Air inlet valve for variable-frequency oil injection screw air compressor

Abstract

The utility model relates to an air inlet valve for a frequency conversion oil injection screw air compressor, which comprises a valve body and a check valve core, a check valve rod is arranged in the valve body, one end of the check valve rod is connected with the check valve core, the other end of the check valve rod is connected with a limit block, a ball shaft sleeve is sleeved on the check valve rod, and a ball shaft sleeve guide pillar is arranged between the ball shaft sleeve and the valve body. The check valve rod is further sleeved with a check spring. The ball shaft sleeve is adopted, initial friction force of movement of the valve element is reduced, and resetting sensitivity of the valve element is guaranteed. The two ends of the check spring are fixed, and the check valve element is effectively prevented from rotating. The two ends of the valve rod are screwed on the check valve element and the limiting block through left-hand external threads, the check valve element and the plane of the limiting block are locked on the valve rod internal threads through right-hand external hexagon bolts and lock washers, and the problem of loosening of the check valve element, the valve rod and the limiting block is effectively solved. And a buffer rubber ring is arranged on the check valve core limiting block, so that impact caused by too high opening speed is prevented.

Description

TECHNICAL FIELD

[0001] The utility model is suitable for oil injection screw air compressor, especially an air inlet valve for variable frequency oil injection screw air compressor. BACKGROUND

[0002] The air inlet valve for variable frequency oil injection screw air compressor is suitable for air inlet check of oil injection screw air compressor. The valve core of the existing air inlet valve is a reciprocating mechanism, and the valve core is reset by a compression spring. The variable frequency oil injection screw air compressor has very high requirements for pressure loss of the air inlet valve. Because the pressure loss of the air inlet valve directly affects the efficiency of the variable frequency oil injection screw air compressor, in order to reduce the pressure loss of the air inlet valve, the spring force value for resetting the valve core in the air inlet valve is generally designed to be small. The original air inlet valve adopts a self-lubricating sliding shaft sleeve. According to market after-sales information feedback and statistics, under certain working conditions, the valve core cannot be reset in place, causing lubricating oil to be sprayed from the air inlet valve and failure, and customers complain a lot.

[0003] In addition, during the working process of the air inlet valve, air flows at high speed through the outer circle of the valve core, and the valve core rotates, thereby causing mechanical wear of the moving parts of the air inlet valve in a short time and a serious failure risk. SUMMARY

[0004] The utility model aims at overcoming the above shortcomings and provides an air inlet valve for variable frequency oil injection screw air compressor.

[0005] The utility model discloses an air inlet valve for variable frequency oil injection screw air compressor, which comprises a valve body and a check valve core, a check valve rod is arranged in the valve body, one end of the check valve rod is connected with the check valve core, the other end of the check valve rod is connected with a limiting block, a ball shaft sleeve is sleeved on the check valve rod, a ball shaft sleeve guide column is arranged between the ball shaft sleeve and the valve body, and a check spring is also sleeved on the check valve rod.

[0006] The utility model further improves that the check valve core moves horizontally or vertically.

[0007] The utility model further improves that the check valve rod is screwed on the check valve core and the limiting block by left-hand external thread at both ends, and the check valve core and the limiting block are locked and screwed on the check valve rod inner thread by right-hand external hexagonal bolt and stop washer at the plane.

[0008] The utility model further improves that the check spring is fixed at both ends.

[0009] The utility model further improves that a sealing ring is arranged between the valve body and the check valve core.

[0010] The utility model further improves that a buffer rubber ring is arranged on the limiting block.

[0011] The advantages of this utility model compared with the prior art are as follows:

[0012] 1. The check valve core reciprocates laterally or vertically, and uses a ball bearing bushing to reduce the initial friction of the valve core movement and ensure sensitive valve core reset.

[0013] 2. When the check valve core is opened, it will rotate due to the airflow. The check spring is designed with two ends extending out to the fulcrum. One end is fixed in the valve body limit hole, and the other end is fixed in the limit block limit hole, which effectively prevents the check valve core from rotating.

[0014] 3. The valve stem is screwed onto the check valve core and the limit block with left-hand external threads at both ends. The check valve core and the limit block are locked onto the valve stem internal threads with right-hand external hex bolts and locking washers, which effectively prevents the check valve core, valve stem and limit block from loosening.

[0015] 4. The check valve core limit block is equipped with a buffer rubber ring to prevent impact caused by excessive opening speed. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the valve core in the closed state of this utility model;

[0017] Figure 2 This is a structural schematic diagram of the valve core in the open state of this utility model;

[0018] The numbers in the diagram are: 1-valve body, 2-check valve core, 3-check valve stem, 4-limit block, 5-ball bearing sleeve, 6-ball bearing sleeve guide post, 7-check spring, 8-sealing ring, 9-buffer rubber ring. Detailed Implementation

[0019] To enhance understanding of this utility model, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. These embodiments are only used to explain the present utility model and do not constitute a limitation on the scope of protection of the present utility model.

[0020] As shown in the specific embodiment of the utility model discloses a variable frequency oil injection screw air compressor with inlet valve: including valve body 1 and check valve core 2, the valve body 1 with check valve core 2 between being equipped with sealing ring 8, be equipped with check valve stem 3 in valve body 1, check valve stem 3 one end connects check valve core 2, check valve core 2 transverse or vertical reciprocating motion, check valve stem 3 other end connects limit block 4, namely check valve stem 3 both ends adopt left-hand thread and be screwed on check valve core 3 with limit block 4, check valve core 2 with limit block 4 plane adopt right-hand thread and locking washer and check valve stem 3 inner thread on, be equipped with buffer rubber ring 9 on limit block 4, check valve stem 3 is covered with ball bushing 5, ball bushing guide column 6 between ball bushing 5 and valve body 1 is equipped with, ball bushing guide column 6 has the characteristics of low friction and high efficiency (low friction: ball rolls between the inner and outer ring of bushing, the friction coefficient is far lower than sliding bushing, significantly reduces energy loss, total stroke = inner ring stroke + outer ring stroke. High efficiency: no need to overcome static friction, suitable for frequent start-stop or precision control scene). Check valve stem 3 is also covered with check spring 7, and both ends of check spring 7 extend from the fulcrum and are fixed, that is, both ends of check spring 7 are fixed on limit block 4 and valve body 1 respectively.

[0021] The working principle of the utility model is:

[0022] As Figure 1 The inlet valve has a check function, and before the normal screw air compressor is started, the check valve core is in the closed state under the influence of the spring force. When the screw air compressor is started, the air suction of the host increases with the frequency rise, the pressure difference before and after the check valve core increases, and the check valve core opens after overcoming the check spring force, realizing the loading state, as Figure 2 When the host stops running, the compressed air backflushes to the host cavity, the pressure difference before and after the check valve core disappears, and the check valve core quickly closes under the influence of the spring force and pressure, preventing the oil-gas mixture in the host cavity from being sprayed out.

[0023] The applicant further declares that the implementation method and device structure of the utility model are illustrated by the above embodiments, but the utility model is not limited to the above embodiments, that is, it does not mean that the utility model must rely on the above method and structure to be implemented. Those skilled in the art should understand that any improvement of the utility model, equivalent replacement of the implementation method selected by the utility model, addition of steps, selection of specific modes, etc. fall within the protection scope and disclosed scope of the utility model.

[0024] The utility model is not limited to the above embodiments, and all modes that adopt similar structures and methods to achieve the purpose of the utility model are within the protection scope of the utility model.

Claims

1. An intake valve for a variable frequency oil-injected screw air compressor, comprising a valve body (1) and a check valve core (2), wherein a check valve stem (3) is provided inside the valve body (1), one end of the check valve stem (3) is connected to the check valve core (2), and the other end of the check valve stem (3) is connected to a limiting block (4), characterized in that: A ball bearing sleeve (5) is sleeved on the check valve rod (3), a ball bearing sleeve guide column (6) is arranged between the ball bearing sleeve (5) and the valve body (1), and a check spring (7) is further sleeved on the check valve rod (3).

2. The inlet valve for a variable frequency oil-injected screw air compressor of claim 1, wherein: The check valve core (2) reciprocates horizontally or vertically.

3. The inlet valve for a variable frequency oil-injected screw air compressor of claim 1, wherein: The check valve rod (3) is screwed on the check valve core (2) and the limiting block (4) by left-hand external threads at both ends, and the check valve core (2) and the limiting block (4) are locked on the internal threads of the check valve rod (3) by right-hand external hexagonal bolts and stop washers.

4. The inlet valve for a variable frequency oil-injected screw air compressor of claim 1, wherein: Both ends of the check spring (7) are fixed.

5. The inlet valve for a variable frequency oil-injected screw air compressor of claim 1, wherein: A sealing ring (8) is arranged between the valve body (1) and the check valve core (2).

6. The inlet valve for a variable frequency oil-injected screw air compressor of claim 1, wherein: A buffer rubber ring (9) is arranged on the limiting block (4).

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