Diaphragm metering pump

Abstract

The utility model provides a diaphragm metering pump, including box, power part, output part and diaphragm, power part is located the top of box, power part is speed reducer, output part sets up in the box, and output part includes eccentric mechanism and push rod, one end of eccentric mechanism is connected with power part, the side of eccentric mechanism and push rod abut, a plurality of grease storage grooves are seted up on push rod, the grease storage groove is recessed from the surface of push rod to the inside, the grease storage groove is used to accommodate solid lubricating grease. Through setting power part as speed reducer to replace original worm and worm gear, make diaphragm metering pump not to adopt oil bath lubrication mode to carry out lubrication, set grease storage groove on push rod to store solid lubricating grease, compared with oil bath lubrication, need not set up sealing structure separately in the box, and the manufacturing cost is reduced, and need not worry about oil leakage. Solid lubricating grease lubrication period is longer, and need not worry about oil leakage in the process of replacing lubricating grease, and maintenance is simpler.

Description

Technical Field

[0001] This utility model specifically relates to a diaphragm metering pump. Background Technology

[0002] The diaphragm metering pump uses an external motor to drive an eccentric mechanism, which in turn pushes a push rod to cause the diaphragm to oscillate back and forth, thus achieving fluid intake and discharge and completing the quantitative delivery of fluid. After the external motor inputs power, the worm gear drives the worm wheel to rotate rapidly. The eccentric mechanism, connected to the worm wheel via a key, rotates along with it. Under the action of a spring, the push rod remains in contact with the eccentric mechanism. The rotation of the eccentric mechanism causes the push rod and the connected diaphragm to oscillate back and forth.

[0003] However, because worm gears require oil bath lubrication to reduce wear and extend service life, a matching sealing structure needs to be designed in the drive housing to prevent oil leakage. This increases the cost of the diaphragm metering pump, and the risk of oil leakage is always present. Furthermore, the sealing structure and lubricating oil require periodic maintenance and replacement, increasing the customer's operating costs. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the defects of high lubrication cost and easy leakage of lubricating medium when the diaphragm metering pump uses worm gear to transmit power in the prior art, and to provide a diaphragm metering pump.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] A diaphragm metering pump includes a housing, a power unit, an output unit, and a diaphragm. The power unit is located above the housing and is a geared motor. The output unit is disposed inside the housing and includes an eccentric mechanism and a push rod. One end of the eccentric mechanism is connected to the power unit, and the side of the eccentric mechanism abuts against the push rod. The push rod has a plurality of grease reservoirs, which are recessed inward from the surface of the push rod and are used to contain solid grease.

[0007] In this design, by replacing the original worm gear reduction and power transmission method with a geared motor as the power unit, the diaphragm metering pump no longer requires oil bath lubrication. Furthermore, the power unit is located above the housing, freeing up internal space due to the elimination of the worm gear structure, resulting in a smaller housing volume and overall pump size, making it suitable for space-constrained environments. The geared motor offers a 15% improvement in transmission efficiency compared to the worm gear structure. Additionally, a grease reservoir on the push rod stores solid grease, eliminating the need for a separate sealing structure within the housing compared to oil bath lubrication, reducing manufacturing costs and eliminating concerns about oil leakage. The solid grease reservoir extends lubrication cycles, and there is no risk of leakage when using oil as the lubricating medium during grease changes, simplifying maintenance.

[0008] Preferably, the grease reservoirs are spaced apart along the axial direction of the push rod.

[0009] In this solution, the amount of grease stored is increased by increasing the number of grease reservoirs along the direction of push rod movement, as described above.

[0010] Preferably, the eccentric mechanism includes an eccentric rod, the end of the eccentric rod for connecting with the power unit has a connecting hole, the inner wall of the connecting hole has a groove, and the power end of the power unit has a protrusion corresponding to the groove;

[0011] Alternatively, the power end of the power unit may be provided with a power groove corresponding to the groove, and the groove and the power groove may be connected by a key.

[0012] In this solution, the above-mentioned settings are used to achieve an effective connection between the eccentric rod and the power end of the power unit.

[0013] Preferably, the eccentric mechanism further includes a mounting bearing, and the housing is provided with a mounting groove on the periphery of the eccentric rod and near the end of the eccentric rod. The mounting bearing is embedded in the mounting groove and the non-eccentric area of ​​the eccentric rod passes through the mounting bearing.

[0014] In this solution, the above-mentioned setup utilizes the installation bearing to support the eccentric rod, preventing the eccentric rod from deviating from the preset area and colliding with the inner wall of the box during rotation.

[0015] Preferably, the eccentric mechanism further includes a fixed bearing, the eccentric region of the eccentric rod passes through the fixed bearing, the fixed bearing is fixedly connected to the surface of the eccentric rod, and the side of the fixed bearing abuts against the push rod.

[0016] In this solution, the above-mentioned arrangement allows the side of the fixed bearing to abut against the push rod. The fixed bearing itself can rotate, which makes the wear more uniform when it contacts the push rod, thus improving the stability of operation.

[0017] Preferably, there are two mounting bearings and two mounting slots in the housing. The two mounting slots are located on the periphery of the two ends of the eccentric rod, and the two mounting bearings are respectively disposed in the two mounting slots. The non-eccentric area of ​​the eccentric rod passes through the two mounting bearings.

[0018] In this solution, by increasing the number of bearings installed through the above settings, load distribution and stability can be achieved.

[0019] Preferably, at least two fixed bearings are provided, and at least two fixed bearings are fixedly connected to the eccentric region of the eccentric rod, and the sides of at least two fixed bearings abut against the push rod.

[0020] In this solution, by increasing the number of fixed bearings, the contact area between the eccentric mechanism and the push rod is increased, preventing a single fixed bearing from forming a cantilever structure when in contact with the push rod and causing the eccentric rod to deviate from the preset area and collide with the inner wall of the housing during rotation.

[0021] Preferably, the output section further includes a base, and a through hole is provided in the housing. The base is used to close the through hole and is fixedly connected to the housing. The push rod is disposed in the through hole. The end of the push rod that abuts against the side of the eccentric mechanism has a large diameter, while the end of the push rod that is away from the eccentric mechanism has a small diameter. The outer edge of the large-diameter end of the push rod and the outer edge of the base are both provided with steps. An elastic element is provided between the step of the push rod and the step of the base. The small-diameter end of the push rod is connected to the diaphragm.

[0022] In this solution, the above settings are used to reset the push rod after it is driven by the eccentric mechanism, so that the push rod and the eccentric mechanism always remain in contact.

[0023] Preferably, the base includes a sleeve portion that extends into the through hole and the smaller diameter end of the push rod extends into the sleeve portion, and the sleeve portion covers the opening of the grease reservoir.

[0024] In this solution, the above-mentioned configuration is used to seal the opening of the grease reservoir by using the sleeve portion, so that the grease in the grease reservoir is always located between the push rod and the sleeve portion, preventing the grease from leaking into the housing and ensuring the lubrication effect.

[0025] Preferably, a connecting block is provided on the side of the diaphragm facing the push rod, the diameter of the connecting block is larger than the diameter of the push rod, the end of the push rod corresponding to the connecting block is provided with a first circular hole, and the connecting block is provided with a second circular hole, and pins are inserted into the first circular hole and the second circular hole.

[0026] In this solution, the above settings are used to connect the push rod to the diaphragm, and the connecting block is used to increase the contact area when connecting to the diaphragm.

[0027] The significant advantages of this invention are as follows: By replacing the traditional worm gear system with a geared motor for power transmission, the diaphragm metering pump eliminates the need for oil bath lubrication. Furthermore, the power unit's location above the housing frees up internal space, reducing the overall size of the housing and the diaphragm metering pump, making it suitable for space-constrained environments. The geared motor offers a 15% increase in transmission efficiency compared to the worm gear system. Additionally, the push rod features a grease reservoir to store solid grease, eliminating the need for a separate sealing structure within the housing compared to oil bath lubrication, thus reducing manufacturing costs and eliminating concerns about oil leakage. The solid grease reservoir extends lubrication cycles, and there is no risk of leakage when using oil as the lubricating medium during grease changes, simplifying maintenance. Attached Figure Description

[0028] Figure 1 This is a perspective view of a diaphragm metering pump according to a preferred embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the structure of a diaphragm metering pump according to a preferred embodiment of the present invention.

[0030] Figure 3 This is a schematic diagram of the eccentric mechanism and push rod of a preferred embodiment of the present invention.

[0031] Figure 4 This is a perspective view of the eccentric rod according to a preferred embodiment of the present invention.

[0032] Figure 5 This is a schematic diagram of the push rod according to a preferred embodiment of the present invention.

[0033] Explanation of reference numerals in the attached figures:

[0034] Box 1

[0035] Mounting slot 11

[0036] Through hole 12

[0037] Power Unit 2

[0038] Output Section 3

[0039] Eccentric mechanism 31

[0040] Eccentric rod 311

[0041] Connection hole 3111

[0042] Putter 32

[0043] Grease tank 321

[0044] First circular hole 322

[0045] Install bearing 33

[0046] Fixed bearing 34

[0047] Base 35

[0048] Sleeve 351

[0049] Step 36

[0050] Elastic element 37

[0051] Diaphragm 4

[0052] Connecting block 5

[0053] Second round hole 51

[0054] Pin 6 Detailed Implementation

[0055] The present invention will be described more clearly and completely below with reference to the accompanying drawings, using a preferred embodiment.

[0056] This embodiment provides a diaphragm metering pump, the specific structure of which is as follows: Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the diaphragm metering pump includes a housing 1, a power unit 2, an output unit 3, and a diaphragm 4. The power unit 2 is located above the housing 1 and is a geared motor. The output unit 3 is located inside the housing 1 and includes an eccentric mechanism 31 and a push rod 32. One end of the eccentric mechanism 31 is connected to the power unit 2, and the side of the eccentric mechanism 31 abuts against the push rod 32. The push rod 32 has several grease reservoirs 321, which are recessed inward from the surface of the push rod 32. The grease reservoirs 321 are used to contain solid grease.

[0057] Specifically, the housing 1 has a cavity to accommodate the output section 3. An opening is provided at the top of the housing 1. The power unit 2 is located at the top of the housing 1 and closes the opening. The power end of the power unit 2 extends into the housing 1 and connects to the eccentric mechanism 31 of the output section 3. The power unit 2 is a geared motor, a drive device including a reduction gear structure and a motor structure. By using a geared motor to replace the original method of using a worm gear to reduce speed and transmit power within the housing 1, the diaphragm metering pump does not need oil bath lubrication. Furthermore, since the power unit 2 is located above the housing 1, the internal space of the housing 1 is freed up due to the elimination of the worm gear structure, reducing the volume of the housing 1 and the overall volume of the diaphragm metering pump, making it suitable for space-constrained environments. Compared to the worm gear structure, the geared motor improves transmission efficiency by 15%.

[0058] In this embodiment, the eccentric mechanism 31 is disposed within the housing 1 along the height direction, and the push rod 32 is disposed within the housing 1 along the length direction, i.e., the push rod 32 is perpendicular to the eccentric mechanism 31. The eccentric region of the eccentric mechanism 31 rotates under the drive of the power unit 2 to abut against the push rod 32, thereby driving the push rod 32 to reciprocate. The push rod 32 has several grease reservoirs 321. Viewed in cross-section, the grease reservoirs 321 are recessed inwards from the surface of the push rod 32 and are rectangular grooves. These rectangular grooves are arranged around the push rod 32. The grease reservoirs 321 are used to contain solid grease. The solid grease is a lubricating medium in the prior art, such as lithium-based grease, calcium-based grease, or perfluoropolyether grease, which will not be elaborated further here. When the grease reservoirs 321 store solid grease for lubrication, compared to oil bath lubrication, the grease is less prone to flow, eliminating the need for a separate sealing structure within the housing 1, reducing manufacturing costs, and eliminating concerns about oil leakage. The grease reservoir 321 stores solid grease, which extends the lubrication cycle. When changing grease, there is no need to worry about leakage when the lubricating medium is lubricating oil, making maintenance simpler.

[0059] In this embodiment, the grease reservoirs 321 are spaced apart along the axial direction of the push rod 32.

[0060] Specifically, multiple grease reservoirs 321 are provided, spaced apart from each other and arranged along the axial direction of the push rod 32, that is, along the length of the housing 1. Compared with a single grease reservoir 321, the amount of grease stored is increased by increasing the number of grease reservoirs. This improves the lubrication and maintenance cycle and eliminates the need for frequent disassembly of the push rod 32.

[0061] like Figure 3 and Figure 4As shown, in this embodiment, the eccentric mechanism 31 includes an eccentric rod 311. The end of the eccentric rod 311 used for connecting with the power unit 2 is provided with a connecting hole 3111. A groove (not shown in the figure) is provided on the inner wall of the connecting hole 3111. A protrusion (not shown in the figure) is provided on the power end of the power unit 2 corresponding to the groove.

[0062] Specifically, the eccentric rod 311 is a rod with an eccentric region and a non-eccentric region. The eccentric region is where the position of the rod is off-center from the axis of the eccentric rod 311, while the non-eccentric region is where the position of the rod coincides with the axis of the eccentric rod 311. This is existing technology and will not be elaborated further here. The power end of the power unit 2 is a cylindrical rod that is inserted into the connection hole 3111 at the end of the power unit 2 corresponding to the non-eccentric region of the eccentric rod 311. At the same time, a groove is provided on the inner wall of the connection hole 3111, and a protrusion is provided on the power end of the power unit 2 corresponding to the groove. When the eccentric rod 311 is connected to the power unit 2, the power end of the power unit 2 can drive the eccentric rod 311 to rotate through the cooperation of the protrusion and the groove.

[0063] Of course, in other embodiments, the power end of the power unit 2 may also be provided with a power groove (not shown in the figure) corresponding to the groove. That is, the power end and the connecting hole 3111 that are inserted into each other are both provided with groove structures. The two groove structures are connected and torque is transmitted by inserting a key. The key connection is a connection method in the prior art. This embodiment has not improved it, so it will not be described in detail here.

[0064] In this embodiment, the eccentric mechanism 31 further includes a mounting bearing 33. The housing 1 is provided with a mounting groove 11 on the periphery of the eccentric rod 311 and near the end of the eccentric rod 311. The mounting bearing 33 is embedded in the mounting groove 11 and the non-eccentric area of ​​the eccentric rod 311 passes through the mounting bearing 33.

[0065] Specifically, the mounting bearing 33 can be a ball bearing in the prior art. The mounting bearing 33 is embedded in the mounting groove 11 of the housing 1. The mounting groove 11 is located on the periphery of the non-eccentric area of ​​the eccentric rod 311 near the power unit 2, so as to support the eccentric rod 311 by using the mounting bearing 33 and prevent the eccentric rod 311 from deviating from the preset area and colliding with the inner wall of the housing 1 during the rotation process.

[0066] In this embodiment, the eccentric mechanism 31 further includes a fixed bearing 34. The eccentric region of the eccentric rod 311 passes through the fixed bearing 34. The fixed bearing 34 is fixedly connected to the surface of the eccentric rod 311, and the side of the fixed bearing 34 abuts against the push rod 32.

[0067] Specifically, the fixed bearing 34 is a ball bearing as used in the prior art. Unlike the mounting bearing 33, the fixed bearing 34 passes through the eccentric region of the eccentric rod 311. The fixed bearing 34 is secured to the eccentric region of the eccentric rod 311 by welding or by a snap ring, thus achieving a surface-fixed connection between the fixed bearing 34 and the eccentric rod 311. While the outer side surface of the fixed bearing 34 abuts against the push rod 32, the fixed bearing 34 itself can rotate, resulting in more even wear and improved operational stability when in contact with the push rod 32.

[0068] It is understandable that in this embodiment, the number of mounting bearings 33 and fixed bearings 34 is one, and both are located close to the power unit 2. Although this can effectively drive the push rod 32 to reciprocate, the eccentric mechanism 31 has a cantilever beam structure due to the small contact area with the push rod 32. Although this results in lower manufacturing costs, it can only withstand a small thrust and has insufficient stability.

[0069] Preferably, there are two mounting bearings 33 and two mounting slots 11 are provided in the housing 1. The two mounting slots 11 are located on the periphery of the two ends near the eccentric rod 311. The two mounting bearings 33 are respectively provided in the two mounting slots 11, and the non-eccentric area of ​​the eccentric rod 311 passes through the two mounting bearings 33.

[0070] Specifically, the housing 1 is provided with two mounting slots 11, which are respectively provided on the periphery of the non-eccentric areas at both ends of the eccentric rod 311. Two mounting bearings 33 are respectively embedded in the two mounting slots 11 to support the two ends of the eccentric rod 311. Compared with the method of supporting with a single mounting bearing 33, the cantilever beam structure is eliminated. By increasing the number of mounting bearings 33, the rotational stability of the eccentric rod 311 is improved, and the load can be distributed when the eccentric rod 311 rotates.

[0071] Furthermore, at least two fixed bearings 34 are provided, and at least two fixed bearings 34 are fixedly connected to the eccentric region of the eccentric rod 311, and the sides of at least two fixed bearings 34 abut against the push rod 32.

[0072] Specifically, at least two fixed bearings 34 are provided on the eccentric region of the eccentric rod 311 at the end of the corresponding push rod 32. Compared with a single fixed bearing 34, by increasing the number of fixed bearings 34, the contact area between the eccentric mechanism 31 and the push rod 32 is increased, preventing a single fixed bearing 34 from forming a cantilever structure when in contact with the push rod 32 and causing the eccentric rod 311 to deviate from the preset area and collide with the inner wall of the housing 1 during rotation.

[0073] In this embodiment, the output part 3 also includes a base 35. A through hole 12 is provided in the housing 1. The base 35 is used to close the through hole 12 and is fixedly connected to the housing 1. The push rod 32 is disposed in the through hole 12. The end of the push rod 32 that abuts against the side of the eccentric mechanism 31 has a large diameter, while the end of the push rod 32 that is away from the eccentric mechanism 31 has a small diameter. The outer edge of the large diameter end of the push rod 32 and the outer edge of the base 35 are both provided with a step 36. An elastic element 37 is provided between the step 36 of the push rod 32 and the step 36 of the base 35. The small diameter end of the push rod 32 is connected to the diaphragm 4.

[0074] Specifically, the through hole 12 extends along the length of the housing 1 and is perpendicular to the eccentric rod 311. The push rod 32 is disposed inside the through hole 12, and the end of the push rod 32 with a larger diameter abuts against the fixed bearing 34 on the eccentric rod 311. The base 35 has a disc structure and one end extends into the through hole 12 to close the through hole 12. A cavity is provided inside the base 35 corresponding to the through hole 12 so that the end of the push rod 32 with a smaller diameter can extend into the base 35. The side of the base 35 away from the housing 1 communicates with the cavity and is provided with a diaphragm 4. When the smaller diameter end of the push rod 32 extends into the through hole 12, there is a gap between it and the inner wall of the through hole 12. The two ends of this gap are the steps 36 on the larger diameter end of the push rod 32 and the steps 36 on the part of the base 35 extending into the through hole 12. An elastic element 37 is provided in the gap. The elastic element 37 is a spring in the prior art. The steps 36 of the push rod 32 and the steps 36 of the base 35 abut against the elastic element 37. When the push rod 32 is pushed by the eccentric rod 311 to reciprocate, the elastic element 27 is compressed and has a force that causes the push rod 32 to return to its original position and press against the fixed bearing 34 on the eccentric rod 311. By setting the steps 36 and the elastic element 37, the push rod 32 is able to return to its original position after being driven by the eccentric mechanism 31, so that the push rod 32 and the eccentric mechanism 31 always maintain contact, ensuring the accuracy of the diaphragm metering pump.

[0075] In this embodiment, the base 35 includes a sleeve portion 351, which extends into the through hole 12 and the end of the push rod 32 with a smaller diameter extends into the sleeve portion 351. The sleeve portion 351 covers the opening of the grease reservoir 321.

[0076] Specifically, the sleeve portion 351 is a hollow sleeve structure, integrally formed with the base 35. The smaller diameter end of the push rod 32 is used to extend into the sleeve portion 351 so that the push rod 32 can pass through the base 35. The sleeve portion 351 extends along the extension direction of the through hole 12. When the push rod 32 extends into the sleeve portion 351, the sleeve portion 351 can cover the opening of each grease reservoir 321. That is, the extension length of the sleeve portion 351 is greater than or equal to the arrangement size of the multiple spaced grease reservoirs 321 on the push rod 32. The sleeve portion 351 closes the opening of the grease reservoir 321, so that the grease in the grease reservoir 321 is always between the push rod 32 and the sleeve portion 351, preventing the grease from leaking into the housing 1, ensuring the lubrication effect without the need for an additional sealing structure, and eliminating concerns about oil leakage.

[0077] In this embodiment, a connecting block 5 is provided on the side of the diaphragm 4 facing the push rod 32. The diameter of the connecting block 5 is larger than the diameter of the push rod 32. A first circular hole 322 is provided on the end of the push rod 32 corresponding to the connecting block 5. A second circular hole 51 is provided on the connecting block 5. A pin 6 passes through the first circular hole 322 and the second circular hole 51.

[0078] Specifically, the connecting block 5 is a disc, and the diaphragm 4 is provided with a receiving groove. The connecting block 5 is embedded in the receiving groove. The side of the connecting block 5 away from the diaphragm 4 has a second circular hole 51. The end of the push rod 32 with a smaller diameter faces the connecting block 5 and has a first circular hole 322. The first circular hole 322 and the second circular hole 51 are fitted with pins 6 to connect the push rod 32 to the diaphragm 4. Compared with the end of the push rod 32 with a smaller diameter directly abutting against the diaphragm 4, the diameter of the connecting block 5 is larger than the diameter of the push rod 32. The connecting block 5 is used to increase the contact area when the push rod 32 is connected to the diaphragm 4, thereby improving the stability when pushing the diaphragm 4.

[0079] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A diaphragm metering pump, the diaphragm metering pump comprising a housing, a power unit, an output unit, and a diaphragm, characterized in that, The power unit is located above the housing and is a geared motor. The output unit is located inside the housing and includes an eccentric mechanism and a push rod. One end of the eccentric mechanism is connected to the power unit, and the side of the eccentric mechanism abuts against the push rod. The push rod has several grease reservoirs that are recessed inward from the surface of the push rod and are used to hold solid grease.

2. The diaphragm metering pump as described in claim 1, characterized in that, The grease reservoirs are spaced apart along the axial direction of the push rod.

3. The diaphragm metering pump as described in claim 1, characterized in that, The eccentric mechanism includes an eccentric rod, the end of which is connected to the power unit has a connecting hole, the inner wall of the connecting hole has a groove, and the power end of the power unit has a protrusion corresponding to the groove. Alternatively, the power end of the power unit may be provided with a power groove corresponding to the groove, and the groove and the power groove may be connected by a key.

4. The diaphragm metering pump as described in claim 3, characterized in that, The eccentric mechanism further includes a mounting bearing. The housing is provided with a mounting groove on the periphery of the eccentric rod and near the end of the eccentric rod. The mounting bearing is embedded in the mounting groove and the non-eccentric area of ​​the eccentric rod passes through the mounting bearing.

5. The diaphragm metering pump as described in claim 4, characterized in that, The eccentric mechanism further includes a fixed bearing, the eccentric region of the eccentric rod passes through the fixed bearing, the fixed bearing is fixedly connected to the surface of the eccentric rod, and the side of the fixed bearing abuts against the push rod.

6. The diaphragm metering pump as described in claim 5, characterized in that, Two mounting bearings are provided, and the housing is provided with two mounting slots. The two mounting slots are respectively located on the periphery of the two ends of the eccentric rod. The two mounting bearings are respectively disposed in the two mounting slots, and the non-eccentric area of ​​the eccentric rod passes through the two mounting bearings.

7. The diaphragm metering pump as described in claim 6, characterized in that, At least two fixed bearings are provided, and at least two fixed bearings are fixedly connected to the eccentric region of the eccentric rod, and the sides of at least two fixed bearings abut against the push rod.

8. The diaphragm metering pump as described in claim 1, characterized in that, The output section also includes a base. A through hole is provided inside the housing. The base is used to close the through hole and is fixedly connected to the housing. The push rod is disposed in the through hole. The end of the push rod that abuts against the side of the eccentric mechanism has a large diameter, while the end of the push rod that is away from the eccentric mechanism has a small diameter. The outer edge of the large diameter end of the push rod and the outer edge of the base are both provided with steps. An elastic element is provided between the step of the push rod and the step of the base. The small diameter end of the push rod is connected to the diaphragm.

9. The diaphragm metering pump as described in claim 8, characterized in that, The base includes a sleeve portion that extends into the through hole, and the smaller diameter end of the push rod extends into the sleeve portion. The sleeve portion covers the opening of the grease reservoir.

10. The diaphragm metering pump as described in claim 8, characterized in that, A connecting block is provided on the side of the diaphragm facing the push rod. The diameter of the connecting block is larger than the diameter of the push rod. A first circular hole is provided on the end of the push rod corresponding to the connecting block, and a second circular hole is provided on the connecting block. A pin passes through the first circular hole and the second circular hole.

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