Spool valve assembly and compressor

Abstract

The application discloses a spool valve assembly and a compressor, which comprises a valve core capable of sliding along a valve cavity, a piston for pushing the valve core, a sliding cavity in which the piston is capable of sliding, the sliding cavity being in axial communication with the valve cavity, the valve core being connected with the piston through a valve rod, and the valve rod being connected with the valve core and / or the piston through a spherical hinge. The structure of the application is fixedly connected with a pressing plate in front of the spool valve and the piston, the spool valve and the pressing plate are connected through screws, and the piston and the piston pressing plate are connected through screws, so that the spool valve structure can be smoothly disassembled. The structure adopts flexible connection, uses a spherical rod to connect parts, and can self-adaptively adjust the centering degree between the spool valve and the piston. Compared with a traditional spool valve structure, the structure has a lower requirement on the machining precision of the valve rod and the spool valve.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of control valve, in particular to a slide valve assembly and a compressor. BACKGROUND

[0002] The slide valve of a screw compressor is an axially movable component, usually installed between two screw rotors. By changing the position of the slide valve, the displacement of the compressor can be adjusted, thereby achieving control of the output gas volume of the compressor. As shown in the figure, when the screw compressor is running at full load, the slide valve is at the leftmost end and does not slide. When the compressor is running at partial load, the slide valve needs to move to the right, at which time the left end of the slide valve is pulled away from the body by a certain distance, and a tooth groove of the rotor is in communication with the air inlet, so that the compression section of the rotor is reduced. Figure 1

[0003] The slide valve mainly includes a slide valve and a valve rod, the slide valve is provided with a threaded hole, and the valve rod is connected with the slide valve through the threaded hole; the valve rod is also provided with a threaded hole, and a piston assembly is connected with the valve rod through a screw. Therefore, the parts of the entire mechanism are rigidly connected. In actual production, the coaxiality between the slide valve and the piston needs to meet high precision, otherwise the entire mechanism is easy to be stuck on the body or the cylinder body, so the processing precision of the parts is required to be particularly high, and therefore the cost of the entire mechanism is particularly high. Moreover, since the slide valve mechanism is a multi-part cooperation, it is difficult to ensure that the coaxiality between the slide valve and the piston finally meets high precision. In addition, due to long-term use, the parts may be deformed, and since the parts are rigidly connected, long-term use will cause the coaxiality between the slide valve and the piston to fail to meet high precision, thereby causing the mechanism to be stuck. SUMMARY

[0004] To solve the problem that the slide valve is stuck due to low coaxiality between the slide valve and the piston, the present application provides a slide valve assembly, which is provided with a ball hinge between the slide valve and the piston, so that the slide valve and the piston can be self-adaptively adjusted to avoid the slide valve being stuck due to low coaxiality.

[0005] The technical scheme adopted by the present application is that a slide valve assembly is designed, which includes a valve core that can slide along a valve cavity and a piston that pushes the valve core, the piston is slidably fitted in a slide cavity, the slide cavity is axially communicated with the valve cavity, the valve core is connected with the piston through a valve rod, and the valve rod is connected with the valve core and / or the piston through a ball hinge.

[0006] In some embodiments, a first return spring is arranged in the slide cavity between the piston and the valve cavity to support the piston.

[0007] In some embodiments, a damper is arranged between the piston and the valve cavity, and the damper is used to limit the moving speed of the piston relative to the valve cavity.

[0008] ​In some embodiments, the damper is a damping telescopic rod, a plurality of the damping telescopic rods are evenly distributed around the valve rod in the circumferential direction, the damping telescopic rod comprises a damping cavity and a top rod telescoped relative to the damping cavity, the top rod and the damping cavity are connected to the end of the piston and the sliding cavity respectively.

[0009] In some embodiments, the damper is a damping telescopic rod, a plurality of the damping telescopic rods are evenly distributed around the valve rod in the circumferential direction, the damping telescopic rod comprises a damping cavity and a top rod telescoped relative to the damping cavity, a second return spring is supported between the damping cavity and the top rod, the damping cavity is connected to the end of the sliding cavity, the top rod is towards the piston, and the maximum stroke of the spool is greater than the maximum length of the damping telescopic rod.

[0010] In some embodiments, the damping cavity is provided with damping liquid, and the damping liquid is a non-Newtonian fluid.

[0011] In some embodiments, the damping cavity is provided with damping liquid, and the damping liquid is a magneto-rheological fluid, and an electromagnetic coil is arranged on the damping cavity, and the electromagnetic coil is used to generate a magnetic field for controlling the viscosity of the magneto-rheological fluid.

[0012] In some embodiments, a pressure sensor is arranged at the end of the top rod, and the electromagnetic coil controls the viscosity of the magneto-rheological fluid according to the information of the pressure sensor.

[0013] In some embodiments, a hydraulic control device for controlling the oil pressure in the sliding cavity is further included, and the hydraulic control device adjusts the oil pressure in the sliding cavity according to the information of the pressure sensor.

[0014] The compressor comprises the sliding valve assembly.

[0015] Compared with the prior art, the present application has the following beneficial effects:

[0016] The present structure is fixedly connected to the piston by a pressing plate, the sliding valve and the pressing plate are connected by a screw, and the piston and the piston pressing plate are connected by a screw, so that the sliding valve structure can be smoothly disassembled. The present structure uses flexible connection and spherical rods to connect parts, and can self-adaptively adjust the centering degree between the sliding valve and the piston. Compared with the traditional sliding valve structure, the requirements for the machining precision of the valve rod and the sliding valve are low. The damper is arranged between the piston and the valve cavity, and when the centering degree of the sliding valve assembly is adjusted, the misalignment between the sliding valve and the piston will change constantly with the sliding of the sliding valve. The damper can buffer this change to stabilize the sliding valve mechanism, so that the valve rod is not easily stuck, and the stability of the sliding valve mechanism is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0017] The present application will be described in detail below with specific embodiments and accompanying drawings. In order to show details and facilitate understanding of principles, the drawings are not necessarily drawn to scale, and similar reference numerals can be used to describe similar components in different views. The drawings generally show the embodiments discussed herein in an exemplary and non-limiting manner. Among them:

[0018] Figure 1 is a schematic diagram of a prior art screw compressor.

[0019] Figure 2 is a schematic diagram of embodiment one.

[0020] Figure 3 is a schematic diagram of embodiment two.

[0021] Figure 4 is a schematic diagram of embodiment three.

[0022] Figure 5 is a schematic diagram of embodiment four.

[0023] Figure 6 is Figure 5 is an enlarged schematic diagram of A in FIG.

[0024] In the figure, 1, screw compressor; 2, valve cavity; 3, valve core; 5, piston; 6, sliding cavity; 7, valve rod; 8, ball hinge; 9, pressing plate; 10, first reset spring; 11, damper; 111, damping cavity; 112, ejector rod; 12, second reset spring; 13, damping liquid; 14, electromagnetic coil; 15, pressure sensor. DETAILED DESCRIPTION

[0025] The following are specific embodiments of the present application, and the technical solutions of the present application will be further described in conjunction with the accompanying drawings. However, the present application is not limited to these embodiments, and the following embodiments do not limit the invention involved in the claims. In addition, all combinations of features described in the embodiments are not necessarily required by the solutions of the invention.

[0026] The principles and structures of the present application will be described in detail below in conjunction with the accompanying drawings and embodiments.

[0027] Embodiment one

[0028] As Figure 2As shown, a sliding valve assembly for a screw compressor 1 comprises a valve core 3 slidable along a valve cavity 2 and a piston 5 pushing the valve core 3, the piston 5 being slidably fitted in a sliding cavity 6, the sliding cavity 6 being in axial communication with the valve cavity 2, the valve core 3 and the piston 5 being connected by a valve rod 7, the valve rod 7 being connected with the valve core 3 and / or the piston 5 by a ball hinge 8. In the embodiment, the valve rod 7 is connected with the valve core 3 and the piston 5 by the ball hinge 8 at both ends, the ball hinge 8 comprises a spherical rod with a spherical head at one end, the spherical rod being connected with the valve rod 7 at both ends, the valve core 3 and the piston 5 are each provided with a spherical cavity in sliding fit with the spherical head, the valve core 3 and the piston 5 are provided with a pressing plate 9, the pressing plate 9 enabling the spherical head to rotate within the spherical cavity. The piston 5 and the sliding cavity 6 correspond to a hydraulic cylinder, the sliding cavity 6 is a hydraulic cavity, by controlling the pressure in the hydraulic cavity, the sliding of the piston 5 along the sliding cavity 6 can be controlled, thereby the movement of the valve core 3 through the valve rod 7 is controlled, thereby the adjustment of the compressor inlet is realized. The valve cavity 2 and the area for the movement of the valve core 3 at the compressor inlet.

[0029] The technical effect of the above design is that the spherical rod is designed as a spherical part plus a connecting rod, the design of the spherical part ensures a certain degree of freedom between the sliding valve and the valve rod 7, and a certain degree of freedom between the valve rod 7 and the piston 5, so that the sliding valve and the piston 5 can be self-adaptively adjusted to the centering degree during the operation of the sliding valve mechanism, and the sliding valve mechanism will not be rigidly connected like the traditional sliding valve mechanism, and cannot be adjusted to the centering degree, and will be stuck due to deformation caused by long-term operation. To ensure that the sliding valve structure can be easily disassembled, the structure is fixedly connected by the pressing plate 9 in front of the sliding valve and the piston 5, the sliding valve and the pressing plate 9 are connected by screws, and the piston 5 and the piston 5 pressing plate 9 are connected by screws, so that the sliding valve structure can be smoothly disassembled. The structure uses flexible connection and uses a spherical rod to connect the parts, which can self-adaptively adjust the centering degree between the sliding valve and the piston 5, and the machining precision requirements of the valve rod 7 and the sliding valve are lower than those of the traditional sliding valve structure.

[0030] A first reset spring 10 supporting the piston 5 is arranged in the sliding cavity 6 between the piston 5 and the valve cavity 2. The first reset spring 10 is a stud spring, the stud spring is sleeved on the valve rod 7, and the two ends of the stud spring support the piston 5 and the end of the sliding cavity 6 adjacent to the valve cavity 2 respectively.

[0031] The technical effect of the above design is that when the hydraulic pressure in the sliding cavity 6 is reduced, the piston 5 moves to the right under the reset supporting force of the first reset spring 10, and then the inlet of the compressor becomes larger.

[0032] Embodiment two

[0033] As Figure 3 different from the above-mentioned embodiments, a damper 11 is arranged between the piston 5 and the valve cavity 2, and the damper 11 is used to limit the moving speed of the piston 5 relative to the valve cavity 2.

[0034] The technical effect of the above design is that the flexible connection has a disadvantage that the valve rod 7 may be stuck or unstable during the adjustment of the valve to the center. The reason is that the machining precision of the slide valve is high, and the slide valve and the slide valve cavity 2 of the machine body are a tight fit. On the other side, in order to prevent oil leakage, the machining precision of the piston 5 is also high, and the piston 5 and the cylinder body cavity also belong to a tight fit. The machining precision affects the dislocation of the slide valve and the piston 5, and the dislocation amount may change at any time with the sliding of the slide valve assembly. At this time, the slide valve assembly is easy to be stuck and unable to slide. Therefore, it is important to solve this problem. The two spherical rods can adaptively adjust the dislocation amount, but the dislocation amount changes with the sliding of the slide valve assembly, and the slide valve assembly is easy to run unstable.

[0035] By arranging the damper 11 between the piston 5 and the valve cavity 2, when the slide valve assembly adjusts to the center, the dislocation amount between the slide valve and the piston 5 will change constantly with the sliding of the slide valve. The damper 11 can buffer this change to achieve the effect of stabilizing the slide valve mechanism, so that the valve rod 7 will not be easily stuck, and the stability of the slide valve mechanism is ensured.

[0036] Specifically, the damper 11 of the embodiment is a damping telescopic rod, a plurality of damping telescopic rods are uniformly distributed circumferentially around the valve rod 7, the damping telescopic rod includes a damping cavity 111 and a top rod 112 telescoped relative to the damping cavity 111, and the top rod 112 and the damping cavity 111 are connected to the end of the piston 5 and the slide cavity 6, respectively.

[0037] The technical effect of the above design is that a plurality of damping telescopic rods are uniformly distributed circumferentially around the valve rod 7, so that the force on each position of the piston 5 circumferentially is uniform, thereby ensuring the damping buffering effect and avoiding the deflection caused by the uneven force on different circumferential positions.

[0038] Embodiment three

[0039] As Figure 4As shown, unlike the above-mentioned embodiments, the damper 11 is a damping telescopic rod, a plurality of the damping telescopic rods are uniformly distributed around the valve stem 7 in the circumferential direction, four damping telescopic rods are arranged in the embodiment, and of course the number can be other, the damping telescopic rod comprises a damping cavity 111 and a top rod 112 telescoped relative to the damping cavity 111, a second return spring 12 is supported between the damping cavity 111 and the top rod 112, the damping cavity 111 is connected with the end of the slide cavity 6, the top rod 112 is towards the piston 5, and the maximum stroke of the valve core 3 is greater than the maximum length of the damping telescopic rod. The piston 5 is not connected with the top rod 112, and the top rod 112 is in a free state.

[0040] The technical effect of the above design is that when the piston 5 moves to the far right end, the piston 5 has a certain spacing with the top rod 112, and only when the piston 5 moves to a certain distance to the left will it touch the top rod 112 and be subjected to damping, because the resistance when the piston 5 moves from the far right end is large, and the misalignment amount between the slide valve and the piston 5 is small at this time, and it is not easy to misalign and be stuck, so damping is not needed at this time, and when the piston 5 moves to a certain distance to the left, the misalignment amount between the slide valve and the piston 5 will become larger and larger, so when the piston 5 touches the top rod 112 at this time, the damping rod can buffer this change to achieve the effect of stabilizing the slide valve mechanism, so that the valve stem 7 will not be easily stuck, and the stability of the slide valve mechanism is ensured.

[0041] Further, the damping cavity 111 is provided with damping liquid 13, and the damping liquid 13 is a non-Newtonian fluid.

[0042] The technical effect of the above design is that the damping liquid 13 in the general damping rod is oil, but the non-Newtonian fluid is used in the embodiment, and the non-Newtonian fluid is a special fluid, and its viscosity is not constant, but changes with the change of external force (such as shear force). Unlike ordinary Newtonian fluid (such as water), the viscosity of non-Newtonian fluid damping liquid 13 can increase with the increase of shear rate (shear thickening fluid), or can decrease with the increase of shear rate (shear thinning fluid). The uniqueness of non-Newtonian fluid is that its viscosity changes with the change of shear force. This characteristic makes them exhibit different damping effects under different working conditions, so as to achieve the effect of vibration and noise reduction.

[0043] Embodiment four

[0044] As Figure 5 , 6As shown, unlike the above-mentioned embodiment, a damping liquid 13 is arranged in the damping cavity 111, the damping liquid 13 is a magneto-rheological liquid, an electromagnetic coil 14 is arranged on the damping cavity 111, and the electromagnetic coil 14 is used to generate a magnetic field for controlling the viscosity of the magneto-rheological liquid.

[0045] The technical effect of the above design is that the magneto-rheological liquid is an intelligent material, which behaves as a viscous liquid without magnetic field, but its viscosity will rapidly increase or even solidify under the action of an external magnetic field. By controlling the strength of the magnetic field, the viscosity of the magneto-rheological liquid can be accurately adjusted, so as to realize accurate control of the damping force, so as to adapt to different damping requirements. The control of the magneto-rheological liquid damper 11 usually adopts a closed-loop control system, which monitors the vibration signal in real time through a sensor and adjusts the strength of the magnetic field according to a control algorithm to realize accurate control of the damping force.

[0046] The end of the top rod 112 is provided with a pressure sensor 15, and the electromagnetic coil 14 controls the viscosity of the magneto-rheological liquid according to the information of the pressure sensor 15.

[0047] The technical effect of the above design is that when the piston 5 is inclined forward and backward at different circumferential positions, the force borne by the pressure sensor 15 on the top rod 112 corresponding to each part of the piston 5 is different. If the pressure borne by the top rod 112 is larger or suddenly becomes larger, it indicates that the part of the piston 5 corresponding to the top rod 112 is inclined forward relative to other circumferential positions, so that the piston 5 has the possibility of being stuck. At this time, the viscosity of the magneto-rheological liquid in the damping cavity 111 of the top rod 112 can be increased relative to the viscosity of the damping liquid 13 of other damping rods, so as to increase the resistance of the top rod 112 to the piston 5, so as to correct the inclination of the piston 5, thereby preventing the piston 5 from being stuck.

[0048] Further comprising a hydraulic control device for controlling the oil pressure in the sliding cavity 6, which adjusts the oil pressure in the sliding cavity 6 according to the information of the pressure sensor 15. The hydraulic control device is, for example, a hydraulic pump or a pressure control valve.

[0049] The technical effect of the above design is that if the piston 5 is stuck, the pressure value detected by the pressure sensor 15 of each top rod 112 does not change even if the hydraulic control device increases the oil pressure in the sliding cavity 6 at this time, which indicates that the piston 5 is stuck. At this time, the oil pressure in the sliding cavity 6 can be reduced by the hydraulic control device, so that the piston 5 is slightly returned and then the pressure is increased to move the piston 5 forward, so as to facilitate the adjustment of the position of the piston 5 under the action of the damper 11, and avoid being stuck.

[0050] The specific embodiments described herein are presented for purposes of illustration only and not limitation. Those skilled in the art will recognize various modifications and changes that can be made to the specific embodiments described herein without departing from the spirit of the application. The scope of the application is defined by the appended claims and their equivalents.

[0051] Although a number of terms are used herein, they are not intended to exclude the use of other terms. The use of these terms is only intended to facilitate the description and explanation of the nature of the application; they are not to be construed as any kind of additional limitation. The order of execution or steps, whether or not explicitly shown in the drawings or described above, of the acts, steps, etc. in the methods and apparatus shown and described can be combined or performed in other orders without departing from the scope of the application. Repetitive description of like elements employed in the different examples is omitted for sake of brevity.

[0052] It will be understood by those within the art that, in this disclosure, relative terms are used to describe one device or component relative to another device or component. These terms are used to describe the relative spatial and / or temporal position of the devices or components. These terms are not intended to limit the scope of the application to only those embodiments which include devices or components in the relative positions described. Terms such as "above," "below," "upper," "lower," "top," "bottom," "side," "end," "front," "back," "rear," "interior," "exterior," and the like are used herein to describe the relative positioning of the components and / or devices shown in the drawings and are not intended to limit the scope of the application to only those embodiments which include devices or components in the relative positions described. The terms "front," "back," "rear," and the like are used herein to describe the relative positioning of the components and / or devices shown in the drawings and are not intended to limit the scope of the application to only those embodiments which include devices or components in the relative positions described.

[0053] For purposes of the description hereinafter, the terms "upper," "lower," "right," "left," "vertical," "horizontal," and the like shall refer to the application as is shown in the drawings and are not intended to limit the scope of the application, unless specifically made part of the specification. Terms such as "front," "back," "rear," and the like are used herein to describe the relative positioning of the components and / or devices shown in the drawings and are not intended to limit the scope of the application to only those embodiments which include devices or components in the relative positions described. The terms "front," "back," "rear," and the like are used herein to describe the relative positioning of the components and / or devices shown in the drawings and are not intended to limit the scope of the application to only those embodiments which include devices or components in the relative positions described.

[0054] In addition, some ambiguous terms (for example, substantially, certain, generally, etc.) can refer to slight inaccuracy or slight deviation of conditions, quantities, values or sizes, etc., some of which are within the manufacturing deviation or tolerance range. It should be noted that the use of the words "first", "second", etc. to define parts is only for the convenience of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, and therefore cannot be understood as limiting the scope of protection of the present application.

Claims

1. A sliding valve assembly comprising a valve core that can slide along a valve cavity and a piston that pushes the valve core, wherein the piston slides in the sliding cavity, the sliding cavity is axially connected to the valve cavity, and the valve core and the piston are connected via a valve stem, characterized in that: The valve stem is connected to the valve core and the piston via a ball hinge; a damper is provided between the piston and the valve cavity, and the damper is used to limit the movement speed of the piston relative to the valve cavity; the damper is a damping telescopic rod, and a plurality of the damping telescopic rods are evenly distributed around the valve stem in the circumferential direction, the damping telescopic rod includes a damping chamber and a push rod that is telescopic relative to the damping chamber, a second return spring is supported between the damping chamber and the push rod, the damping chamber is connected to the end of the sliding chamber, the push rod faces the piston, and the maximum stroke of the valve core is greater than the maximum length of the damping telescopic rod; A pressure sensor is provided at the end of the push rod.

2. The sliding valve assembly according to claim 1, characterized in that The damping chamber is provided with a damping fluid, which is a non-Newtonian fluid.

3. The sliding valve assembly according to claim 1, wherein: The damping cavity is provided with a damping fluid, which is a magnetorheological fluid. The damping cavity is provided with an electromagnetic coil, which is used to generate a magnetic field for controlling the viscosity of the magnetorheological fluid.

4. The sliding valve assembly according to claim 3, characterized in that The electromagnetic coil controls the viscosity of the magnetorheological fluid according to information from the pressure sensor.

5. The sliding valve assembly according to claim 3, wherein: It also includes a hydraulic control device for controlling the oil pressure in the sliding cavity, and the hydraulic control device adjusts the oil pressure in the sliding cavity according to information from a pressure sensor.

6. A compressor, characterized in that The sliding valve assembly comprises the sliding valve assembly according to any one of claims 1 to 5.

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