Cold start protection mechanism for pump, pre-pump filtering device and oil suction device

Abstract

The utility model discloses a pump cold start protection mechanism, a pump front filter device and an oil suction device, and relates to the technical field of hydraulic control, the pump cold start protection mechanism comprises a protection valve body, a valve core and a retainer, the protection valve body is provided with a first oil cavity, a second oil cavity and an oil drainage port, the first oil cavity is used for being communicated with an oil inlet of a filter, and the second oil cavity is used for being communicated with an oil outlet of the filter; the second oil cavity is used for being communicated with an oil outlet of the filter, the oil drainage port is used for being communicated with the first oil cavity, the valve element can be kept in a first state under the pressure effect of the maintaining piece, the first oil cavity is not communicated with the oil drainage port, and during cold start, the first oil cavity pressure borne by the valve element is larger than the second oil cavity pressure and the protection piece pressure, and the valve element is in a second state. The first oil cavity is communicated with the oil drainage port, oil in the first oil cavity is discharged, the phenomenon that the oil pump sucks air is avoided, and key components in the oil pump are protected; the before-pump filtering device comprises a filter and a cold start protection mechanism for a pump; the oil suction device comprises an oil pump and a pre-pumping filtering device.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic control technology, and in particular to a cold start protection mechanism for a pump, a pre-pump filter device, and an oil suction device. Background Technology

[0002] In hydraulic circulation systems, the hydraulic fluid may contain various impurities, such as metal shavings, dust, and fibers. If these solid particles enter the hydraulic pump, they can cause severe wear to the pump's internal components. Chinese invention patent CN1796766B provides an oil supply device with an oil pump and a filter. This device includes an oil pump housed in an oil tank, and a suction filter connected to the pump inlet to remove foreign substances from the fuel being pumped into the pump. However, during cold starts, the viscosity of the hydraulic fluid is usually high, and the intermolecular forces within it are strong, allowing only a small amount of fluid to pass through the filter. Under normal circumstances, the oil pump relies on a certain negative pressure formed at the inlet end to draw in oil. When only a small amount of oil passes through the filter screen, the resistance of the oil inlet pipeline increases sharply, and the oil flow rate is forced to decrease significantly. According to Bernoulli's equation, the pressure at the oil pump inlet end will drop sharply, leading to cavitation in the oil pump. When the oil pressure at the oil pump inlet end is lower than the saturated vapor pressure of the oil, the oil will vaporize and generate bubbles. These bubbles will enter the pump body with the oil and burst in the high-pressure area. The resulting local high temperature and high pressure impact the surface of the pump's internal parts, causing explosions and corrosion and wear to the key internal components of the oil pump. Utility Model Content

[0003] The purpose of this utility model is to provide a cold start protection mechanism for a pump, a pre-pump filter device, and an oil suction device to solve the problems existing in the prior art, prevent the oil pump from sucking in air during cold start, and protect the key internal components of the oil pump.

[0004] To achieve the above objectives, this utility model provides the following solution:

[0005] This utility model provides a cold start protection mechanism for a pump, including a protective valve body, a valve core, and a retainer. The protective valve body is provided with a first oil chamber, a second oil chamber, and an oil drain port. The first oil chamber is used to communicate with the oil inlet of a filter, the second oil chamber is used to communicate with the oil outlet of the filter, and the oil drain port is used to communicate with the outside. The valve core can be kept in a first state under the pressure of the retainer, in which case the first oil chamber is not connected to the oil drain port. When the pressure of the first oil chamber on the valve core is greater than the pressure of the second oil chamber and the pressure of the retainer, the valve core is in a second state, in which case the first oil chamber is connected to the oil drain port.

[0006] In some embodiments, the protective valve body is provided with an oil chamber, and the valve core is disposed in the oil chamber and divides the oil chamber into a first oil chamber and a second oil chamber.

[0007] In some embodiments, the outer wall of the valve core has a protrusion. When the valve core switches between the first state and the second state, the circumferential sidewall of the protrusion contacts the inner wall of the oil cavity and can slide along the inner wall of the oil cavity. The protrusion divides the oil cavity into a first oil cavity and a second oil cavity.

[0008] In some embodiments, the retainer includes an elastic element, one end of which is connected to the inner wall of the oil cavity end and the other end is connected to the protrusion, and the valve core blocks the oil drain port under the elastic force of the elastic element.

[0009] In some embodiments, a guide hole is provided at the end of the protective valve body away from the drain port. The guide hole communicates with the oil chamber. When the valve core switches between the first state and the second state, the end of the valve core away from the drain port extends into the guide hole and slides along the inner wall of the guide hole along the valve core axis.

[0010] In some embodiments, an oil outlet line is also included, one end of which is connected to the second oil chamber, and the other end is used to connect to the oil inlet of the oil pump.

[0011] In some embodiments, a pressure valve plug is provided at the oil drain port, and a pressure relief channel is provided through the pressure valve plug. A first sealing surface is provided at the end of the valve core near the oil drain port. The distance from the first sealing surface to the oil drain port gradually decreases from the outside to the inside. A second sealing surface matching the first sealing surface is provided on the pressure valve plug. In a first state, the first sealing surface and the second sealing surface are in contact to block the oil drain port. In a second state, the first sealing surface and the second sealing surface are separated, and the pressure relief channel communicates with the first oil chamber.

[0012] In some embodiments, an annular sealing groove is provided on the outer wall of the pressure valve plug, and a sealing gasket is provided between the sealing groove and the inner wall of the oil drain port. The sealing gasket is used to seal the gap between the oil drain port and the pressure valve plug.

[0013] This utility model also provides a pre-pump filtration device, including a filter and the pump cold start protection mechanism described in any of the above.

[0014] This utility model also provides an oil suction device, including an oil pump and the above-mentioned pre-pump filter device.

[0015] The present invention achieves the following technical advantages over the prior art:

[0016] The pump cold start protection mechanism, pre-pump filter, and oil suction device provided by this utility model address the following issues: During cold start, the oil viscosity is high, and only a small amount of oil passes through the filter element. At this time, the pressure on the valve core in the first oil chamber is greater than the pressure in the second oil chamber and the pressure of the retaining element. The valve core is in the second state, and the first oil chamber is connected to the drain port. The oil in the first oil chamber is discharged through the drain port, preventing the oil pump from establishing control pressure. The oil pump will not change direction and will be in a zero-swing state, avoiding cavitation and protecting the key internal components of the oil pump. After the oil temperature rises, the amount of oil passing through the filter increases. At this time, the pressure on the valve core in the first oil chamber is less than the pressure in the second oil chamber and the pressure of the retaining element. The valve core is in the first state, and the first oil chamber is not connected to the drain port. The oil passes through the first oil chamber, the filter, and the second oil chamber in sequence before entering the oil pump for normal operation. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the pre-pump filtration device in one embodiment;

[0019] Figure 2 This is a top view of the pre-pump filtration device in one embodiment;

[0020] Figure 3 for Figure 2 Cross-sectional view of the pre-pump filter unit (AA);

[0021] Figure 4 for Figure 2 Cross-sectional view of the pre-pump filter unit (BB);

[0022] Figure 5 This is a schematic diagram of the valve core structure in one embodiment;

[0023] Figure 6 This is a schematic diagram of a pressure valve plug structure in one embodiment;

[0024] In the diagram: 1-Protective valve body; 11-First oil chamber; 12-Second oil chamber; 13-Drain port; 14-Guide hole; 15-Pressure valve plug; 151-Second sealing surface; 152-Sealing groove; 2-Valve core; 21-Protrusion; 22-First sealing surface; 3-Retaining element; 31-Elastic element; 4-Filter; 41-Filter inlet; 42-Filter outlet; 43-Filter element; 5-Inlet pipeline; 6-Outlet pipeline. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] The purpose of this utility model is to provide a cold start protection mechanism for a pump, a pre-pump filter, and an oil suction device to solve the problems existing in the prior art, prevent the oil pump from sucking in air during cold start, and protect the key internal components of the pump.

[0027] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Example 1

[0029] This utility model provides a cold start protection mechanism for pumps, such as... Figures 1-6 As shown, the device includes a protective valve body 1, a valve core 2, and a retainer 3. The protective valve body 1 is provided with a first oil chamber 11, a second oil chamber 12, and an oil drain port 13. The first oil chamber 11 is used to communicate with the filter inlet 41, the second oil chamber 12 is used to communicate with the filter outlet 42, and the oil drain port 13 is used to communicate with the outside. The valve core 2 can be held in a first state under the pressure of the retainer 3. At this time, the first oil chamber 11 and the oil drain port 13 are not connected. During cold start, the oil viscosity is high, and only a small amount of oil passes through the filter element 43. At this time, the pressure of the first oil chamber 11 on the valve core 2 is greater than the pressure of the second oil chamber 12 and the pressure of the retainer 3. In the second state, the first oil chamber 11 is connected to the drain port 13, and the oil in the first oil chamber 11 is discharged through the drain port 13, so that the pump cannot build up control pressure, and the oil pump will not change direction and will be in a zero swing angle state, avoiding the occurrence of cavitation, thereby protecting the key internal components of the pump. After the oil temperature rises, the amount of oil passing through the filter element 43 increases. At this time, the pressure of the valve core 2 on the first oil chamber 11 is less than the pressure of the second oil chamber 12 and the pressure of the retainer 3. The valve core 2 is in the first state, the first oil chamber 11 is not connected to the drain port 13, and the oil passes through the first oil chamber 11, the filter 4, and the second oil chamber 12 in sequence before entering the oil pump to work normally.

[0030] In another embodiment of this example, such as Figure 3As shown, the inner wall of the first oil chamber 11 is provided with a first oil inlet and a first oil outlet. The first oil inlet is used to connect with the oil inlet pipe 5, and the first oil outlet is used to connect with the filter inlet 41. The inner wall of the second oil chamber 12 is provided with a second oil inlet and a second oil outlet. The filter outlet 42 is connected with the second oil inlet, and the second oil outlet is used to connect with the oil pump inlet. The valve core 2 is in the second state, and the first oil chamber 11 is not connected with the drain port 13. The oil enters the first oil chamber 11 from the oil inlet pipe 5 through the first oil inlet, and then enters the filter 4 through the first oil outlet and the filter inlet 41 in sequence. After being filtered by the filter element 43 in the filter 4, the oil enters the second oil chamber 12 through the filter outlet 42 and the second oil inlet in sequence, and then reaches the oil pump inlet through the second oil outlet.

[0031] In another embodiment of this example, such as Figure 3 As shown, the protective valve body 1 is provided with an oil chamber, the valve core 2 is disposed in the oil chamber and the oil chamber is divided into a first oil chamber 11 and a second oil chamber 12. The pressure of the first oil chamber 11 and the second oil chamber 12 acts on both sides of the valve core 2, causing the valve core 2 to switch between the first state and the second state.

[0032] In another embodiment of this example, such as Figure 3 As shown, the outer wall of the valve core 2 has a protrusion 21. When the valve core switches between the first state and the second state, the circumferential sidewall of the protrusion 21 contacts the inner wall of the oil cavity and can slide along the inner wall of the oil cavity. The protrusion divides the oil cavity into a first oil cavity 11 and a second oil cavity 12. The pressure of the first oil cavity 11 and the second oil cavity 12 acts on the protrusion 21, causing the circumferential sidewall of the protrusion 21 to slide along the inner wall of the oil cavity, thereby switching the valve core 2 between the first state and the second state.

[0033] In another embodiment of this example, such as Figure 3 As shown, the retainer 3 includes an elastic element 31. One end of the elastic element 31 is connected to the inner wall of the oil chamber end, and the other end is connected to the protrusion 21. Under the elastic force of the elastic element 31, the valve core 2 blocks the oil drain port 13 to prevent the first oil chamber from communicating with the oil drain port. When cold starting, only a small amount of oil can pass through the filter into the second oil chamber. At this time, the pressure of the first oil chamber 11 on the valve core is greater than the pressure of the second oil chamber 12 and the pressure of the elastic element 31. The valve core 2 separates from the oil drain port 13, and the first oil chamber 11 communicates with the oil drain port 13.

[0034] In another embodiment of this example, such as Figure 3 As shown, the elastic element 31 is a spring. Under the action of the spring force, the valve core 2 blocks the oil drain port 13. When the pressure of the first oil chamber 11 on the valve core is greater than the pressure of the second oil chamber 12 and the spring pressure, the valve core 2 separates from the oil drain port 13.

[0035] In another embodiment of this example, such as Figure 3 and Figure 5 As shown, the protrusion 21 divides the valve core into three sections. The first section of the valve core is located in the first oil chamber 11. The second section of the valve core includes the protrusion 21, and the circumferential sidewall of the second section of the valve core is in contact with the inner wall of the oil chamber. The third section of the valve core is located in the second oil chamber 12. The protrusion 21 extends outward relative to the outer sidewall of the first section of the valve core to form a first stepped surface, and the protrusion 21 extends outward relative to the outer sidewall of the third section of the valve core to form a second stepped surface. The area of ​​the first stepped surface is smaller than the area of ​​the second stepped surface, so that a pressure difference can be more easily formed between the first oil chamber 11 and the second oil chamber 12.

[0036] In another embodiment of this example, such as Figure 3 As shown, a guide hole 14 is provided at the end of the valve body 1 away from the oil drain port 13. The guide hole 14 is connected to the oil chamber. When the valve core 2 switches between the first state and the second state, the end of the valve core 2 away from the oil drain port 13 extends into the guide hole 14 and slides along the inner wall of the guide hole 14 along the axial direction of the valve core 2. The guide hole 14 can guide the direction of the valve core 2 when sliding, and prevent the valve core 2 from deviating in the direction of movement under the action of oil pressure.

[0037] In another embodiment of this example, such as Figure 3 As shown, the pump cold start protection mechanism also includes an oil outlet pipe 6. One end of the oil outlet pipe 6 is connected to the second oil chamber 12, and the other end is used to connect to the oil inlet of the oil pump, so that the filtered oil can reach the oil inlet of the oil pump from the second oil chamber 12 through the oil outlet pipe.

[0038] In another embodiment of this example, such as Figure 3 and Figure 6 As shown, a pressure valve plug 15 is provided at the oil drain port 13, and a pressure relief channel is provided through the pressure valve plug 15. A first sealing surface 22 is provided at the end of the valve core 2 near the oil drain port 13. The distance of the first sealing surface 22 from the outside to the inside of the oil drain port 13 gradually decreases. A matching second sealing surface 151 is provided on the pressure valve plug 15. In the first state, the first sealing surface 22 and the second sealing surface 151 are in contact to block the oil drain port 13. In the second state, the first sealing surface 22 and the second sealing surface 152 are separated, and the pressure relief channel is connected to the first oil chamber 11. The arrangement of the first sealing surface 22 and the second sealing surface 151 can improve the sealing effect of the valve core 2 on the oil drain port 13 and prevent oil leakage in the first oil chamber 11.

[0039] In another embodiment of this example, such as Figure 3 and Figure 6As shown, an annular sealing groove 152 is provided on the outer wall of the pressure valve plug 15. A sealing gasket is provided between the sealing groove 152 and the inner wall of the oil drain port 13. The sealing gasket is used to seal the gap between the oil drain port 13 and the pressure valve plug 15 to prevent oil leakage in the first oil chamber 11.

[0040] Example 2

[0041] This embodiment provides a pre-pump filtration device, such as... Figure 4 As shown, the pump includes filter 4 and the pump cold start protection mechanism in Embodiment 1. By setting the pump cold start protection mechanism, when only a small amount of oil passes through filter element 43 of filter 4 during cold start, the oil in the first oil chamber 11 is discharged through the oil drain port 13, so that the pump cannot build up control pressure, and the oil pump will not change direction and will be in a zero swing angle state, avoiding the occurrence of cavitation and thus protecting the key internal components of the pump.

[0042] In another embodiment of this example, such as Figure 4 As shown, the filter 4 includes a filter housing and a filter element 43, a protective valve body, a filter chamber formed inside the filter housing, the filter housing is fixed on the protective valve body, the filter element 43 is disposed in the filter chamber and fixed on the protective valve body, the filter element 42 is an annular filter element, a first filter chamber and a second filter chamber are formed on the inner and outer sides of the filter element 42 respectively, the filter inlet 41 is connected to the first filter chamber, and the filter outlet 42 is connected to the second filter chamber.

[0043] In another embodiment of this example, such as Figure 4 As shown, a sealing ring is provided between the filter housing and the protective valve body to prevent oil leakage. The filter element 43 is fixed to the protective valve body by a buffer spring. When the protective valve body is impacted by oil, the impact energy is converted into the elastic potential energy of the spring, avoiding the direct transmission of impact energy and reducing the impact of oil on the protective valve body on the filter element 43.

[0044] Example 3

[0045] This embodiment provides an oil suction device, including an oil pump and a pre-pump filter device as in Embodiment 2. By setting a cold start protection mechanism for the pump in the pre-pump filter device, when only a small amount of oil passes through the filter element 43 of the filter 4 during cold start, the oil in the first oil chamber 11 is discharged through the oil drain port 13, so that the pump cannot build up control pressure, and the oil pump will not change direction and will be in a zero swing angle state, avoiding the occurrence of cavitation and thus protecting the key internal components of the pump.

[0046] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A cold start protection mechanism for a pump, characterized in that, The device includes a protective valve body, a valve core, and a retainer. The protective valve body is provided with a first oil chamber, a second oil chamber, and an oil drain port. The first oil chamber is used to communicate with the oil inlet of the filter, the second oil chamber is used to communicate with the oil outlet of the filter, and the oil drain port is used to communicate with the outside. The valve core can be kept in a first state under the pressure of the retainer. At this time, the first oil chamber and the oil drain port are not connected. When the pressure of the first oil chamber on the valve core is greater than the pressure of the second oil chamber and the pressure of the retainer, the valve core is in a second state. At this time, the first oil chamber and the oil drain port are connected.

2. The pump cold start protection mechanism according to claim 1, characterized in that, The protective valve body is provided with an oil chamber, and the valve core is disposed in the oil chamber and divides the oil chamber into a first oil chamber and a second oil chamber.

3. The pump cold start protection mechanism according to claim 2, characterized in that, The valve core has a protrusion on its outer side wall. When the valve core switches between the first state and the second state, the circumferential side wall of the protrusion contacts the inner wall of the oil cavity and can slide along the inner wall of the oil cavity. The protrusion divides the oil cavity into a first oil cavity and a second oil cavity.

4. The pump cold start protection mechanism according to claim 3, characterized in that, The retaining element includes an elastic element, one end of which is connected to the inner wall of the oil cavity end, and the other end is connected to the protrusion. The valve core blocks the oil drain port under the elastic force of the elastic element.

5. The pump cold start protection mechanism according to claim 1, characterized in that, The protective valve body has a guide hole at one end away from the drain port. The guide hole is connected to the oil chamber. When the valve core switches between the first state and the second state, the end of the valve core away from the drain port extends into the guide hole and slides along the inner wall of the guide hole along the valve core axis.

6. The pump cold start protection mechanism according to claim 1, characterized in that, It also includes an oil outlet pipeline, one end of which is connected to the second oil chamber, and the other end is used to connect to the oil inlet of the oil pump.

7. The pump cold start protection mechanism according to claim 1, characterized in that, A pressure valve plug is provided at the oil drain port, and a pressure relief channel is provided through the pressure valve plug. A first sealing surface is provided at the end of the valve core near the oil drain port. The distance of the first sealing surface from the outside to the oil drain port gradually decreases. A second sealing surface matching the first sealing surface is provided on the pressure valve plug. In a first state, the first sealing surface and the second sealing surface are in contact to block the oil drain port. In a second state, the first sealing surface and the second sealing surface are separated, and the pressure relief channel is connected to the first oil chamber.

8. The pump cold start protection mechanism according to claim 7, characterized in that, An annular sealing groove is provided on the outer wall of the pressure valve plug, and a sealing gasket is provided between the sealing groove and the inner wall of the oil drain port. The sealing gasket is used to seal the gap between the oil drain port and the pressure valve plug.

9. A pre-pump filtration device, characterized in that, Includes a filter and a cold start protection mechanism for pumps according to any one of claims 1 to 8.

10. An oil suction device, characterized in that, It includes an oil pump and the pre-pump filter device as described in claim 9.

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