Hydrostatic gearbox and engineering machinery

Abstract

The invention relates to the technical field of engineering machinery, and particularly discloses a hydrostatic gearbox and engineering machine.The hydrostatic gearbox comprises a box body, a first oil distribution cover, a second oil distribution cover and a speed change control valve, the first oil distribution cover, the second oil distribution cover and the speed change control valve are all fixed to the box body, and a first gear shaft and a second gear shaft are arranged in the box body at intervals; the first gear shaft is covered with the first oil distribution cover, the second gear shaft is covered with the second oil distribution cover, the box body is provided with a first flow channel and a second flow channel, the first oil distribution cover is provided with a second-gear flow channel, the second-gear flow channel is communicated with the second gear shifting mechanism, the second-gear flow channel is communicated with a second-gear working oil port of the speed change control valve through the first flow channel, and the second-gear working oil port is communicated with a second-gear working oil port of the speed change control valve through the second flow channel. The first-gear flow channel is communicated with a first-gear working oil port of the variable-speed control valve through a second flow channel; the engineering machinery comprises the hydrostatic gearbox. According to the hydrostatic gearbox, arrangement of external pipelines is reduced, the overall structure is more compact, and the oil conveying efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, and in particular to a hydrostatic transmission and engineering machinery. Background Technology

[0002] In the field of transmission technology, the design of the shift hydraulic circuit directly affects transmission efficiency and reliability. Traditional solutions generally adopt an external hydraulic circuit structure, the core drawback of which is that the hydraulic system needs to be connected to the transmission housing through multiple independent connectors, leading to a surge in assembly complexity. Such structures require an average of multiple hydraulic connectors, which not only significantly extends assembly time but also, due to the cumulative effect of interface tolerances, significantly increases the assembly error rate. This design flaw is particularly prominent in mass production and has become a key factor restricting the yield rate of transmissions.

[0003] From a spatial layout perspective, externally mounted oil lines require additional space around the transmission, increasing the overall volume by approximately 25%-30% compared to similar internal designs. With the increasing integration of new energy vehicles, this drawback directly squeezes the layout space for core components such as the motor and battery, forcing compromises in the overall vehicle design. More seriously, externally mounted oil lines, exposed to the external environment, require protective sleeves, further increasing weight and cost. Test data from a major transmission manufacturer shows that this structure increases the cost of a single transmission by approximately 15%-20%, and the protective sleeves are prone to fatigue cracks under long-term vibration, leading to the risk of hydraulic leakage.

[0004] Furthermore, in terms of hydraulic performance, external hydraulic circuits result in significant pressure loss due to their extended path. Experiments show that when the circuit length exceeds 1.5 meters, the shift response time delay reaches 120-150 milliseconds, exacerbating the shift shock. Additionally, in low-temperature environments, the external hydraulic circuit, due to its larger exposed area, causes the hydraulic oil temperature to rise 40%-50% slower than that of an internal structure, affecting cold-start performance. These technical bottlenecks have become major obstacles to the transmission industry's development towards higher efficiency and compactness. Summary of the Invention

[0005] The purpose of this invention is to provide a hydrostatic transmission that reduces the need for external piping, makes the overall structure more compact, and improves the efficiency of oil delivery.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] The hydrostatic transmission includes a housing, a first oil valve cover, a second oil valve cover, and a transmission control valve; wherein,

[0008] The first oil distribution cap, the second oil distribution cap, and the transmission control valve are all fixed to the housing. A first gear shift shaft and a second gear shift shaft are spaced apart inside the housing. The first oil distribution cap covers the first gear shift shaft, and the second oil distribution cap covers the second gear shift shaft. The housing has a first flow channel and a second flow channel.

[0009] The first oil distribution cap has a two-stage flow channel, which is connected to the second gear shifting mechanism. The first end of the first flow channel is connected to the second gear working oil port of the transmission control valve, and the second end is connected to the two-stage flow channel.

[0010] The second oil distribution cap has a flow channel, which is connected to the first shifting mechanism. The first end of the second flow channel is connected to the first working oil port of the transmission control valve, and the second end is connected to the first flow channel.

[0011] Preferably, a third flow channel is provided inside the box, the first oil distribution cap is provided with a connected oil inlet and a first oil outlet, the second oil distribution cap is provided with a second oil outlet, and the first end of the third flow channel is connected to the first oil outlet and the second end is connected to the second oil outlet.

[0012] The lubricating oil flowing into the first oil distribution cover through the oil inlet can flow into the lubrication hole of the first gear shaft and the first oil delivery hole, and the lubricating oil flowing into the first oil delivery hole can sequentially enter the second oil distribution cover through the third flow channel and the second oil delivery hole and flow into the lubrication hole of the second gear shaft.

[0013] Preferably, the housing has a first mounting groove and a second mounting groove, the first gear shaft portion extends into the first mounting groove, the second gear shaft portion extends into the second mounting groove, the first oil distribution cap is inserted into the first mounting groove, and the second oil distribution cap is inserted into the second mounting groove.

[0014] The second end of the first flow channel extends through the wall of the first mounting groove and connects to the second baffle flow channel; the second end of the second flow channel extends through the wall of the second mounting groove and connects to the first baffle flow channel; the first end of the third flow channel extends through the wall of the first mounting groove and connects to the first oil supply hole; and the second end of the third flow channel extends through the wall of the second mounting groove and connects to the second oil supply hole.

[0015] Preferably, the outer peripheral wall of the first oil distribution cap is provided with a first oil collection groove, and the first oil collection groove and the groove wall of the first mounting groove together form a first oil delivery chamber, and the second end of the first flow channel is connected to the second flow channel through the first oil delivery chamber.

[0016] The outer peripheral wall of the second oil distribution cap is provided with a second oil collection groove. The second oil collection groove and the groove wall of the second mounting groove together form a second oil delivery chamber. The second end of the second flow channel is connected to the first flow channel through the second oil delivery chamber.

[0017] Preferably, a third oil delivery chamber is formed between the outer peripheral wall of the first oil distribution cap and the groove wall of the first mounting groove, and the first end of the third flow channel is connected to the first oil delivery hole through the third oil delivery chamber;

[0018] A fourth oil delivery chamber is formed between the outer peripheral wall of the second oil distribution cap and the groove wall of the second mounting groove, and the second end of the third flow channel is connected to the second oil delivery hole through the fourth oil delivery chamber.

[0019] Preferably, the first oil distribution cap has a first slot, and one end of the first gear shaft facing the first oil distribution cap is inserted into the first slot, forming a first lubrication cavity with the first slot. The oil inlet is connected to the lubrication hole of the first gear shaft and the first oil delivery hole through the first lubrication cavity.

[0020] The second oil distribution cap has a second slot, and the end of the second gear shaft facing the second oil distribution cap is inserted into the second slot, forming a second lubrication cavity with the second slot. The second oil supply hole is connected to the lubrication hole of the second gear shaft through the second lubrication cavity.

[0021] Preferably, the housing has an installation end face, the speed control valve is fixedly mounted on the installation end face, the first end of the first flow channel extends through the installation end face and connects to the second working port of the speed control valve, and the first end of the second flow channel extends through the installation end face and connects to the first working port of the speed control valve.

[0022] Preferably, the mounting end face has multiple fixing holes, and the fixing member passes through the speed control valve and is fixedly connected to the corresponding fixing holes.

[0023] Preferably, the housing has a first detection channel and a second detection channel. The first end of the first detection channel is connected to the first channel, and the second end of the first detection channel extends to the surface of the housing and is provided with a first plug. The first end of the second detection channel is connected to the second channel, and the second end of the second detection channel extends to the surface of the housing and is provided with a second plug.

[0024] The present invention also provides an engineering machine, including the above-mentioned hydrostatic gearbox, which reduces the layout of external pipelines, lowers costs, makes the overall structure more compact, and improves the efficiency of oil delivery.

[0025] An engineering machine includes a hydrostatic gearbox as described in any of the above claims, and also includes a chassis, with the gearbox body fixed to the chassis.

[0026] Beneficial effects:

[0027] The hydrostatic transmission provided by this invention has a second-gear working port of the transmission control valve connected to a second shifting mechanism via a first flow channel and a second-gear flow channel, and a first-gear working port of the transmission control valve connected to a first shifting mechanism via a second flow channel and a first-gear flow channel. When shifting to second gear, the valve body inside the transmission control valve reverses direction, connecting the inlet port of the transmission control valve to the second-gear working port, thereby allowing shifting fluid to sequentially enter the second shifting mechanism via the second-gear working port, the first flow channel, and the second-gear flow channel, pushing the piston of the second shifting mechanism to move and shift gears. When shifting to first gear, the valve body inside the transmission control valve reverses direction, connecting the inlet port of the transmission control valve to the first-gear working port, thereby allowing shifting fluid to sequentially enter the first shifting mechanism via the first-gear working port, the second flow channel, and the first-gear flow channel, pushing the piston of the first shifting mechanism to move and shift gears. This hydrostatic transmission has a first flow channel and a second flow channel forming a second-gear shifting oil circuit, and a second flow channel and a first flow channel forming a first-gear shifting oil circuit. The first and second flow channels are located inside the gearbox body, while the second and first flow channels are located inside the first and second oil distribution caps, respectively. Both the first and second shifting oil circuits are built-in, eliminating the need for external pipes, connectors, and other components, thus reducing operating costs, shortening the oil circuit length, making the overall structure more compact, and improving oil delivery efficiency.

[0028] The engineering machinery provided by the present invention includes the above-mentioned hydrostatic transmission. The first shift oil circuit and the second shift oil circuit are both built-in, eliminating the need for external pipelines, connectors and other components, reducing costs, making the overall structure more compact, and improving the efficiency of oil delivery. Attached Figure Description

[0029] Figure 1 A schematic diagram of the structure of the hydrostatic transmission provided by the present invention;

[0030] Figure 2 A partial cross-sectional schematic diagram of the first oil distribution cap portion provided for the present invention;

[0031] Figure 3 A partial cross-sectional schematic diagram of the second oil distribution cap portion provided by the present invention;

[0032] Figure 4 A cross-sectional schematic diagram of the hydrostatic transmission provided by the present invention from one perspective;

[0033] Figure 5 A cross-sectional schematic diagram from another perspective of the hydrostatic transmission provided by the present invention;

[0034] Figure 6 This is a schematic diagram of the first gear shaft and the second gear shaft provided by the present invention;

[0035] Figure 7 This is a cross-sectional view of the housing provided by the present invention below the mounting end face;

[0036] Figure 8 This is a schematic diagram of the mounting end face of the housing provided by the present invention.

[0037] In the picture:

[0038] 1. Housing; 101. First oil delivery chamber; 102. Second oil delivery chamber; 103. Third oil delivery chamber; 104. Fourth oil delivery chamber; 11. First flow channel; 12. Second flow channel; 13. Third flow channel; 14. First mounting groove; 15. Second mounting groove; 16. Mounting end face; 161. Fixing hole; 171. First detection flow channel; 172. Second detection flow channel; 181. First plug; 182. Second plug;

[0039] 2. First oil distribution cap; 201. First lubrication cavity; 21. Second flow channel; 22. Oil inlet; 23. First oil delivery hole; 24. First oil collection groove; 241. First sealing plug; 25. First slot;

[0040] 3. Second oil distribution cap; 301. Second lubrication cavity; 31. First flow channel; 32. Second oil delivery hole; 33. Second oil collection groove; 331. Second sealing plug; 34. Second slot;

[0041] 4. Speed ​​control valve; 41. Second gear working port; 42. First gear working port;

[0042] 51. First gear shaft; 511. First conveying channel; 512. First main oil hole; 5121. First oil distribution hole; 52. Second gear shaft; 521. Second conveying channel; 522. Second main oil hole; 5221. Second oil distribution hole. Detailed Implementation

[0043] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Furthermore, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0045] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0046] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0047] This embodiment provides a hydrostatic transmission. (Refer to...) Figures 1 to 8As shown, the hydrostatic transmission includes a housing 1, a first oil distribution cap 2, a second oil distribution cap 3, and a transmission control valve 4. The first oil distribution cap 2, the second oil distribution cap 3, and the transmission control valve 4 are all fixed to the housing 1. A first gear shaft 51 and a second gear shaft 52 are spaced apart inside the housing 1. The first oil distribution cap 2 covers the first gear shaft 51, and the second oil distribution cap 3 covers the second gear shaft 52. The housing 1 has a first flow channel 11 and a second flow channel 12. The first oil distribution cap 2 has a second-gear flow channel 21, which connects to a second shifting mechanism. The first end of the first flow channel 11 connects to the second-gear working port 41 of the transmission control valve 4, and the second end connects to the second-gear flow channel 21. The second oil distribution cap 3 has a first-gear flow channel 31, which connects to the first shifting mechanism. The first end of the second flow channel 12 connects to the first-gear working port 42 of the transmission control valve 4, and the second end connects to the first-gear flow channel 31.

[0048] In this embodiment, the second gear working port 41 of the transmission control valve 4 is connected to the second shifting mechanism through the first flow channel 11 and the second gear flow channel 21, and the first gear working port 42 of the transmission control valve 4 is connected to the first shifting mechanism through the second flow channel 12 and the first gear flow channel 31. When shifting to first gear, the valve body inside the transmission control valve 4 reverses, connecting the oil inlet of the transmission control valve 4 with the second gear working oil port 41. This allows the shifting oil to sequentially enter the second shifting mechanism through the second gear working oil port 41, the first flow channel 11, and the second gear flow channel 21, pushing the piston of the second shifting mechanism to move and shift gears. When shifting to second gear, the valve body inside the transmission control valve 4 reverses, connecting the oil inlet of the transmission control valve 4 with the first gear working oil port 42. This allows the shifting oil to sequentially enter the first shifting mechanism through the first gear working oil port 42, the second flow channel 12, and the first gear flow channel 31, pushing the piston of the first shifting mechanism to move and shift gears. In this hydrostatic transmission, the first flow channel 11 and the second-gear flow channel 21 form a second-gear shifting oil circuit, and the second flow channel 12 and the first-gear flow channel 31 form a first-gear shifting oil circuit. The first flow channel 11 and the second flow channel 12 are located inside the housing 1, and the second-gear flow channel 21 and the first-gear flow channel 31 are located inside the first oil distribution cap 2 and the second oil distribution cap 3, respectively. Both the first and second shifting oil circuits are built-in, eliminating the need for external pipelines, connectors, and other components, thus reducing operating costs, shortening the length of the shifting oil circuit, improving shifting response, making the overall structure more compact, and improving oil delivery efficiency.

[0049] Specifically, in this embodiment, the first gear shaft 51 has a first conveying channel 511, and the second gear shaft 52 has a second conveying channel 521. The second gear channel 21 is connected to the second shifting mechanism through the first conveying channel 511; the first gear channel 31 is connected to the first shifting mechanism through the second conveying channel 521. When the oil inlet of the transmission control valve 4 is connected to the second gear working oil port 41, the shifting oil sequentially enters the second shifting mechanism through the second gear working oil port 41, the first channel 11, the second gear channel 21, and the first conveying channel 511, pushing the piston of the second shifting mechanism to move and shift gears; when the oil inlet of the transmission control valve 4 is connected to the first gear working oil port 42, the shifting oil sequentially enters the first shifting mechanism through the first gear working oil port 42, the second channel 12, the first gear channel 31, and the second conveying channel 521, pushing the piston of the first shifting mechanism to move and shift gears.

[0050] In this embodiment, a third flow channel 13 is provided inside the housing 1, a first oil distribution cap 2 has a connected oil inlet hole 22 and a first oil outlet hole 23, and a second oil distribution cap 3 has a second oil outlet hole 32. The first end of the third flow channel 13 is connected to the first oil outlet hole 23, and the second end is connected to the second oil outlet hole 32. The lubricating oil flowing into the first oil distribution cap 2 through the oil inlet hole 22 can flow into the lubrication hole of the first gear shaft 51 and the first oil outlet hole 23, and the lubricating oil flowing into the first oil outlet hole 23 can sequentially enter the second oil distribution cap 3 through the third flow channel 13 and the second oil outlet hole 32 and flow into the lubrication hole of the second gear shaft 52. Specifically, lubricating oil flows from the inlet hole 22 into the first oil distribution cap 2. Part of the lubricating oil flowing into the first oil distribution cap 2 flows into the lubrication hole of the first gear shaft 51, thus lubricating the first gear shaft 51. The other part flows into the first oil delivery hole 23. The lubricating oil flowing into the first oil delivery hole 23 can sequentially pass through the third flow channel 13 and the second oil delivery hole 32 into the second oil distribution cap 3 and then into the lubrication hole of the second gear shaft 52, thus lubricating the second gear shaft 52. This arrangement allows the lubrication circuits involving the first gear shaft 51 and the second gear shaft 52 in the hydrostatic transmission to be built-in, eliminating the need for external pipes, connectors, and other components, reducing operating costs, shortening the length of the internal lubrication circuits, making the overall structure more compact, and improving oil delivery efficiency.

[0051] Specifically, the lubrication holes of the first gear shaft 51 include a first main oil hole 512 and a first distributor oil hole 5121. The first main oil hole 512 is located at the end of the first gear shaft 51 facing the first oil distribution cap 2. Multiple first distributor oil holes 5121 are evenly distributed on the outer peripheral wall of the first gear shaft 51, and are connected to the first main oil hole 512. Specifically, the lubricating oil in the first oil distribution cap 2 can enter the interior of the first gear shaft 51 through the first main oil hole 512 and flow evenly to the surface of the first gear shaft 51 through the first distributor oil holes 5121, thereby providing comprehensive and reliable lubrication to the first gear shaft 51. The lubrication holes of the second gear shaft 52 include a second main oil hole 522 and a second distributor oil hole 5221. The second main oil hole 522 is located at the end of the second gear shaft 52 facing the second oil distribution cover 3. Multiple second oil distribution holes 5221 are provided, evenly distributed on the outer peripheral wall of the second gear shaft 52, and connected to the second main oil hole 522. Specifically, the lubricating oil in the second oil distribution cover 3 can enter the interior of the second gear shaft 52 through the second main oil hole 522, and flow evenly to the surface of the second gear shaft 52 through the second oil distribution holes 5221, thereby providing comprehensive and reliable lubrication to the second gear shaft 52.

[0052] In this embodiment, the housing 1 has a first mounting groove 14 and a second mounting groove 15. A first stop shaft 51 extends into the first mounting groove 14, and a second stop shaft 52 extends into the second mounting groove 15. A first oil distribution cap 2 is inserted into the first mounting groove 14, and a second oil distribution cap 3 is inserted into the second mounting groove 15. The second end of the first flow channel 11 extends through the groove wall of the first mounting groove 14 and connects to the second stop flow channel 21. The second end of the second flow channel 12 extends through the groove wall of the second mounting groove 15 and connects to the first stop flow channel 31. The first end of the third flow channel 13 extends through the groove wall of the first mounting groove 14 and connects to the first oil supply hole 23. The second end of the third flow channel 13 extends through the groove wall of the second mounting groove 15 and connects to the second oil supply hole 32. Specifically, a first shaft hole is provided inside the housing 1 at the bottom of the first mounting groove 14. A first gearing shaft 51 is rotatably disposed in the first shaft hole, with one end of the first gearing shaft 51 facing the first oil distribution cap 2 passing through the first shaft hole and partially extending into the first mounting groove 14. A second shaft hole is provided inside the housing 1 at the bottom of the second mounting groove 15. A second gearing shaft 52 is rotatably disposed in the second shaft hole, with one end of the second gearing shaft 52 facing the second oil distribution cap 3 passing through the second shaft hole and partially extending into the second mounting groove 15.

[0053] When the first oil distribution cap 2 is installed in the first mounting groove 14, the second end of the first flow channel 11 is in a position directly connected to the second baffle flow channel 21; when the second oil distribution cap 3 is installed in the second mounting groove 15, the second end of the second flow channel 12 is in a position directly connected to the first baffle flow channel 31.

[0054] Specifically, the first oil distribution cap 2 and the second oil distribution cap 3 can be fixedly connected to the housing 1 by bolts or other connecting parts.

[0055] Furthermore, the outer peripheral wall of the first oil distribution cap 2 is provided with a first oil collecting groove 24, and the first oil collecting groove 24 and the groove wall of the first mounting groove 14 together form a first oil delivery cavity 101. The second end of the first flow channel 11 is connected to the second baffle flow channel 21 through the first oil delivery cavity 101. The outer peripheral wall of the second oil distribution cap 3 is provided with a second oil collecting groove 33, and the second oil collecting groove 33 and the groove wall of the second mounting groove 15 together form a second oil delivery cavity 102. The second end of the second flow channel 12 is connected to the first baffle flow channel 31 through the second oil delivery cavity 102.

[0056] Specifically, the first oil collection tank 24 is connected to the second-gear flow channel 21. After the first oil collection tank 24 and the wall of the first mounting groove 14 together form the first oil delivery chamber 101, one side of the first oil delivery chamber 101 is connected to the first flow channel 11, and the other side is connected to the second-gear flow channel 21. The shifting oil can sequentially enter the second shifting mechanism through the second-gear working oil port 41, the first flow channel 11, the first oil delivery chamber 101, and the second-gear flow channel 21, pushing the piston of the second shifting mechanism to move and shift gears. The second oil collection tank 33 is connected to the first-gear flow channel 31. After the second oil collection tank 33 and the wall of the second mounting groove 15 together form the second oil delivery chamber 102, one side of the second oil delivery chamber 102 is connected to the second flow channel 12, and the other side is connected to the first-gear flow channel 31. The shifting fluid can sequentially enter the first shifting mechanism through the first shifting working port 42, the second flow channel 12, the second oil supply chamber 102, and the first shifting flow channel 31, pushing the piston of the first shifting mechanism to move and shift gears.

[0057] Specifically, the first oil collecting tank 24 is provided with a first sealing plug 241, which is used to seal the gap between the first oil distribution cap 2 and the first mounting groove 14. The second oil collecting tank 33 is provided with a second sealing plug 331, which is used to seal the gap between the second oil distribution cap 3 and the second mounting groove 15. Specifically, the provision of the first sealing plug 241 and the second sealing plug 331 can effectively prevent oil leakage between the first oil distribution cap 2 and the first mounting groove 14 of the housing 1, and between the second oil distribution cap 3 and the second mounting groove 15 of the housing 1, thus ensuring airtightness.

[0058] For example, both the first sealing plug 241 and the second sealing plug 331 are annular. Both the first sealing plug 241 and the second sealing plug 331 are made of rubber.

[0059] Furthermore, a third oil delivery chamber 103 is formed between the outer peripheral wall of the first oil distribution cap 2 and the groove wall of the first mounting groove 14, and the first end of the third flow channel 13 is connected to the first oil delivery hole 23 through the third oil delivery chamber 103; a fourth oil delivery chamber 104 is formed between the outer peripheral wall of the second oil distribution cap 3 and the groove wall of the second mounting groove 15, and the second end of the third flow channel 13 is connected to the second oil delivery hole 32 through the fourth oil delivery chamber 104. Specifically, the gap between the outer peripheral wall of the first oil distribution cap 2 and the groove wall of the first mounting groove 14 can form the third oil delivery chamber 103, and the gap between the outer peripheral wall of the second oil distribution cap 3 and the groove wall of the second mounting groove 15 can form the fourth oil delivery chamber 104. During the flow process, the lubricating oil entering the first oil supply hole 23 flows sequentially through the first oil supply hole 23, the third oil supply chamber 103, the third flow channel 13, the fourth oil supply chamber 104, and the second oil supply hole 32 into the second oil distribution cover 3 and into the lubrication hole of the second gear shaft 52, thereby lubricating the second gear shaft 52.

[0060] In this embodiment, the first oil distribution cap 2 has a first slot 25, and the end of the first stop shaft 51 facing the first oil distribution cap 2 is inserted into the first slot 25, forming a first lubrication cavity 201 with the first slot 25. The oil inlet 22 is connected to the lubrication hole of the first stop shaft 51 and the first oil delivery hole 23 through the first lubrication cavity 201. The second oil distribution cap 3 has a second slot 34, and the end of the second stop shaft 52 facing the second oil distribution cap 3 is inserted into the second slot 34, forming a second lubrication cavity 301 with the second slot 34. The second oil delivery hole 32 is connected to the lubrication hole of the second stop shaft 52 through the second lubrication cavity 301.

[0061] Specifically, the end of the first gear shaft 51 facing the first oil distribution cap 2 is inserted into the first slot 25, and the end of the second gear shaft 52 facing the second oil distribution cap 3 is inserted into the second slot 34, thereby improving the reliability and stability of the installation of the first gear shaft 51 and the second gear shaft 52. Lubricating oil enters the first lubrication cavity 201 through the oil inlet hole 22, and then enters the lubrication hole and the first oil delivery hole 23 of the first gear shaft 51 through the first lubrication cavity 201. The lubricating oil in the first oil delivery hole 23 enters the second lubrication cavity 301 through the third flow channel 13 and the second oil delivery hole 32, and then enters the lubrication hole of the second gear shaft 52 through the second lubrication cavity 301.

[0062] In this embodiment, the housing 1 is provided with a mounting end face 16, and the transmission control valve 4 is fixedly mounted on the mounting end face 16. The first end of the first flow channel 11 extends through the mounting end face 16 and connects to the second-gear working port 41 of the transmission control valve 4. The first end of the second flow channel 12 extends through the mounting end face 16 and connects to the first-gear working port 42 of the transmission control valve 4. Specifically, the mounting end face 16 provides reliable and effective support and installation space for the transmission control valve 4. When the transmission control valve 4 is installed on the mounting end face 16, the first end of the first flow channel 11 and the second-gear working port 41 are in a coaxial communication position, and the first end of the second flow channel 12 and the first-gear working port 42 are in a coaxial communication position.

[0063] Specifically, the mounting end face 16 has multiple fixing holes 161, through which the speed control valve 4 is fixedly connected. Specifically, the fixing member is a bolt, and the fixing holes 161 are threaded holes. The bolt passes through the speed control valve 4 and is threaded into the corresponding fixing holes 161, ensuring that the speed control valve 4 is reliably and securely fixed.

[0064] For example, a plurality of fixing holes 161 are distributed at a plurality of corners of the mounting end face 16.

[0065] For example, the mounting end face 16 is also provided with an overflow channel that communicates with the overflow port of the speed control valve 4, so that the speed control valve 4 can realize the overflow pressure relief function.

[0066] In this embodiment, the housing 1 has a first detection channel 171 and a second detection channel 172. The first end of the first detection channel 171 is connected to the first channel 11, and the second end of the first detection channel 171 extends to the surface of the housing 1 and is provided with a first plug 181. The first end of the second detection channel 172 is connected to the second channel 12, and the second end of the second detection channel 172 extends to the surface of the housing 1 and is provided with a second plug 182. Specifically, the first detection channel 171 and the second detection channel 172 are reserved for the transmission phase structure. When not in use, the first plug 181 is sealed on the first detection channel 171, and the second plug 182 is sealed on the second detection channel 172. When in use, the first plug 181 and the second plug 182 can be removed, and pressure sensors can be installed accordingly to detect the pressure in the first channel 11 and the second channel 12.

[0067] This embodiment also provides an engineering machinery, which includes the aforementioned hydrostatic transmission and a chassis, with the housing 1 fixed to the chassis. The engineering machinery includes the aforementioned hydrostatic transmission, with both the first and second shift oil circuits built-in, eliminating the need for external pipelines, connectors, and other components, thus reducing costs, making the overall structure more compact, and improving oil delivery efficiency.

[0068] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A hydrostatic transmission, characterized in that, It includes a housing (1), a first oil distribution cap (2), a second oil distribution cap (3), and a transmission control valve (4); among which, The first oil distribution cap (2), the second oil distribution cap (3), and the transmission control valve (4) are all fixed on the housing (1). The housing (1) contains a first gear shaft (51) and a second gear shaft (52) spaced apart. The first oil distribution cap (2) covers the first gear shaft (51), and the second oil distribution cap (3) covers the second gear shaft (52). The housing (1) has a first flow channel (11) and a second flow channel (12). The first oil distribution cap (2) has a second-gear flow channel (21), which is connected to the second gear shifting mechanism. The first end of the first flow channel (11) is connected to the second gear working oil port (41) of the speed control valve (4), and the second end is connected to the second-gear flow channel (21). The second oil distribution cap (3) has a first flow channel (31), which is connected to the first shifting mechanism. The first end of the second flow channel (12) is connected to the first working oil port (42) of the speed control valve (4), and the second end is connected to the first flow channel (31).

2. The hydrostatic transmission according to claim 1, characterized in that, The housing (1) has a third flow channel (13) inside, the first oil distribution cap (2) has a connected oil inlet (22) and a first oil outlet (23), the second oil distribution cap (3) has a second oil outlet (32), the first end of the third flow channel (13) is connected to the first oil outlet (23), and the second end is connected to the second oil outlet (32). The lubricating oil flowing into the first oil distribution cover (2) through the oil inlet (22) can flow into the lubrication hole of the first gear shaft (51) and the first oil delivery hole (23), and the lubricating oil flowing into the first oil delivery hole (23) can sequentially enter the second oil distribution cover (3) through the third flow channel (13) and the second oil delivery hole (32) and flow into the lubrication hole of the second gear shaft (52).

3. The hydrostatic transmission according to claim 2, characterized in that, The housing (1) has a first mounting groove (14) and a second mounting groove (15). The first gear shaft (51) extends into the first mounting groove (14), and the second gear shaft (52) extends into the second mounting groove (15). The first oil distribution cap (2) is inserted into the first mounting groove (14), and the second oil distribution cap (3) is inserted into the second mounting groove (15). The second end of the first flow channel (11) extends through the wall of the first mounting groove (14) and connects to the second-block flow channel (21). The second end of the second flow channel (12) extends through the wall of the second mounting groove (15) and connects to the first-block flow channel (31). The first end of the third flow channel (13) extends through the wall of the first mounting groove (14) and connects to the first oil supply hole (23). The second end of the third flow channel (13) extends through the wall of the second mounting groove (15) and connects to the second oil supply hole (32).

4. The hydrostatic transmission according to claim 3, characterized in that, The outer peripheral wall of the first oil distribution cap (2) is provided with a first oil collection groove (24), and the first oil collection groove (24) and the groove wall of the first mounting groove (14) together form a first oil delivery chamber (101), and the second end of the first flow channel (11) is connected to the second flow channel (21) through the first oil delivery chamber (101). The outer peripheral wall of the second oil distribution cap (3) is provided with a second oil collection groove (33). The second oil collection groove (33) and the groove wall of the second installation groove (15) together form a second oil delivery chamber (102). The second end of the second flow channel (12) is connected to the first flow channel (31) through the second oil delivery chamber (102).

5. The hydrostatic transmission according to claim 3, characterized in that, A third oil delivery chamber (103) is formed between the outer peripheral wall of the first oil distribution cap (2) and the groove wall of the first mounting groove (14), and the first end of the third flow channel (13) is connected to the first oil delivery hole (23) through the third oil delivery chamber (103). A fourth oil delivery chamber (104) is formed between the outer peripheral wall of the second oil distribution cap (3) and the groove wall of the second mounting groove (15), and the second end of the third flow channel (13) is connected to the second oil delivery hole (32) through the fourth oil delivery chamber (104).

6. The hydrostatic transmission according to claim 2, characterized in that, The first oil distribution cap (2) has a first slot (25). The first stop shaft (51) is inserted into the first slot (25) at one end facing the first oil distribution cap (2), and forms a first lubrication cavity (201) with the first slot (25). The oil inlet (22) is connected to the lubrication hole of the first stop shaft (51) and the first oil delivery hole (23) through the first lubrication cavity (201). The second oil distribution cap (3) has a second slot (34). The end of the second gear shaft (52) facing the second oil distribution cap (3) is inserted into the second slot (34) and forms a second lubrication cavity (301) with the second slot (34). The second oil supply hole (32) is connected to the lubrication hole of the second gear shaft (52) through the second lubrication cavity (301).

7. The hydrostatic transmission according to claim 1, characterized in that, The housing (1) is provided with an installation end face (16), and the speed control valve (4) is fixedly installed on the installation end face (16). The first end of the first flow channel (11) extends through the installation end face (16) and connects to the second working oil port (41) of the speed control valve (4). The first end of the second flow channel (12) extends through the installation end face (16) and connects to the first working oil port (42) of the speed control valve (4).

8. The hydrostatic transmission according to claim 7, characterized in that, The mounting end face (16) has multiple fixing holes (161), and the fastener passes through the speed control valve (4) and is fixedly connected to the corresponding fixing hole (161).

9. The hydrostatic transmission according to claim 1, characterized in that, The housing (1) has a first detection channel (171) and a second detection channel (172). The first end of the first detection channel (171) is connected to the first channel (11), and the second end of the first detection channel (171) extends to the surface of the housing (1) and is provided with a first plug (181). The first end of the second detection channel (172) is connected to the second channel (12), and the second end of the second detection channel (172) extends to the surface of the housing (1) and is provided with a second plug (182).

10. An engineering machinery, characterized in that, The system includes the hydrostatic transmission according to any one of claims 1-9, and also includes a chassis, wherein the housing (1) is fixed to the chassis.

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