CN211737473U - A drain pump for domestic appliance - Google Patents

Abstract

The utility model relates to a drain pump for domestic appliance, the drain pump includes: impeller (1), motor (2) and damper (6). The motor (2) comprises a motor housing (21), and a rotor (22) and a stator assembly (23) arranged within the motor housing (21), the stator assembly (23) comprising a coil (231) and an iron core (232). When the coil (231) is powered on, the alternating magnetic field generated by the coil (231) drives the rotor (22) to rotate around the axis of the drainage pump in a certain direction. The damper (6) can rotate around the axis of the drainage pump by the action of the rotor (22) and impact the impeller (1). During the starting process of the drainage pump, the maximum angle which the rotor (22) rotates from the initial position to the position when the shock absorber (6) collides with the impeller (1) is the starting angle of the drainage pump, and the length (L) of the iron core (232) of the stator assembly (23) is determined according to the starting angle.

Description

A drain pump for domestic appliance

Technical Field

The present invention relates to a drain pump, particularly for household appliances, and which can be started at low pressure and with low noise.

Background

A permanent magnet synchronous motor is generally used for a drain pump of a household appliance such as a washing machine and a dishwasher. The relevant national standards make specific demands on the low-voltage starting performance of the motor of the drain pump. Therefore, the magnitude of the starting torque of the motor of the drain pump is an important index in design. Meanwhile, as the living standard is improved, the user pays more attention to the comfort at home, the requirement for silence is higher and higher when the household appliance is purchased, and larger vibration and noise can be brought when the starting torque is increased. In order to obtain a suitable starting torque to simultaneously satisfy the low-pressure starting performance requirement and the low noise requirement, the motor of the drain pump needs to be specially designed.

The electric motor for a drain pump generally comprises two parts, a stator, which is an electromagnet with laminated cores and corresponding coils, and a permanent-magnet rotor, which is placed in the center of the stator. The rotor may rotate a load, such as an impeller of a drain pump, by interacting with the magnetic field of the stator. It is known that the greater the inertia of the load applied to the synchronous machine, the more difficult it is to start it.

During the starting process of the drainage pump, the stator generates a sine wave magnetic field to drive the rotor to rotate, so that the rotor and the load are impacted back and forth. In the process, the current and the power of the motor, the rotation direction and the speed of the rotor can be changed until the magnetic field of the rotor is aligned with the magnetic field of the stator, the rotor reaches a synchronous state, and the starting process is finished.

In the process that the motor achieves a synchronous state through back-and-forth impact, the kinetic energy obtained by the rotor continuously changes back and forth under the condition that the magnetic field intensity of the stator and the magnetic field intensity of the rotor are not changed. When sufficient kinetic energy aligns the rotor and stator fields to achieve synchronization, the rotor and load are also in a relatively stationary state.

As can be seen from the above description, the starting process of the drain pump can be divided into an electromagnetic transmission process in which the stator drives the rotor to rotate and a mechanical transmission process in which the kinetic energy of the rotor is transmitted to the load. The electromagnetic transmission process can be adjusted by adjusting the strength of the electromagnet of the stator, and the mechanical transmission process needs to optimize the transmission device between the rotor and the load. The quality of the transmission between the rotor and the load has a self-evident important influence on the starting noise, starting stability and starting reliability of the start-up.

In particular, kinetic energy is transferred between the rotor and the load, usually through an elastomer as an intermediate member. The elastomer may be fixed to the impeller (as a load of the motor) or to the rotor, or may also slide around the central shaft on the impeller or on the rotor. In the starting process, the rotor is driven by the starting torque of the alternating magnetic field of the stator to rotate in an accelerating mode, and after the rotor rotates for a certain angle (namely, a starting angle), the rotor is impacted with the impeller through the elastic body, so that the kinetic energy is transmitted to the impeller. It will be appreciated that the magnitude of the starting torque and the magnitude of the starting angle determine the starting process.

Under the condition of a given permanent magnet rotor, the weaker the electromagnet of the stator is, the smaller the generated starting torque is, and if the starting angle is too small, the low-pressure starting performance of the drainage pump cannot be ensured; the stronger the electromagnet of stator, the bigger the starting torque that produces, if start angle is too big, the moment of elastomer striking impeller is too big, not only produces the noise, uses moreover for a long time and can shorten the life of rotor, elastomer, impeller.

SUMMERY OF THE UTILITY MODEL

Therefore, an object of the present invention is to provide a drain pump for a household appliance, wherein a stator and a starting structure of a motor of the drain pump are specially designed, so as to effectively improve the starting reliability of the drain pump, especially under a low-voltage condition; meanwhile, the noise of the draining pump in the starting process can be reduced, the draining pump can stably operate, and the service life of the draining pump is greatly prolonged.

The purpose is through a drain pump for domestic appliance according to an embodiment of the utility model, it includes impeller, motor, and the motor includes the motor casing and arranges rotor and stator module in the motor casing, and stator module includes iron core and coil. When the coil is connected with a power supply, the alternating magnetic field generated by the coil drives the rotor to rotate around the axis of the drainage pump in a certain direction. The drain pump further includes a damper made of, for example, rubber, elastic resin, or the like. Under the action of the rotor, the shock absorption body can rotate around the axis of the drainage pump and impact the impeller. During the start-up of the drain pump, the maximum angle through which the rotor rotates from its initial position to the position at which the damper body collides with the impeller is the start-up angle of the drain pump. Through adjusting stator module's iron core length, can adjust the intensity of the alternating magnetic field that the stator produced, and then adjust start-up moment. The starting angle of the drain pump determines the kinetic energy of the shock absorber when it hits the impeller, given the same starting torque. In order to improve the starting reliability of the drainage pump, reduce the noise during starting and prolong the service life of the shock absorber, the motor and the impeller, the length of the iron core of the stator component is determined according to the starting angle of the drainage pump. Generally, the greater the starting angle of the drain pump, the shorter the length of the iron core of the stator assembly.

According to a preferred embodiment of the present invention, the starting angle of the drain pump is between 200 ° and 250 °, and the length of the iron core of the stator assembly is between 15mm and 20 mm.

According to a preferred embodiment of the present invention, the starting angle of the drain pump is between 250 ° and 400 °, and the length of the iron core of the stator assembly is between 10mm and 15 mm.

According to a preferred embodiment of the present invention, the starting angle of the drain pump is between 400 ° and 600 °, and the iron core length of the stator assembly is between 5mm and 10 mm.

According to a preferred embodiment of the present invention, the starting angle of the drain pump is between 250 ° and 300 °, and the length of the iron core of the stator assembly is between 10mm and 15 mm.

According to different requirements, the drainage pump can have different sizes, namely the lengths of the iron cores of the stator assemblies are different. Correspondingly, the drainage pump can have different starting structure designs to meet the requirement of a starting angle.

According to the utility model discloses an optional embodiment, the impeller is including holding the chamber, hold and be provided with the spacing muscle that extends along the radial direction of impeller in the chamber, this spacing muscle includes a pair of spacing wall, be provided with the sliding tray between the spacing wall. The drain pump also comprises a coupler, wherein the coupler comprises a tubular main body and a starting rib which radially protrudes outwards from the outer wall of the tubular main body, the tubular main body is sleeved on a rotating shaft of the rotor, and the coupler is driven by the rotor to synchronously rotate with the rotor. The shock absorber is embedded in the sliding groove and slides in the sliding groove through the action of the starting rib of the coupler so as to rotate around the axis of the drainage pump. Specifically, as the rotor rotates, the actuating rib of the coupling beats an end surface of the damper in the circumferential direction, so that the damper slides in the slide groove. The damper body in turn transmits kinetic energy to the impeller. When being started the muscle and patting, the shock absorber can take place the deformation, extension kinetic energy transmission time to strike between buffering rotor and the impeller, promoted the life-span of rotor and impeller by a wide margin. In addition, the sliding groove can limit the sliding stroke of the shock absorber, thereby limiting the starting angle of the drainage pump.

According to an optional embodiment of the present invention, the start rib of the coupling and the limit rib of the impeller are staggered in the axial direction. For example, the activation rib may be located entirely above the stopper rib with respect to the bottom surface of the slide groove. Thus, after the damper is removed, the rotor and the impeller can be rotated relatively without interference. Thereby, the drain pump can obtain a starting angle as large as possible, for example a starting angle of 600 °.

According to an optional embodiment of the present invention, the shock absorbing body is provided with a hollow portion. Thus, when the shock absorber is flapped by the starting rib, the shock absorber can increase the compressible space due to the hollow part, and the deformation amount and the deformation time of the shock absorber are improved.

According to an alternative embodiment of the invention, the hollow portion has a groove-like structure. Alternatively, the hollow portion may have an open structure. Depending on different requirements, the hollow portion may completely penetrate the damper body in the axial direction, or may be provided only in a part of the damper body in the axial direction.

According to an alternative embodiment of the invention, the impeller comprises a positioning column axially protruding from the bottom surface of the housing chamber. The positioning post is located in a sliding groove in a circumferential direction, and the damper is installed such that the positioning post extends into a hollow portion of the damper. The positioning column also has a limiting effect on the rotation of the rotor. Further, it is conceivable that when the impact of beating of the actuating rib of the coupling is excessive, one side of the hollow portion of the damper presses the positioning column, and the positioning column cushions the impact of the damper by elastic deformation. The elastic force from the positioning post effectively increases the cushioning amount and the deformation time, and can avoid excessive deformation of the shock absorbing body. The starting angle of the drainage pump with the starting structure can reach 300 degrees.

According to an optional embodiment of the present invention, the damper is of a stepped structure in the axial direction, and includes a sliding portion near the bottom of the accommodating chamber and a starting portion axially protruding outward from the sliding portion, the sliding portion having a size larger than that of the starting portion, and the hollow portion running through the sliding portion. In the starting process, the starting rib of the coupler flaps the starting part of the shock absorber, and the shock absorber slides in the sliding groove until the sliding part of the shock absorber impacts the limiting wall of the limiting rib. Thus, the positions of the actuating rib and the limiting rib acting on the shock absorber are staggered in the axial direction. This feature allows the damper to have a certain amount of deformation in the axial direction, thereby increasing the amount of deformation and the deformation time of the damper even more. In addition, under the condition that cooperation reference column used, the atress point that the shock attenuation body extrudeed the reference column will keep away from the bottom of reference column more to make the deflection and the deformation time of reference column increase effectively.

According to an optional embodiment of the present invention, the damper body is provided with a protruding cushioning rib on a circumferential end surface thereof. It is conceivable that the buffer rib may be provided on only one end surface in the circumferential direction, or may be provided on both end surfaces opposed to each other in the circumferential direction. For a damper comprising a sliding part and an activation part, the damping rib may be provided on an end face of the sliding part and/or the activation part. The buffer ribs reduce the contact surface of the shock absorber in collision with the starting ribs and/or the limiting ribs, so that the deformation is increased, and the starting performance is improved. Preferably, the cross section of the buffer rib has a tapered shape with a narrow outer part and a wide inner part. For example, the cross-section of the buffer rib has a triangular shape or a semicircular shape. Through such design, the shock absorber will be switched into line contact by the face contact with the collision of starting muscle and/or spacing muscle, further increases the deflection, improves the startability.

The utility model discloses still relate to a drain pump, it includes as above the drain pump.

Drawings

In the following, the invention is described in more detail by way of example and with reference to the accompanying drawings, in which

Fig. 1A and 1B are a side view and an exploded view of a drain pump according to an embodiment of the present invention, respectively.

Fig. 2A-2B illustrate a starting structure of a drain pump according to an embodiment of the present invention.

Figure 3 shows in detail the impeller of the drain pump in the embodiment shown in figures 2A-2B.

Fig. 4 shows in detail the coupling of the drain pump in the embodiment shown in fig. 2A-2B.

FIG. 5 shows the damper of the drain pump in the embodiment shown in FIGS. 2A-2B in detail.

Fig. 6A to 6C show a starting structure of a drain pump according to another embodiment of the present invention.

Fig. 7A to 7D show a starting structure of a drain pump according to another embodiment of the present invention.

Throughout the drawings, identical or similar parts are indicated by identical reference numerals.

List of reference numerals

1 impeller 3 end cover

11 holding cavity 4 card

12 spacing rib 5 shaft coupling

121a, 121b limiting wall 51 tubular body

122 intermediate stop 52 actuating rib

13 sliding groove 6 shock absorber

14 positioning column 61 sliding part

2 starting part of motor 62

21 motor case 63 hollow part

22 rotor 64 buffer rib

23 stator Assembly O axis of Drain Pump

Length of 231 coil L-core

232 iron core

Detailed Description

In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the following will combine the drawings of the embodiments of the present invention to carry out clear and complete description on the technical solution of the embodiments of the present invention. It is to be understood that the described embodiments are only a few, and not all, of the disclosed embodiments. Features, integers or characteristics described in conjunction with a particular aspect, embodiment or example of the invention are applicable to any other aspect, embodiment or example described herein unless incompatible therewith.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of the words "a," "an," or "the" and similar referents in the specification and claims of the present application does not denote a limitation of quantity, but rather denotes the presence of at least one. The word "comprising" or "comprises", and the like, means that the element or item preceding the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items.

Although various elements of the present invention may be described using expressions such as "first" and "second," they are not intended to limit the corresponding elements. For example, the above expressions are not intended to limit the order or importance of the corresponding elements. The above expressions are used to distinguish one element from another.

When an element is referred to as being "coupled" or "connected" to another element, it can be directly coupled or coupled to the other element, but it is understood that intervening elements may be present. Alternatively, when an element is referred to as being "directly coupled" or "directly coupled" to another element, it is understood that there are no intervening elements present between the two elements. References herein to "front", "rear", "upper", "lower", and the like are merely intended to indicate relative positional relationships, which may also change accordingly when the absolute position of the object being described changes.

Fig. 1A-1B show a side view and an exploded view, respectively, of a drain pump according to one embodiment of the present invention. For the sake of clarity, parts of the drain pump that are not relevant for understanding the solution of the invention have been omitted.

Referring to fig. 1A and 1B, the drain pump according to the present invention includes an impeller 1 and a motor 2, wherein the motor 2 includes a motor housing 21, a rotor 22 and a stator assembly 23 accommodated in the motor housing 21. The stator assembly 23 also includes a coil 231 and a core 232. The motor casing 21 is closed by an end cover 3, and the impeller 1 is positioned outside the end cover 3.

When the coil 231 is powered on, the iron core 232 is magnetized, thereby generating an alternating magnetic field of the stator assembly 23. The rotor 22 comprises a magnetic ring injection molded assembly which is driven by the magnetic field of the stator assembly 23 to rotate in a direction about the axis O of the drain pump. The length L of the core 232 can affect the magnetic field strength of the stator assembly 23 and, in turn, the rotational torque experienced by the rotor 22 (i.e., the starting torque of the drain pump).

The kinetic energy of the rotation of the rotor 22 is transmitted to the impeller 1 by the starting structure of the drain pump. Fig. 2A-2B illustrate a first embodiment of a starting structure for a drain pump. The starting structure of the drain pump comprises a coupling 5 and a shock-absorbing body 6, which are entirely enclosed in a housing chamber 11 of the impeller 1 by means of a card 4.

Fig. 2B shows the receiving cavity 11 after removal of the card 4. As shown in fig. 2B, and with further reference to fig. 3, the accommodating chamber 11 is provided therein with a stopper rib 12 extending in the radial direction of the impeller 1. In the embodiment shown in fig. 2B, the stopper rib 12 includes a pair of stopper walls 121a, 121B on the outer side and an intermediate stopper 122. A sliding groove 13 is formed between the stopper walls 121a and 121 b. It should be understood that the spacing ribs 12 may also have a different configuration, for example a plurality of intermediate stops may be provided or no intermediate stops may be provided. It is also possible that the receiving chamber 11 may include a plurality of stopper ribs therein. The number of sliding grooves varies accordingly. As shown in fig. 3, the housing chamber 11 of the impeller 1 is further provided with a positioning column 14 axially protruding from the bottom surface of the slide groove 13. As will be described in detail below, the positioning post 14 can position the damper 6 and limit the rotation angle of the rotor 22.

As shown in fig. 2B, and with further reference to fig. 4, the coupling 5 includes a tubular body 51 fitted over the shaft of the rotor 22 and an actuating rib 52 projecting radially outward from the outer wall of the tubular body 51. In the axial direction, the activating rib 52 is offset from the restricting rib 12, i.e. the activating rib 52 is located completely above the restricting rib 12. When the rotor 22 rotates, the coupling 5 rotates in synchronization with the rotor 22. The actuating rib 52 taps one end surface of the damper 6 in the circumferential direction so that the damper 6 slides in the slide groove 13.

Referring to fig. 5 in conjunction with fig. 2B, the shock-absorbing body 6 is fitted in the slide groove 13, and has an arc shape matching the slide groove 13 as a whole, so as to slide therein. As shown in fig. 5, the damper body 6 has a stepped structure in the axial direction, and includes a sliding portion 61 near the bottom of the accommodation chamber 11 and an actuating portion 62 axially protruding outward from the sliding portion 61, and the size of the sliding portion 61 is larger than that of the actuating portion 62. That is, the sliding portion 61 extends at a larger angle in the circumferential direction than the activating portion 62. In the axial direction, the start portions 62 correspond to the start ribs 52 of the coupling 5, and the sliding portions 61 correspond to the limit ribs 12 of the impeller 1.

Further, the damper body 6 is provided with a hollow portion 63. As shown in fig. 5, the hollow portion 63 is a groove-like hollow portion, and has an arc shape that substantially conforms to the shape of the body of the damper body 6. It is contemplated that the shape of the hollow 63 may be other suitable shapes. In the radial direction, the hollow portion 63 is located substantially at the center of the damper body 6. Of course, the hollow 63 may also be appropriately off-centered in the radial direction. In the axial direction, the hollow 63 penetrates the sliding part 61, but not the activation part 62, only extending a distance therein. It is contemplated that hollow 63 may also extend completely through damper body 6. In the construction in which the installation of the drain pump is completed, the positioning column 14 extends into the hollow portion 63, and the top of the positioning column 14 is not in contact with the bottom surface of the hollow portion 63.

When the drain pump is started, the rotor 22 drives the coupling 5 to rotate, and the starting rib 52 beats the starting part 62 of the damper 6. The damper body 6 thus gains kinetic energy and slides in the slide groove 13 until the sliding portion 61 hits the stopper wall 121a of the stopper rib 12 (for the sake of convenience of discussion only, the disclosure herein also applies to the case where the sliding portion 61 hits the stopper wall 121 b). The impeller 1 thus receives the impact of the damper 6 to start rotating. The above process is repeated until the rotor 22 reaches a synchronous state with the alternating magnetic field of the stator 23 and the starting process of the drain pump is completed. When the actuating rib 52 beats the actuating portion 62 of the damper 6 and the sliding portion 61 of the damper 6 strikes the limiting wall 121a of the limiting rib 12, the corresponding portion of the damper 6 is deformed, so that the stress time is prolonged and the beating and striking are buffered.

In the sliding process of the shock absorber 6, the position of the positioning column 14 is set to be capable of limiting the position of the shock absorber 6. Specifically, at both ends of the stroke of the damper 6 sliding in the slide groove 13, the positioning posts 14 abut against both inner end walls of the hollow portion 63 in the circumferential direction, so that the damper 6 cannot rotate any further. The positions of the damper body 6 and the positioning post are designed such that the sliding portion 61 hits the stopper wall 121a of the stopper rib 12 when the positioning post 14 contacts the inner end wall of the hollow portion 63 away from the stopper wall 121a in the circumferential direction. The deformation of the damping body 6 presses the positioning post 14, whereby the positioning post 14 provides a stop for the actuating rib 52.

Correspondingly, the starting position and the end position of the maximum possible stroke of the start rib 52 during the rotation are respectively: in the initial position, the starting rib 52 contacts with the outer end face of the starting part 62 close to the limiting wall 121a in the circumferential direction, and the positioning column 14 contacts with the inner end wall of the hollow part 63 close to the limiting wall 121a in the circumferential direction; in the end position, the start rib 52 contacts the outer end face of the start portion 62 away from the stopper wall 121a in the circumferential direction, and the positioning post 14 contacts the inner end wall of the hollow portion 63 away from the stopper wall 121a in the circumferential direction. Through the effect of reference column, the start angle of drain pump is restricted to be less than 360. The starting angle of the drain pump can be up to approximately 300 deg. taking into account the wall thickness of the hollow 63 at the start 62 and the width of the start rib 52 itself.

Fig. 6A-6C illustrate a second embodiment of a startup configuration for a drain pump. In this embodiment, the structure of the coupling and the positioning post is the same as that of the first embodiment shown in fig. 2A to 5. One difference is that the spacing ribs include two intermediate stops 122. In addition, the second embodiment differs from the first embodiment mainly in the design of the damper 6.

In the second embodiment, the damper body 6 also has a stepped structure in the axial direction, including a sliding portion 61 near the bottom of the accommodation chamber 11 and an actuating portion 62 projecting axially outward from the sliding portion 61, the sliding portion 61 having a size larger than that of the actuating portion 62. Similarly, in the axial direction, the start portion 62 corresponds to the start rib 52 of the coupling 5, and the sliding portion 61 corresponds to the limit rib 12 of the impeller 1. The activation portion 62 is provided with protruding buffer ribs 64 on both end surfaces in the circumferential direction thereof. Although not shown, it is conceivable that the buffer rib 64 may also be provided on an end surface of the sliding portion 61 in the circumferential direction. The cross section of the buffer rib 64 has a triangular shape with a narrow outside and a wide inside, so that the contact surface area when colliding with the start rib 52 can be reduced, the deformation amount is increased, and the start performance is improved. The cross-section of the cushioning ribs 64 may also have other suitable shapes, such as semi-circular, etc.

As shown in fig. 6B and 6C, the hollow portion 63 of the damper body 6 has an open structure. In the axial direction, the hollow 63 penetrates the sliding part 61, but not the activation part 62, only extending a distance therein. It is contemplated that hollow 63 may also extend completely through damper body 6.

In the second embodiment, the positioning post is still provided, so that the starting angle of the drain pump is still limited to less than 360 °, and can be up to 300 ° approximately.

In order to obtain as large an actuation angle as possible, it is necessary to remove the positioning post to avoid interfering with the rotation of the actuation rib. The third embodiment of the start-up structure shown in fig. 7A-7D has a similar structure.

As shown in fig. 7A and 7B, no positioning post is provided in the accommodation chamber 11 of the impeller 1, and the restricting rib 12 includes only two restricting walls 121a and 121B without providing an intermediate stopper. By removing the positioning post, the start rib 52 can rotate freely without interference because the start rib 52 and the limit rib 12 are staggered in the axial direction without installing a damper.

Referring to fig. 7C, the structure of the damper 6 is also simplified. In the axial direction, the dimension of the shock absorbing body 6 is uniform without being divided into two parts. In the mounted configuration of the drain pump, the axial position of the lower portion of the shock-absorbing body 6 close to the bottom of the housing chamber 11 corresponds to the stop walls 121a and 121b, while the axial position of the upper portion thereof corresponds to the activation rib 52.

The damper body 6 is provided with a hollow portion 63, and the hollow portion 63 is a groove-like hollow portion and penetrates the damper body 6. When the shock absorber 6 collides with the starting rib 52 and the limiting walls 121a and 121b, the shock absorber 6 can increase a compressible space due to the hollow part 63, so that the starting moment can be buffered, the starting noise can be reduced, and the service life of the drain pump can be prolonged.

In the third embodiment, both end surfaces of the damper 6 in the circumferential direction are Sa and Sb, respectively. The end face Sa is an end face in contact with the stopper wall 121a, and Sb is an end face in contact with the stopper wall 121 b. The maximum possible travel of the actuating rib 52 during rotation is: at the initial position, the start rib 52 contacts with the end face Sa of the damper 6, and the limit wall 121b contacts with the end face Sb of the damper 6; the starting rib 52 rotates to flap the end surface Sb of the damper 6 and starts to push the damper 6 to rotate; in the end position, the end face Sa of the damper body 6 hits the stopper wall 121a under the urging of the actuating rib 52. During this stroke, the angle of rotation of the activating rib 52 may be through 360 °.

As shown in fig. 7D, a is the angle occupied by the limit rib 12 of the impeller 1, B is the angle occupied by the damper 6, and C is the angle occupied by the start rib 52 of the coupling 5, and the start angle of the drain pump is 720-a-2B-C. The starting angle of the drain pump can be up to approximately 600 deg. taking into account the value of A, B, C.

As described above, in order to obtain good starting performance, extend the life of the drain pump, and at the same time reduce the starting noise, it is necessary to optimally design the starting angle of the drain pump and the length L of the iron core of the stator assembly. For this purpose, the present inventors tested the starting structure of the drain pump of each of the above embodiments.

Test conditions and requirements

The test was directed to a drain pump for a washing machine. The service life of the washing machine is calculated according to the use requirement of 10 years, 4 times of washing are carried out every day, the washing times of the washing machine in ten years are 365 multiplied by 10 multiplied by 4 times of 14600 times, 4 times of dehydration calculation is carried out according to one washing period of the washing machine, 5 times of starting and stopping of the dewatering drainage pump are carried out every time, the starting and stopping periods of the drainage pump are calculated according to the use requirement of the washing machine in 10 years, 4 multiplied by 5 multiplied by 14600 times of 292000 times, and therefore 300000 work cycles are required to be carried out when the durability of the starting structure of the drainage.

Specifically, under the rated voltage and the rated frequency, the drainage pump is switched on for 5 seconds and switched off for 5 seconds, and is a working cycle, and the water temperature is controlled to be 60 ℃ during the test. The requirement for the starting noise of the drain pump is that the noise is less than 55dB after 300000 work cycles (the noise is judged to be unqualified if the noise exceeds the standard). In addition, the motor which works for a short time according to the regulation of the national standard GB/T12350-2009 safety requirement of low-power motors can be started for 50 times under 0.85 times of rated voltage. The utility model provides a motor of drain pump belongs to the motor of short-time work, and its rated voltage/frequency is: 220V/50HZ, the low-voltage starting voltage required to be met is 187V.

The results achieved are shown in the following table:

according to the above experimental results, the optimal relationship between the starting angle of the drain pump and the length L of the iron core is obtained, as shown in the following table:

NO.	starting angle/°	Length L/mm of iron core
			1	200-250	15≤L≤20
2	250-400	10≤L＜15
			3	400-600	5≤L＜10

The inventors have further determined that a particularly preferred design of the drain pump is one in which the length L of the iron core is 13mm and the starting angle is 305 °, 335 ° or 365 °.

Compare in current design, according to the utility model discloses a drain pump possesses good startability. Particularly, according to the utility model discloses a drain pump can improve the start reliability of drain pump effectively under the low pressure condition, reduces the noise in the start-up process simultaneously for the drain pump can the steady operation, thereby prolongs the life-span of start-up structure.

It is to be understood that the structures described above and shown in the attached drawings are merely examples of the present invention, which can be replaced by other structures exhibiting the same or similar function for obtaining the desired end result. Furthermore, it should be understood that the embodiments described above and shown in the drawings are to be regarded as only constituting non-limiting examples of the present invention and that it can be modified in a number of ways within the scope of the patent claims.

Claims (16)

1. A drain pump, comprising:

an impeller (1);

the motor (2) comprises a motor shell (21), and a rotor (22) and a stator assembly (23) which are arranged in the motor shell (21), wherein the stator assembly (23) comprises a coil (231) and an iron core (232), and when the coil (231) is powered on, an alternating magnetic field generated by the stator assembly (23) drives the rotor (22) to rotate around the axis (O) of the drainage pump in a certain direction;

a damper (6), which, under the action of a rotor (22), can rotate about the axis (O) of the drainage pump and which strikes the impeller (1);

wherein, in the starting process of the drainage pump, the maximum angle which is passed by the rotor (22) to rotate from the initial position to the position when the shock absorber (6) collides with the impeller (1) is the starting angle of the drainage pump, and the length (L) of the iron core (232) of the stator component (23) is determined according to the starting angle.

2. A drain pump according to claim 1,

the starting angle of the draining pump is between 200 DEG and 250 DEG, and the length (L) of the iron core (232) of the stator component (23) is between 15mm and 20 mm.

3. A drain pump according to claim 1,

the starting angle of the draining pump is between 250 DEG and 400 DEG, and the length (L) of the iron core (232) of the stator component (23) is between 10mm and 15 mm.

4. A drain pump according to claim 3,

the length (L) of the iron core (232) of the stator assembly (23) is 13mm, and the starting angle of the drain pump is 305 DEG, 335 DEG or 365 deg.

5. A drain pump according to claim 1,

the starting angle of the draining pump is between 400 degrees and 600 degrees, and the length (L) of the iron core (232) of the stator component (23) is between 5mm and 10 mm.

6. A drain pump according to claim 1,

the starting angle of the draining pump is between 250 DEG and 300 DEG, and the length (L) of the iron core (232) of the stator component (23) is between 10mm and 15 mm.

7. Drain pump according to any of claims 1-6,

the impeller (1) comprises an accommodating cavity (11), a limiting rib (12) extending along the radial direction of the impeller (1) is arranged in the accommodating cavity (11), the limiting rib (12) comprises a pair of limiting walls (121a and 121b), a sliding groove (13) is arranged between the limiting walls (121a and 121b), and

the drain pump also comprises a coupler (5) which comprises a tubular main body (51) and an actuating rib (52) protruding outwards from the outer wall of the tubular main body (51) in the radial direction, the tubular main body (51) is sleeved on a rotating shaft of the rotor (22), the coupler (5) is driven by the rotor (22) to rotate synchronously with the rotor (22),

wherein the damper body (6) is embedded in the sliding groove (13) and rotates around the axis (O) of the drainage pump in a manner of sliding in the sliding groove (13) by the action of an activation rib (52) of the coupling (5).

8. A drain pump according to claim 7,

the starting ribs (52) of the coupler (5) and the limiting ribs (12) of the impeller (1) are staggered in the axial direction.

9. A drain pump according to claim 7,

the damper body (6) is provided with a hollow portion (63).

10. A drain pump according to claim 9,

the hollow portion (63) has a groove-like structure or an open structure.

11. A drain pump according to claim 9 or 10,

the impeller (1) comprises a positioning post (14) axially protruding from the bottom surface of the sliding groove (13), and the damper body (6) is mounted such that the positioning post (14) extends into a hollow (63) of the damper body (6).

12. A drain pump according to claim 9 or 10,

the shock absorption body (6) is of a stepped structure in the axial direction and comprises a sliding portion (61) close to the bottom of the accommodating cavity (11) and an actuating portion (62) protruding outwards from the sliding portion (61) in the axial direction, and the radial dimension of the sliding portion (61) is larger than that of the actuating portion (62).

13. A drain pump according to claim 12,

the hollow portion (63) penetrates the sliding portion (61) and extends in at least a part of the activation portion (62).

14. A drain pump according to claim 9 or 10,

the damper body (6) is provided with a protruding cushioning rib (64) on the end surface in the circumferential direction thereof.

15. A drain pump according to claim 14,

the cross section of the buffer rib (64) has a tapered shape with a narrow outer part and a wide inner part.

16. A drain pump according to claim 15,

the cross section of the buffer rib (64) has a triangular shape or a semicircular shape.

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