CN112780439A

CN112780439A - Engine and crankcase thereof

Info

Publication number: CN112780439A
Application number: CN202010649836.XA
Authority: CN
Inventors: 不公告发明人
Original assignee: Nine Intelligent Changzhou Tech Co Ltd
Current assignee: Nine Intelligent Changzhou Tech Co Ltd
Priority date: 2019-11-04
Filing date: 2020-07-08
Publication date: 2021-05-11
Also published as: CN212690200U

Abstract

The invention discloses an engine and a crankcase thereof, wherein the crankcase comprises: a first case; a second case connected to a lower portion of the first case, the second case and the first case defining a crank chamber and a crank hole, the crank chamber communicating with the crank hole, the crank hole being formed at one end of the first case and the second case; an oil pan connected to a lower portion of the second case; and the side cover is connected to the other ends of the first box body and the second box body. From this, through rationally setting up first box and second box, can make things convenient for the bent axle to stretch out crankcase and rotor cooperation to can be applicable to and increase form power assembly, overall structure arranges rationally moreover, and structural reliability is high.

Description

Engine and crankcase thereof

Technical Field

The invention relates to the technical field of engines, in particular to an engine and a crankcase thereof.

Background

In the related art, all terrain vehicles are generally driven by a single power source, which is typically a fuel powered engine. Wherein, the all-terrain vehicle generally has insufficient power under the working condition of low rotating speed of an engine; meanwhile, because the engine needs to participate in working under all working conditions, the mixed gas is not fully combusted in the process of changing the working conditions at low rotating speed, the heat efficiency is low, the fuel consumption is high, the content of harmful gas in tail gas is high, and the structure of the engine also restricts the application of the engine to all-terrain vehicles.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. To this end, it is an object of the invention to provide a crankcase which can be adapted to an extended range power unit, which can improve the engine, and which can reduce the emission of harmful gases.

The invention further provides an engine.

The crankcase according to the invention comprises: a first case; a second case connected to a lower portion of the first case, the second case and the first case defining a crank chamber and a crank hole, the crank chamber communicating with the crank hole, the crank hole being formed at one end of the first case and the second case; an oil pan connected to a lower portion of the second case; and the side cover is connected to the other ends of the first box body and the second box body.

Therefore, according to the crankcase provided by the embodiment of the invention, the first box body and the second box body are reasonably arranged, so that the crankshaft can conveniently extend out of the crankcase to be matched with the rotor, the crankcase can be suitable for a range-extending power assembly, and the crankcase is reasonable in overall structural arrangement and high in structural reliability.

In some examples of the present invention, a plurality of first shaft holes are formed in a lower side of the first casing, a plurality of second shaft holes are formed in an upper side of the second casing, and the plurality of first shaft holes correspond to the plurality of second shaft holes one to be suitable for mounting a crankshaft.

In some examples of the present invention, a plurality of third shaft holes are formed in a lower side of the first casing, a plurality of fourth shaft holes are formed in an upper side of the second casing, and the plurality of third shaft holes correspond to the plurality of fourth shaft holes one to be suitable for mounting a balance shaft.

In some examples of the invention, the first shaft hole, the second shaft hole, the third shaft hole and the fourth shaft hole are all semi-circular holes.

In some examples of the present invention, oil grooves are provided inside the first shaft hole, the second shaft hole, the third shaft hole, and the fourth shaft hole.

In some examples of the invention, the crankcase further comprises: the first box cover is connected to one side of the first box body, and a first containing cavity is formed between the first box cover and the first box body.

In some examples of the present invention, the first cover is disposed to be inclined with respect to a mounting plane of the first case with respect to a coupling plane of the first case and the second case.

In some examples of the invention, the crankcase further comprises: the second box cover is connected to one side of the second box body, a second containing cavity is formed between the second box cover and the second box body, and the second containing cavity is communicated with the first containing cavity.

In some examples of the present invention, the second cover is disposed perpendicular to a mounting plane of the second case with respect to a coupling plane of the first case and the second case.

In some examples of the present invention, the first casing is provided with at least two through holes, and the two through holes communicate with the crank chamber.

In some examples of the present invention, at least one of the first case and the second case may be provided at one end of the crank hole with a stopper for stopping the motor.

An engine according to the present invention includes: the crankcase.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic illustration of an extended range power assembly according to an embodiment of the present disclosure;

FIG. 2 is an exploded view of the engine;

FIG. 3 is an exploded view of an extended range powertrain at a generator according to an embodiment of the present invention;

FIG. 4 is an exploded view of the generator;

FIG. 5 is a cross-sectional view of the motor mounting cover, motor casing and motor cover;

FIG. 6 is an exploded view of the crankcase;

FIG. 7 is an exploded view of the crankcase;

FIG. 8 is a schematic view of an oil pan and a propeller shaft;

FIG. 9 is a schematic view of an oil pan;

FIG. 10 is a schematic view of an oil pan;

fig. 11 is an exploded view of the crankcase.

Reference numerals:

a range-extending power assembly 1000;

an engine 100; a crankshaft 10; an outer conical surface 11;

a crankcase 20; a first case 21; a first shaft hole 21 a; the third shaft hole 21 b;

a second case 22; the second shaft hole 22 a; a fourth shaft hole 22 b;

an oil pan 23; a bottom wall 23 a; side walls 23 b; an avoidance zone 23 c; an oil guide portion 23 d; an oil guiding rib 23 e; a blocking cover 23 f;

a side cover 24; a first cover 25; a second cover 26; a sixth stopper 27;

a cylinder block 30; a piston linkage 40;

a generator 200; a motor mounting cover 210; a receiving groove 211; a first limiting portion 212; a fifth stopper 213;

a motor case 220; a housing hole 221; a second limiting portion 222; a third stopper 223; an inlet port 224; a liquid outlet 225;

a motor cover 230; a fourth stopper 231; a stator 240; a rotor 250; a box cover 260;

a drive shaft 300.

Detailed Description

Embodiments of the present invention will be described in detail below, the embodiments described with reference to the drawings being illustrative, and the embodiments of the present invention will be described in detail below.

Referring now to fig. 1-11, a range-extended powertrain 1000 in accordance with an embodiment of the present invention is described, the range-extended powertrain 1000 being utilized in an all-terrain vehicle.

As shown in fig. 1, an extended range powertrain 1000 according to an embodiment of the present invention may include: engine 100 and generator 200, generator 200 is disposed on one axial side of engine 100, for example, generator 200 is disposed on the right side of engine 100. The power of the engine 100 and the power of the generator 200 are transmitted, the engine 100 drives the generator 200 to work, the generator 200 can generate electric energy, the generator 200 is connected with a power battery and a motor of the all-terrain vehicle, and the power battery is connected with the motor, so that the electric energy of the generator 200 can be supplied to the motor, and the all-terrain vehicle can be driven to move.

Therefore, the range-extending power assembly 1000 composed of the engine 100 and the generator 200 can convert the power generated by the engine 100 into electric energy and supply the electric energy to the motor, so that the endurance mileage of the all-terrain vehicle can be effectively increased, the problem of insufficient power can be solved, and the range-extending power assembly 1000 is small in size, small in occupied space and better in integrity as the generator 200 is arranged on one side of the engine 100. It should be noted that the engine 100 in the extended range power assembly 1000 can ensure continuous normal operation, thereby improving energy efficiency, reducing energy waste, and reducing harmful gas emission.

As shown in fig. 2, the engine 100 includes a crankshaft 10 and a crankcase 20, the crankshaft 10 is mounted on the crankcase 20, and an axial end (i.e., a right axial end) of the crankshaft 10 extends out of the crankcase 20, and the axial end of the crankshaft 10 can facilitate power transmission between the engine 100 and the generator 200.

As shown in fig. 3 and 4, the generator 200 includes: motor mounting cover 210 is mounted on one side of crankcase 20, motor housing 220 is mounted between motor mounting cover 210 and motor cover 230, stator 240 is fixed in motor housing 220, rotor 250 is arranged on the inner periphery of stator 240, rotor 250 can rotate relative to stator 240, and rotor 250 is in transmission with the shaft end of crankshaft 10. That is, the shaft end of the crankshaft 10 substantially passes through the motor mounting cap 210 to be engaged with the rotor 250, and then rotates the rotor 250 to generate electricity. This way, the integration of the engine 100 and the motor 200 is high, and the transmission efficiency is high.

Therefore, the generator 200 can be firmly installed on one side of the crankcase 20 by arranging the motor installation cover 210, the volume of the extended range power assembly 1000 can be further reduced, and the stator 240 and the rotor 250 can be reasonably installed by arranging the motor installation cover 210, the motor casing 220 and the motor cover 230, the installation reliability of the stator 240 and the rotor 250 can be ensured, and the transmission reliability of the shaft end of the crankshaft 10 and the rotor 250 can be ensured.

According to an alternative embodiment of the present invention, the rotor 250 is formed with a rotor hole through which the shaft end of the crankshaft 10 passes, and the shaft end of the crankshaft 10 is driven with the rotor 250. That is to say, the rotor 250 is sleeved on the shaft end of the crankshaft 10, and then the rotor and the crankshaft are sleeved and matched, so that the synchronous rotation can be better ensured, the power transmission between the engine 100 and the generator 200 can be realized, and the power transmission stability between the engine 100 and the generator 200 can be ensured.

Alternatively, the rotor 250 may be formed with internal splines at the rotor bore and the shaft end of the crankshaft 10 may be formed with external splines that mate with the external splines. The matching of the internal spline and the external spline is simple and reliable and is easy to implement.

Alternatively, as shown in fig. 3 and 4, the rotor hole is formed with an inner tapered surface, and the shaft end of the crankshaft 10 is formed with an outer tapered surface 11, the inner tapered surface and the outer tapered surface 11 being engaged with each other. The inner and outer

conical surfaces

11 and 11 can be fitted against each other, so that the rotor 250 can be firmly mounted on the shaft end, and the reliability and the transmission stability of the two can be ensured.

Specifically, as shown in fig. 3 and 4, the motor case 220 is formed with a receiving hole 221, the motor mounting cover 210 and the motor cover 230 are formed with a receiving groove 211 facing the motor case 220, and the stator 240 is received in the receiving hole 221 and the two receiving grooves 211. That is, the middle portion of the stator 240 is accommodated in the accommodating hole 221, and both sides of the stator 240 are respectively accommodated in the corresponding accommodating grooves 211, so that the stator 240 can be effectively accommodated, the installation reliability of the stator 240 can be ensured, and the axial size of the motor casing 220 can be reduced.

Optionally, the receiving hole 221 is interference fit with the stator 240. The interference fit mode is simple and reliable, so that the installation reliability of the stator 240 in the motor casing 220 can be ensured.

According to an embodiment of the present invention, as shown in fig. 5, the motor mounting cover 210 is provided with a first limiting portion 212, two sides of the motor casing 220 are provided with a second limiting portion 222 and a third limiting portion 223, the motor cover 230 is provided with a fourth limiting portion 231, the first limiting portion 212 is in limiting fit with the second limiting portion 222, and the third limiting portion 223 is in limiting fit with the fourth limiting portion 231. The first limiting part 212 and the second limiting part 222 can play a role in limiting the motor mounting cover 210 and the motor casing 220 in advance, can reduce the mounting difficulty of the generator 200, and can improve the mounting reliability between the motor mounting cover 210 and the motor casing 220. The third limiting part 223 and the fourth limiting part 231 can play a role in limiting the motor casing 220 and the motor cover 230 in advance, the installation difficulty of the generator 200 can be reduced, and the installation reliability between the motor casing 220 and the motor cover 230 can be improved.

As shown in fig. 5, one of the first and second position-limiting

portions

212, 222 is a convex position-limiting ring and the other is a concave position-limiting groove, and one of the third and fourth position-limiting

portions

223, 231 is a convex position-limiting ring and the other is a concave position-limiting groove. For example, the first limiting portion 212 and the fourth limiting portion 231 are both limiting rings, and the second limiting portion 222 and the third limiting portion 223 are both limiting grooves, so that the manufacturing difficulty of the motor casing 220 can be reduced to at least a certain extent. Through the cooperation of spacing groove and spacing ring, can improve generator 200's structural reliability to and can reduce generator 200's the installation degree of difficulty.

As shown in fig. 5 and 11, the motor mounting cover 210 is provided with a fifth limiting portion 213, the crankcase 20 is provided with a sixth limiting portion 27, and the fifth limiting portion 213 is in limiting fit with the sixth limiting portion 27. The fifth stopper 213 and the sixth stopper 27 may serve to pre-stopper the motor mounting cover 210 and the crankcase 20, may reduce the difficulty of mounting the generator 200, and may improve the reliability of mounting the motor mounting cover 210 and the crankcase 20.

As shown in fig. 5 and 11, one of the fifth limiting portion 213 and the sixth limiting portion 27 is a convex limiting ring and the other is a concave limiting groove. For example, the fifth position-limiting portion 213 may be a position-limiting groove, and the sixth position-limiting portion 27 may be a position-limiting ring. The motor mounting cover 210 may be provided with a through hole for the shaft end of the crankshaft 10 to pass through, the through hole may be provided with a bearing, and the limit ring is disposed around the bearing.

Alternatively, as shown in fig. 3 and 4, an outlet terminal is connected to the stator 240, a portion of the motor cover 230 protrudes away from the motor casing 220 to form a receiving space for receiving the outlet terminal, and the generator 200 further includes: the box cover 260, the box cover 260 is covered on the accommodation space. Therefore, the generator 200 can effectively solve the problem of arrangement of the outlet end, and only the box cover 260 needs to be added, so that the manufacturing difficulty of the generator 200 can be simplified. A gasket may be provided between the cover 260 and the motor cover 230.

Specifically, as shown in fig. 4, a liquid cooling channel is formed in the motor casing 220, and the motor casing 220 is further provided with a liquid inlet 224 and a liquid outlet 225 which are communicated with the liquid cooling channel. That is to say, the cooling liquid can flow in the motor casing 220, and the heat that the generator 200 during operation produced can be taken away to the cooling liquid that sets up in cooling channel to can effectively reduce the temperature of generator 200, can make the temperature of generator 200 keep in reasonable operating temperature interval.

Alternatively, the motor mounting cover 210 may be detachably mounted at one side of the crank case 20, the motor housing 220 may be detachably mounted at one side of the motor mounting cover 210, and the motor cover 230 may be detachably mounted at one side of the motor housing 220. The detachable mode can adopt the fastener fixed connection. The generator 200 thus arranged is simple in structure and convenient to install, so that the installation difficulty of the generator 200 can be reduced, and subsequent maintenance can be facilitated.

As shown in fig. 4, the engine 100 may further include: the cylinder block 30 is disposed at an upper portion of the crankcase 20, the cylinder block 30 has two cylinders, pistons of the two piston linkages 40 are disposed in the two cylinders, and connecting rods are connected to the crankshaft 10.

The crankcase 20 of the engine 100 according to the embodiment of the invention will be described in detail below with reference to the drawings.

As shown in fig. 6, 7 and 11, the crankcase 20 according to an embodiment of the invention may include: the crankcase includes a first case 21, a second case 22, an oil pan 23, and a side cover 24, the second case 22 being connected to a lower portion of the first case 21, the second case 22 and the first case 21 defining a crank chamber and a crank hole, the crank chamber being communicated with the crank hole, the crank hole being formed at one end of the first case 21 and the second case 22, the oil pan 23 being connected to a lower portion of the second case 22, and the side cover 24 being connected to the other end of the first case 21 and the second case 22. The first casing 21 and the second casing 22 are vertically matched, so that the first casing 21 and the second casing 22 can define a crankshaft cavity, the crankshaft 10 can be accommodated in the crankshaft cavity, and the shaft end of the crankshaft 10 can extend out of the crankshaft cavity through a crankshaft hole and then extend into the generator 200 to be matched with the rotor 250, wherein a bearing or a bearing bush can be arranged at the crankshaft hole, so that the rotational stability of the crankshaft 10 can be ensured. The edge cover 24 may serve as a cover, so that structural reliability of the crankcase 20 may be further improved.

Therefore, according to the crankcase 20 of the embodiment of the invention, by reasonably arranging the first case 21 and the second case 22, the crankshaft 10 can conveniently extend out of the crankcase 20 to be matched with the rotor 250, so that the crankcase is suitable for the extended range power assembly 1000, and the overall structure is reasonable in arrangement and high in structural reliability.

As shown in fig. 6 and 7, a plurality of first shaft holes 21a are formed in a lower side of the first casing 21, a plurality of second shaft holes 22a are formed in an upper side of the second casing 22, and the plurality of first shaft holes 21a and the plurality of second shaft holes 22a are in one-to-one correspondence to be suitable for mounting the crankshaft 10. That is, the first shaft hole 21a of the first casing 21 and the second shaft hole 22a of the second casing 22 cooperate with the crankshaft 10, so that the installation and arrangement of the crankshaft 10 can be facilitated, and the difficulty in the arrangement of the first casing 21 and the second casing 22 can be reduced.

Further, as shown in fig. 6 and 7, a plurality of third shaft holes 21b are formed at a lower side of the first casing 21, a plurality of fourth shaft holes 22b are formed at an upper side of the second casing 22, and the plurality of third shaft holes 21b correspond to the plurality of fourth shaft holes 22b one to be suitable for mounting the balance shaft. The third shaft holes 21b and the first shaft holes 21a are arranged at intervals on the lower side of the first box 21, the second shaft holes 22a and the fourth shaft holes 22b are arranged at intervals on the upper side of the second box 22, the first box 21 and the second box 22 which are arranged in this way can also contain balance shafts, the balance shafts are in transmission with the crankshaft 10, and the balance shafts can be used for balancing reciprocating inertia force generated when the piston connecting rod group 40 moves, so that the running smoothness of the engine 100 can be improved.

Specifically, as shown in fig. 6 and 7, the first shaft hole 21a, the second shaft hole 22a, the third shaft hole 21b, and the fourth shaft hole 22b may all be semicircular holes. The semicircular holes are easy to design and manufacture, and the shaft holes with the shapes are easy to support the crankshaft 10 and the balance shaft, and can also facilitate the installation and arrangement of the bearings and the bearing bushes.

Optionally, oil grooves are disposed inside the first shaft hole 21a, the second shaft hole 22a, the third shaft hole 21b and the fourth shaft hole 22 b. The interior flow of oil groove has lubricating oil, and bearing or axle bush can communicate with the oil groove, and lubricating oil can effectively lubricate the contact surface of bent axle 10 and balanced axle like this, can reduce the wearing and tearing of bent axle 10 and balanced axle, can prolong the life of bent axle 10 and balanced axle, can improve the reliability of bent axle 10 and balanced axle.

According to an alternative embodiment of the invention, as shown in fig. 6, the crankcase 20 further comprises: the first box cover 25 is connected to one side of the first box 21, and a first accommodating cavity is formed between the first box cover 25 and the first box 21. The first accommodating cavity can play an accommodating role, the structure of the crankcase 20 can be changed, and the overall layout of the crankcase 20 can be more reasonable.

As shown in fig. 6, the first cover 25 is disposed to be inclined with respect to a coupling plane of the first casing 21 and the second casing 22 with respect to a mounting plane of the first casing 21. The first cover 25 thus configured can effectively adapt to the surface of the first box 21, and can ensure the installation reliability on the surface of the first box 21, and the first cover 25 and the first box 21 can be fixedly connected by fasteners.

Further, as shown in fig. 6, the crankcase 20 may further include: and the second box cover 26 is connected to one side of the second box body 22, a second accommodating cavity is formed between the second box cover 26 and the second box body 22, and the second accommodating cavity is communicated with the first accommodating cavity. The second accommodating cavity can play an accommodating role, the structure of the crankcase 20 can be changed, and the overall layout of the crankcase 20 can be more reasonable.

As shown in fig. 6 and 11, the second cover 26 is disposed perpendicular to the mounting plane of the second casing 22 with respect to the joint plane of the first casing 21 and the second casing 22. The second cover 26 is configured to effectively conform to the surface of the second housing 22, so as to ensure the reliability of the installation on the surface of the second housing 22, and the second cover 26 and the second housing 22 can be fixedly connected by fasteners.

Optionally, the first case 21 is provided with at least two through holes, which communicate with the crank chamber. The two through holes may correspond to two cylinders of the cylinder block 30, or correspond to two piston connecting rod sets 40, that is, the crankcase 20 thus configured may be suitable for a two-cylinder engine 100, so as to improve the power performance of the engine 100, and may enable the power generation efficiency of the generator 200 to be high.

Specifically, at least one of the first case 21 and the second case 22 is provided with a stopper portion for stopping the generator 200 at one side of the crank hole. The first case 21 and the second case 22 thus provided with the stopper, i.e., the above-described sixth stopper 27, can ensure the mounting reliability of the generator 200.

The oil pan 23 of the crankcase 20 according to the embodiment of the invention will be described in detail with reference to the drawings.

As shown in fig. 8 to 10, the oil pan 23 according to the embodiment of the invention may include: a bottom wall 23a and a plurality of side walls 23b, the plurality of side walls 23b being connected to different sides of the bottom wall 23a, and the plurality of side walls 23b defining an open oil sump above the bottom wall 23 a. It can be understood that the oil groove is used for containing lubricating oil, the lubricating oil for lubricating the kinematic pair of the engine 100 flows downwards under the action of gravity and finally converges in the oil groove, and the lubricating oil in the oil groove can be supplied upwards in a certain manner, for example, the oil supply manner may be a sputtering manner or a suction manner. Wherein, the adjacent side walls 23b adopt circular arc transition. The circular arc transition can make the transition of the oil pan 23 natural, the structural reliability is high, and the integrity is good.

As shown in fig. 8, at least one side wall 23b is provided with an escape area 23c for escaping the transmission shaft 300. That is to say, be provided with transmission shaft 300 around the diapire 23a of this oil pan 23, dodge district 23c and can effectively dodge transmission shaft 300, can give transmission shaft 300 certain accommodation space to can make all terrain vehicle overall structure rationally distributed, can improve all terrain vehicle's minimum ground clearance moreover to at least a certain extent, can promote all terrain vehicle's trafficability characteristic.

Alternatively, as shown in fig. 8 and 9, the surface of the avoidance zone 23c may be an arcuate surface that is concave toward the inside of the oil groove. The arc-shaped surface can effectively avoid the transmission shaft 300, the manufacturing difficulty of the oil pan 23 can be reduced, and the structural reliability of the oil pan 23 can be improved.

Wherein, as shown in fig. 8, two opposite side walls 23b are each provided with an escape area 23 c. That is to say, two lateral walls 23b of the left and right sides of oil pan 23 all are provided with dodge district 23c, and two transmission shafts 300 set up respectively in the both sides of oil pan 23, and the oil pan 23 that so sets up is overall reasonable in layout, can effectively avoid two transmission shafts 300, can make the overall layout of all-terrain vehicle reasonable moreover.

Alternatively, as shown in fig. 9, each side wall 23b is provided with an oil guide portion 23d extending obliquely from the upper end toward the bottom wall 23 a. The oil guiding portion 23d may be an oil guiding inclined surface, which may be beneficial for the lubricating oil to flow downward to the bottom of the oil pan 23, and may improve the ability of the oil pan 23 to gather the lubricating oil.

Wherein, as shown in fig. 9, an inner surface of each side wall 23b is formed with an oil guiding bead 23 e. Lead oily muscle 23e and can be convex rib, lead the setting up of oily muscle 23e and can play the effect of leading oil on the one hand, on the other hand can improve oil pan 23's structural reliability.

Specifically, as shown in fig. 8 and 9, the bottom wall 23a is formed with an oil drain hole where a cap 23f is provided. When not changing lubricating oil for a long time, the user or maintenance person can open the blanking cover 23f, discharge lubricating oil, and then change lubricating oil, so that the change of lubricating oil can be facilitated, and the performance of the engine 100 can be improved.

Alternatively, as shown in fig. 8 and 10, the cross-sectional area of the oil pan 23 decreases from the opening toward the bottom. That is, the oil pan 23 is constructed in a structure that is tapered from the top to the bottom, and the oil pan 23 thus provided facilitates the collection of the lubricating oil, and may facilitate the lubricating oil to lubricate the kinematic pair again.

The oil pan 23 is an aluminum alloy shell. The aluminum alloy shell has high structural strength and light weight, and the oil pan 23 arranged in the way meets the light weight design target of the all-terrain vehicle.

The all-terrain vehicle comprises the extended range power assembly 1000, a power battery, a motor and a transmission system, wherein the extended range power assembly is connected with the generator 200, the motor is connected with the power battery, and the input end of the transmission system is connected with the motor.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A crankcase, comprising:

a first case;

a second case connected to a lower portion of the first case, the second case and the first case defining a crank chamber and a crank hole, the crank chamber communicating with the crank hole, the crank hole being formed at one end of the first case and the second case;

an oil pan connected to a lower portion of the second case;

and the side cover is connected to the other ends of the first box body and the second box body.

2. The crankcase according to claim 1, wherein a plurality of first shaft holes are formed in a lower side of the first case, and a plurality of second shaft holes are formed in an upper side of the second case, the plurality of first shaft holes corresponding to the plurality of second shaft holes one to be adapted to receive a crankshaft.

3. The crankcase according to claim 2, wherein a plurality of third shaft holes are formed in a lower side of the first case, and a plurality of fourth shaft holes are formed in an upper side of the second case, the plurality of third shaft holes corresponding to the plurality of fourth shaft holes in a one-to-one manner so as to be adapted to mount the balance shaft.

4. The crankcase of claim 3, wherein the first shaft hole, the second shaft hole, the third shaft hole, and the fourth shaft hole are all semi-circular holes.

5. The crankcase of claim 3, wherein oil grooves are disposed in the first shaft hole, the second shaft hole, the third shaft hole, and the fourth shaft hole.

6. The crankcase of claim 1, further comprising: the first box cover is connected to one side of the first box body, and a first containing cavity is formed between the first box cover and the first box body.

7. The crankcase according to claim 6, wherein the first cover is disposed obliquely to a mounting plane of the first case with respect to a joining plane of the first case and the second case.

8. The crankcase of claim 6, further comprising: the second box cover is connected to one side of the second box body, a second containing cavity is formed between the second box cover and the second box body, and the second containing cavity is communicated with the first containing cavity.

9. The crankcase of claim 8, wherein the second cover is disposed perpendicular to a mounting plane of the second case with respect to a joining plane of the first case and the second case.

10. The crankcase according to claim 1, wherein the first case is provided with at least two through holes, and the two through holes communicate with the crank chamber.

11. The crankcase according to claim 1, wherein at least one of the first case and the second case is provided with a stopper portion for stopping the motor at an end of the crank hole.

12. An engine, comprising: the crankcase of any one of claims 1-11.