An engine gear train and an engine

Abstract

The application provides an engine gear train and an engine, the engine gear train comprises an engine rear end gear train, the engine rear end gear train comprises a crankshaft rear end gear, a camshaft gear and a plurality of rear end intermediate gears, the crankshaft rear end gear is meshed with the camshaft gear through the plurality of rear end intermediate gears; the engine comprises at least two engine rear end accessories, the engine rear end gear train further comprises engine rear end accessory gears connected with driving shafts of the engine rear end accessories, and each engine rear end accessory gear is meshed on a rear end intermediate gear. According to the application, the gear tooth number ratio of the engine rear end gear train is adjusted to realize that the transmission ratio of the crankshaft rear end gear to the camshaft gear is 2:1, and each engine rear end accessory is driven by a separate rear end intermediate gear, so that the adaptability of the engine accessories and the engine gear train and the universality of the engine gear train are improved, and the problem of engine gear train and engine accessory arrangement is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engine parts, in particular to an engine gear train and an engine. BACKGROUND

[0002] An engine is a machine that converts the chemical energy of fuel into kinetic energy, which includes two major mechanisms, i.e., a valve train and a crankshaft mechanism, and five systems. The valve train is a mechanism for controlling the intake and exhaust valves of the engine, and needs to meet the functions of opening and closing the intake and exhaust valves on time and accurately. The working principle of the valve train relies on the rotational power of the crankshaft, and through a series of transmission mechanisms, such as a camshaft and a rocker arm, precise control of the valve movement is achieved. In a complete working cycle of a four-stroke engine, the crankshaft rotates 720 degrees, while the intake and exhaust valves are opened and closed only once, which means that the camshaft only needs to rotate 360 degrees to complete the control of the valves. Therefore, the valve train needs to meet the power transmission requirements from the crankshaft to the valves via the camshaft, and the transmission ratio from the crankshaft to the camshaft needs to be 2:1.

[0003] According to the position of the camshaft, the arrangement of the camshaft of the valve train can be divided into three types, i.e., camshaft bottom, camshaft middle and camshaft top. Among them, the arrangement of the camshaft middle and the camshaft bottom makes the camshaft and the crankshaft closer, and the rocker arm is pushed by a tappet or a push rod to control the valve; while the arrangement of the camshaft top allows the camshaft to directly push the rocker arm, thereby reducing the intermediate transmission link, but this arrangement also increases the distance between the camshaft and the crankshaft, and needs to use a chain or a gear train to achieve power transmission.

[0004] In order to improve the efficiency of the engine and meet the emission regulations, the control accuracy and function of the valve train of the engine have higher requirements, and the camshaft top arrangement of the valve train is beneficial to reduce the reciprocating inertia force of the engine, improve the engine speed and facilitate more precise control of the valve. However, the current camshaft top scheme generally adopts a single gear transmission mode for driving the engine rear end accessories, which limits the size and arrangement flexibility of the engine accessories to some extent. With the reduction of the size of the engine, the arrangement and design of the gear train and the engine accessories are significantly increased, especially for different derivative models matching different types of accessories, due to the difference in the size of the accessories, it is often difficult to achieve universality and adaptability.

[0005] Therefore, it is necessary to provide a new technical scheme to solve the above technical problems. SUMMARY

[0006] The present application provides an engine gear train and an engine to solve the arrangement difficulty problem of the existing engine gear train and engine accessories.

[0007] The application provides an engine gear train, which comprises an engine rear end gear train on the side of an engine flywheel, the engine rear end gear train comprising a crankshaft rear end gear, a camshaft gear and a plurality of rear end intermediate gears, the crankshaft rear end gear being engaged with the camshaft gear through the plurality of rear end intermediate gears;

[0008] The engine comprises at least two engine rear end accessories, the engine rear end gear train further comprising engine rear end accessory gears connected with driving shafts of the engine rear end accessories, each of the engine rear end accessory gears being engaged with one of the rear end intermediate gears, the crankshaft rear end gear transmitting power of an engine crankshaft to the engine rear end accessories and the camshaft gear through the rear end intermediate gears, and the transmission ratio of the crankshaft rear end gear to the camshaft gear being 2:1 by adjusting the gear tooth ratio of the engine rear end gear train.

[0009] According to the engine gear train provided by the application, at least one pair of double gears coaxially arranged is included in the plurality of rear end intermediate gears, the double gears being composed of any two of the plurality of rear end intermediate gears, the crankshaft rear end gear being engaged with one of the rear end intermediate gears in the double gears, and the camshaft gear being engaged with the other rear end intermediate gear in the double gears.

[0010] According to the engine gear train provided by the application, the engine rear end accessories comprise an air compressor and a fuel pump, the engine rear end accessory gears comprise an air compressor gear and a fuel pump gear, and the rear end intermediate gears comprise an air compressor intermediate gear and a fuel pump intermediate gear.

[0011] The air compressor gear is connected with a driving shaft of the air compressor, and the air compressor gear is engaged with the crankshaft rear end gear through the air compressor intermediate gear; the fuel pump gear is connected with a driving shaft of the fuel pump, and the fuel pump gear is engaged with the crankshaft rear end gear through the fuel pump intermediate gear and the air compressor intermediate gear in sequence.

[0012] According to the engine gear train provided by the application, a first intermediate gear, a second intermediate gear and a third intermediate gear are further included in the plurality of rear end intermediate gears, the first intermediate gear and the fuel pump intermediate gear being coaxially arranged to form the double gears, and the first intermediate gear being engaged with the camshaft gear through the second intermediate gear and the third intermediate gear in sequence.

[0013] According to the engine gear train provided by the application, the gear tooth ratio of the fuel pump intermediate gear to the first intermediate gear is 2:1, and the gear tooth ratio of the crankshaft rear end gear to the camshaft gear is 1:1.

[0014] Alternatively, the first intermediate gear and the camshaft gear have a tooth number ratio of 1:1, and the fuel pump intermediate gear and the crankshaft rear end gear have a tooth number ratio of 2:1.

[0015] According to the engine gear train provided by the present application, the camshaft gear is connected with the camshaft of the engine, and the camshaft gear is located at one end of the engine rear end gear train close to the cylinder head of the engine.

[0016] According to the engine gear train provided by the present application, the engine gear train further comprises an engine front end gear train, the engine front end gear train is located at the engine fan side, and the engine comprises at least one engine front end accessory.

[0017] The engine front end gear train comprises a crankshaft front end gear, an engine front end accessory gear and a front end intermediate gear, the engine front end accessory gear is connected with the transmission shaft of the engine front end accessory one by one, each engine front end accessory gear is engaged with the front end intermediate gear one by one, and the engine front end accessory gear is engaged with the crankshaft front end gear through the front end intermediate gear.

[0018] According to the engine gear train provided by the present application, all gears in the engine front end gear train and the engine rear end gear train are involute spur gears, and the tooth numbers of two gears engaged with each other are relatively prime.

[0019] According to the engine gear train provided by the present application, the ratio of the diameter of the largest gear in the engine gear train to the vertical height of the engine gear train is less than 0.25.

[0020] The present application further provides an engine comprising the engine gear train according to any one of the above, further comprising a body, a cylinder head, a crankshaft and a camshaft, the crankshaft penetrates through the body, the cylinder head is located on the body, the camshaft is located above the exhaust side of the cylinder head, and the engine gear train is located at the side of the body and connected with the crankshaft and the camshaft.

[0021] The above technical solution of the present application has the following beneficial effects:

[0022] The engine gear train and the engine of the present application connect the crankshaft rear end gear and the camshaft gear in the engine rear end gear train through multiple rear end intermediate gears, the transmission ratio of the crankshaft rear end gear to the camshaft gear can be 2 to 1 by adjusting the gear tooth ratio of the engine rear end gear train, which can meet the power transmission demand from the crankshaft to the valve through the camshaft; and each engine rear end accessory gear is engaged on a corresponding rear end intermediate gear, so that the power of the crankshaft is transmitted to the camshaft gear through the rear end intermediate gear, and at the same time, the power of the crankshaft is also transmitted to the engine rear end accessory through the rear end intermediate gear, since each engine rear end accessory is driven by a separate rear end intermediate gear, the rear end intermediate gears can be adjusted to adapt to engine accessories of different sizes and models, which improves the adaptability of the engine accessories to the engine gear train and the universality of the engine gear train, and solves the difficulty problem of arranging the engine gear train and the engine accessories. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort based on these drawings.

[0024] Figure 1 The assembly schematic diagram of the engine provided by the embodiment of the present application;

[0025] Figure 2 The structural diagram of the engine gear train provided by the embodiment of the present application.

[0026] Reference signs:

[0027] 1, oil pump intermediate gear; 2, oil pump gear; 3, crankshaft front end gear; 4, engine body; 5, fuel pump; 6, air compressor; 7, air compressor gear; 8, crankshaft rear end gear; 9, air compressor intermediate gear; 10, fuel pump intermediate gear; 11, fuel pump gear; 12, first intermediate gear; 13, second intermediate gear; 14, third intermediate gear; 15, camshaft gear; 16, camshaft; 17, crankshaft; 100, engine front end gear train; 200, engine rear end gear train. DETAILED DESCRIPTION

[0028] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0029] Referring to Figure 1 The present application provides an engine, comprising a block 4, a cylinder head, a crankshaft, a camshaft 16 and an engine gear train. The crankshaft penetrates the block 4, the cylinder head is located above the block 4, the camshaft 16 is located above the exhaust side of the cylinder head, and the engine gear train is located on the side of the block 4 and connected with the crankshaft and the camshaft 16. The engine of the embodiment can adopt a top camshaft valve mechanism arrangement, and the power of the crankshaft is transmitted to the camshaft through the engine gear train to realize the top camshaft, so as to reduce the reciprocating inertia force of the engine.

[0030] Referring to Figure 1 and Figure 2 The engine gear train can play the role of camshaft timing and drive engine accessories. Specifically, the engine gear train comprises an engine front end gear train 100 and an engine rear end gear train 200. The engine front end gear train 100 is located on the engine fan side, and the engine rear end gear train 200 is located on the engine flywheel side.

[0031] The engine rear end gear train 200 comprises a crankshaft rear end gear 8, a camshaft gear 15 and a plurality of rear end intermediate gears (9, 10, 12, 13, 14). The crankshaft 17 penetrates the entire block 4, the crankshaft rear end gear 8 is fixedly connected to the rear end of the crankshaft 17, the camshaft gear 15 is fixedly connected to the rear end of the camshaft 16, the crankshaft rear end gear 8 is meshed with the camshaft gear 15 through the plurality of rear end intermediate gears, and the camshaft gear 15 is located at one end of the engine rear end gear train 200 close to the cylinder head of the engine. The crankshaft rear end gear 8 is the driving gear of the engine rear end gear train 200, and the rotating speed thereof is the same as that of the crankshaft 17.

[0032] A plurality of engine accessories can be provided on the engine, including but not limited to fuel pump, air compressor, water pump, oil pump, and rear power take-off device, etc. In the embodiment, the plurality of engine accessories includes at least two rear-end engine accessories located at the rear end of the engine. The rear-end engine gear train 200 further includes a rear-end engine accessory gear connected with the drive shaft of each rear-end engine accessory, each of which is engaged with a rear-end intermediate gear. The rear-end crank gear 8 transmits the power of the engine crankshaft 17 to the rear-end engine accessories and the camshaft gear 15 through the rear-end intermediate gears, and the transmission ratio of the rear-end crank gear 8 to the camshaft gear 15 is 2 to 1 by adjusting the gear tooth ratio of the rear-end gear train, so as to meet the power transmission requirement from the crankshaft 17 to the camshaft 16 to the valve.

[0033] Since each rear-end engine accessory is driven by a separate rear-end intermediate gear, the rear-end intermediate gears can be adjusted to adapt to engine accessories of different sizes and models, thereby improving the adaptability of the engine accessories to the engine gear train and the universality of the engine gear train, and solving the arrangement difficulty of the engine gear train and the engine accessories.

[0034] In an embodiment, the rear-end engine accessories include an air compressor 6 and a fuel pump 5, which are arranged at the rear end of the engine body 4. The rear-end engine accessory gears include an air compressor gear 7 and a fuel pump gear 11, and the rear-end intermediate gears include an air compressor intermediate gear 9 and a fuel pump intermediate gear 10.

[0035] The air compressor gear 7 is fixedly connected with the drive shaft of the air compressor 6, and is engaged with the rear-end crank gear 8 through the air compressor intermediate gear 9. The rear-end crank gear 8 drives the air compressor gear 7 to rotate through the air compressor intermediate gear 9, thereby driving the air compressor 6 to work. At the same time, the rear-end crank gear 8 also transmits the power of the crankshaft 17 to the side of the camshaft 16 through the air compressor intermediate gear 9.

[0036] The fuel pump gear 11 is fixedly connected with the drive shaft of the fuel pump 5, and is engaged with the rear-end crank gear 8 through the fuel pump intermediate gear 10 and the air compressor intermediate gear 9 in sequence. The rear-end crank gear 8 drives the fuel pump gear 11 to rotate through the air compressor intermediate gear 9 and the fuel pump intermediate gear 10, thereby driving the fuel pump 5 to work. At the same time, the rear-end crank gear 8 also transmits the power of the crankshaft 17 to the side of the camshaft 16 through the air compressor intermediate gear 9 and the fuel pump intermediate gear 10.

[0037] The air compressor intermediate gear 9 and the fuel pump intermediate gear 10 are intermediate gears of the entire engine rear end gear train 200, and are driving gears of the air compressor 6 and the fuel pump 5 respectively. In this way, the function of the rear end intermediate gear is increased, that is, the rear end intermediate gear is used to drive the engine rear end accessories while realizing the adjustment of the transmission ratio from the crankshaft rear end gear to the camshaft gear, so that the number of gears in the entire gear train is reduced. In addition, the size or the number of teeth of the air compressor intermediate gear 9 and the fuel pump intermediate gear 10 can be adjusted to adapt to different sizes of engine accessories.

[0038] Further, the plurality of rear end intermediate gears includes at least one pair of coaxially arranged double gears, and the double gears are composed of any two of the plurality of rear end intermediate gears. Here, taking the plurality of rear end intermediate gears including a pair of double gears as an example, the crankshaft rear end gear 8 is meshed with one of the rear end intermediate gears of the double gears, and the camshaft gear 15 is meshed with the other of the rear end intermediate gears of the double gears.

[0039] Specifically, the plurality of rear end intermediate gears further includes a first intermediate gear 12, a second intermediate gear 13 and a third intermediate gear 14, and the first intermediate gear 12 and the fuel pump intermediate gear 10 are coaxially arranged to form a double gear. The first intermediate gear 12 is meshed with the camshaft gear 15 through the second intermediate gear 13 and the third intermediate gear 14 in sequence, so as to transmit the power output by the crankshaft 17 to the camshaft 16. The crankshaft rear end gear 8, the air compressor intermediate gear 9, the air compressor gear 7, the fuel pump intermediate gear 10 and the fuel pump gear 11 are meshed, so as to transmit the power output by the crankshaft rear end gear 8.

[0040] The air compressor intermediate gear 9, the fuel pump intermediate gear 10, the first intermediate gear 12, the second intermediate gear 13 and the third intermediate gear 14 are intermediate gears of the engine rear end gear train 200, and the crankshaft rear end gear 8 can transmit the power of the crankshaft 17 to the camshaft 16 through the air compressor intermediate gear 9, the fuel pump intermediate gear 10, the first intermediate gear 12, the second intermediate gear 13, the third intermediate gear 14 and the camshaft gear 15 in sequence. The design of the double gear can reduce the size of the gear train in the vertical direction, and is conducive to realizing the driving of each engine rear end accessory by a separate gear.

[0041] The transmission ratio of 2:1 from the crankshaft rear end gear 8 to the camshaft gear 15 is achieved by adjusting the gear tooth ratio of the engine rear end gear train 200. For example, the gear tooth ratio of the fuel pump intermediate gear 10 to the first intermediate gear 12 is adjusted to be 2:1, the gear tooth ratio of the crankshaft rear end gear 8 to the camshaft gear 15 is adjusted to be 1:1, and the gear tooth ratio of the rest of the rear end intermediate gears to the crankshaft rear end gear 8 or the camshaft gear 15 is adjusted to be 1:1, so that the transmission ratio from the crankshaft rear end gear 8 to the camshaft gear 15 is 2:1. Alternatively, the gear tooth ratio of the first intermediate gear 12 to the camshaft gear 15 is adjusted to be 1:1, the gear tooth ratio of the fuel pump intermediate gear 10 to the crankshaft rear end gear 8 is adjusted to be 2:1, and the gear tooth ratio of the rest of the rear end intermediate gears to the camshaft gear 15 is adjusted to be 1:1, so that the transmission ratio from the crankshaft rear end gear 8 to the camshaft gear 15 is also 2:1. In this way, the size of the crankshaft rear end gear 8 and the camshaft gear 15 can be reduced, and there is no need to make the size of the two gears be 1:2, which is beneficial to the small size design of the entire gear train.

[0042] Of course, the gear tooth ratio adjustment scheme is not limited to the above two, and a multi-stage gradient method can also be used to gradually achieve the adjustment of the transmission ratio, as long as the final transmission ratio from the crankshaft rear end gear 8 to the camshaft gear 15 is 2:1.

[0043] It can be understood that the double gear can be arranged at any one of the air compressor intermediate gear 9, the fuel pump intermediate gear 10, the first intermediate gear 12, the second intermediate gear 13, or the third intermediate gear 14, and the double gear can be combined by any two gears of the air compressor intermediate gear 9, the fuel pump intermediate gear 10, the first intermediate gear 12, the second intermediate gear 13, and the third intermediate gear 14. The number of double gears can be one pair, two pairs, or more pairs, which is not limited here.

[0044] Please continue to refer to Figure 1 and Figure 2 , the engine front end gear train 100 is located at the engine fan side, and the engine includes at least one engine front end accessory located at the front end of the engine, and the engine front end accessory includes any one or more than one of the engine accessories described above. The engine front end gear train 100 includes a crankshaft front end gear 3, an engine front end accessory gear, and a front end intermediate gear. The engine front end accessory gear is connected to the transmission shaft of the engine front end accessory one by one, each engine front end accessory gear is engaged with a front end intermediate gear one by one, and the engine front end accessory gear is engaged with the crankshaft front end gear 3 through the front end intermediate gear.

[0045] In one embodiment, the engine front-end accessory includes an oil pump. The engine front-end gear system 100 includes an oil pump gear 2 and an oil pump intermediate gear 1. The oil pump gear 2 is fixedly connected to the drive shaft of the oil pump, and meshes with the crankshaft front-end gear 3 through the oil pump intermediate gear 1. The crankshaft front-end gear 3 is the driving gear in the engine front-end gear system 100, and its rotational speed is the same as that of the crankshaft 17. The crankshaft front-end gear 3 transmits the power of the crankshaft 17 to the oil pump gear 2 through the oil pump intermediate gear 1. The oil pump gear 2 drives the oil pump to deliver oil from the oil pan to the entire engine.

[0046] Of course, in other embodiments, the intermediate gear 1 of the oil pump may not be provided, that is, the front gear 3 of the crankshaft directly meshes with the oil pump gear 2.

[0047] In one embodiment, all gears in the engine front gear train 100 and / or engine rear gear train 200 are involute spur gears, and the number of teeth between meshing gears is coprime. Involute spur gears have a constant transmission ratio characteristic, and gears with coprime teeth can maintain higher precision and stability during meshing, thereby reducing transmission errors and further enhancing the constant transmission ratio characteristic, enabling the gear train to transmit torque and speed more accurately. Furthermore, when the number of teeth of two meshing gears is coprime, each tooth of one gear meshes with each tooth of the mating gear, thus avoiding the occurrence of fixed wear points. Because wear is evenly distributed across each tooth, the wear degree of a single tooth is significantly reduced, thereby extending the life of the entire gear train.

[0048] In one embodiment, the gear ratio between the two meshing gears is between 0.60 and 1.62.

[0049] In one embodiment, all gears in the engine front gear train 100 and / or engine rear gear train 200 are helical gears or V-type gears, and the gear arrangement can all be modified gears.

[0050] In one embodiment, the front gear train 100 and the rear gear train 200 of the engine have the same gear module, pressure angle and helix angle.

[0051] In addition, the engine of the present invention, while satisfying the requirements of an overhead camshaft in the engine valve train and a crankshaft-camshaft transmission ratio of 2:1, can also achieve a small-size design of the engine gear system because it does not require the size ratio of the crankshaft rear gear to the camshaft gear to be 1:2.

[0052] In one embodiment, the ratio of the diameter of the largest gear in the engine gear train to the vertical height of the engine gear train is less than 0.25.

[0053] Further, the ratio of the diameter of the largest gear in the front end gear train of the engine to the vertical height of the front end gear train of the engine is less than 0.25, and / or the ratio of the diameter of the largest gear in the rear end gear train of the engine to the vertical height of the rear end gear train of the engine is less than 0.25.

[0054] In addition, each engine accessory of the engine of the present application is driven by a separate intermediate gear, and the engine accessories of different sizes and models can be adapted by adjusting the size and position of the intermediate gears, so as to improve the adaptability of the engine accessories to the engine gear train and the universality of the engine gear train, meet the engine overall arrangement adjustment upgrade space, and solve the arrangement difficulty of the engine gear train and the engine accessories. The engine of the present application has higher rotating speed, smaller reciprocating inertia force and higher transmission efficiency.

[0055] As shown in Figure 2 The present application also provides an engine gear train, which is applied to an engine, and can be applied to a single overhead camshaft engine or a double overhead camshaft engine. The engine gear train of the present application is described above, and will not be described here.

[0056] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application. Various changes or deformations based on the principles and ideas of the present application, such as changing the gear shift coefficient to reduce the number of teeth to achieve the purpose of optimizing the size of the gear set, or changing the number of intermediate gears to achieve the purpose of transmission effect, are all within the protection scope of the present application.

Claims

1. An engine gear train, characterized by, The engine rear end gear train includes a crankshaft rear end gear, a camshaft gear and a plurality of rear end intermediate gears, the crankshaft rear end gear is engaged with the camshaft gear through the plurality of rear end intermediate gears; The engine includes at least two engine rear end accessories, the engine rear end gear train further includes engine rear end accessory gears connected with drive shafts of the engine rear end accessories, each of the engine rear end accessory gears is engaged with one of the rear end intermediate gears one by one, the crankshaft rear end gear transmits power of the engine crankshaft to the engine rear end accessories and the camshaft gear through the rear end intermediate gears, and a transmission ratio of the crankshaft rear end gear to the camshaft gear is 2 to 1 by adjusting gear tooth number ratios of the engine rear end gear train; The engine rear end accessories include an air compressor and a fuel pump, the engine rear end accessory gears include an air compressor gear and a fuel pump gear, and the rear end intermediate gears include an air compressor intermediate gear and a fuel pump intermediate gear; The air compressor gear is connected with a drive shaft of the air compressor, and the air compressor gear is engaged with the crankshaft rear end gear through the air compressor intermediate gear; the fuel pump gear is connected with a drive shaft of the fuel pump, and the fuel pump gear is engaged with the crankshaft rear end gear through the fuel pump intermediate gear and the air compressor intermediate gear one by one; A ratio of a diameter of a largest gear in the engine gear train to a vertical height of the engine gear train is less than 0.

25.

2. The engine gear train of claim 1, wherein, The plurality of rear end intermediate gears includes at least a pair of coaxial double gears, the double gears are composed of any two of the plurality of rear end intermediate gears, the crankshaft rear end gear is engaged with one of the double gears, and the camshaft gear is engaged with the other of the double gears.

3. The engine gear train of claim 2, wherein, The plurality of rear end intermediate gears further includes a first intermediate gear, a second intermediate gear and a third intermediate gear, the first intermediate gear and the fuel pump intermediate gear are coaxially arranged to form the double gears, and the first intermediate gear is engaged with the camshaft gear through the second intermediate gear and the third intermediate gear one by one.

4. The engine gear train of claim 3, wherein, A gear tooth number ratio of the fuel pump intermediate gear to the first intermediate gear is 2 to 1, and a gear tooth number ratio of the crankshaft rear end gear to the camshaft gear is 1 to 1; Alternatively, a gear tooth number ratio of the first intermediate gear to the camshaft gear is 1 to 1, and a gear tooth number ratio of the fuel pump intermediate gear to the crankshaft rear end gear is 2 to 1.

5. The engine gear train of claim 1, wherein, The camshaft gear is connected with a camshaft of the engine, and the camshaft gear is located at one end of the engine rear end gear train close to a cylinder head of the engine.

6. The engine gear train of claim 1, wherein, The engine further includes an engine front end gear train, the engine front end gear train is located at an engine fan side, and the engine includes at least one engine front end accessory. The engine front end gear train comprises a crankshaft front end gear, engine front end accessory gears and front end intermediate gears, the engine front end accessory gears are connected one by one with driving shafts of the engine front end accessories, each of the engine front end accessory gears is engaged one by one on a front end intermediate gear, and the engine front end accessory gears are engaged with the crankshaft front end gear through the front end intermediate gears.

7. The engine gear train of claim 6, wherein, All gears in the engine front end gear train and the engine rear end gear train are involute spur gears, and the number of teeth between two gears engaged with each other are relatively prime.

8. An engine characterized by, The engine gear train as claimed in any one of claims 1-7, further comprising a block, a cylinder head, a crankshaft and a camshaft, the crankshaft penetrates through the block, the cylinder head is located on the block, the camshaft is located above the cylinder head on the exhaust side, and the engine gear train is located on the side of the block and connected with the crankshaft and the camshaft.

Images