley 5 drive 4 differential rotations of pivot through the response dish 12 that can produce magnetic force induction and the permanent magnet 7d on the heat dissipation dish 7, the low-speed rotation is realized to the water pump.

Because the induction disc 12 is fixed on the outer edge of the belt pulley 5, the heat dissipation disc 7 is directly fixed on the rotating shaft 4, a magnet attaching plate in the original electromagnetic clutch is cancelled, namely, the axial space occupied by the magnet attaching plate between the limiting plate 10 and the heat dissipation disc 7 and the gap between the magnet attaching plate and the heat dissipation disc 7 are cancelled, meanwhile, the mounting ring 7a for fixing the permanent magnet 7d is positioned on the outer peripheral side of the limiting plate 10, namely, the axial space occupied by the permanent magnet 7d between the limiting plate 10 and the heat dissipation disc 7 is cancelled, and therefore the axial length of the electromagnetic clutch can be shortened. Simultaneously, the mounting hole 5a is arranged between the mounting groove 5b and the inner hole of the belt pulley 5, so that the axial length of the belt pulley 5 increased for mounting the elastic driving part 11 is avoided, and the axial length of the electromagnetic clutch can be further shortened. Further, the reinforcing ring 14a of the sleeve 14 is inserted into the through hole 1b of the housing 1, and the axial length of the electromagnetic clutch can be shortened. Therefore, the electromagnetic clutch in the water pump assembly can shorten the axial length, so that the structure is more compact, and the installation of the water pump assembly in an engine compartment is facilitated.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications, additions and substitutions for the specific embodiments described herein may be made by those skilled in the art without departing from the spirit of the invention or exceeding the scope of the invention as defined in the accompanying claims.

Claims

1. The utility model provides a lose electromagnetic clutch, includes pivot (4), belt pulley (5), coil iron core subassembly (6) and heat dissipation dish (7), install cavity (16) have between belt pulley (5) and heat dissipation dish (7), have set gradually coupling piece (8), friction disc (9) and limiting plate (10) along the axial in install cavity (16), coupling piece (8) circumference is fixed on belt pulley (5) and can axial displacement, coupling piece (8) can be through coil iron core subassembly (6) and belt pulley (5) actuation after the circular telegram, friction disc (9) circumference is fixed on pivot (4) and can axial displacement, limiting plate (10) fixed connection is on belt pulley (5), be provided with elastic drive spare (11) between belt pulley (5) and coupling piece (8), when coil iron core subassembly (6) loses the electricity elastic drive spare (11) are used in coupling piece (8) and make coupling piece (8) and axial displacement Limiting plate (10) centre gripping friction disc (9) between the two, its characterized in that, heat dissipation dish (7) fixed connection is on pivot (4), the outer edge of heat dissipation dish (7) is gone up and is had to convex collar (7a) of belt pulley (5), collar (7a) are located the periphery side of limiting plate (10), be fixed with on collar (7a) along circumference evenly distributed's several permanent magnet (7d), the outer edge of belt pulley (5) is fixed with response dish (12) that correspond with collar (7a), rotating gap (13) have between response dish (12) and permanent magnet (7d), and can produce the magnetic force response between response dish (12) and permanent magnet (7 d).

2. The electromagnetic loss clutch according to claim 1, wherein the end surface of the belt pulley (5) facing the heat dissipation disc (7) is axially provided with a mounting hole (5a), the elastic driving member (11) is installed in the mounting hole (5a), the end surface of the belt pulley (5) facing away from the heat dissipation disc (7) is provided with an annular mounting groove (5b), the coil core assembly (6) is installed in the mounting groove (5b), and the mounting hole (5a) is located between the mounting groove (5b) and the inner hole of the belt pulley (5).

3. The electromagnetic loss clutch according to claim 1 or 2, characterized in that the outer edge of the induction disc (12) is bent towards the heat dissipation disc (7) to form a blocking edge (12a), and the blocking edge (12a) axially extends to the outer peripheral side of the mounting ring (7 a).

4. The electromagnetic loss clutch according to claim 1 or 2, wherein a clamping groove (5c) is formed in the belt pulley (5), and the inner edge of the induction disc (12) is embedded in the clamping groove (5c) and fixed.

5. The electromagnetic loss clutch according to claim 1 or 2, characterized in that an annular iron plate (7b) is embedded in the mounting ring (7a), a fixing hole (7c) is formed in the end face, facing the induction disc (12), of the mounting ring (7a), the fixing hole (7c) penetrates through the iron plate (7b), a plurality of fixing holes (7c) are formed and correspond to the permanent magnets (7d) in a one-to-one mode, and the permanent magnets (7d) are embedded in the fixing holes (7c) and adsorbed on the iron plate (7 b).

6. A water pump assembly comprising a housing (1) and an impeller (2), wherein the water pump assembly further comprises the electromagnetic clutch according to any one of claims 1 to 5, the belt pulley (5) is sleeved on the housing (1) through a main bearing (17), the coil core assembly (6) is fixedly connected to the housing (1), the rotating shaft (4) is rotatably inserted into the housing (1), and the impeller (2) is fixedly connected to the rotating shaft (4).

7. The water pump assembly according to claim 6, wherein the housing (1) is provided with a mounting portion (1a), the main bearing (17) is sleeved on the mounting portion (1a), a retaining shoulder (1a1) and a retaining ring (1a2) are arranged on the outer peripheral surface of the mounting portion (1a), the inner ring of the main bearing (17) is clamped and fixed between the retaining shoulder (1a1) and the retaining ring (1a2), the inner hole wall surface of the inner hole of the belt pulley (5) is provided with a clamping ring (5d) and a clamping shoulder (5e), and the outer ring of the main bearing (17) is clamped and fixed between the clamping ring (5d) and the clamping shoulder (5 e).

8. The water pump assembly according to claim 6, wherein a through hole (1b) is formed in the housing (1), the rotating shaft (4) is inserted into the through hole (1b), one end of the rotating shaft (4) extends out of the housing (1) and is fixedly connected with the impeller (2), the other end of the rotating shaft (4) extends out of the housing (1) and is fixedly connected with a shaft sleeve (14), one end of the shaft sleeve (14) is provided with a reinforcing ring (14a) inserted into the through hole (1b), the outer peripheral surface of the shaft sleeve (14) is provided with a protruding connecting ring (14b), the friction plate (9) is connected to the connecting ring (14b) through a spline structure, and the heat dissipation disc (7) is attached to the end surface of the connecting ring (14b) and is fixed through a bolt (15).