A hydraulic transmission gearbox for large-tonnage forklift

Abstract

The present invention relates to the technical field of hydraulic transmission gearboxes, and specifically provides a hydraulic transmission gearbox for a large-tonnage forklift, comprising a gearbox and a torque converter. The torque converter is provided with a filter assembly, the filter assembly comprising a filter ring, and the filter ring is provided with an oil inlet and an oil filter port, so that the oil flowing between a pump wheel and a housing can be filtered by the filter ring, thereby reducing metal debris carried in the oil, and further reducing the degree to which the metal debris accompanies the flow of the oil and aggravates the wear of the torque converter, which can effectively improve the service life of the torque converter. A first switch assembly is provided on the oil inlet, so that when the forklift brakes and the pump wheel does not drive the turbine to rotate, the oil can enter the filter ring and filter the oil. When the forklift releases the brake, the oil filtering is stopped, thereby avoiding additional increase in the energy consumption of the engine, and at the same time reducing the frequency of the filter ring being blocked.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic transmission gearboxes, and in particular to a hydraulic transmission gearbox for large-tonnage forklifts. Background Art

[0002] A hydraulic transmission is a transmission that uses hydraulic transmission and gear ratio changes to achieve vehicle transmission and speed regulation. Its core components include a torque converter and an automatic transmission, which work together to automatically transmit engine power.

[0003] Large-tonnage forklifts are usually used to carry heavy goods. They are widely used in ports, warehouses, construction sites, manufacturing plants and other occasions. The hydraulic transmission gearbox is one of the key components in its power transmission system. For example, Chinese patent CN201896923U discloses a hydraulic transmission gearbox for a forklift, including a gearbox and a torque converter. The gearbox includes a housing and an input shaft. The torque converter includes a housing, a driving wheel, a turbine, a turbine hub, a turbine shaft, a pump wheel and a guide wheel. The housing is mounted on the housing. The guide wheel and the turbine are arranged in a sealed cavity formed by connecting the driving wheel and the pump wheel. The turbine is mounted on the turbine hub. The turbine hub is connected to the turbine shaft through a spline. The input shaft of the gearbox is connected to the turbine shaft. A first bearing seat is provided on the side of the turbine hub close to the driving wheel. The inner ring of the driving wheel is supported on the first bearing seat through a bearing. The above scheme makes the structure of the torque converter more compact, facilitates the arrangement and connection of the surrounding components, and enables the torque converter to smoothly engage with the gearbox of the forklift, thereby reducing the gearbox oil temperature and improving the climbing ability of the forklift.

[0004] However, during the use of the forklift in the above scheme, since it often needs to carry heavy goods, the gearbox works for a long time under high load conditions, which is prone to torque converter wear. Wear will produce metal debris, and long-term use will lead to an increase in metal debris. The metal debris accompanied by the flow of oil will accelerate the wear of the torque converter, thereby reducing the service life of the torque converter, and may cause damage in severe cases. Summary of the invention

[0005] Based on this, it is necessary to provide a large-tonnage forklift hydraulic transmission gearbox to address the problem of severe wear of the current hydraulic torque converter.

[0006] The above purpose is achieved through the following technical solutions:

[0007] A large-tonnage forklift hydraulic transmission gearbox, comprising:

[0008] A gearbox and a torque converter, wherein the gearbox has a housing and an input shaft, and the torque converter includes a pump wheel, a turbine and a guide wheel, wherein the pump wheel is fixedly connected to a housing, the turbine is located in a cavity between the pump wheel and the housing, the pump wheel is drivingly connected to the engine, the turbine is drivingly connected to the input shaft, the guide wheel is located between the turbine and the pump wheel, and the axes of the three coincide;

[0009] A filter assembly, wherein the filter assembly includes a filter ring, the interior of the filter ring is hollow, the filter ring is fixedly arranged on the turbine and located between the turbine and the guide wheel, and the filter ring is also provided with an oil inlet and an oil filter port. The oil in the cavity enters the filter ring through the oil inlet and is re-discharged into the cavity through the oil filter port, and metal debris in the oil is intercepted in the filter ring.

[0010] Furthermore, a first switch component is provided on the oil inlet, and the first switch component can open or close the oil inlet, and the switch component is configured as follows:

[0011] When the turbine stops rotating, the first switch assembly opens the oil inlet, and the liquid in the cavity flows through the filter ring to filter the metal debris therein;

[0012] When the turbine starts to rotate, the first switch assembly closes the oil inlet, and the metal debris in the filter ring is moved away from the oil filter port due to centrifugal force.

[0013] Further, the first switch assembly includes an elastic member and a small ball, both of which are located inside the filter ring, one end of the elastic member is connected to the inside of the filter ring and the connection position corresponds to the oil inlet, the small ball is fixedly connected to the other end of the elastic member, and the diameter of the small ball is greater than the diameter of the oil inlet;

[0014] When the turbine stops, the elastic member is at its original length and the ball is away from the oil inlet. When the turbine rotates, the ball is subjected to a centrifugal force greater than the elastic force of the elastic member and moves toward the oil inlet to close the oil inlet.

[0015] Furthermore, the elastic member is a spring.

[0016] Furthermore, a collecting groove is provided on the side wall of the filter ring away from the axis thereof, and a second switch component is provided on the collecting groove, and the second switch component is used to open or close the collecting groove, and the second switch component is configured as follows:

[0017] When the turbine rotates, the second switch assembly opens the collection groove, and the metal debris in the filter ring enters the collection groove under the action of centrifugal force;

[0018] When the turbine stops, the second switch assembly closes the collecting tank, and the metal debris in the collecting tank is not disturbed by the oil.

[0019] Furthermore, the second switch assembly includes an elastic plate and a connecting shaft, the connecting shaft is fixedly disposed in the collecting groove and arranged along the radial direction of the filter ring, there are a plurality of connecting shafts and elastic plates, the middle position of the elastic plate is fixedly connected to the connecting shaft, and they are all arranged in a circular array in the filter ring, a plurality of elastic plates are in end-to-end contact to close the collecting groove, and when the turbine rotates, centrifugal force is applied to the elastic plate, the two ends of the elastic plate are deformed, and a gap is generated between two adjacent elastic plates to open the collecting groove.

[0020] Furthermore, adsorbent cotton is arranged in the filter ring, and the adsorbent cotton is attached to a surface of the collecting tank away from the axis of the filter ring, and the adsorbent cotton can adsorb metal debris.

[0021] Furthermore, the filter assembly also includes a contraction piece, which is arranged in the filter ring and can contract. When the contraction piece is subjected to centrifugal force, it shrinks, the volume in the filter ring increases, and the oil in the cavity enters the filter ring through the oil filter port to backwash the oil filter port.

[0022] Furthermore, the shrinking member includes a plurality of annular elastic oil bags, each of which has an opening on its surface. When the plurality of annular elastic oil bags shrink, the oil inside is discharged from the filter ring. When the plurality of annular elastic oil bags are reset, the oil is absorbed from the opening.

[0023] Furthermore, there are two annular elastic oil bags.

[0024] The beneficial effects of the present invention are:

[0025] The present invention provides a filter ring on the turbine so that the oil flowing between the pump wheel and the housing can be filtered by the filter ring, thereby reducing metal debris carried in the oil, thereby reducing the degree to which the metal debris accompanying the flow of oil aggravates the wear of the torque converter, and can effectively increase the service life of the torque converter.

[0026] The present invention provides a first switch assembly so that when the forklift brakes and the pump wheel does not drive the turbine to rotate, the oil can enter the filter ring and filter the oil. When the forklift releases the brake, the oil filtering is stopped, thereby avoiding additional increase in engine energy consumption and avoiding long-term use of the oil filter port, thereby reducing the frequency of filter ring clogging.

[0027] The present invention arranges a collecting groove and a second switch assembly in the filter ring so that metal debris can be collected while preventing the collected metal debris from being disturbed by oil; and arranges a plurality of deformable elastic plates so that the metal debris can be evenly distributed in the collecting groove.

[0028] The present invention provides a contraction piece so that oil can enter the filter ring to backwash the oil filter port, thereby cleaning the oil filter port and further reducing the frequency of the filter ring being blocked. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic structural diagram of a hydraulic transmission gearbox for a large-tonnage forklift provided by an embodiment of the present invention;

[0030] Figure 2 An exploded view of a hydraulic transmission gearbox for a large-tonnage forklift provided by an embodiment of the present invention;

[0031] Figure 3 A schematic diagram of the structure of a filter ring of a hydraulic transmission gearbox for a large-tonnage forklift provided by an embodiment of the present invention;

[0032] Figure 4 A schematic diagram of the internal structure of a large-tonnage forklift hydraulic transmission gearbox when the filter ring rotates according to an embodiment of the present invention;

[0033] Figure 5 A schematic diagram of a torque converter of a hydraulic transmission gearbox for a large-tonnage forklift provided by an embodiment of the present invention;

[0034] Figure 6 for Figure 5 A cross-sectional view of a hydraulic transmission gearbox for a large-tonnage forklift along AA provided in an embodiment;

[0035] Figure 7 for Figure 6 An enlarged view of a portion X of a hydraulic transmission gearbox for a large-tonnage forklift provided in an embodiment;

[0036] Figure 8 A schematic diagram of a torque converter of a hydraulic transmission gearbox for a large-tonnage forklift provided by an embodiment of the present invention from another angle;

[0037] Fig. 9 for Figure 8 A cross-sectional view along BB of a filter ring of a hydraulic transmission gearbox for a large-tonnage forklift provided in an embodiment of the present invention when the filter ring rotates;

[0038] Fig.10 for Fig. 9 An enlarged view of the Y portion of the hydraulic transmission gearbox of a large-tonnage forklift provided in the first embodiment;

[0039] Fig.11 for Figure 8 A cross-sectional view along BB of a filter ring of a hydraulic transmission gearbox for a large-tonnage forklift provided in an embodiment of the present invention when the filter ring is stationary;

[0040] Fig.12 for Fig.11 An enlarged view of part Z of a hydraulic transmission gearbox for a large-tonnage forklift provided in one embodiment.

[0041] in:

[0042] 100, gearbox; 110, housing; 120, input shaft;

[0043] 200, torque converter; 210, pump wheel; 220, guide wheel; 221, one-way bearing; 230, turbine; 231, boss; 240, locking clutch; 250, housing; 260, cavity;

[0044] 300, filter assembly; 310, filter ring; 320, oil inlet; 321, elastic member; 322, small ball; 330, oil filter port; 340, collecting tank; 341, connecting shaft; 342, elastic plate; 350, annular elastic oil pan. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0046] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in the present invention, unless otherwise specified, include direct and indirect connections (couplings). In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0047] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0048] Refer to the following Figure 1-Figure 12 The invention will now be described in detail with reference to a hydraulic transmission gearbox for a large-tonnage forklift truck.

[0049] A large-tonnage forklift hydraulic transmission gearbox includes a gearbox 100 and a torque converter 200. The gearbox 100 includes a housing 110 and an input shaft 120. The housing 110 has a transmission. One end of the input shaft 120 is transmission-connected to the transmission, and the other end of the input shaft 120 is connected to the torque converter 200. The torque converter 200 includes a pump wheel 210, a turbine 230, and a guide wheel 220. The pump wheel 210 is fixedly connected to a housing 250. The housing 250 of the pump wheel 210 is connected to an output shaft of an engine (not shown in the figure). The output shaft of the engine drives the pump wheel 210 and the housing 250 to rotate synchronously. A cavity 260 is provided between the pump wheel 210 and the housing 250. The cavity 260 contains oil, and the turbine 230 and the guide wheel 220 are located in the cavity 260. The turbine 230 is transmission-connected to the input shaft 120 of the gearbox 100. When the turbine 230 rotates, the input shaft 120 of the gearbox 100 is driven to rotate. A one-way bearing 221 is provided at the axis of the guide wheel 220. The guide wheel 220 is specifically located between the turbine 230 and the pump wheel 210, and the axes of the three coincide. At the same time, a locking clutch 240 is also provided between the pump wheel 210 housing 250 and the turbine 230. It should be noted that the connection methods of the guide wheel 220, the turbine 230, the pump wheel 210 and the locking clutch 240 of the present invention are all prior arts, and the connection details of the specific structure are no longer described in detail. However, a filter assembly 300 is provided on the torque converter 200 of the present invention, and the filter assembly 300 is used to filter metal debris in the oil. Since the forklift needs to stop and start frequently during work and carries heavy goods, the gearbox 100 is in a high-load state for a long time, and wear is inevitable. The metal debris generated by the wear will synchronously accompany the flow of the oil and thereby aggravate the wear. Therefore, a filter assembly 300 is added to the torque converter 200 to reduce the metal debris in the oil, thereby achieving the purpose of slowing down the wear.

[0050] The filter assembly 300 includes a filter ring 310, which is arranged on the turbine 230. Since the oil flows frequently between the turbine 230 and the pump wheel 210 in the torque converter 200, it is most appropriate to arrange the filter ring 310 between the turbine 230 and the pump wheel 210. The turbine 230 is connected to the input shaft 120 of the gearbox 100. When the forklift brakes to lift the goods, the turbine 230 is stationary, and the pump wheel 210 connected to the engine keeps rotating. Therefore, when it is arranged on the turbine 230, the oil passes through the filter ring 310 more efficiently. The filter ring 310 is specifically fixed on the boss 231 of the turbine 230 and does not contact the blades of the turbine 230. The filter ring 310 is hollow inside, and is provided with an oil inlet 320 and an oil filter port 330. There are a plurality of oil inlets 320 and oil filter ports 330, and they are arranged in a circumferential direction. The oil inlet 320 is specifically located on the outer peripheral wall of the filter ring 310, and the oil filter port 330 is provided on the side wall of the filter ring 310 and on the side wall close to the guide wheel 220, and the oil filter port 330 is strip-shaped.

[0051] It should be noted that the configuration of the above-mentioned filter ring 310 allows the oil in the cavity 260 between the pump wheel 210 and the housing 250 to flow into the filter ring 310 through the oil inlet 320 of the filter ring 310, and then be discharged from the oil filter port 330 of the filter ring 310. The oil filter port 330 is provided with a plurality of sieve holes (not shown in the figure). The size of the sieve holes is small enough to intercept metal debris in the oil without affecting the passage of the oil.

[0052] For example Figure 6 As shown, the engine starts and drives the pump wheel 210 to rotate. The pump wheel 210 rotates at a high speed so that the oil in the cavity 260 is subjected to centrifugal force, and the flow direction of the oil Figure 6 As shown by the middle arrow, the oil flows through the arc surface of the side wall of the pump wheel 210 to the arc surface side wall of the turbine 230 and then passes through the blades of the turbine 230 to drive the turbine 230 to rotate. If the forklift is in a braking state at this time, the turbine 230 will not rotate. After passing through the blades of the turbine 230, the oil will pass through the filter ring 310. The oil can enter the filter ring 310 through the oil inlet 320 and then be discharged through the oil filter port 330. The discharged oil passes through the guide wheel 220 and flows back to the side wall of the pump wheel 210 again, so as to circulate and filter metal debris in the oil, reduce wear, and thus increase the service life of the gearbox 100 and the torque converter 200.

[0053] In a further embodiment, a first switch assembly is provided at the oil inlet 320 of the filter ring 310. The first switch assembly is used to open or close the oil inlet 320. The provision of the first switch assembly can reduce the clogging frequency of the oil filter port 330 of the filter ring 310. It is understandable that if the oil filter port 330 is always used, the oil filter port 330 will be clogged by metal debris. Therefore, the first switch assembly is configured as follows:

[0054] When the forklift brakes to lift cargo, the turbine 230 is stationary, and the oil cannot drive the turbine 230 to rotate. The oil circulates continuously in the cavity 260, and the direction of the oil circulation is more suitable for the oil to pass through the filter ring 310. Therefore, the first switch assembly opens the oil inlet 320, allowing the oil to enter the filter ring 310 to filter the oil.

[0055] When the forklift releases the brake, the turbine 230 is no longer restricted, and the oil can drive the turbine 230 to rotate. At this time, the oil in the cavity 260 is slightly deflected by the rotation of the turbine 230, and the oil is not easy to enter the filter ring 310. Therefore, the first switch component closes the oil inlet 320 to avoid increasing the additional energy consumption of the engine. When the turbine 230 drives the filter ring 310 to rotate, the oil in the filter ring 310 is completely discharged and the metal debris intercepted in the filter ring 310 moves toward the outer peripheral wall of the filter ring 310 due to the centrifugal force, thereby reducing the metal debris attached to the oil filter port 330, and also reducing the frequency of blockage of the oil filter port 330.

[0056] Specifically, the first switch assembly in this embodiment includes an elastic member 321 and a small ball 322, and the elastic member 321 and the small ball 322 are both located in the filter ring 310. One end of the elastic member 321 is fixedly arranged on the inner wall of the inner diameter of the filter ring 310, and the fixed position corresponds to the oil inlet 320. The other end of the elastic member 321 is fixedly connected to the small ball 322. The oil inlet 320 in this embodiment is circular in shape, and the diameter of the small ball 322 is larger than the diameter of the oil inlet 320. When the elastic member 321 is in its original length, the small ball 322 does not contact the oil inlet 320. That is to say, when the forklift brakes and causes the turbine 230 to stop rotating, the elastic member 321 in the filter ring 310 is in At the original length, there is a gap between the ball 322 and the oil inlet 320, so that the oil inlet 320 is opened; when the forklift moves to release the restriction on the turbine 230, the turbine 230 drives the filter ring 310 to rotate, and the ball 322 in the filter ring 310 has a tendency to move radially outward along the filter ring 310 when subjected to centrifugal force. When the centrifugal force overcomes the elastic force of the elastic member 321, the elastic member 321 is stretched, and the ball 322 is always in contact with the oil inlet 320 under the action of the centrifugal force, thereby closing the oil inlet 320. When the speed of the turbine 230 decreases or stops rotating, the ball 322 reopens the oil inlet 320 under the pulling force when the elastic member 321 is reset.

[0057] It should be noted that the first switch component is not limited to the above-mentioned structure, but may also be other structures. For example, a solenoid valve is provided at the oil inlet 320 to control the opening or closing of the oil inlet 320 through the solenoid valve. Any structure that can control the opening and closing of the oil inlet 320 is acceptable and is not specifically limited here.

[0058] More specifically, the elastic member 321 in this embodiment is a spring.

[0059] In a further embodiment, a collecting groove 340 is provided in the filter ring 310. The collecting groove 340 is specifically provided on the side wall of the filter ring 310 away from the axis thereof and close to the side wall where the oil filter port 330 is provided. Since the oil flows from the oil inlet 320 to the oil filter port 330, more metal debris gathers at the side wall close to the oil filter port 330. Therefore, providing the collecting groove 340 at a position close to the side wall can better collect the metal debris. The collecting groove 340 is used to collect the metal debris in the filter ring 310, so as to prevent the debris from being disturbed by the oil. Meanwhile, a second switch component is provided on the collecting groove 340. The second switch component can open or close the collecting groove 340. The second switch component is configured as follows:

[0060] When the forklift brakes and causes the turbine 230 to stop rotating, the second switch assembly closes the collection tank 340 so that the debris in the collection tank 340 is not disturbed by the oil, thereby preventing the metal debris from re-entering the filter ring 310; when the brake is released, the turbine 230 drives the filter ring 310 to rotate, and the second switch assembly opens the collection tank 340 so that the intercepted metal debris in the filter ring 310 enters the collection tank 340 after being centrifuged.

[0061] Specifically, the second switch assembly in this embodiment includes an elastic plate 342 and a connecting shaft 341. One end of the connecting shaft 341 is fixedly disposed in the collecting groove 340, and the connecting shaft 341 is arranged radially along the filter ring 310. The other end of the connecting shaft 341 is connected to the elastic plate 342. In this embodiment, there are several connecting shafts 341 and elastic plates 342, and they are all arranged in a circular array in the filter ring 310. The connection position of the connecting shaft 341 and the elastic plate 342 is located in the middle position of each elastic plate 342. The head and tail of several elastic plates 342 are in contact to form a complete ring to close the collecting groove 340. When the filter ring 310 rotates, each elastic plate 342 is subjected to centrifugal force, and the position of the elastic plate 342 that is not in contact with the connecting shaft 341 is deformed, thereby generating a gap between two adjacent elastic plates 342, that is, the collecting slot 340 is opened; when the filter ring 310 is stationary, several elastic plates 342 are reset, thereby eliminating the gap between two adjacent elastic plates 342, that is, closing the collecting slot 340.

[0062] It should be noted that a number of elastic plates 342 are provided so that the debris in the filter ring 310 can pass through the gap between each elastic plate 342 and enter the collecting groove 340, so that the debris is evenly distributed in the collecting groove 340, thereby avoiding the uneven centrifugal force of the filter ring 310 caused by the uneven distribution of debris in the collecting groove 340 when the filter ring 310 rotates at high speed. In severe cases, this situation will cause the filter ring 310 to vibrate and fall off.

[0063] In a further embodiment, adsorption cotton is provided inside the collection tank 340. The adsorption cotton is specifically located on a surface of the collection tank 340 away from the axis of the filter ring 310 (that is, the bottom of the collection tank 340). The adsorption cotton can adsorb metal debris entering the collection tank 340 to prevent the metal debris from moving in the collection tank 340.

[0064] A surface of the elastic plate 342 close to the axis of the filter ring 310 may be polished smooth so as to allow all metal debris to enter the collecting tank 340 as much as possible.

[0065] In a further embodiment, the filter assembly 300 of the present invention also includes a contraction piece, which is arranged in the filter ring 310. When the contraction piece is subjected to centrifugal force, it shrinks and deforms, thereby increasing the volume in the filter ring 310. The filter ring 310 is in a negative pressure state, so that the oil in the cavity 260 can be sucked in from the oil filter port 330. It can be understood that the contraction piece can only be subjected to centrifugal force when the filter ring 310 rotates, and the oil inlet 320 is closed by the ball 322 at this time, so that the oil can only be sucked in from the oil filter port 330. The oil sucked in from the oil filter port 330 is equivalent to backflushing the oil filter port 330, thereby cleaning the oil filter port 330 and further reducing the frequency of the oil filter port 330 being blocked.

[0066] Specifically, the contraction member in the present embodiment includes a plurality of annular elastic oil naans 350, and an opening is provided on the surface of the annular elastic oil naan 350 (not shown in the figure). When the filter ring 310 rotates, the oil inside the elastic annular oil naan is discharged from the filter ring 310 through the opening, thereby increasing the volume inside the filter ring 310. The negative pressure inside the filter ring 310 absorbs the oil and then backwashes the oil filter port 330. When the filter ring 310 stops rotating, the annular elastic oil naan 350 is no longer subjected to centrifugal force and is reset.

[0067] It should be noted that the shrinkage member of the present invention is not limited to the above structure, but may also be other structures, such as elastic oil cakes of other shapes. As long as the structure can increase the internal volume of the filter ring 310 by shrinking due to centrifugal force, no specific limitation is made here.

[0068] Specifically, there are two annular elastic oil naans 350 in the embodiment of the present invention, and the two annular elastic oil naans 350 can better match the volume inside the filter ring 310.

[0069] The specific working process of a large-tonnage forklift hydraulic transmission gearbox provided by the present invention is described in combination with the above embodiments:

[0070] Filtering oil when forklift brakes:

[0071] When the forklift brakes to lift cargo, the turbine 230 is restricted and stops, the filter ring 310 on the turbine 230 stops synchronously, and the pump wheel 210 connected to the engine output shaft continues to rotate. The pump wheel 210 and the housing 250 rotate synchronously so that the oil in the cavity 260 formed between the two continuously circulates. Although the oil circulates continuously, it cannot drive the turbine 230 to rotate. When the oil flows, it passes through the oil inlet 320 of the filter ring 310. Since the filter ring 310 is stationary at this time, The elastic member 321 in the filter ring 310 is in its original length state so that the ball 322 opens the oil inlet 320, and the oil enters the filter ring 310. At this time, the elastic plate 342 on the collecting groove 340 in the filter ring 310 is not deformed by the centrifugal force, and the two adjacent elastic plates 342 are in end-to-end contact to close the collecting groove 340. The oil does not pass through the collecting groove 340, but is discharged through the oil filter port 330. The sieve holes on the oil filter port 330 intercept the metal debris in the oil, thereby filtering the oil.

[0072] Release the brake to allow the metal chips to enter the collection tank 340:

[0073] When the forklift has finished lifting the cargo and needs to transport it to the designated location and needs to release the brake, the turbine 230 is no longer restricted. The turbine 230 starts to rotate under the force of the oil flow, thereby driving the input shaft 120 of the gearbox 100, and the forklift can move. When the turbine 230 rotates and drives the filter ring 310 to rotate synchronously, the small ball 322 in the filter ring 310 is pulled by the centrifugal force to extend the elastic member 321, and the small ball 322 closes the oil inlet 320. In addition, the plurality of elastic plates 342 in the filter ring 310 are deformed by the centrifugal force, so that a gap is generated between two adjacent elastic plates 342 to open the collection tank 340. The debris in the filter ring 310 and the debris attached to the oil filter port 330 enter the collection tank 340 through the gap between the two adjacent elastic plates 342 under the action of centrifugal force. The adsorption cotton in the collection tank 340 can absorb the metal debris entering the collection tank 340. At the same time, the two annular elastic oil holes 350 in the filter ring 310 are reduced by centrifugal force, which increases the volume of the filter ring 310. The filter ring 310 has a negative pressure, so that part of the oil in the cavity 260 enters the filter ring 310 through the oil filter port 330 to backwash the oil filter port 330, thereby cleaning the oil filter port 330 and reducing the frequency of blockage of the oil filter port 330.

[0074] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The above-described embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A hydraulic transmission gearbox for a large tonnage forklift, characterized in that: include: A gearbox and a torque converter, wherein the gearbox has a housing and an input shaft, and the torque converter includes a pump wheel, a turbine and a guide wheel, wherein the pump wheel is fixedly connected to a housing, the turbine is located in a cavity between the pump wheel and the housing, the pump wheel is drivingly connected to the engine, the turbine is drivingly connected to the input shaft, the guide wheel is located between the turbine and the pump wheel, and the axes of the three coincide; The filter assembly comprises a filter ring, the interior of the filter ring is hollow, the filter ring is fixedly arranged on the turbine and located between the turbine and the guide wheel, the filter ring is also provided with an oil inlet and an oil filter port, the oil inlet is located on the outer peripheral wall of the filter ring, the oil filter port is provided on the side wall of the filter ring close to the guide wheel, when the pump wheel rotates, the oil in the cavity is subjected to centrifugal force, the oil flows to the arcuate side wall of the turbine through the arc surface of the pump wheel side wall, and then passes through the turbine blades, thereby driving the turbine to rotate, when the turbine does not rotate, the oil passes through the blades of the turbine and then passes through the filter ring, the oil in the cavity enters the filter ring through the oil inlet and is discharged into the cavity again through the oil filter port, the metal debris in the oil is intercepted in the filter ring, a first switch assembly is provided on the oil inlet, the first switch assembly can open or close the oil inlet, and the switch assembly is configured as follows: When the turbine stops rotating, the first switch assembly opens the oil inlet, and the liquid in the cavity flows through the filter ring to filter the metal debris therein; When the turbine starts to rotate, the first switch assembly closes the oil inlet, and the metal debris in the filter ring is moved away from the oil filter port by centrifugal force. The first switch assembly includes an elastic member and a small ball, and the elastic member and the small ball are both located inside the filter ring. One end of the elastic member is connected to the inside of the filter ring and the connection position corresponds to the oil inlet. The small ball is fixedly connected to the other end of the elastic member, and the diameter of the small ball is larger than the diameter of the oil inlet. When the turbine stops, the elastic member is at its original length, and the ball is away from the oil inlet. When the turbine rotates, the ball moves toward the oil inlet to close the oil inlet after the centrifugal force is greater than the elastic force of the elastic member. A collecting groove is provided on the side wall of the filter ring away from its axis, and a second switch assembly is provided on the collecting groove. The second switch assembly is used to open or close the collecting groove, and the second switch assembly is configured as follows: When the turbine rotates, the second switch assembly opens the collection groove, and the metal debris in the filter ring enters the collection groove under the action of centrifugal force; When the turbine stops, the second switch assembly closes the collection tank, and the metal debris in the collection tank is not disturbed by the oil; the second switch assembly includes an elastic plate and a connecting shaft, the connecting shaft is fixedly arranged in the collection tank and arranged along the radial direction of the filter ring, there are a plurality of connecting shafts and elastic plates, the middle position of the elastic plate is fixedly connected to the connecting shaft, and they are all arranged in a circular array in the filter ring, and a plurality of elastic plates are in end-to-end contact to close the collection tank, and the centrifugal force is applied to the elastic plate when the turbine rotates, and both ends of the elastic plate are deformed , a gap is generated between two adjacent elastic plates to open the collection groove; the filter assembly also includes a contraction piece, which is arranged in the filter ring and can shrink. When the contraction piece is subjected to centrifugal force, it shrinks, and the volume in the filter ring increases. The oil in the cavity enters the filter ring through the oil filter port to backwash the oil filter port; the contraction piece includes a plurality of annular elastic oil bags, and openings are arranged on the surfaces of the plurality of annular elastic oil bags. When the plurality of annular elastic oil bags shrink, the oil inside is discharged from the filter ring, and when the plurality of annular elastic oil bags are reset, the oil is absorbed from the openings.

2. The large-tonnage forklift hydraulic transmission gearbox according to claim 1 is characterized in that: The elastic member is a spring.

3. The large-tonnage forklift hydraulic transmission gearbox according to claim 1, characterized in that: Adsorbent cotton is arranged in the filter ring, and the adsorbent cotton is attached to a surface of the collecting tank away from the axis of the filter ring, and the adsorbent cotton can absorb metal debris.

4. The large-tonnage forklift hydraulic transmission gearbox according to claim 1, characterized in that: There are two annular elastic oil bags.

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