JP2011075010A - Power unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power unit capable of eliminating agitating resistance of lubricating oil. <P>SOLUTION: The lubricating oil 67 of an oil pan 62 is pumped up by an oil pump 54, is pressurized, and is made to pass through a main lubricating oil passage 58 (arrow (1)), and lubricates a lubricated portion in a cylinder block 25 or a cylinder head 27, and then, is returned to the oil pan 62 (arrow (2)). Simultaneously, a part of the lubricating oil passing through the main lubricating oil passage 58 is branched to a feed oil passage 61 (arrow (3)), and reaches an inside of a reduction gear case 18 from lubricating oil supply ports 65 (arrow (4)), and lubricates tooth tips of gears 47, 48, 49 and 51. After the lubrication, the lubricating oil hardly stays in a bottom of the reduction gear case 18, and goes to a return oil passage 63 from a lubricating oil discharge port 66, and flows down with gravity action (arrow (5)), and is returned to the oil pan 62. In the reduction gear case, the gear 47 or the like is not immersed in an oil sump, and thus the agitating resistance is not generated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power unit including an engine, a speed change mechanism, and a speed reduction mechanism.

  A power unit including an engine, a speed change mechanism that changes the output of the engine, and a speed reduction mechanism that reduces the output of the speed change mechanism and transmits the output to the drive wheel axle has been proposed in various structures (for example, (See Patent Document 1 (FIGS. 2 and 3).)

  FIG. 2 of Patent Document 1 shows a plan sectional view of a power unit (P) (a bracketed symbol or numeral indicates a reference described in Patent Document; the same applies hereinafter), and the power unit (P) is an engine ( 4) and a belt-type continuously variable transmission (5). The output of the engine (4) is shifted by the belt-type continuously variable transmission (5), and the belt-type continuously variable transmission (5) and the rear wheel. After being decelerated by a final reduction gear provided between (Wr) (there is no sign, but a gear reduction mechanism comprising an output shaft gear, an idle gear and an axle gear of the belt type continuously variable transmission (5)). It is transmitted to the rear wheel (Wr).

In the engine (4), it is necessary to lubricate the bearings, and in the final reduction gear, it is necessary to lubricate the gear.
Therefore, as shown in FIG. 3 of Patent Document 1, an oil reservoir (29) is provided in the lower part of the crankcase (6) to collect lubricating oil, and the accumulated oil is oil driven by the crankshaft (10). It is pumped up by the pump (32) and supplied to each part of the engine (4). The supplied lubricating oil lubricates each part and then returns to the oil reservoir (29).

  In FIG. 2 of Patent Document 1, a final reduction gear is shown between the belt type continuously variable transmission (5) and the rear wheel (Wr). Patent Document 1 does not explain the lubrication related to the final reduction gear, but the lower part of the output shaft gear, the idle gear, and the axle gear of the belt-type continuously variable transmission (5) are submerged. Oil reservoir is provided. It can be considered that the lubricating oil pumped up by the gear falls along the ceiling and walls of the transmission case and returns to the oil sump.

  As apparent from FIG. 2 of Patent Document 1, since the engine (4) and the final reduction gear are separated from each other, an oil sump on the crankcase side and an oil sump on the final reduction gear side are provided. In each of these oil reservoirs, the oil level is monitored by an oil level gauge.

Such a power unit (P) of Patent Document 1 has room for improvement in the following points.
First, in the final reduction gear, since a part of the gear is always immersed in the oil reservoir, a resistance force from the lubricating oil acts on the gear and a so-called stirring resistance is generated. This agitation resistance affects fuel consumption.
In addition, the oil level gauge is checked with the oil level gauge in a timely manner, but since there are two oil level gauges, the inspection time tends to be extended. And when replenishing and exchanging lubricating oil, the time for replenishing and exchanging lubricating oil tends to increase.

  There is a demand for a power unit that can eliminate the agitation resistance of the lubricating oil and reduce the time for replenishing and replacing the lubricating oil.

JP 2000-310189 A

  It is an object of the present invention to provide a power unit that can eliminate the stirring resistance of the lubricating oil and can shorten the time for replenishing and replacing the lubricating oil.

The invention according to claim 1 is a power unit comprising an engine, a speed change mechanism that changes the output of the engine, and a gear speed reduction mechanism that reduces the output of the speed change mechanism and transmits it to the drive wheel axle.
A crankcase is provided at one end of the transmission case that houses the transmission mechanism, and a reduction gear case that houses the gear reduction mechanism is provided at the other end,
The crankcase is provided with an oil pan for storing lubricating oil for lubricating the engine, and an oil pump for pumping up the lubricating oil,
The crankcase and the lubricating oil supply port are connected by a feed oil passage, the lubricating oil discharge port and the crankcase are connected by a return oil passage, and the lubricating oil used on the crankcase side and the gear reduction mechanism side are connected. It is characterized in that oil is supplied from the outside of the reduction gear case to the reduction gear case in common with the lubricating oil to be used.

  The invention according to claim 2 is characterized in that the feed oil passage is branched from the main lubricant passage toward the cylinder downstream of the oil pump.

  In the invention according to claim 3, the lubricating oil discharge port is provided at a position higher than the oil level of the lubricating oil accumulated in the oil pan, and the return oil path can return the lubricating oil to the oil pan by gravity. It is characterized by a downward slope toward the oil pan.

  The invention according to claim 4 is characterized in that the lubricating oil supply port is provided above the gear so that the lubricating oil supplied from the lubricating oil supply port directly hits the gear.

  The invention according to claim 5 is characterized in that the feed oil passage and the return oil passage are formed within the thickness of the case of the power unit.

  In the invention according to claim 1, since the speed reducer case is lubricated by a so-called dry sump and the gear is not immersed in the oil reservoir, the stirring resistance is not generated or the stirring resistance is small. As a result, fuel efficiency can be improved.

  Furthermore, the invention according to claim 1 connects the crankcase and the lubricating oil supply port by a feed oil passage, connects the lubricating oil discharge port and the crankcase by a return oil passage, and uses the lubricating oil and gear used on the crankcase side. The lubricant used on the speed reduction mechanism side is shared. Since the lubricating oil used on the crankcase side and the lubricating oil used on the gear reduction mechanism side are shared, the lubricating oil can be checked and replaced only once, reducing the time for checking and replacing the lubricating oil. .

  In the case of a dry sump, it is necessary to provide an oil tank outside the deceleration case. However, according to the present invention, the oil tank can be omitted by substituting the oil pan on the crankcase side. The number of parts can be reduced.

In the invention according to claim 2, the feed oil passage is branched from the main lubricating oil passage toward the cylinder downstream of the oil pump.
In the case of a dry sump, an oil tank is provided outside the deceleration case, and a pump that sends lubricating oil to the oil tank is required. According to the present invention, the oil tank and the oil pump can be omitted by substituting the oil pan and the oil pump on the crankcase side. The number of parts can be reduced and the power unit can be made compact.

  In the invention which concerns on Claim 3, the lubricating oil which reached | attained the bottom of the reduction gear case can be returned to an oil pan by gravity action. A return pump for returning the lubricating oil can be omitted.

  According to the invention which concerns on Claim 4, lubricating oil can be directly applied to a gear, gear lubrication becomes more reliable, and stirring resistance can further be reduced.

  In the invention which concerns on Claim 5, a feed oil path and a return oil path are formed in the thickness of the case of a power unit. The feed oil passage and the return oil passage can be formed by placing a tube along the outside of the case, but according to the present invention, the feed oil passage and the return oil passage are provided in the case. As a result, the protrusion outside the case can be suppressed, and the power unit can be made compact.

It is a plane sectional view of the power unit concerning the present invention. It is 2-2 arrow line view of FIG. FIG. 3 is a view taken along arrow 3-3 in FIG. 1. It is a figure explaining arrangement | positioning of a feed oil path and a return oil path. FIG. 5 is a sectional view taken along line 5-5 of FIG. It is a figure explaining the flow of the lubricating oil in a power unit.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.

Embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the power unit 10 includes an engine 11, a speed change mechanism 12 that changes the output of the engine 11, and a gear speed reduction mechanism 14 that reduces the output of the speed change mechanism 12 and transmits it to the drive wheel axle 13. It consists of.
As shown in the figure, a crankcase 16 that houses the crankshaft 15 of the engine 11, a transmission case 17 that houses the speed change mechanism 12, and a speed reducer case 18 that houses the gear speed reduction mechanism 14 are connected to each other to form a power unit. The case 19 is formed.

  The engine 11 includes a crankcase 16, a crankshaft 15 rotatably supported by the crankcase 16 via bearings 21 and 21, a piston 23 connected to the crankshaft 15 by a connecting rod 22, A cylinder block 25 having a cylinder 24 that movably accommodates the piston 23, a spark plug 26, a cylinder head 27 that closes the cylinder 24, and a head cover 29 that covers a valve mechanism 28 provided on the cylinder head 27. And the main element.

  At one end of the crankshaft 15, a pump drive gear 31 and an outer rotor 33 of an ACG or a generator (generator) 32 are provided. The outer rotor 33 rotates around the inner stator 34. A cooling fan 35 is integrally provided in such an outer rotor 33, and outside air is taken in from an outside air inlet 37 provided in the engine cover 36. The inside of the case 29 of the power unit is forcibly cooled by the outside air taken in by the cooling fan 35.

A drive pulley 41 for the speed change mechanism 12 is provided at the other end of the crankshaft 15. In this example, the speed change mechanism 12 is a belt type continuously variable transmission.
The transmission mechanism 12 is disposed in parallel with the crankshaft 15 and at a distance from the crankshaft 15 so as to be integrally extended from the crankcase 16, and is rotatably supported by the transmission case 17. A driven shaft 42, a driven pulley 43 supported by the driven shaft 42, and an endless belt 44 passed to the driven pulley 43 and the driving pulley 41 are used to change the pulley diameter.

  The transmission case 17 includes a transmission lid 44 and can be divided by removing the bolts 45.

Details of the gear reduction mechanism 14 will be described with reference to FIG.
As shown in FIG. 2, the gear reduction mechanism 14 includes a first gear 47 integrally formed with the driven shaft 42, and a second gear 48 that is driven by the first gear 47 and has a larger diameter than the first gear 47. The third gear 49 that rotates integrally with the second gear 48 and has a smaller diameter than the second gear 48, and the fourth gear 51 that has a larger diameter than the third gear 49 and rotates integrally with the drive wheel axle 13. An idler shaft 52 that is rotatably supported by the speed reducer case 18 and supports the second gear 48 and the third gear 49, and a speed reducer case 18 that accommodates the gears 47, 48, 49, 51 collectively. Consists of. The second gear 48 and the third gear 49 supported by the idle shaft 52 are so-called idle gears.

  When the first gear 47 and the second gear 48 are decelerated at a reduction ratio (R1), and the third gear 49 and the fourth gear 51 are decelerated at a reduction ratio (R2), a drive wheel axle is obtained. 13 is rotated at a low speed rotation obtained by multiplying the rotational speed of the driven shaft 42 by the reduction ratio (R1) and the reduction ratio (R2).

Next, the oil pump will be described with reference to FIG.
As shown in FIG. 3, the cylinder shaft 53 extends from the crankshaft 15 to the upper right of the drawing. An oil pump 54 is arranged on the lower right side of the crankshaft 15, and a pump shaft gear 55 of the oil pump 54 is engaged with the pump drive gear 31 on the crankshaft 15 side.
The crankcase 16 is provided with a suction-side oil passage 56 and a discharge-side oil passage 57 of the oil pump 54, and the tip of the discharge-side oil passage 57 becomes a main lubricating oil passage 58, and the cylinder block 25, the crankcase 16, And then extends parallel to the cylinder shaft 53 to the valve operating chamber.

Next, the feed oil passage branched from the main lubricant passage 58 will be described.
As shown in FIG. 4, the power unit case 19 is provided with a feed oil passage 61 extending substantially horizontally from the top of the crankcase 16 to the reduction gear case 18, and from the bottom of the reduction gear case 18 to the bottom of the crankcase 16. A return oil passage 63 extending to the oil pan 62 is provided.

  As shown in FIG. 5, the feed oil passage 61 and the return oil passage 63 are provided within the thickness of the case 19 of the power unit including the reduction gear case 18. A tube 64 such as a faucet is attached to the outlet of the feed oil passage 61, and the outlet (lubricating oil supply port 65) of this tube 64 faces, for example, directly above the fourth gear 51. Lubricating oil 67 flowing down or dripping from the lubricating oil supply port 65 can be applied directly to the tooth tip of the fourth gear 51.

Further, as shown in FIG. 4, a lubricating oil discharge port 66 is opened at the bottom of the speed reducer case 18, and this lubricating oil discharge port 66 is connected to the return oil path 63. The return oil path 63 is extended to the oil pan 62 of the crankcase 16 with a so-called downward gradient so that the lubricating oil naturally flows down by gravity.
As a result, the lubricating oil 67 can hardly be accumulated at the bottom of the reduction gear case 18 and can be quickly discharged.

Next, the flow (how to flow) of the lubricating oil in the power unit 10 having the above configuration will be described.
As shown in FIG. 6, a predetermined amount (predetermined level) of lubricating oil 67 is stored in the oil pan 62. The lubricating oil 67 is pumped up and pressurized by the oil pump 54, passes through the main lubricating oil passage 58 (arrow (1)), lubricates the lubricated parts in the cylinder block 25 and the cylinder head 27, and then the oil pan 62. Return to (arrow (2)).

  In parallel, a part of the lubricating oil passing through the main lubricating oil passage 58 branches to the feed oil passage 61 (arrow (3)) and reaches the reduction gear case 18 from the lubricating oil supply ports 65 and 65 (arrow ( 4)), the gear tips of the gears 47, 48, 49, 51 are lubricated. After this lubrication, the lubricating oil hardly accumulates at the bottom of the speed reducer case 18, proceeds from the lubricating oil discharge port 66 to the return oil path 63, flows down by gravity (arrow (5)), and returns to the oil pan 62.

As apparent from the above description, in the present invention, as shown in FIG. 6, the reduction gear case 18 is lubricated by a so-called dry sump, and the gears 47, 48, 49, 51 are not submerged in the oil sump. Therefore, the stirring resistance does not occur or the stirring resistance is small. As a result, fuel efficiency can be improved.
In the embodiment, the number of the oil pump 54 is one. However, an oil pump other than the oil pump 54 is placed outside the speed reducer case 18 and a sump tank is disposed, and dry sump lubrication is performed around the speed reducer case 18. May be performed. In short, the gear reduction mechanism 14 only needs to be dry sump lubricated, and the configuration is not limited to the embodiment.

Also, the crankcase 16 and the lubricating oil supply ports 65 and 65 are connected by a feed oil passage 61, the lubricating oil discharge port 66 and the crankcase 16 are connected by a return oil passage 63, and the lubricating oil used on the crankcase 16 side The same lubricant is used on the gear reduction mechanism side.
By performing the normal inspection work of checking the oil level with the crankcase 16, checking for deterioration of the oil, and replacing the oil, it is possible to eliminate all oil check replacements in the gear reduction mechanism 14. In other words, since the lubricating oil used on the crankcase side and the lubricating oil used on the gear reduction mechanism side are shared, the lubricating oil can be checked and replaced only once, reducing the time for checking and replacing the lubricating oil. Can be planned.

  In the case of dry sump, it is necessary to provide an oil tank (sump tank) outside the deceleration case. However, according to the present invention, the oil tank can be omitted by substituting the oil pan on the crankcase side. The number of parts can be reduced.

Further, the feed oil passage 61 is branched from the main lubricating oil passage 58 toward the cylinder downstream of the oil pump 54.
In the case of a dry sump, an oil tank is provided outside the deceleration case, and a pump that sends lubricating oil to the oil tank is required. According to the present invention, the oil tank and the oil pump can be omitted by substituting the oil pan and the oil pump on the crankcase side. The number of parts can be reduced and the power unit can be made compact.

  Further, the lubricating oil that has reached the bottom of the speed reducer case 18 can be returned to the oil pan by gravity. A return pump for returning the lubricating oil can be omitted.

  In addition, the lubricating oil can be directly applied to the gear 48 and the like from the lubricating oil supply ports 65 and 65, so that the gear lubrication becomes more reliable and the stirring resistance can be further reduced.

  Moreover, as shown in FIG. 5, the feed oil path 61 and the return oil path 63 are formed in the thickness of the case 19 of the power unit. The feed oil path 61 and the return oil path 63 can also be formed by placing a tube (preferably a metal pipe) outside the case 19, but according to the present invention, the feed oil path 61 and the return oil path 63 are provided in the case. As a result, the protrusion outside the case can be suppressed, and the power unit can be made compact.

  The present invention is suitable for a power unit mounted on a scooter type vehicle.

  DESCRIPTION OF SYMBOLS 10 ... Power unit, 11 ... Engine, 12 ... Transmission mechanism, 13 ... Drive wheel axle, 14 ... Gear reduction mechanism, 15 ... Crankshaft, 16 ... Crank case, 17 ... Transmission case, 18 ... Reduction gear case, 19 ... Power unit 24 ... cylinder, 25 ... cylinder block, 27 ... cylinder head, 47 ... first gear, 48 ... second gear, 49 ... third gear, 51 ... fourth gear, 52 ... idle shaft, 54 ... oil pump 58 ... main lubricating oil passage, 61 ... feed oil passage, 62 ... oil pan, 63 ... return oil passage, 65 ... lubricating oil supply port, 66 ... lubricating oil discharge port, 67 ... lubricating oil.

Claims (5)

In a power unit comprising an engine, a speed change mechanism that changes the output of the engine, and a gear speed reduction mechanism that reduces the output of the speed change mechanism and transmits it to the drive wheel axle.
A crankcase is provided at one end of the transmission case that houses the transmission mechanism, and a reduction gear case that houses the gear reduction mechanism is provided at the other end,
The crankcase is provided with an oil pan for storing lubricating oil for lubricating the engine, and an oil pump for pumping up the lubricating oil,
The reduction gear case is provided with a lubricating oil supply port for supplying lubricating oil to a built-in gear, and a lubricating oil discharge port for discharging the lubricating oil after lubricating the gear,
The crankcase and the lubricating oil supply port are connected by a feed oil passage, the lubricating oil discharge port and the crankcase are connected by a return oil passage, and the lubricating oil used on the crankcase side and the gear reduction mechanism side are connected. A power unit characterized in that oil is supplied to the reduction gear case from outside the reduction gear case in common with the lubricating oil to be used.   The power unit according to claim 1, wherein the feed oil passage is branched from a main lubricating oil passage toward the cylinder downstream of the oil pump.   The lubricating oil discharge port is provided at a position higher than the oil level of the lubricating oil accumulated in the oil pan, and the return oil passage is provided in the oil pan so that the lubricating oil can be returned to the oil pan by gravity. The power unit according to claim 1, wherein the power unit is inclined downward.   The power unit according to claim 1, wherein the lubricating oil supply port is provided above the gear so that the lubricating oil supplied from the lubricating oil supply port directly hits the gear.   The power unit according to claim 1, wherein the feed oil path and the return oil path are formed within a thickness of a case of the power unit.

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