Small electric diaphragm pump

Abstract

The utility model discloses a small-sized electric diaphragm pump, which belongs to the technical field of electric pumps and comprises a rotating shaft with a power part, a pump body, a cam part driven by the rotating shaft to rotate and a piston driven by the piston to reciprocate. The rotating cam piece abuts against the local hole wall of the transmission hole so as to drive the piston to do linear reciprocating motion, the reciprocating piston enables the volume of the pump cavity to change in a reciprocating mode, and at least the position, abutting against the cam piece, of the piston is provided with a wear-resisting piece made of metal materials. The rotating cam part abuts against the abrasion-resistant part so as to drive the piston to do linear reciprocating motion. The service life of the piston is prolonged through structural improvement, the working performance of the piston is guaranteed, and the overall working life of the pump is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to electric pump technical field especially relates to a small -size electric diaphragm pump. BACKGROUND

[0002] Diaphragm pump is a kind of positive displacement pump for pumping fluid, is widely used in industry, agriculture, life, diaphragm pump mainly utilizes the reciprocating deformation of diaphragm to make the volume of pump cavity reciprocating change to realize the suction and pumping of fluid. As a specific example of diaphragm pump, diaphragm pump can be electric diaphragm pump driven by motor.

[0003] Electric diaphragm pump mainly includes micro motor, runner, bearing, piston, diaphragm, import, export, pump cavity, suction check valve, discharge check valve etc. component, the output shaft of micro motor drives eccentric runner rotation, and rotating runner drives piston to make linear reciprocating motion, and reciprocating piston drives diaphragm to reciprocate deformation, and reciprocating diaphragm makes the volume of pump cavity reciprocating change. When the volume of pump cavity increases, suction check valve opens and discharge check valve closes, fluid flows from import to pump cavity. When the volume of pump cavity decreases, suction check valve closes and discharge check valve opens, fluid flows from pump cavity to export and is discharged outward. The continuous rotary output of motor is utilized to make diaphragm periodic reciprocating deformation, so that diaphragm pump can continuously suck and pump fluid.

[0004] In the existing electric diaphragm pump, the piston is generally a high-hardness plastic part, due to the high speed of the runner, the contact frequency of the runner and the piston is high, and the runner has large wear on the plastic piston, which is not conducive to ensuring the service life and working performance of the piston. UTILITY MODEL CONTENTS

[0005] In order to solve the above-mentioned shortcomings and deficiencies in the prior art, the utility model provides a small -size electric diaphragm pump, improves the service life of piston through structural improvement, ensures the working performance of piston, thereby prolongs the working life of pump whole.

[0006] In order to realize the above technical purpose, the utility model provides a small -size electric diaphragm pump, including:

[0007] Power piece, it has the rotation of output shaft;

[0008] Pump body, it has the hole, the hole, the pump cavity and the accommodation cavity, the hole and the pump cavity are intermittently connected through suction check valve, and the pump cavity and the hole are intermittently connected through discharge check valve;

[0009] Cam piece, it is eccentrically sleeved on the rotation of output shaft and is rotated by the rotation of output shaft;

[0010] A piston movably arranged in a containing cavity and having a transmission hole matched with a cam member, the rotating cam member abutting against a partial hole wall of the transmission hole to drive the piston to make linear reciprocating motion, and the reciprocating piston makes the volume of the pump cavity reciprocate.

[0011] The piston is provided with a wear-resistant member made of metal material at least at the position abutting against the cam member, and the rotating cam member abuts against the wear-resistant member to drive the piston to make linear reciprocating motion.

[0012] Preferably, the wear-resistant member is in the shape of a sheet and is fixed to the hole wall of the transmission hole.

[0013] Preferably, the surface of the wear-resistant member towards the center of the transmission hole is a plane or a curved surface.

[0014] Preferably, the thickness of the wear-resistant member is T, 2mm≤T≤5mm, the width of the wear-resistant member is W, the outer diameter of the cam member is D, and 0.25≤W / D≤0.4.

[0015] Preferably, the piston is provided with a limiting groove outside the transmission hole, and the wear-resistant member is arranged on the piston and faces the cam member through cooperation with the limiting groove.

[0016] Preferably, the limiting groove and the sheet-shaped wear-resistant member are both arranged with a narrow inner part and a wide outer part, and the limiting groove is communicated with the transmission hole.

[0017] Preferably, the pump cavity is provided with two and is located at both ends of the movement direction of the piston respectively, and the wear-resistant member is provided with two and is distributed correspondingly to the two pump cavities.

[0018] Preferably, the wear-resistant member is in the shape of a ring and is fixed to the piston, and the transmission hole is formed by the ring-shaped wear-resistant member.

[0019] Preferably, the piston is made of metal material as a whole.

[0020] Preferably, the cam member comprises a rotating wheel and a bearing, the rotating wheel comprises an integrally formed wheel body and a limiting part, the rotating wheel is eccentrically sleeved outside a rotating shaft, the bearing is sleeved outside the wheel body, and the limiting part is located on the side of the bearing away from the motor.

[0021] After the above technical scheme is adopted, the utility model has the following advantages:

[0022] 1. The small-sized electric diaphragm pump provided by the utility model is provided with a wear-resistant member at least at the position abutting against the cam member, the wear-resistant member is made of metal material with high hardness, the rotating cam member abuts against the wear-resistant member to drive the piston to make linear reciprocating motion, the wear-resistant member has high wear resistance, the wear of the piston caused by the frequent abutment of the cam member and the piston is greatly reduced through the wear-resistant member, the service life of the piston is improved, the working performance of the piston is ensured, and thus the working life of the pump as a whole is prolonged.

[0023] 2、The wear-resistant piece can be provided in a sheet shape, and the sheet-shaped wear-resistant piece is fixed to the hole wall of the transmission hole. The shape of the wear-resistant piece is reasonably arranged, so that the piston meets the wear-resistant requirement while reasonably reducing the weight of the piston, and the piston can smoothly perform linear reciprocating motion under the driving of the cam piece, which is beneficial to reducing the driving load of the power piece.

[0024] 3、The thickness T of the wear-resistant piece is reasonably arranged to ensure the wear-resistant performance of the wear-resistant piece. If the thickness T of the wear-resistant piece is less than 2 mm, the wear-resistant piece is relatively thin, which is not conducive to ensuring the service life of the wear-resistant piece. If the thickness T of the wear-resistant piece is greater than 5 mm, the groove for installing the wear-resistant piece needs to be designed to be relatively deep, which will cause the outer dimension of the piston to be significantly increased, which is not conducive to miniaturization of the whole pump.

[0025] The ratio of the width W of the wear-resistant piece to the outer diameter D of the cam piece is reasonably arranged to ensure that the width of the wear-resistant piece meets the contact amplitude requirement when the cam piece and the piston are in contact, to reduce or eliminate the contact amplitude between the cam piece and the non-metallic part of the piston, and to improve the service life of the piston.

[0026] 4、The wear-resistant piece is arranged on the piston through cooperation with the limiting groove, and the limiting groove and the sheet-shaped wear-resistant piece are preferably arranged in a narrow inside and wide outside manner. The installation mode of the wear-resistant piece is reasonably arranged to reduce the installation difficulty of the wear-resistant piece while ensuring the structural stability of the wear-resistant piece, and to avoid displacement of the wear-resistant piece under frequent contact of the cam piece.

[0027] 5、The wear-resistant piece can also be provided in a ring shape, at this time, the transmission hole is formed by the ring-shaped wear-resistant piece. In addition, the whole piston can also be made of a high-hardness metal material to improve the overall wear-resistant performance of the piston. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is the overall view of the small-sized electric diaphragm pump in Example 1.

[0029] Figure 2 It is the exploded view of part of the structure of the small-sized electric diaphragm pump in Example 1.

[0030] Figure 3 It is the structure view of the cam piece in Example 1.

[0031] Figure 4 It is the structure view of the rotating wheel in Example 1.

[0032] Figure 5 It is the cooperation structure view of the piston and the cam piece in Example 1.

[0033] Figure 6 It is the front-rear direction sectional view of the front part of the small-sized electric diaphragm pump in Example 1.

[0034] Figure 7Fig. 2 is a left-right sectional view of the pump body in Example 1;

[0035] Figure 8 Fig. 4 is a structural view of the piston in Example 1;

[0036] Figure 9 Fig. 5 is an exploded view of the piston and the wear-resistant piece in Example 1;

[0037] Figure 10 Fig. 6 is a schematic view of the cooperation between the bearing and the transmission hole in Example 1;

[0038] Figure 11 Fig. 7 is a structural view of the main housing in Example 1;

[0039] Figure 12 Fig. 8 is a schematic view of the cooperation between the bearing and the transmission hole in Example 2.

[0040] In the figures, 10 is an electric diaphragm pump,

[0041] 100 is a power piece, 110 is a rotating shaft,

[0042] 200 is a pump body, 201 is an inlet hole, 202 is an outlet hole, 203 is a pump cavity, 204 is a containing cavity, 210 is a suction check valve, 211 is a suction valve body, 211a is a suction valve hole, 212 is a suction valve core, 213 is a first spring, 220 is a discharge check valve, 221 is a discharge valve body, 221a is a discharge valve hole, 222 is a discharge valve core, 223 is a second spring, 230 is a main housing, 231 is a suction passage, 232 is a discharge passage, 233 is an inflow joint, 234 is an outflow joint, 240 is a diaphragm, 250 is a shell cover, 250 is a front cover, 260 is a cover shell, 270 is a stop switch, 280 is a trigger assembly, 281 is a hoop ring, 282 is a flexible diaphragm, 283 is a movable sleeve, 284 is a third spring, 291 is a trigger cavity, 292 is a small hole,

[0043] 300 is a cam piece, 310 is a rotating wheel, 311 is a wheel body, 312 is a limiting part, 320 is a bearing,

[0044] 400 is a piston, 410 is a transmission hole, 421 is an upper protruding column, 422 is a lower protruding column, 430 is a protruding ring, 440 is a limiting groove, 450 is a wear-resistant piece, 451 is an abutting surface. DETAILED DESCRIPTION

[0045] The utility model makes further illustration below combining the drawing and specific embodiment. It is understood that the following "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "vertical", "horizontal", "top", "bottom" and other words of indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawing, only for the convenience of describing the utility model and simplifying the description, and not indicating or implying that the indicated device / element must have a particular orientation or be constructed and operated in a particular orientation, therefore, cannot be understood as the limitation of the utility model.

[0046] Embodiment one

[0047] In combination Figures 1 to 11 The utility model embodiment one provides small -size electric diaphragm pump 10, including:

[0048] Power part 100 has the rotating shaft 110 of output rotation movement;

[0049] Pump body 200 has the hole 201 of going in, the hole 202 of going out, pump cavity 203 and accommodation cavity 204, the hole 201 is communicated intermittently with pump cavity 203 through suction check valve 210, and pump cavity 203 is communicated intermittently with the hole 202 through discharge check valve 220;

[0050] Cam part 300 is eccentrically covered on the rotating shaft 110 and is rotated by the rotating shaft 110;

[0051] Piston 400 is movably arranged in the accommodation cavity 204 and has the transmission hole 410 matched with the cam part 300, and the rotating cam part 300 is in contact with the partial hole wall of the transmission hole 410 to drive the piston 400 to make linear reciprocating motion, and the reciprocating piston 400 makes the volume of pump cavity 203 reciprocate;

[0052] Piston 400 is provided with wear-resistant part 450 made of metal material at least in the position in contact with cam part 300, and the rotating cam part 300 is in contact with wear-resistant part 450 to drive the piston 400 to make linear reciprocating motion.

[0053] Wear-resistant part 450 is made of high-hardness metal material, and the rotating cam part 300 is in contact with wear-resistant part 450 to drive the piston 400 to make linear reciprocating motion, since the wear-resistant performance of wear-resistant part 450 is high, the abrasion of the piston 400 caused by the frequent contact of cam part 300 and piston 400 can be greatly reduced through wear-resistant part 450, the service life of piston 400 is improved, the working performance of piston 400 is ensured, thereby being favorable for prolonging the working life of the pump as a whole.

[0054] In combination Figure 1 , Figure 2In the embodiment, the axis direction of the rotating shaft 110 is arranged along the front-rear direction, the power member 100 can specifically adopt an electric motor, and the rotating shaft 110 can be one of components of a rotor assembly in the electric motor. Alternatively, the rotating shaft 110 can be a shaft separately arranged relative to a shaft of the electric motor and connected to the shaft of the electric motor through a shaft coupling. In an alternative of the embodiment, the power member 100 can also adopt a combined structure of an electric motor and a speed reducer, and in this case, an output shaft of the speed reducer can serve as the rotating shaft 110.

[0055] In combination Figure 3 , Figure 4 , Figure 5 In the embodiment, the cam member 300 includes a rotating wheel 310 and a bearing 320. The rotating wheel 310 includes an integral wheel body 311 and a limiting portion 312. The rotating wheel 310 is eccentrically sleeved outside the rotating shaft 110 through a non-circular shaft hole fitting structure. The bearing 320 is sleeved outside the wheel body 311. The limiting portion 312 abuts against the front side of the bearing 320. The outer diameter of the limiting portion 312 is smaller than the outer diameter of the bearing 320. The central axis of the rotating wheel 310 coincides with the central axis of the bearing 320. Figure 3 In the embodiment, a straight line L1 represents the central axis of the rotating shaft 110, and a straight line L2 represents the central axis of the rotating wheel 310 and the bearing 320. The straight line L1 and the straight line L2 are arranged in a staggered manner, i.e., the straight line L1 and the straight line L2 do not coincide and have a certain distance therebetween, so that the bearing 320 is eccentrically sleeved outside the rotating shaft 110 and rotates eccentrically around the straight line L1. The rotating shaft 110 rotating around the straight line L1 drives the bearing 320 to rotate eccentrically through the rotating wheel 310.

[0056] In combination Figure 6 In the embodiment, the pump body 200 includes a main housing 230, two diaphragms 240, and two housing covers 250. The two diaphragms 240 are respectively arranged at the top side and the bottom side of the main housing 230. Correspondingly, the two housing covers 250 are respectively arranged at the top and the bottom of the main housing 230. The housing covers 250 are arranged outside the diaphragms 240. The circumferential edges of the diaphragms 240 are clamped between the main housing 230 and the housing covers 250. The diaphragms 240 and the housing covers 250 are in circumferential sealing cooperation. The space enclosed by the diaphragms 240 and the housing covers 250 forms a pump cavity 203. The diaphragms 240 are elastic, and the deformed diaphragms 240 change the volume of the pump cavity 203.

[0057] In the embodiment, the accommodating cavity 204 is formed by the inner cavity of the main shell 230, the piston 400 is movably arranged in the accommodating cavity 204, the top side of the piston 400 is provided with an upper protruding column 421 connected with the upper diaphragm 240, the bottom side of the piston 400 is provided with a lower protruding column 422 connected with the lower diaphragm 240, the bearing 320 is located in the transmission hole 410 of the piston 400, the eccentric rotation of the bearing 320 drives the piston 400 to move up and down in the accommodating cavity 204, the up and down movement of the piston 400 drives the two diaphragms 240 to deform reciprocatingly, so that the volume of the pump cavity 203 changes reciprocatingly.

[0058] In combination Figure 7 , in the embodiment, the main shell 230 is provided with an intake passage 231 and an exhaust passage 232, the intake passage 231 extends along the up and down direction and is communicated with the inlet hole 201, the intake one-way valve 210 is provided with two and is arranged at the upper and lower ends of the intake passage 231 respectively, the intake one-way valve 210 intermittently opens and closes the end of the intake passage 231, so that the end of the intake passage 231 is intermittently communicated with the corresponding pump cavity 203. The exhaust passage 232 extends along the up and down direction and is communicated with the outlet hole 202, the exhaust one-way valve 220 is provided with two and is arranged at the upper and lower ends of the exhaust passage 232 respectively, the exhaust one-way valve 220 intermittently opens and closes the end of the exhaust passage 232, so that the end of the exhaust passage 232 is intermittently communicated with the corresponding pump cavity 203.

[0059] The intake one-way valve 210 includes an intake valve body 211 provided with an intake valve hole 211a, an intake valve core 212 movably arranged in the intake valve body 211 and used for opening and closing the intake valve hole 211a, and a first spring 213 biasing the intake valve core 212 towards the direction of closing the intake valve hole 211a, the intake valve body 211 is fixed to the end of the intake passage 231, the intake valve core 212 biased by the first spring 213 closes the intake valve hole 211a in the normal state, that is, the intake one-way valve 210 is in the closed state in the normal state. When the pressure in the intake passage 231 is greater than the pressure in the pump cavity 203, the intake valve core 212 moves against the bias of the first spring 213, the moving intake valve core 212 opens the intake valve hole 211a, the intake one-way valve 210 switches to the open state, at this time, the fluid can flow into the pump cavity 203 through the inlet hole 201, the intake passage 231 and the intake valve hole 211a, so that the pump cavity 203 sucks the fluid.

[0060] The discharge check valve 220 comprises a discharge valve body 221 provided with a discharge valve hole 221a, a discharge valve core 222 movably arranged in the discharge valve body 221 and used for opening and closing the discharge valve hole 221a, and a second spring 223 used for biasing the discharge valve core 222 towards the direction of closing the discharge valve hole 221a. The discharge valve body 221 is fixed to the end of the discharge passage 232. The discharge valve core 222 biased by the second spring 223 closes the discharge valve hole 221a in the normal state, i.e. the discharge check valve 220 is in the closed state in the normal state. When the pressure in the pump cavity 203 is greater than the pressure in the discharge passage 232, the discharge valve core 222 moves against the bias of the second spring 223, the moving discharge valve core 222 opens the discharge valve hole 221a, and the discharge check valve 220 switches to the open state. At this time, the fluid in the pump cavity 203 can flow to the outlet hole 202 through the discharge valve hole 221a and the discharge passage 232, so as to discharge the fluid in the pump cavity 203.

[0061] When the eccentrically rotating cam member 300 drives the piston 400 to move upwards, the volume of the upper pump cavity 203 becomes smaller and the volume of the lower pump cavity 203 becomes larger, the upper pump cavity 203 discharges fluid, and the lower pump cavity 203 sucks in fluid. When the eccentrically rotating cam member 300 drives the piston 400 to move downwards, the volume of the upper pump cavity 203 becomes larger and the volume of the lower pump cavity 203 becomes smaller, the upper pump cavity 203 sucks in fluid, and the lower pump cavity 203 discharges fluid.

[0062] In combination with Figure 8 , Figure 10 , in the embodiment, the piston 400 is provided with a protruding ring 430 between the upper end and the lower end, the protruding ring 430 encloses a transmission hole 410. The transmission hole 410 is substantially oblate and has a larger diameter D1 in the left-right direction than a diameter D2 in the up-down direction. The outer diameter of the bearing 320 is D3, and D1>D2>D3. D1-D2 can be set to a reasonable size such as 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc., and D2-D3 can be set to a reasonable size such as 0.5mm, 0.7mm, 1mm, 1.2mm, 1.5mm, 1.7mm, 2mm, etc. When the cam member 300 rotates eccentrically, the outer circumferential surface of the bearing 320 abuts against part of the hole wall on the top side and part of the hole wall on the bottom side of the transmission hole 410, thereby driving the piston 400 to move up and down reciprocatingly.

[0063] In this embodiment, the wear-resistant piece 450 is in the form of a sheet and is fixed to the hole wall of the transmission hole 410. Further, the wear-resistant piece 450 is provided with two and is located at the top side and the bottom side of the transmission hole 410 respectively. The wear-resistant piece 450 at the top side is provided corresponding to the upper pump cavity 203, and the wear-resistant piece 450 at the bottom side is provided corresponding to the lower pump cavity 203. When the outer circumferential surface of the bearing 320 is in contact with the lower wear-resistant piece 450, the piston 400 is driven to move downward, and when the outer circumferential surface of the bearing 320 is in contact with the upper wear-resistant piece 450, the piston 400 is driven to move upward. Specifically, the wear-resistant piece 450 can be made of high-hardness alloy steel or high-precision titanium alloy metal material, and the other parts of the piston 400 except the wear-resistant piece 450 can be made of high-hardness plastic material.

[0064] In combination Figure 9 In order to set the wear-resistant piece 450, the piston 400 is provided with a limiting groove 440 at the top side and the bottom side of the lug 430. The limiting groove 440 is open to one side of the transmission hole 410 to make the limiting groove 440 communicate with the transmission hole 410. The wear-resistant piece 450 is set at the lug 430 by cooperating with the limiting groove 440. The surface of the wear-resistant piece 450 towards the center of the transmission hole 410 constitutes the local hole wall of the transmission hole 410. This surface forms an abutting surface 451 which can be in contact with the outer circumferential surface of the bearing 320. The distance between the upper and lower abutting surfaces 451 determines the hole diameter D2 of the transmission hole 410 in the up-down direction. In order to ensure the stability of the piston 400 driven by the bearing 320 to move up and down, the left and right ends of the abutting surface 451 are smoothly aligned with the inner surface of the lug 430, avoiding the generation of steps between the end of the abutting surface 451 and the inner surface of the lug 430. The abutting surface 451 can be a flat surface or a curved surface which is adapted to the outer circumferential surface of the bearing 320. Further, the limiting groove 440 is in the shape of a T-shaped groove and the groove width near the center of the transmission hole 410 is smaller than the groove width far from the center of the transmission hole 410, that is, the limiting groove 440 is narrow inside and wide outside. Correspondingly, the wear-resistant piece 450 is also narrow inside and wide outside and the width near the center of the transmission hole 410 is smaller than the width far from the center of the transmission hole 410. The wear-resistant piece 450 can be inserted into the limiting groove 440 from back to front during installation, and the front end of the wear-resistant piece 450 inserted into the limiting groove 440 is limited by contact. Reasonably setting the shapes of the limiting groove 440 and the wear-resistant piece 450 can ensure the structural stability of the wear-resistant piece 450 and avoid the wear-resistant piece 450 from separating from the limiting groove 440.

[0065] In order to ensure the structural strength of the wear-resistant piece 450, the thickness T of the wear-resistant piece 450 needs to be reasonably set, 2mm≤T≤5mm. Specifically, the thickness T of the wear-resistant piece 450 can be reasonably determined according to the size of the transmission hole 410, the thickness of the lug 430 and other factors. The thickness T of the wear-resistant piece 450 can be set to 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm and other reasonable sizes.

[0066] In order to ensure that the outer circumferential surface of the bearing 320 is in contact with the wear-resistant piece 450 only to drive the piston 400 to reciprocate, the width W of the wear-resistant piece 450 and the outer diameter D of the cam piece 300 need to be reasonably set, and 0.25≤W / D≤0.4. Specifically, the width W of the wear-resistant piece 450 refers to the width of the abutting surface, the outer diameter D of the cam piece 300 is consistent with the outer diameter D3 of the bearing 320, and W / D can be set to 0.25, 0.27, 0.3, 0.32, 0.35, 0.37, 0.4, etc. reasonable size, for example, when the outer diameter D3 of the bearing 320 is 26 mm, the width of the wear-resistant piece 450 can be set to 6.5 mm, 7 mm, 8 mm, 9 mm, 10 mm, etc. reasonable size.

[0067] In combination Figure 11 The main housing 230 is provided with an inflow connector 233 protruding outward around the inlet hole 201 and an outflow connector 234 protruding outward around the outlet hole 202. The inflow connector 233 can be connected to a fluid source through a pipeline, and the outflow connector 234 can be connected to other objects through a pipeline.

[0068] The front side of the main housing 230 is provided with a front cover 250, and the front side of the front cover 250 is fixed with a stop switch 270 through a cover 260. The front cover 250 and the main housing 230 form a cavity, and a trigger assembly 280 for triggering the stop switch 270 is arranged in the cavity. When the fluid discharge is blocked, the trigger assembly 280 triggers the stop switch 270, and the motor stops working, so that the electric diaphragm pump 10 stops pumping. The electric diaphragm pump 10 can be successfully started only when the stop switch 270 is in an untriggered state, thereby ensuring the safety of the electric diaphragm pump 10. Specifically, the trigger assembly 280 includes a fixed hoop 281, a flexible diaphragm 282 whose circumferential edge is pressed by the hoop 281, a movable sleeve 283 which is located in the inner circumference of the hoop 281 and in front of the flexible diaphragm 282, a third spring 284 which biases the movable sleeve 283 rearward so that the movable sleeve 283 releases the stop switch 270 in a normal state, a trigger cavity 291 is formed between the flexible diaphragm 282 and the front surface of the main housing 230, and a small hole 292 for connecting the discharge channel 232 and the trigger cavity 291 is arranged on the front side wall of the main housing 230. When the fluid cannot be discharged smoothly, the fluid in the discharge channel 232 accumulates and the pressure increases, the fluid flows into the trigger cavity 291 through the small hole 292, the fluid flowing into the trigger cavity 291 causes the flexible diaphragm 282 to elastically deform, the flexible diaphragm 282 driven by the fluid drives the movable sleeve 283 to move forward against the bias of the third spring 284, the movable sleeve 283 moving forward triggers the stop switch 270, and the control panel of the motor commands the motor to stop according to the trigger signal of the stop switch 270, so that the electric diaphragm pump 10 stops working. After the obstacle of fluid discharge is removed, the third spring 284 which restores the deformation drives the movable sleeve 283 to move backward to release the stop switch 270, and the movable sleeve 283 moving backward extrudes the flexible diaphragm 282, and the fluid in the trigger cavity 291 flows back into the discharge channel 232 under the extrusion.

[0069] When the small electric diaphragm pump 10 of the embodiment works, the shaft 110 drives the bearing 320 to rotate eccentrically, the outer circumferential surface of the eccentrically rotating bearing 320 repeatedly collides with the two wear-resistant pieces 450 to drive the piston 400 to move up and down, and the piston 400 moving up and down makes the pump body 200 continuously suck and discharge fluid, thereby realizing the pumping of fluid.

[0070] The small electric diaphragm pump 10 of the embodiment can be applied in electric tool products with pumping requirements, including but not limited to electric spray guns, electric cleaning machines, electric sprayers, etc.

[0071] Embodiment Two

[0072] Combination Figure 12In the embodiment, the wear-resistant part 450 is in the shape of a ring and is fixed on the piston 400, and the transmission hole 410 is formed by the ring-shaped wear-resistant part 450. Specifically, the convex ring 430 on the piston 400 is the wear-resistant part 450 made of a metal material with high hardness.

[0073] The other structures of the second embodiment are the same as those of the first embodiment, and thus will not be described herein.

[0074] Embodiment Three

[0075] In the embodiment, the piston 400 is made of a metal material with high hardness as a whole.

[0076] The other structures of the third embodiment are the same as those of the first embodiment, and thus will not be described herein.

[0077] In addition to the preferred embodiments, the utility model also has other implementation manners, and those skilled in the art can make various changes and deformation according to the utility model, as long as it does not deviate from the spirit of the utility model, and it should belong to the range defined in the claim of the utility model.

Claims

1. A small electric diaphragm pump, comprising: a power element having a rotating shaft outputting rotary motion; a pump body having an inlet hole, an outlet hole, a pump cavity and a containing cavity, the inlet hole being intermittently communicated with the pump cavity through a suction check valve, the pump cavity being intermittently communicated with the outlet hole through a discharge check valve; a cam element eccentrically sleeved on the rotating shaft and driven to rotate by the rotating shaft; a piston movably arranged in the containing cavity and having a transmission hole matched with the cam element, the rotating cam element being in contact with the partial hole wall of the transmission hole to drive the piston to make linear reciprocating motion, the reciprocating piston making the volume of the pump cavity reciprocate; characterized in that the piston is provided with a wear-resistant element made of metal material at least at the position in contact with the cam element, the rotating cam element being in contact with the wear-resistant element to drive the piston to make linear reciprocating motion.

2. The small electric diaphragm pump according to claim 1, characterized in that, The wear-resistant element is in the shape of a sheet and fixed on the hole wall of the transmission hole.

3. The small electric diaphragm pump according to claim 2, characterized in that, The surface of the wear-resistant element towards the center of the transmission hole is a plane or a curved surface.

4. The small electric diaphragm pump according to claim 2, characterized in that, The thickness of the wear-resistant element is T, 2mm≤T≤5mm; the width of the wear-resistant element is W, the outer diameter of the cam element is D, and 0.2≤W / D≤0.

4.

5. The compact electric diaphragm pump of claim 2, wherein, The piston is provided with a limiting groove outside the transmission hole, and the wear-resistant element is arranged on the piston and faces the cam element through cooperation with the limiting groove.

6. The small electric diaphragm pump according to claim 5, characterized in that The limiting groove and the sheet-shaped wear-resistant element are both arranged with a narrow inside and a wide outside, and the limiting groove is communicated with the transmission hole.

7. The compact electric diaphragm pump of claim 2, wherein, The pump cavity is provided with two and located at both ends of the piston movement direction respectively, and the wear-resistant element is provided with two and distributed corresponding to the two pump cavities respectively.

8. The compact electric diaphragm pump of claim 1, wherein, The wear-resistant element is in the shape of a ring and fixed on the piston, and the transmission hole is formed by the ring-shaped wear-resistant element.

9. The compact electric diaphragm pump of claim 1, wherein, The piston is made of metal material as a whole.

10. The small electric diaphragm pump according to any one of claims 1 to 9, characterized by The cam element comprises a rotating wheel and a bearing, the rotating wheel comprises an integrally formed wheel body and a limiting part, the rotating wheel is eccentrically sleeved on the outside of the rotating shaft, the bearing is sleeved on the outside of the wheel body, and the limiting part is located on the side of the bearing away from the motor.

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