Engine

Abstract

The engine comprises an outer shell, the outer shell comprises a crankcase, a speed change mechanism is installed in the crankcase, the speed change mechanism comprises a power input shaft and a power output shaft, and the power input shaft and the power output shaft are installed in the crankcase and can rotate relative to the crankcase in the circumferential direction of the power input shaft and the power output shaft; the crankcase comprises an upper crankcase body and a lower crankcase body, the power input shaft and the power output shaft are located between the upper crankcase body and the lower crankcase body, the upper crankcase body is connected with the lower crankcase body through a crankcase closing bolt, and the upper crankcase body comprises a bolt mounting hole allowing the crankcase closing bolt to penetrate through, a first shaft seat used for mounting the power input shaft and a second shaft seat used for mounting the power output shaft. At least part of the bolt mounting hole is located between the first shaft seat and the second shaft seat, the upper box body is provided with an oil channel extending from the first shaft seat to the second shaft seat, and the oil channel does not coincide with the bolt mounting hole. Through the arrangement, the sealing performance in the crankcase is improved, and lubricating oil is prevented from leaking from the crankcase.

Description

Technical Field

[0001] This application relates to the technical field of power systems, and in particular, to an engine. Background Art

[0002] The power input shaft and the power output shaft of the engine are meshed through gears, and the gear shift of the transmission mechanism is realized by adjusting the meshed gears between them. There is an oil passage provided on the bearing bush on the crankcase. The power input shaft and the power output shaft are respectively installed on their respective opposite bearing bushes, and the power input shaft and the power output shaft are lubricated by the lubricating oil flowing through the oil passage.

[0003] The upper and lower casings of the crankcase are fixedly connected by mating bolts. The crankcase is provided with bolt mounting holes for mounting the mating bolts, and the bolt mounting holes are located between two sets of bearing bushes. Since the oil passage passes through the bolt mounting holes, the lubricating oil flowing through the oil passage may leak from the engine through the bolt mounting holes. Utility Model Content

[0004] In order to solve the deficiencies of the prior art, the purpose of the present utility model is to provide an engine with higher sealing performance of the crankcase.

[0005] To achieve the above purpose, the present application adopts the following technical solutions:

[0006] An engine, which includes an outer casing and a transmission mechanism. The outer casing includes a crankcase, and the transmission mechanism is installed in the crankcase. The transmission mechanism includes a power input shaft and a power output shaft. The power input shaft and the power output shaft are installed in the crankcase and can both rotate relative to the crankcase along their circumferences. The crankcase includes an upper casing and a lower casing. The power input shaft and the power output shaft are located between the upper casing and the lower casing. The upper casing is connected to the lower casing by mating bolts. The upper casing includes bolt mounting holes for the mating bolts to pass through, a first shaft seat for mounting the power input shaft, and a second shaft seat for mounting the power output shaft. At least part of the bolt mounting holes are located between the first shaft seat and the second shaft seat. The upper casing has an oil passage extending from the first shaft seat to the second shaft seat, and the oil passage does not coincide with the bolt mounting holes.

[0007] Further, the oil passage includes a first oil passage located on the first shaft seat and a second oil passage located on the second shaft seat, and the extending directions of the first oil passage and the second oil passage are substantially parallel.

[0008] Further, the power output shaft is rotatably connected to the crankcase through a bearing member, and the bearing member covers the second oil passage.

[0009] Further, the extending directions of the first oil passage and the second oil passage are parallel and do not coincide.

[0010] Further, a third oil passage for avoiding the bolt mounting hole is provided between the first oil passage and the second oil passage. The third oil passage communicates with the first oil passage and the second oil passage, and the third oil passage is arc-shaped.

[0011] Further, an installation space is formed between the upper housing body and the lower housing body, and the third oil passage is located on the side of the bolt mounting hole away from the installation space.

[0012] Further, the part between the oil passage and the bolt mounting hole is the isolation part of the upper housing body. The length range of the isolation part extending along the axial direction of the power input shaft is 2 mm to 20 mm.

[0013] Further, the length range of the isolation part extending along the axial direction of the power input shaft is 4 mm to 18 mm.

[0014] Further, the outer housing body further includes an oil pan. The crankcase is connected to the oil pan and forms an oil storage space for storing lubricating oil with the oil pan. An oil port communicating with the oil storage space is formed on the side of the crankcase facing the oil pan. The engine further includes an oil strainer. The oil strainer is installed in the oil storage space and communicates with the oil port. The oil pan includes a bottom wall and a support structure. The support structure extends from the bottom wall towards the crankcase; the oil strainer includes a mounting structure. The oil strainer is connected to the crankcase through the mounting structure. At least part of the mounting structure is embedded in the oil port, and the side of the mounting structure facing away from the crankcase abuts against the support structure.

[0015] Further, the mounting structure includes a first limiting part, and a second limiting part cooperating with the first limiting part is provided on the side of the crankcase facing the oil pan. The first limiting part and the second limiting part are mutually engaged.

[0016] Further, the mounting structure includes two columnar first limiting parts. A preset gap is formed between the two first limiting parts. When the oil strainer is connected to the crankcase, the second limiting part is located in the preset gap, and the two first limiting parts limit the second limiting part along the width direction of the preset gap.

[0017] By arranging part of the oil passage outside the bolt mounting hole, the engine enables the oil passage to avoid the bolt mounting hole in the axial direction of the power input shaft, improves the sealing performance inside the crankcase, and prevents lubricating oil from leaking from the crankcase along the bolt mounting hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the engine provided by the embodiment of the present application;

[0019] Figure 2 It is an exploded view of the crankcase of the engine provided by the embodiment of the present application;

[0020] Figure 3 It is a bottom view of the upper housing body of the engine provided by the embodiment of the present application;

[0021] Figure 4 is Figure 3 The partial enlarged view of position A;

[0022] Figure 5 is the schematic structural view of the crankcase of the engine provided by the embodiment of the present application;

[0023] Figure 6 is the first schematic structural view of the oil pan of the engine provided by the embodiment of the present application;

[0024] Figure 7 is the second schematic structural view of the oil pan of the engine provided by the embodiment of the present application;

[0025] Figure 8 is the schematic structural view of the lower crankcase of the engine provided by the embodiment of the present application;

[0026] Figure 9 is the schematic view of the lubricating oil path of the engine provided by the embodiment of the present application;

[0027] Figure 10 is the schematic view of the pressure control assembly of the engine provided by the embodiment of the present application;

[0028] Figure 11 is the sectional view of the pressure control assembly of the engine provided by the embodiment of the present application along the I-I direction;

[0029] Figure 12 is the exploded view of the pressure limiting valve of the engine provided by the embodiment of the present application. Specific Embodiments

[0030] In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the specific embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application.

[0031] The terms used in the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. "First", "second", "third", "fourth" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first", "second", "third", "fourth" may explicitly or implicitly include at least one of the features. The singular forms "a", "the" and "said" used in the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0032] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0033] As Figure 1 shown, the present application provides an engine 100, which can be used as a power supply device for vehicles such as automobiles and motorcycles. In an embodiment of the present application, the engine 100 belongs to a reciprocating piston internal combustion engine, which can convert the chemical energy of fuel into the mechanical energy of piston movement and output power externally. The engine 100 includes a housing 10, and the housing 10 constitutes the main frame of the engine 100. The housing 10 includes an oil pan 11, a crankcase 12, a cylinder block 13, a cylinder head 14 and a cylinder head cover 15 connected in sequence from bottom to top.

[0034] As Figure 2 shown, as an implementation, the crankcase 12 includes an upper housing 121 and a lower housing 122. The upper housing 121 and the lower housing 122 are fixedly connected by a mating bolt 123, and an installation space 124 is formed between the upper housing 121 and the lower housing 122. The engine 100 is connected to a transmission, and the engine 100 and the transmission are integrally formed, that is, the crankcase 12 of the engine 100 is reused as the housing of the transmission. The engine includes a crankshaft connecting rod mechanism (not shown in the figure). The transmission includes a power input shaft 361 and a power output shaft 362. The crankshaft connecting rod mechanism, the power input shaft 361 and the power output shaft 362 are all arranged in the installation space 124. The rotation axes of the power input shaft 361 and the power output shaft 362 are arranged parallel to each other. The crankshaft connecting rod mechanism meshes with a gear on the power input shaft 361, and the power input shaft and the power output shaft 362 are meshed with each other through gears. The engine 100 drives the crankshaft connecting rod mechanism to rotate by burning a fuel-air mixture, and transmits the power in the direction from the crankshaft connecting rod mechanism, the power input shaft 361 to the power output shaft 362 outside the engine 100.

[0035] As Figure 3As shown in the figure, taking the upper box body 121 as an example, the upper box body 121 includes bolt mounting holes 1212, a first shaft seat 1213, and a second shaft seat 1214. The bolt mounting holes 1212 are used to set the box-combining bolts 123, and their interiors have threads that cooperate with the box-combining bolts 123. The first shaft seat 1213 is used to mount the power input shaft 361, and the end of the power input shaft 361 is located in the first shaft seat 1213. The power input shaft 361 can rotate relative to the first shaft seat 1213 along its own circumferential direction. The second shaft seat 1214 is used to mount the power output shaft 362, and the end of the power output shaft 362 is located in the second shaft seat 1214. The power output shaft 362 can rotate relative to the second shaft seat 1214 along its own circumferential direction.

[0036] The number of the bolt mounting holes 1212 is set to be several. Among them, some bolt mounting holes 1212 are located between the first shaft seat 1213 and the second shaft seat 1214. The upper box body 121 has an oil passage 1215 extending from the first shaft seat 1213 to the second shaft seat 1214, and this oil passage 1215 does not coincide with the bolt mounting holes 1212.

[0037] Through the above settings, the lubricating oil flowing through the power input shaft 361 and the power output shaft 362 is avoided from the bolt mounting holes 1212, preventing the lubricating oil from leaking along the bolt mounting holes 1212 during the lubrication process.

[0038] As Figure 4 shown, as a realization method, the part between the oil passage 1215 and the bolt mounting holes 1212 is the isolation part 1216 of the upper box body 121. The length L1 of the isolation part 1216 extending along the axial direction of the power input shaft 361 ranges from 2 mm to 20 mm. Further, the length L1 of the isolation part 1216 extending along the axial direction of the power input shaft 361 ranges from 4 mm to 18 mm. More preferably, the length L1 of the isolation part 1216 extending along the axial direction of the power input shaft 361 ranges from 6 mm to 16 mm. It should be noted that if the wall thickness of the isolation part 1216 used to isolate the oil passage 1215 from the bolt mounting holes 1212 is too small, the pressure generated in the oil passage 1215 will cause the lubricating oil to leak from the bolt mounting holes 1212. By setting the isolation part 1216 with a thickness of at least 2 mm, the sealing effect of the oil passage 1215 is ensured.

[0039] Further, the oil passage 1215 includes a first oil passage 1215a located on the first shaft seat 1213 and a second oil passage 1215b located on the second shaft seat 1214. The extending directions of the first oil passage 1215a and the second oil passage 1215b are basically parallel, and the two do not coincide. Compared with the second oil passage 1215b, the position of the first oil passage 1215a is closer to the outside of the installation space 124.

[0040] The oil passage 1215 further includes a third oil passage 1215c, which is located between the first oil passage 1215a and the second oil passage 1215b, and the third oil passage 1215c is connected to the first oil passage 1215a and the second oil passage 1215b. The third oil passage 1215c is substantially arc-shaped to avoid the bolt installation hole 1212.

[0041] like Figures 2 to 3 As shown, the power transmission assembly 36 also includes a bearing member 363 sleeved on the power output shaft 362, the bearing member 363 is installed on the second shaft seat 1214, and the power transmission assembly 36 is rotatably connected to the crankcase 12 through the bearing member 363. The bearing member 363 covers the second oil passage 1215b, and the bearing member 363 is reused as an oil seal of the second oil passage 1215b to prevent the lubricating oil from leaking out of the crankcase 12 along the second oil passage 1215b.

[0042] As an implementation method, the bolt mounting hole 1212 of the upper case 121 is defined as a first bolt mounting hole, the oil passage 1215 of the upper case 121 is defined as an upper oil passage, and the lower case 122 has a second bolt mounting hole and a lower oil passage corresponding to the first bolt mounting hole and the upper oil passage, respectively. The structure of the lower oil passage is basically the same as that of the upper oil passage, and there is also a certain interval between the lower oil passage and the second bolt mounting hole, so that the oil passage formed by the lower oil passage avoids the second bolt mounting hole. Through the above arrangement, the sealing of the crankcase 12 is ensured, and the leakage of lubricating oil from the crankcase 12 is avoided. In addition, since the oil passage 1215 avoids the bolt mounting hole 1212, the processing of the oil passage 1215 is simpler.

[0043] like Figure 5 and Figure 6 As shown, the engine 100 includes a crankcase 12 and an oil pan 11 connected to each other, and an oil storage space 111 for storing lubricating oil is formed between the oil pan 11 and the crankcase 12. The crankcase 12 has an oil passage 125 on one side facing the oil pan 11, which is connected to the oil storage space 111. The lubricating oil passage 42 inside the engine 100 obtains lubricating oil from the oil storage space 111 through the oil passage 125, so that the lubricating oil circulates in the lubricating oil passage 42.

[0044] The engine 100 also includes a lubrication system 40, which is used to obtain lubrication oil from the oil storage space 111 and transmit the lubrication oil along the lubrication oil path 42. The lubrication system 40 includes a filter 41, which is installed in the oil storage space 111 and communicates with the oil channel port 125. The filter 41 usually adopts a metal filter structure, and its main function is to intercept and prevent larger mechanical impurities from entering the lubrication oil path 42. This design takes into account the characteristics of the lubrication oil itself, which has high viscosity and contains more impurities. Through the filtering effect of the filter 41, the cleanliness of the lubrication oil can be improved, thereby protecting the lubrication system 40.

[0045] As an implementation, the oil pan 11 includes a support structure 112 located within the oil storage space 111, and at least a part of the support structure 112 extends in the direction of the oil port 125. The oil strainer 41 includes a mounting structure 411. The oil strainer 41 is connected to the crankcase 12 through the mounting structure 411. At least a part of the mounting structure 411 is embedded in the oil port 125, and the side of the mounting structure 411 facing away from the crankcase 12 abuts against the support structure 112. The oil strainer 41 is clamped to the inner wall of the oil port 125 through the mounting structure 411, thereby limiting the mounting structure 411 in the radial direction of the oil port 125, and further fixing the oil strainer 41. Further, since the support structure 112 supports the mounting structure 411 in the axial direction of the oil port 125, it prevents the mounting structure 411 from disengaging from the oil port 125, limits the mounting structure 411 in the axial direction of the oil port 125, and further fixes the oil strainer 41. Through the above settings, the installation and fixation of the oil strainer 41 can be achieved without fastening by fasteners, improving the assembly efficiency of the engine 100 and reducing the number of components of the engine 100.

[0046] Specifically, the oil pan 11 includes a bottom wall 113 and side walls 114 distributed around the outer edge of the bottom wall 113. The oil pan 11 is fixedly connected to the crankcase 12 through the side walls 114. A plurality of fixing holes 1141 are provided on the side walls 114. Fasteners for fixing the oil pan 11 pass through the fixing holes 1141 and are fixedly connected to the crankcase 12. The support structure 112 is provided on the bottom wall 113 and is fixedly connected to the bottom wall 113. The support structure 112 extends from the bottom wall 113 in the direction of the oil port 125 and limits the mounting structure 411 in the axial direction of the oil port 125.

[0047] Exemplarily, the support structure 112 is integrally formed with the bottom wall 113, reducing costs and improving the assembly efficiency of the oil strainer 41.

[0048] Optionally, the support structure 112 and the bottom wall 113 can also be fixedly connected by fasteners. By providing a plurality of bolt holes on the bottom wall 113, it is possible to accommodate support structures 112 with different shapes and lengths. The support structure 112 is fixedly connected to the corresponding bolt holes, making it possible for the engine 100 to accommodate oil strainers 41 of different models.

[0049] Further, the mounting structure 411 includes a first limiting portion 4111, and a second limiting portion 126 is provided on the side of the crankcase 12 facing the oil pan 11. By the mutual engagement of the first limiting portion 4111 and the second limiting portion 126, the mounting structure 411 is limited in the circumferential direction of the oil port 125.

[0050] In some examples, the mounting structure 411 includes a mounting disk 4112 and two columnar first limiting portions 4111. The first limiting portions 4111 are distributed on the outer edge of the mounting disk 4112, and there is a preset gap 4113 between the two first limiting portions 4111. The second limiting portion 126 is embedded in the preset gap 4113, and the second limiting portion 126 abuts against the first limiting portions 4111 on both sides. The two first limiting portions 4111 limit the second limiting portion 126 in the width direction of the preset gap 4113. Through the mutual cooperation of the first limiting portion 4111 and the second limiting portion 126, the mounting structure 411 is limited to prevent the mounting structure 411 from rotating relative to the crankcase 12 along the circumferential direction of the oil port 125.

[0051] In other examples, the first limiting portion 4111 may be a protrusion provided on the mounting structure 411, and the second limiting portion 126 may be a groove provided on the crankcase 12 and recessed in a direction away from the oil pan 11. During the assembly process of the oil strainer 41, at least a part of the mounting structure 411 is embedded in the oil port 125, and the first limiting portion 4111 is embedded in the second limiting portion 126 to limit the oil strainer 41 from moving relative to the crankcase 12 in the radial and circumferential directions of the oil port 125.

[0052] It should be noted that the present application does not specifically limit the structures and shapes of the first limiting portion 4111 and the second limiting portion 126.

[0053] As Figure 6 shown, as a implementation manner, the support structure 112 includes a plurality of support bosses 1121. The support bosses 1121 are arranged around the circumference of the mounting structure 411. The heights of the plurality of support bosses 1121 are different, and the height of the support boss 1121 is determined by the distance between the bottom wall 113 and the crankcase 12. It should be noted that the present application does not specifically limit the number of the support bosses 1121.

[0054] Furthermore, the bottom wall 113 includes a first oil storage portion 1131 and a second oil storage portion 1132. Along the extending direction of the support structure 112, the longest distance between the first oil storage portion 1131 and the crankcase 12 is defined as the first length, and the longest distance between the second oil storage portion 1132 and the crankcase 12 is defined as the second length. The first length is greater than the second length, that is, the first oil storage portion 1131 is deeper than the second oil storage portion 1132. As a implementation manner, the support bosses 1121 are respectively installed on the first oil storage portion 1131 and the second oil storage portion 1132. By providing a plurality of support bosses 1121 with shorter lengths, the overall strength of the support structure 112 is improved to ensure the stable connection between the oil strainer 41 and the crankcase 12.

[0055] As Figure 7As shown, in some other examples, the support structure 112 includes a support boss 1121 that is circumferentially arranged around the mounting structure 411 and is substantially annular. A notch 1122 is formed on one side of the support boss 1121. The oil strainer 41 includes an oil strainer pipe 412 connected to the mounting structure 411. At least a part of the oil strainer pipe 412 is located in the area surrounded by the support boss 1121, and the oil strainer pipe 412 also extends toward the notch 1122 to the outside of the area surrounded by the support boss 1121. The oil strainer pipe 412 is avoided through the notch 1122 to prevent interference between the support structure 112 and the oil strainer pipe 412.

[0056] As Figure 8 shown, as an implementation manner, the lubrication system 40 further includes a pressure control component 43 and a lubricating oil path 42. The lubricating oil path 42 communicates with the oil storage space 111 through an oil port 125. The pressure control component 43 is installed in the crankcase 12 and communicates with the lubricating oil path 42. Specifically, the pressure control component 43 is installed in the lower crankcase 122 and fixedly connected to the lower crankcase 122. Under the action of the pressure control component 43, the lubricating oil stored in the oil storage space 111 is pumped into the lubricating oil path 42 through the oil port 125 to lubricate the components arranged in the engine 100, such as the cam mechanism, the transmission mechanism 30, the piston connecting rod mechanism, etc.

[0057] As Figure 9 shown, the lubricating oil path 42 includes a first oil path 421 and a second oil path 422. The first oil path 421 and the second oil path 422 are respectively connected to the input end and the output end of the pressure control component 43. One end of the first oil path 421 is connected to the input end of the pressure control component 43, and the other end of the first oil path 421 communicates with the oil storage space 111 through the oil port 125. The pressure control component 43 obtains the lubricating oil stored in the oil storage space 111 through the first oil path 421. One end of the second oil path 422 is connected to the output end of the pressure control component 43, and the pressure control component 43 pumps the lubricating oil into each component to be lubricated in the engine 100 through the second oil path 422.

[0058] It should be noted that the second oil path 422 communicates with the crankcase 12, the cylinder block 13, and the cylinder head 14, and lubricates the components in the above structures through the second oil path, thereby forming a lubricating oil circulation in the engine 100.

[0059] As Figure 10As shown in the figure, the pressure control assembly 43 includes an oil pump 431 and a pressure limiting valve 432 connected to the oil pump 431. The function of the oil pump 431 is to raise the lubricating oil to a certain pressure and then forcibly pump it to the moving surfaces of various parts of the engine 100. The oil pump 431 includes a rotatable gear 4311 and an oil inlet chamber 4312 and an oil outlet chamber 4313 located on both sides of the gear 4311. The oil inlet chamber 4312 and the oil outlet chamber 4313 are distributed radially along the gear 4311. When the engine 100 is working, the gear 4311 of the oil pump 431 is rotated, and the lubricating oil is sent from the oil inlet chamber 4312 to the oil outlet chamber 4313 along the tooth gap 4314. In this way, a low pressure is formed at the oil inlet chamber 4312 to generate suction, sucking the lubricating oil in the oil storage space 111 into the oil inlet chamber 4312, and the lubricating oil is continuously pumped to the parts of the engine 100 that need it.

[0060] As Figure 11 and Figure 12 shown in the figure, the pressure limiting valve 432 is a device that controls the flow rate of the lubricating oil and limits the pressure of the lubricating oil. It can automatically adjust the pressure of the lubrication system 40 and protect it under overpressure or low pressure conditions. Specifically, the pressure limiting valve 432 includes a valve body 4321, a valve core 4322, an elastic member 4323, and a first seal 4324. The valve body 4321 constitutes the basic framework of the pressure limiting valve 432. The valve body 4321 is formed with a hollow pressure regulating chamber 4325 around it, and a first mounting port 4321d is opened on the valve body 4321. The pressure regulating chamber 4325 is communicated with the outside of the valve body 4321 through the first mounting port.

[0061] The valve core 4322 is installed in the pressure regulating chamber 4325, and the valve core 4322 enters or exits the pressure regulating chamber 4325 through the first mounting port 4321d. Therefore, the radial length of the valve core 4322 is less than or equal to the radial length of the first mounting port 4321d. The valve core 4322 is in clearance fit with the valve body 4321, and the valve core 4322 can move relative to the valve body 4321 along the extending direction of the pressure regulating chamber 4325. The valve body 4321 further includes a first pressure limiting chamber 4326 and a second pressure limiting chamber 4327 communicated with the pressure regulating chamber 4325. One end of the first pressure limiting chamber 4326 facing away from the pressure regulating chamber 4325 is communicated with the first oil passage 421, and one end of the second pressure limiting chamber 4327 facing away from the pressure regulating chamber 4325 is communicated with the second oil passage 422. By adjusting the position of the valve core 4322 in the pressure regulating chamber 4325, the flow rate or flow velocity of the lubricating oil between the first pressure limiting chamber 4326 and the second pressure limiting chamber 4327 is controlled, so as to protect the lubrication system 40 under overpressure or low pressure conditions.

[0062] The elastic member 4323 is installed in the pressure regulating chamber 4325, and the elastic member 4323 abuts against the valve core 4322 in the direction from the first installation port 4321d to the pressure regulating chamber 4325, and the oil pressure in the lubricating oil circuit 42 is balanced through the interaction between the elastic member 4323 and the valve core 4322. When the pressure in the first pressure limiting chamber 4326 increases, the valve core 4322 compresses the elastic member 4323 in the direction close to the first installation port 4321d, so that the gap between the first pressure limiting chamber 4326 and the second pressure limiting chamber 4327 increases, so that more lubricating oil enters the second oil circuit 422, thereby reducing the oil pressure in the oil storage space 111. When the pressure in the first pressure limiting chamber 4326 decreases, the elastic potential energy of the elastic member 4323 is converted into mechanical energy. The elastic member 4323 acts on the valve core 4322 and pushes the valve core 4322 to move away from the first mounting port 4321d, so that the gap between the first pressure limiting chamber 4326 and the second pressure limiting chamber 4327 is reduced, allowing less lubricating oil to enter the second oil circuit 422, thereby avoiding insufficient oil pressure in the oil storage space 111.

[0063] The first sealing member 4324 is installed in the pressure regulating chamber 4325 and is located at one end of the elastic member 4323 away from the valve core 4322 and abuts against the elastic member 4323. The side of the first sealing member 4324 away from the elastic member 4323 abuts against the valve body 4321 along the extension direction of the pressure regulating chamber 4325 and covers the first installation port 4321d, thereby preventing the elastic member 4323 and the valve core 4322 from being separated from the pressure regulating chamber 4325 from the first installation port 4321d, wherein the first sealing member 4324 is a gasket.

[0064] Through the above-mentioned arrangement, along the length direction of the valve body 4321, the valve core 4322, the elastic member 4323 and the first sealing member 4324 are sequentially installed in the pressure regulating chamber 4325, so that the valve core 4322 can move relative to the valve body 4321 under the action of pressure, thereby balancing the oil pressure in the lubrication system 40 and maintaining the stability of the lubrication system 40, and the first sealing member 4324 closes the first installation port 4321d, thereby improving the assembly efficiency of the pressure limiting valve 432 and the production cost of the engine 100.

[0065] It should be noted that in the prior art, the first mounting port 4321d is generally blocked by bolts. Since the engine generates vibrations when it is working, the vibrations cause the bolts and the valve body connection parts to move relative to each other and the friction to be gradually offset. In a vibrating environment, small relative movements will occur between the bolts and the valve body, and these movements will gradually offset the friction between them. Eventually, this repetitive movement will cause the bolts to loosen. The above-mentioned arrangement exerts a force on the first seal 4324 through the elastic member 4323, so that the first seal 4324 has a higher stability, and the risk of the first seal 4324 being detached due to the vibration of the engine 100 is relatively small.

[0066] A reference plane perpendicular to the extension direction of the pressure regulating chamber 4325 is defined, and the projection of the first sealing component 4324 along the extension direction of the pressure regulating chamber 4325 on the reference plane is defined as a first projection plane. The projection of the first mounting port 4321d along the extension direction of the pressure regulating chamber 4325 on the reference plane is defined as a second projection plane. The first projection plane basically covers the second projection plane, thereby preventing the first sealing component 4324 from falling off from the first mounting port 4321d.

[0067] Specifically, the valve body 4321 includes a valve tail 4321a (see Figure 10 ), the valve tail 4321a is located at one end of the valve body 4321 away from the first pressure limiting chamber 4326 and / or the second pressure limiting chamber 4327, and the valve tail 4321a is distributed along the circumference of the first installation opening 4321d. The valve tail 4321a is provided with a second installation opening 4321b through which the first sealing member 4324 can pass. The valve core 4322 and the elastic member 4323 enter the pressure regulating chamber 4325 along the first installation opening 4321d, and the elastic member 4323 is compressed to shorten the length of the elastic member 4323, so that the end of the elastic member 4323 close to the first installation opening 4321d avoids the second installation opening 4321b, and the first sealing member 4324 can enter the pressure regulating chamber 4325 through the second installation opening 4321b. When the first seal 4324 covers the first installation port 4321d, the elastic member 4323 returns to its natural state and abuts against the first seal 4324 to limit the movement of the first seal 4324 along the extension direction of the pressure regulating chamber 4325, thereby preventing the first seal 4324 from detaching from the pressure regulating chamber 4325 from the second installation port 4321b.

[0068] Furthermore, the valve tail 4321a includes a limiting portion 4321c, which limits the first sealing member 4324 in the radial direction of the first installation port 4321d. The limiting portion 4321c is located between the first installation port 4321d and the second installation port 4321b when viewed from the assembly direction of the first sealing member 4324. Therefore, when maintaining or replacing the first sealing member 4324, it is necessary to compress the elastic member 4323 along the extension direction of the pressure regulating chamber 4325 so that the first sealing member 4324 is separated from the limiting portion 4321c, and then the first sealing member 4324 can be taken out from the second installation port 4321b, thereby ensuring the stability of the first sealing member 4324.

[0069] Optionally, the limiting portion 4321c may be a groove 311 whose inner contour is substantially consistent with the outer contour of the first sealing member 4324 .

[0070] In some examples, the pressure limiting valve 432 further includes a second seal 4328. The second seal 4328 is embedded in the first mounting port 4321d and / or the second mounting port 4321b. By blocking the first mounting port 4321d and / or the second mounting port 4321b with the second seal 4328, the stability of the first seal 4324 is further improved, and the first seal 4324 is prevented from detaching from the first mounting port 4321d and / or the second mounting port 4321b.

[0071] In the examples of the present application, the first seal 4324 is made of a metal material, and the hardness of the first seal 4324 is greater than or equal to 50 HRC. This prevents the valve core 4322 from repeatedly pressing the first seal 4324 and causing deformation of the first seal 4324.

[0072] It should be understood that for those of ordinary skill in the art, improvements or modifications can be made according to the above description, and all such improvements and modifications shall fall within the protection scope of the appended claims of the present application.

Claims

1. An engine, comprising: An outer shell, the outer shell comprising a crankcase, a speed change mechanism being installed in the crankcase, the speed change mechanism comprising a power input shaft and a power output shaft, the power input shaft and the power output shaft being installed in the crankcase and both being able to rotate relative to the crankcase along their own circumferential directions; It is characterized in that The crankcase includes an upper case and a lower case, the power input shaft and the power output shaft are located between the upper case and the lower case, the upper case is connected to the lower case by a case bolt, the upper case includes a bolt mounting hole for the case bolt to pass through, a first shaft seat for mounting the power input shaft, and a second shaft seat for mounting the power output shaft, at least part of the bolt mounting hole is located between the first shaft seat and the second shaft seat, the upper case has an oil passage extending from the first shaft seat to the second shaft seat, and the oil passage does not overlap with the bolt mounting hole.

2. The engine according to claim 1, characterized in that The oil passage comprises a first oil passage located on the first shaft seat and a second oil passage located on the second shaft seat, and the extension directions of the first oil passage and the second oil passage are substantially parallel.

3. The engine according to claim 2, characterized in that The power output shaft is rotatably connected to the crankcase via a bearing component, and the bearing component covers the second oil passage.

4. The engine according to claim 2, characterized in that An extending direction of the first oil channel and an extending direction of the second oil channel are parallel and do not overlap.

5. The engine according to claim 2, characterized in that A third oil passage is provided between the first oil passage and the second oil passage to avoid the bolt installation hole. The third oil passage communicates with the first oil passage and the second oil passage, and the third oil passage is arc-shaped.

6. The engine according to claim 1, characterized in that The portion between the oil passage and the bolt mounting hole is a partition of the upper housing, and the partition extends in an axial direction of the power input shaft over a length ranging from 2 mm to 20 mm.

7. The engine according to claim 6, characterized in that The length of the isolating portion extending in the axial direction of the power input shaft ranges from 4 mm to 18 mm.

8. The engine according to claim 1, characterized in that The outer shell also includes an oil pan, the crankcase is connected to the oil pan, and forms an oil storage space for storing lubricating oil with the oil pan, the crankcase is formed with an oil passage opening connected to the oil storage space on a side facing the oil pan, the engine also includes a strainer, the strainer is installed in the oil storage space and is connected to the oil passage opening, the oil pan includes a bottom wall and a supporting structure, the supporting structure extends from the bottom wall toward the crankcase; the strainer includes a mounting structure, the strainer is connected to the crankcase through the mounting structure, at least a portion of the mounting structure is embedded in the oil passage opening, and the mounting structure abuts against the supporting structure on a side facing away from the crankcase.

9. The engine according to claim 8, characterized in that The mounting structure includes a first limiting portion, and a second limiting portion cooperating with the first limiting portion is provided on a side of the crankcase facing the oil pan, and the first limiting portion and the second limiting portion are embedded with each other.

10. The engine according to claim 9, characterized in that The mounting structure includes two first limiting portions in a columnar shape, a preset gap is formed between the two first limiting portions, and when the filter is connected to the crankcase, the second limiting portion is located in the preset gap, and the two first limiting portions limit the second limiting portion along the width direction of the preset gap.

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