Eccentric indexing type quantity adjusting mechanism of metering pump

Abstract

The utility model discloses an eccentric indexing type quantity adjusting mechanism of a metering pump, which relates to the field of hydraulic pumps and comprises a rack and a pump head of an adjusting component, the rack is fixedly connected with the pump head, a pump shaft and an eccentric hand wheel connector are fixed on the rack, one end of the head of the pump shaft is contacted with an eccentric body of an eccentric hand wheel, and the other end of the head of the pump shaft is contacted with an eccentric wheel. The outer surface of the pump shaft is sleeved with a spring for generating pre-pressing force, the tail end of the spring is connected with a diaphragm, the front end of the pump head is connected with a first valve body of an inlet one-way valve, the rear end of the pump head is connected with a second valve body of an outlet one-way valve, and the first valve body wraps a first valve ball. The second valve body wraps the second valve ball. The adjusting assembly is used for adjusting the stroke of the diaphragm, namely the flow of liquid pressed in and out is adjusted.

Description

Technical Field

[0001] The utility model relates to the application field of a hydraulic pump, in particular to an eccentric indexing type metering mechanism of a metering pump. Background Art

[0002] The principle of using a threaded adjustment rod to achieve stroke flow regulation: the stroke adjustment mechanism consists of a handwheel and an adjustment rod fixed together, and the adjustment rod is threadedly connected to the frame. Assuming this thread pair is right-handed, when the handwheel is rotated clockwise, the adjustment rod moves to the left under the action of the thread pair, which limits the return displacement of the pump shaft. This means that the effective stroke of the plunger (or piston, or diaphragm) is reduced, and the change in the sealed volume is correspondingly reduced, thereby reducing the controlled flow rate. Conversely, the return displacement of the pump shaft increases, the effective stroke of the plunger (or piston, or diaphragm) increases, the change in the sealed volume increases, and the flow rate increases.

[0003] The shortcomings of the existing technology are: 1. Due to the structural design, the pump shaft stroke requires axial limit, and the adjustment mechanism composed of the adjustment rod also moves linearly along the axis due to the side effect of the thread. Therefore, the pump stroke size is the linear displacement of the adjustment rod. When the pump stroke is large, a longer adjustment rod and a thread pair of sufficient length are required. Therefore, the axial dimension cannot be compressed, and the structure is not compact. 2. In order to ensure that the rear end of the pump shaft is well stressed (to avoid excessive overturning torque), the axis of the adjustment rod must be as close to the pump shaft axis as possible. However, due to the influence of the structure, the diameter of the adjustment rod cannot be made sufficiently thick (it will interfere with the eccentric wheel), resulting in the adjustment rod becoming a slender rod with a large aspect ratio, which is prone to rod instability and bending. 3. Because the metering pump operates intermittently, the impact load applied by the pump shaft to the adjustment rod end needs to be fully borne by the thread teeth. Therefore, the internal and external thread processing precision must be high to avoid excessive tooth side clearance and impact damage. In addition, the thread teeth cannot be too small, otherwise they will not be able to withstand the impact load. Utility Model Content

[0004] The technical problem solved by the utility model is to provide an eccentric indexing type metering adjustment mechanism of a metering pump which has the advantages of simple structure, small size, good processing technology, high strength and rigidity.

[0005] The technical solution adopted by the utility model to solve its technical problems is: an eccentric indexing volume adjustment mechanism of a metering pump, comprising an adjustment component and a pump head, the adjustment component consisting of an eccentric handwheel, a pump shaft, an eccentric wheel and a frame, the eccentric handwheel consisting of an eccentric body, a connecting body and an operating handwheel, the eccentric body, the connecting body and the operating handwheel are all rotating bodies, the pump shaft is a T-shaped structure, the eccentric body of the eccentric handwheel is in contact with one end of the pump shaft head, the eccentric wheel is in contact with the other end of the pump shaft head, the connecting body is supported by the frame, the eccentric body is inside the frame, and the operating handwheel is outside the frame.

[0006] Furthermore, the rotation centers of the eccentric body and the operating handwheel rotating body differ by a certain eccentricity e. The rotation center of the eccentric handwheel is a fixed point. The return stroke of the pump shaft is controlled by changing the center position of the eccentric body. The outer surface of the pump shaft is provided with a spring that generates a pre-compression force. The pump shaft passes through the frame to connect the diaphragm.

[0007] Furthermore, the operating handwheel is engraved with an annular scale, which is the percentage of the pump shaft stroke. When the annular scale is at 0%, the center of the eccentric rotating body is closest to the pump shaft direction; when the annular scale is at 100%, the center of the eccentric rotating body is farthest from the pump shaft direction.

[0008] Furthermore, the lower end of the pump head is connected to the first valve body of the inlet one-way valve; the rear end of the pump head is connected to the second valve body of the outlet one-way valve, and the inlet one-way valve has a first valve ball wrapped by the first valve body; the outlet one-way valve has a second valve ball wrapped by the second valve body.

[0009] The beneficial effects of the present invention are as follows: the adjustment component in the present invention is used to adjust the stroke of the diaphragm, that is, to adjust the flow rate of liquid suction and extrusion, the eccentric handwheel is used to limit the displacement of the pump shaft, the eccentric wheel is used to drive the pump shaft to move left and right, and the pump shaft is used to drive the diaphragm to move left and right to thereby change the flow rate of liquid suction and extrusion of the metering pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 The diagram is a structural diagram of an eccentric indexing type metering mechanism of a metering pump.

[0011] Figure 2 This is a schematic diagram of the structure of the eccentric handwheel.

[0012] Figure 3 Schematic diagram of the eccentric handwheel scale structure.

[0013] Figure 4 This is the calculation diagram for the eccentric handwheel scale.

[0014] The markings in the figure are: 1. Frame; 2. Pump head; 3. Diaphragm; 4. Eccentric handwheel; 41. Operating handwheel; 411. Annular scale; 42. Connecting body; 43. Eccentric body; 5. Pump shaft; 6. Spring; 7. Eccentric wheel; 8. Inlet check valve; 81. First valve body; 82. First valve ball; 9. Outlet check valve; 91. Second valve body; 92. Second valve ball. DETAILED DESCRIPTION

[0015] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0016] like Figure 1The illustrated eccentric indexing flow control mechanism of a metering pump features an adjustment assembly, one of the core components of the metering pump. Its primary function is to adjust the stroke of the diaphragm 3. The diaphragm stroke directly affects the amount of liquid drawn in and out, and thus the overall pump flow rate. The adjustment assembly, consisting of two main components: a frame 1 and a pump head 2, allows for fine-tuning of the diaphragm position to accommodate varying flow requirements. The frame 1 forms the foundation of the entire mechanism, providing support and anchoring for the pump shaft 5, eccentric handwheel 4, and other components. The pump head 2, connected to the frame 1, is the pump's actuator, responsible for both liquid intake and discharge. The pump shaft 5 is a key component connecting the eccentric handwheel 4 and the eccentric wheel 7. One end of its head is in horizontal contact with the eccentric body 43 of the eccentric handwheel 4, while the other end is in horizontal contact with the eccentric wheel 7. Rotating the eccentric handwheel 4 changes the position of the pump shaft 5, thereby adjusting the pump stroke and output. The eccentric handwheel 4 is connected to the frame 1 via an eccentric handwheel connector 42. The connector 42 is connected to the eccentric body 43 inside the frame 1, ensuring that the rotation of the eccentric handwheel 4 can be accurately transmitted to the eccentric body 43. Outside the frame 1, the connector 42 is connected to the operating handwheel 41, and the output of the pump can be adjusted by rotating the operating handwheel 41.

[0017] Based on the above, the pump shaft is the key component connecting the eccentric and the diaphragm. Its design must ensure sufficient strength and stability to withstand the forces generated during operation. The outer surface of the pump shaft 5 is sheathed with a spring 6 that generates a preload, ensuring stable contact between the pump shaft 5, the eccentric body 43, and the eccentric 7. The rear end of the pump shaft 5 is connected to the diaphragm 3. Left and right movement of the pump shaft 5 causes the diaphragm 3 to move accordingly. This movement changes the rate of change of the enclosed volume, thereby regulating the liquid flow rate. The diaphragm 3 is a disc-shaped component with a convex periphery and a concave center, connected to the rear end of the pump shaft 5. The concave center portion of the diaphragm 3 forms a chamber whose volume changes periodically during pump operation, thereby allowing the intake and discharge of liquid. The diaphragm 3 is the component in the metering pump that directly contacts the liquid, and its movement controls the intake and discharge of liquid. The design of the diaphragm must take into account sealing, chemical resistance, and durability to ensure stable operation under various operating conditions. The lower end of the pump head 2 is connected to the first valve body 81 of the inlet one-way valve 8 , and the upper end of the pump head 2 is connected to the second valve body 91 of the outlet one-way valve 9 .

[0018] On the basis of the above, if Figure 2The eccentric handwheel composition structural diagram shown in the figure shows that the eccentric handwheel 4 is part of the adjustment component, which limits the displacement range of the pump shaft 5 through an eccentric design. This design allows the user to control the movement range of the pump shaft 5 by rotating the eccentric handwheel 4, thereby accurately controlling the flow rate. The eccentricity of the eccentric handwheel 4 can usually be adjusted as needed to adapt to different working conditions. The eccentric body 43, the connecting body 42 and the operating handwheel 41 are all rotating bodies. The rotation centers of the eccentric body 43 and the operating handwheel 41 are a certain distance apart. The operating handwheel 41 is engraved with a ring scale 411.

[0019] On the basis of the above, if Figure 3 The diagram shows the scale structure of the eccentric handwheel. The annular scale 411 represents the percentage of the pump shaft 5's stroke. The scale 411 is bilaterally symmetrical. When the scale 411 is at 0%, the center of the eccentric body 43 is closest to the pump shaft 5. When the scale 411 is at 100%, the center of the eccentric body 43 is farthest from the pump shaft 5.

[0020] On the basis of the above, the eccentric handwheel 4 has a very small axial dimension and a compact structure. It forms a self-adjusting mechanism and does not require the use of parts such as a scale ring. It is simple to configure and can be obtained in a conventional manner, with low processing costs. Influenced by the structural design, the stroke of the pump shaft 5 only requires lateral limitation. The adjustment mechanism composed of the eccentric body 43 rotates and moves along the center of the operating handwheel 41, and the angular displacement of the eccentric indexing handwheel is equivalently converted into a linear displacement to control the return amount of the pump shaft to achieve flow control. Therefore, the pump stroke size is twice the eccentricity of the eccentric body 43. The design takes into account that the tail end of the pump shaft is well stressed (so as not to generate excessive overturning torque). The eccentric body 43 needs to be as close to the axis of the pump shaft 5 as possible, tangent to the pump shaft 5, and will not interfere with the eccentric wheel 7. The dimensions in all directions are comparable, so the strength and rigidity are high.

[0021] On the basis of the above, if Figure 4 The eccentric handwheel scale calculation diagram shown in the figure shows the state when the metering pump stroke is 0, that is, the eccentric wheel 7 rotates around the fixed axis, but the pump shaft 5 is at the front dead center and does not move, which corresponds to the zero scale of the eccentric handwheel 4. Figure 4 This diagram illustrates the displacement control principle of the eccentric handwheel 4. The centroid of the operating handwheel 41 remains unchanged during adjustment. The initial position of the eccentric body 43 is when the eccentric handwheel 4 is at its initial 0% position, and the position after the eccentric body 43 is when the eccentric handwheel 4 is at its 10% relative travel position. The vertical line represents the end face of the pump shaft 5, which is always tangential to and in contact with the eccentric body 43.

[0022] On the basis of the above, Figure 4From the geometric relationship in , it can be seen that in this system, point O is a key fixed point. It is the center of rotation of the eccentric handwheel 4. This point remains stationary throughout the entire system, providing a stable reference point for the movement of other components. The position of the center of the eccentric body 43 will change with the adjustment of the operating handwheel 41. In different states of the system, points a and b represent the center positions of the eccentric body 43 respectively. The radius of the eccentric body 43 is the eccentricity e, and the diameter is the pump shaft stroke S, that is, the relationship S = 2e. In the initial state, that is, when the relative stroke is 0%, the pump shaft 5 is tangent to the radius oa of the eccentric body 43 at point c, and the two maintain a vertical relationship. At this time, the pump shaft 5 is at the starting position of its stroke, and the center point a of the eccentric body 43 is on the horizontal line.

[0023] On the basis of the above, in one embodiment, as the system is adjusted, the eccentric handwheel 4 will rotate clockwise by a certain angle ∠aob. This change in angle directly causes the center of the eccentric body 43 to move from point a to point b. At the new position, point b becomes the new center of the eccentric body 43. By drawing a horizontal line from point b, a new point d where this line intersects with the eccentric body 43 can be found. At this time, the pump shaft 5 and the eccentric body 43 intersect at point d, which is the changed position of the pump shaft 5. It can be clearly seen that ch=af, where the af value represents the change in the stroke of the pump shaft 5. If af is equal to 10% of S at this time, then the angle change corresponding to ∠aob can be mapped to the scale on the operating handwheel 41, indicating a relative stroke of 10%. The same method can be applied to other percentages such as 20%, 30%, etc., so that the operator can find any scale between 0% and 100% on the operating handwheel 41.

[0024] Based on the above, when the metering pump is started, the eccentric wheel 7 begins to rotate. The eccentric wheel is designed to convert the rotational motion of the motor or other power source into linear motion of the pump shaft 5. The rotation of the eccentric wheel 7 applies a driving force to the pump shaft 5. This force acts along the axis of the pump shaft 5, pushing the pump shaft 5 forward. At this time, the movement of the pump shaft 5 causes the spring 6 on its outer surface to be compressed. The spring 6 stores energy in this process. When the pump shaft 5 reaches its maximum stroke, the spring 6 begins to release energy, pushing the pump shaft 5 in the opposite direction to return to its initial position. This reciprocating motion is driven by the continuous rotation of the eccentric wheel 7, causing the pump shaft 5 to periodically compress and release the spring 6.

[0025] Based on the above, the diaphragm 3 connected to the rear end of the pump shaft 5 is a key component, sealing and transferring liquid during the reciprocating motion of the pump shaft 5. The diaphragm 3 is designed with a convex periphery and a concave center. This design allows the central portion of the diaphragm to move toward the eccentric 7 when the pump shaft 5 is pulled back, increasing the sealed volume of the liquid chamber and creating a partial vacuum. Under the influence of external atmospheric pressure, the inlet check valve 8 opens, allowing liquid to be drawn in. When the pump shaft 5, propelled by the eccentric 7, moves toward the pump head 2, the central portion of the diaphragm 3 also moves toward the pump head 2, reducing the sealed volume of the liquid chamber and increasing pressure. This opens the outlet check valve 9, allowing liquid to be pumped out of the outlet. The stroke length of the pump shaft 5 directly determines the volume of liquid drawn in and out each time, thereby controlling the flow rate of the metering pump. By adjusting the eccentric handwheel 4, the stroke of the pump shaft 5 can be varied, allowing fine-tuning of the flow rate.

[0026] Based on the above, the first valve ball 82, located within the inlet check valve 8, primarily prevents liquid from flowing back into the inlet pipe from the pump head 2. During the pump's intake phase, the first valve ball 82 is lifted by the suction force, leaving its seat and allowing liquid to flow into the pump head 2. When the pump's discharge phase begins, the pressure differential causes the first valve ball 82 to descend and seal against the seat, preventing reverse flow. This one-way flow design ensures that liquid can only enter the pump head 2 through the inlet check valve 8 and cannot flow back when the pump is stopped. The second valve ball 92, located within the outlet check valve 9, functions similarly to the first valve ball 82, but in the opposite direction. During the pump's discharge phase, the second valve ball 92 is pushed toward the open position by pressure, allowing liquid to flow out of the pump head 2 and into the outlet pipe. During the pump's intake phase, the second valve ball 92 descends due to the pressure differential and seals against the seat, preventing liquid from flowing back into the pump head 2 from the outlet pipe. This ensures that liquid can only flow in one direction, out of the pump head 2, during pump operation, preventing possible backflow.

[0027] Based on the above, the operating principle of the entire system is based on the change in the stroke of the diaphragm 3. When the adjustment assembly is adjusted, the eccentric handwheel 4 limits the displacement range of the pump shaft 5, and the eccentric wheel 7 drives the pump shaft 5 to move, which in turn pushes the diaphragm 3 to change its position. This movement of the diaphragm 3 changes the rate of change of the sealed volume, achieving precise control of the liquid flow rate. The pump flow rate is adjusted by rotating the eccentric handwheel 4. The design of the eccentric handwheel 4 allows it to rotate around a fixed axis, and its eccentric body 43 is connected to one end of the pump shaft 5. When the eccentric handwheel 4 rotates, its eccentric body 43 moves along a circular trajectory, thereby changing the tangential position of contact with the pump shaft 5. This position change causes the maximum displacement distance of the pump shaft 5 during rotation to change, directly affecting the movement of the pump shaft 5. The maximum displacement distance of the pump shaft 5, that is, its stroke, directly determines the degree of compression and release of the diaphragm 3, and thus affects the volume of liquid drawn in and out each time. When the eccentric hand wheel 4 is rotated to increase the stroke of the pump shaft 5, the amount of liquid pumped each time increases, resulting in an increase in flow rate; conversely, reducing the stroke reduces the flow rate.

[0028] Based on the above, to provide intuitive flow rate adjustment feedback, the outer surface of the operating handwheel 41 is engraved with an annular scale 411. These scales are generally expressed in percentages, allowing the operator to adjust the stroke of the pump shaft 5 to a specific percentage as needed. For example, if the operator rotates the handwheel to the 30% scale, this indicates that the stroke of the pump shaft 5 has been set to 30% of the maximum stroke, thereby controlling the pump's output flow rate.

[0029] This eccentric indexing adjustment mechanism primarily changes the structure, position, and connection relationship between the eccentric handwheel 4 and the pump shaft 5, integrating the eccentric handwheel 4 into a single component with a more optimized geometry to improve its load-bearing capacity and resistance to deformation. This integrated design simplifies the manufacturing process, requiring only one component to be machined instead of multiple, reducing processing time and costs. It also potentially improves machining accuracy by reducing errors caused by improperly fitting multiple components.

[0030] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An eccentric indexing type metering pump adjustment mechanism, comprising a frame (1) of an adjustment assembly connected to a pump head (2), characterized in that: A pump shaft (5) and an eccentric hand wheel (4) connecting body (42) are fixed on the frame (1); One end of the head of the pump shaft (5) contacts the eccentric body (43) of the eccentric hand wheel (4), and the other end contacts the eccentric wheel (7).

2. The eccentric indexing type metering pump adjustment mechanism according to claim 1, characterized in that: The connecting body (42) is connected to the eccentric body (43) inside the frame (1), and is connected to the operating hand wheel (41) outside the frame (1).

3. The eccentric indexing type metering pump adjustment mechanism according to claim 2, characterized in that: The eccentric body (43), the connecting body (42) and the operating hand wheel (41) are all rotating bodies; The rotation centers of the eccentric body (43) and the operating hand wheel (41) are spaced apart.

4. The eccentric indexing type metering pump adjustment mechanism according to claim 2, characterized in that: The operating hand wheel (41) is engraved with an annular scale (411) on the outside.

5. The eccentric indexing type metering pump adjustment mechanism according to claim 4, characterized in that: The annular scale (411) is a percentage of the stroke of the pump shaft (5); When the annular scale (411) is at the 0% scale, the center of the eccentric body (43) is closest to the pump shaft (5); When the annular scale (411) is at 100% scale, the center of the eccentric body (43) is farthest away from the pump shaft (5).

6. The eccentric indexing type metering pump adjustment mechanism according to claim 1, characterized in that: The outer surface of the pump shaft (5) is sleeved with a spring (6) for generating a pre-compression force, and the tail end is connected to the diaphragm (3).

7. The eccentric indexing type metering pump adjustment mechanism according to claim 6, characterized in that: The diaphragm (3) is in the shape of a disk with a convex periphery and a concave center.

8. The eccentric indexing type metering pump adjustment mechanism according to claim 1, characterized in that: The front end of the pump head (2) is connected to the first valve body (81) of the inlet one-way valve (8); The rear end of the pump head (2) is connected to the second valve body (91) of the outlet one-way valve (9).

9. The eccentric indexing type metering pump adjustment mechanism according to claim 8, characterized in that: The inlet one-way valve (8) comprises a first valve body (81) enclosing a first valve ball (82); The outlet one-way valve (9) comprises a second valve body (91) enclosing a second valve ball (92).

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