A floating side plate with rapid unloading

Abstract

A floating side plate with rapid unloading, where a spool (4) and a spring (3) are installed in the mounting holes of a side plate base body (1). The connection between the side plate base body (1) and an oil plug (2) is a plane. One end of the spring (3) is fixed on the fifth face (A5) of the spool (4), and the other end is fixed on the oil plug (2). The first face (A1) of the spool (4) cooperates with the end face of a positioning cavity (1-5) to achieve axial positioning of the spool (4), and a guiding shoulder (4-2) cooperates with the wall surface of a guiding cavity (1-4) to achieve linear movement of the spool (4). The first face (A1) of the spool (4) is in contact with the oil phase at the pump suction port through an oil discharge cavity (1-6) and an oil guiding groove (1-7). The second face (A2) and the third face (A3) are in contact with the high-pressure oil phase in the trapped oil area through a rectangular groove (1-3) and a high-pressure oil guiding hole (1-1). The fourth face (A4) is in contact with the oil phase at the pump discharge port through an oil guiding hole (1-2).

Description

Technical Field

[0001] The invention relates to the technical field of floating side plates of hydraulic external gear pumps, in particular to a floating side plate technology for rapid unloading. Background Art

[0002] Involute external gear pumps are widely used in engineering machinery, agricultural machinery and other fields due to their mature processing technology and low cost. Involute external gear pumps usually have trapped oil areas, which produce trapped oil pressure far higher than the outlet pressure, causing increased radial force on gears and bearings, intensified outlet pressure pulsation, cavitation vibration noise and other adverse effects. The conventional method to alleviate such phenomena is to open a relief groove at the corresponding position of the floating side plate, such as the patent of an external gear pump with ear-shaped relief groove (CN103527470A), a floating side plate for high-pressure and large-displacement gear pumps (CN103591021A), etc., to discharge the trapped volume of oil through the relief groove to reduce the trapped oil pressure, and replenish the oil through the oil replenishment groove in the area where the gear is out of meshing, so as to suppress cavitation. However, the conventional relief groove structure can only reduce the maximum trapped oil pressure. The pressure after relief is still relatively large relative to the pump outlet pressure and the pulsation rate is high, and the trapped oil pressure cannot be maintained at a low and stable level. Summary of the invention

[0003] The object of the present invention is to provide a floating side plate with rapid unloading.

[0004] The present invention is a floating side plate with rapid unloading, comprising a side plate base, an oil plug, a spring and a valve core, the valve core and the spring are mounted in the mounting hole of the side plate base, the connection between the side plate base and the oil plug is a plane, one end of the spring is fixed on the fifth face of the valve core, and the other end is fixed on the oil plug; the first face of the valve core cooperates with the end face of the positioning cavity to realize the axial positioning of the valve core, and the guide shoulder cooperates with the wall face of the guide cavity to realize the linear movement of the valve core; the first face of the valve core contacts with the oil at the pump suction port through the oil discharge cavity and the oil guide groove, the second face and the third face contact with the high-pressure oil in the oil trapped area through the rectangular groove and the high-pressure oil guide hole, and the fourth face contacts with the oil at the pump discharge port through the oil guide hole.

[0005] The benefits of the present invention lie in that, through the static unloading of the rectangular groove and the dynamic unloading of the valve core, the oil pressure and pulsation rate in the oil trapped area of ​​the gear can be significantly reduced, causing the pressure to fluctuate up and down at a certain multiple of the pump outlet pressure. The size of this multiple can be set by designing the area of ​​the relevant surface of the valve core. In addition, the high-pressure oil discharged by the valve core can effectively suppress cavitation at the point where the gear disengages from the meshing position. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a front view of the present invention, Figure 2 This is a full cross-sectional view of the side panel. Figure 3It is a diagram showing the relationship between the side plate structure and the gear. Figure 4 It is a three-dimensional view of the side plate. Figure 5 It is a full sectional view of the side plate base. Figure 6 It is a three-dimensional view of the spool valve. The reference numerals and names are as follows: side plate base 1, high-pressure oil guiding hole 1-1, oil guiding hole 1-2, rectangular groove 1-3, guiding cavity 1-4, positioning cavity 1-5, oil discharge cavity 1-6, oil guiding groove 1-7, flat groove 1-8, low-pressure hole 1-9, oil plug 2, spring 3, spool valve 4, positioning shoulder 4-1, guiding shoulder 4-2. First surface A1, second surface A2, third surface A3, fourth surface A4, fifth surface A5. Embodiment

[0007] The present invention is a floating side plate with rapid unloading, which includes a side plate base 1, an oil plug 2, a spring 3 and a spool valve 4. The spool valve 4 and the spring 3 are installed in the installation hole of the side plate base 1. The connection between the side plate base 1 and the oil plug 2 is a plane. One end of the spring 3 is fixed on the fifth surface A5 of the spool valve 4, and the other end is fixed on the oil plug 2. The first surface A1 of the spool valve 4 is matched with the end face of the positioning cavity 1-5 to realize the axial positioning of the spool valve 4, and the guiding shoulder 4-2 is matched with the wall surface of the guiding cavity 1-4 to realize the linear movement of the spool valve 4. The first surface A1 of the spool valve 4 is in contact with the oil phase at the pump suction port through the oil discharge cavity 1-6 and the oil guiding groove 1-7. The second surface A2 and the third surface A3 are in contact with the high-pressure oil phase in the trapped oil area through the rectangular groove 1-3 and the high-pressure oil guiding hole 1-1. The fourth surface A4 is in contact with the oil phase at the pump discharge port through the oil guiding hole 1-2. The movement of the spool valve is realized through the dynamic balance between the unbalanced fluid force acting on the spool valve and the spring force.

[0008] For the above-mentioned floating side plate with rapid unloading, the side plate base 1 is provided with a high-pressure oil guiding hole 1-1, an oil guiding hole 1-2, a rectangular groove 1-3, a guiding cavity 1-4, a positioning cavity 1-5, an oil discharge cavity 1-6, an oil guiding groove 1-7, a flat groove 1-8 and a low-pressure hole 1-9. The guiding cavity 1-4 is communicated with the rectangular groove 1-3 through the high-pressure oil guiding hole 1-1 and the oil guiding hole 1-2. The guiding cavity 1-4 is communicated with the oil guiding groove 1-7 through the positioning cavity 1-5 and the oil discharge cavity 1-6.

[0009] For the above-mentioned floating side plate with rapid unloading, the oil guiding holes 1-2 on the side plate base 1 are symmetrically distributed with respect to the central plane of the side plate, and are located between the position where the gear starts to mesh and the position of the minimum trapped oil area of the gear. The oil guiding groove 1-7 is opened in the middle of the side plate, is located at the position where the gear starts to disengage, and is in a V shape. The low-pressure holes 1-9 are symmetrically distributed with respect to the central plane and are communicated with the V-shaped oil guiding groove.

[0010] For the above-mentioned floating side plate with rapid unloading, the spool valve 4 is provided with a positioning shoulder 4-1 and a guiding shoulder 4-2, and the area relationship of the second surface A2, the third surface A3 and the fourth surface A4 is A4 > A3 > A2.

[0011] Next, the principles and features of the present invention will be further described in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0012] As Figure 1 , Figure 2 , Figure 6 shown, the main structure includes a side plate base 1, an oil plug 2, a spring 3 and a valve core 4. Among them, the spring 3 and the valve core 4 are installed in the installation hole of the side plate base 1. One end of the spring 3 is fixed on the fifth surface A5 of the valve core 4, and the other end is fixed on the oil plug 2. The connection between the side plate base 1 and the oil plug 2 is a plane; the first surface A1 of the valve core 4 cooperates with the end surface of the positioning cavity 1-5 to realize the axial positioning of the valve core 4; the guiding shoulder 4-2 cooperates with the wall surface of the guiding cavity 1-4 to realize the linear movement of the valve core 4.

[0013] As Figures 3 - 5 shown, the side plate base 1 is provided with a high-pressure oil guiding hole 1-1, an oil guiding hole 1-2, a rectangular groove 1-3, a guiding cavity 1-4, a positioning cavity 1-5, an oil discharge cavity 1-6, an oil guiding groove 1-7, a plane groove 1-8 and a low-pressure hole 1-9. The high-pressure oil guiding hole 1-1 is symmetrically distributed with respect to the central plane of the side plate, located between the gear starting meshing position and the gear minimum trapped oil area position, and communicates with the guiding cavity 1-4; the oil guiding hole 1-2 is located in the middle plane of the side plate, connecting the rectangular groove 1-3 and the guiding cavity 1-4; the guiding cavity 1-4 is connected with the oil guiding groove 1-7 through the positioning cavity 1-5 and the oil discharge cavity 1-6; the oil guiding groove 1-7 is symmetrically distributed with respect to the central plane of the side plate, located at the gear starting to disengage, and is V-shaped; the low-pressure holes 1-9 are symmetrically distributed with respect to the central plane and communicate with the V-shaped oil guiding groove.

[0014] As Figures 1 - 6 shown, the first surface A1 of the valve core 4 is in contact with the oil phase of the pump suction port through the oil discharge cavity 1-6 and the oil guiding groove 1-7. The second surface A2 and the third surface A3 are in contact with the high-pressure oil phase in the trapped oil area through the rectangular groove 1-3 and the high-pressure oil guiding hole 1-1. The fourth surface A4 is in contact with the oil phase of the pump discharge port through the oil guiding hole 1-2. The areas of the second surface A2, the third surface A3 and the fourth surface A4 are A2, A3 and A4 respectively, and A4 > A2 > A3. The movement of the valve core is realized through the dynamic balance between the unbalanced fluid force and the spring force received by the valve core.

[0015] The working process of the present invention is as follows: When the gear pump starts to work, the gears mesh with each other to discharge pressurized oil. Since the overlap coefficient is greater than 1, there is a trapped oil area between the two gears that is not connected to both the high-pressure and low-pressure areas of the pump, generating high-pressure oil. At this time, most of the high-pressure oil is unloaded through the rectangular groove 1-3 to reduce the oil pressure in the trapped oil area. Another part of the pressure is p 困The high-pressure oil will contact the second surface A2 and the third surface A3 of the spool 4 through the high-pressure oil guiding hole 1-1, and at the same time, the pump outlet pressure is p The pressurized oil of passes through the oil guiding hole 1-2 and contacts the fourth surface A4. At this time, the condition for the spool 4 to open is

[0016] ;

[0017] The spring 3 is a light spring, and the spring force generated F 弹 is negligible compared with the hydraulic force. At this time, the key factor affecting the opening of the spool 4 is the coefficient λ :

[0018]

[0019] λ can be set according to the area relationship. When λ is too small, the volumetric efficiency of the pump will be reduced. When λ is too large, there will be a relatively high trapped oil pressure. Therefore, it is necessary to balance the relationship between the two during design.

[0020] When the forces on the spool 4 are unbalanced, the spool opens, allowing the trapped oil to communicate with the oil in the area where the gear disengages through the high-pressure oil guiding hole 1-1, the positioning cavity 1-5, the oil discharge cavity 1-6, and the oil guiding groove 1-7. At the same time, under the action of the plane groove 1-8 and the low-pressure hole 1-9, the cavitation phenomenon at the pump inlet can be effectively alleviated. When p 困 ≤ λ · p , the spool 4 closes under the combined action of the hydraulic force and the spring force of the spring 3.

Claims

1. A floating side plate with rapid unloading, comprising a side plate base body (1), an oil plug (2), a spring (3) and a valve core (4), characterized in that: The spool (4) and the spring (3) are installed in the mounting holes of the side plate base body (1). The connection between the side plate base body (1) and the oil plug (2) is a flat surface. One end of the spring (3) is fixed on the fifth surface (A5) of the spool (4), and the other end is fixed on the oil plug (2). The first surface (A1) of the spool (4) is fitted with the end face of the positioning cavity (1-5) to achieve the axial positioning of the spool (4), and the guiding shoulder (4-2) is fitted with the wall surface of the guiding cavity (1-4) to achieve the linear movement of the spool (4). The first surface (A1) of the spool (4) is in contact with the oil phase at the pump suction port through the oil discharge cavity (1-6) and the oil guiding groove (1-7). The second surface (A2) and the third surface (A3) are in contact with the high-pressure oil phase in the trapped oil area through the rectangular groove (1-3) and the high-pressure oil guiding hole (1-1). The fourth surface (A4) is in contact with the oil phase at the pump discharge port through the oil guiding hole (1-2).

2. The floating side plate with rapid unloading according to claim 1, wherein: The side plate base body (1) is provided with a high-pressure oil guiding hole (1-1), an oil guiding hole (1-2), a rectangular groove (1-3), a guiding cavity (1-4), a positioning cavity (1-5), an oil discharge cavity (1-6), an oil guiding groove (1-7), a flat surface groove (1-8) and a low-pressure hole (1-9). The guiding cavity (1-4) is communicated with the rectangular groove (1-3) through the high-pressure oil guiding hole (1-1) and the oil guiding hole (1-2). The guiding cavity (1-4) is communicated with the oil guiding groove (1-7) through the positioning cavity (1-5) and the oil discharge cavity (1-6).

3. The floating side plate with rapid unloading according to claim 1, characterized in that: The oil guiding holes (1-2) on the side plate base body (1) are symmetrically distributed about the central plane of the side plate, and are located between the starting position of gear meshing and the position of the minimum trapped oil area of the gear. The opening position of the oil guiding groove (1-7) is in the middle of the side plate, at the position where the gear starts to disengage from meshing, and is V-shaped. The low-pressure holes (1-9) are symmetrically distributed about the central plane and are communicated with the V-shaped oil guiding groove.

4. The floating side plate with rapid unloading according to claim 1, characterized in that: The spool (4) is provided with a positioning shoulder (4-1) and a guiding shoulder (4-2), and the area relationship of the second surface (A2), the third surface (A3) and the fourth surface (A4) is A4 > A3 > A2.

5. The floating side plate with rapid unloading according to claim 1, characterized in that: The pressure is p 困 The high-pressure oil fluid passes through the high-pressure oil guide hole (1-1) and contacts the second surface (A2) and the third surface (A3) of the spool (4). The pressure of the pump outlet is p The pressure oil fluid passes through the oil guide hole (1-2) and contacts the fourth surface (A4). The condition for the spool (4) to open is: ； The spring (3) is a light spring, and the key factor affecting the opening of the valve core (4) is the coefficient λ :[[]]END]] 。

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