JP2021042816A - Power transmission device - Google Patents

Abstract

To suppress changes in height of an oil level of an oil bath in a power transmission device.SOLUTION: A power transmission device 30 includes: a case 40 that forms an oil bath 41 capable of collecting a lubricant; a power transmission mechanism 30a that has a sprocket 31 at least partially immersed in the lubricant in the oil bath 41, and a sprocket 32 transmitting power to and from the sprocket 31 by a chain 21 wound between the sprocket 31 and the sprocket 32; and a gap filling member 50 that suppresses scattering of the lubricant from the oil path 41 due to the rotation of the chain 21 provided in the gap between the sprocket 31 and the case 40.SELECTED DRAWING: Figure 2

Description

The present invention relates to a power transmission device.

Patent Document 1 discloses an automatic transmission provided with a chain transmission mechanism having a scraping means for collecting hydraulic oil scattered by the rotation of the chain in the vicinity of the chain peripheral circuit and dropping it downward.

The scraping means of this chain transmission mechanism collects the hydraulic oil scattered by the drive of the chain and drops it into the return chamber, so that the scattered hydraulic oil can be returned to the transmission side.

Japanese Unexamined Patent Publication No. 4-175559

However, since the scraping means of Patent Document 1 collects the scattered hydraulic oil, the hydraulic oil that the scraping means cannot collect is scattered in the case. If the hydraulic oil that could not be collected was scattered in the case, the height of the oil level in the oil bath might change.

The present invention has been made in view of such technical problems, and an object of the present invention is to suppress a change in the oil level of an oil bath in a power transmission device.

According to an aspect of the present invention, the power transmission device includes a case for forming an oil bath in which lubricating oil is stored, a first sprocket in which at least a part is immersed in the lubricating oil in the oil bath, and the above. In a gap between a power transmission mechanism having a second sprocket in which power is transmitted to and from the first sprocket by a chain wound between the first sprocket and the first sprocket and the case. Provided is a power transmission device provided, which comprises a gap filling portion provided and which suppresses scattering of lubricating oil from the oil bath due to rotation of the chain.

In the above aspect, since the space is filled by providing the gap filling portion in the gap between the first sprocket and the case, that is, the space where the lubricating oil is scattered from the oil surface of the oil bath, the lubricating oil due to the rotation of the chain Scattering is suppressed. As a result, the scattering of the lubricating oil in the case is suppressed, and the change in the oil level of the oil bath can be suppressed.

It is a schematic block diagram of the hybrid vehicle to which the power transmission device which concerns on embodiment of this invention is applied. It is a schematic diagram of the power transmission device which concerns on embodiment of this invention. It is a perspective view of the gap filling part which concerns on embodiment of this invention. It is an enlarged perspective view of the vicinity of the gap filling part in the power transmission device which concerns on embodiment of this invention. It is a schematic diagram of the main part of the power transmission device which concerns on the modification of embodiment of this invention. It is an enlarged view of the main part of the power transmission device which concerns on the modification of embodiment of this invention. It is an enlarged view of the main part of the power transmission device which concerns on the modification of embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Hereinafter, with reference to FIGS. 1 to 4, the power transmission device 30 according to the embodiment of the present invention and the hybrid vehicle (hereinafter, simply referred to as “vehicle”) 100 to which the power transmission device 30 is applied will be described. ..

First, the overall configuration of the vehicle 100 will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a vehicle 100 to which the power transmission device 30 is applied.

The vehicle 100 includes a low-voltage battery 1, a high-voltage battery 2, an engine 3, a motor generator 4 (hereinafter, referred to as “MG4”), and a starter motor 5 (hereinafter, “SM5”) used for starting the engine 3. ), A starter generator 6 (hereinafter referred to as "SG6") used for power generation, assisting and starting the engine 3, a DC-DC converter 7, an inverter 8, and a mechanical oil pump as a hydraulic source. 9, the electric oil pump 10, the torque converter 11 constituting the transmission, the forward / backward switching mechanism 12, the stepless speed change mechanism 13 (hereinafter referred to as “CVT 13”), the differential mechanism 14, the drive wheels 18, and so on. It includes a controller 20 and.

The low voltage battery 1 is a lead acid battery having an output voltage of DC12V. The low-voltage battery 1 is connected to the low-voltage circuit 16 together with electrical components 15 (automatic driving camera 15a and sensor 15b, navigation system 15c, audio 15d, air conditioner blower 15e, etc.) that operate at SM5 and 12V. The low voltage battery 1 may be a lithium ion battery having an output voltage of 12 V.

The high-voltage battery 2 is a DC48V lithium-ion battery having a higher output voltage than the low-voltage battery 1. The output voltage of the high voltage battery 2 may be lower or higher than this, and may be, for example, 30V or 100V. The high-voltage battery 2 is connected to the high-voltage circuit 17 together with the MG4, SG6, inverter 8, electric oil pump 10, and the like.

The low-voltage circuit 16 and the high-voltage circuit 17 are connected via a DC-DC converter 7. The DC-DC converter 7 has a boosting function that boosts 12V of the low-voltage circuit 16 to 48V and outputs 48V to the high-voltage circuit 17, and steps down 48V of the high-voltage circuit 17 to 12V to 12V to the low-voltage circuit 16. It has a step-down function to output. As a result, the DC-DC converter 7 can output a voltage of 12 V to the low voltage circuit 16 regardless of whether the engine 3 is running or stopped. When the remaining capacity of the high-voltage battery 2 is low, the 12V of the low-voltage circuit 16 can be boosted to 48V and output to the high-voltage circuit 17 to charge the high-voltage battery 2.

The engine 3 is an internal combustion engine that uses gasoline, light oil, or the like as fuel, and its rotation speed, torque, or the like is controlled based on a command from the controller 20.

The torque converter 11 is provided on the power transmission path between the engine 3 and the forward / backward switching mechanism 12, and transmits power via a fluid. Further, the torque converter 11 can improve the power transmission efficiency of the driving force from the engine 3 by engaging the lockup clutch 11a when the vehicle 100 is traveling at a predetermined lockup vehicle speed or higher.

The forward / backward switching mechanism 12 is provided on the power transmission path between the torque converter 11 and the CVT 13, and includes a planetary gear mechanism 12a, a forward clutch 12b, and a reverse brake 12c. When the forward clutch 12b is engaged and the reverse brake 12c is released, the rotation of the engine 3 input to the forward / backward switching mechanism 12 via the torque converter 11 is transferred from the forward / backward switching mechanism 12 to the CVT 13 while maintaining the rotation direction. It is output. On the contrary, when the forward clutch 12b is released and the reverse brake 12c is engaged, the rotation of the engine 3 input to the forward / backward switching mechanism 12 via the torque converter 11 is decelerated and the rotation direction is reversed to switch forward / backward. It is output from the mechanism 12 to the CVT 13. The flood control required by the forward / backward switching mechanism 12 is generated by a hydraulic circuit (not shown) using the flood pressure generated by the mechanical oil pump 9 or the electric oil pump 10 as the original pressure.

The CVT 13 is arranged on the power transmission path between the forward / backward switching mechanism 12 and the differential mechanism 14, and changes the gear ratio steplessly according to the vehicle speed, the accelerator opening degree which is the operation amount of the accelerator pedal, and the like. The CVT 13 includes a primary pulley 13a, a secondary pulley 13b, and a belt 13c wound around both pulleys. The CVT 13 can change the gear ratio steplessly by changing the groove widths of the primary pulley 13a and the secondary pulley 13b by flood control and changing the contact radius between the pulleys 13a and 13b and the belt 13c. The flood pressure required by the CVT 13 is generated by a hydraulic circuit (not shown) using the flood pressure generated by the mechanical oil pump 9 or the electric oil pump 10 as the original pressure.

The MG4 is a synchronous rotary electric machine in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator. The MG4 is of the primary pulley 13a via a chain 21 wound between a sprocket 31 as a first sprocket provided on the shaft of the primary pulley 13a and a sprocket 32 as a second sprocket provided on the shaft of the MG4. Connected to the shaft.

The MG 4 is branched and connected to the power transmission path connecting the engine 3 and the drive wheels 18 on the engine 3 side of the secondary pulley 13b. Further, the MG 4 is branched and connected to the power transmission path on the drive wheel 18 side of the forward / backward switching mechanism 12 including the clutch provided between the engine 3 and the primary pulley 13a of the power transmission path. Connecting the belt 13c to the shaft of the primary pulley 13a from the side opposite to the engine 3 with the belt 13c in between is included in the branch connection to the power transmission path.

The MG 4 is controlled by applying a three-phase alternating current generated by the inverter 8 based on a command from the controller 20. The MG 4 operates as an electric motor that is rotationally driven by receiving electric power supplied from the high-voltage battery 2. Further, the MG 4 functions as a generator that generates electromotive force at both ends of the stator coil when the rotor receives rotational energy from the engine 3 and the drive wheels 18, and can charge the high voltage battery 2.

The sprocket 32 provided on the shaft of the MG4 and the sprocket 31 provided on the shaft of the primary pulley 13a are configured so that the latter has a large number of teeth (for example, the number of teeth = 1: 3), and the output rotation of the MG3. Decelerates and is transmitted to the primary pulley 13a. As a result, the torque required for the MG4 is reduced, the MG4 is miniaturized, and the degree of freedom in arranging the MG4 is improved.

The SM5 is a DC motor, and is arranged so that the pinion gear 5a can be meshed with the outer peripheral gear 3b of the flywheel 3a of the engine 3. When the engine 3 is started from a cold state for the first time (hereinafter referred to as "first start"), electric power is supplied from the low voltage battery 1 to the SM5, the pinion gear 5a is meshed with the outer gear 3b, the flywheel 3a, and further. The crankshaft is rotated. Since the low-voltage battery 1 is a lead-acid battery, the SM5 is used when the engine 3 is started for the first time, so that power can be stably supplied from the low-voltage battery 1 to the SM5 even at extremely low temperatures. This is because the SM5 can generate the torque and output required to start the engine 3 for the first time.

The torque and output required to start the engine 3 are the largest at the first start, and are smaller at the start from the warm-up state, that is, at the restart than at the first start. This is because the temperature of the engine oil is low and the viscosity of the engine oil is high at the first start, whereas the temperature of the engine oil rises and the viscosity of the engine oil decreases after the first start.

The SG6 is a synchronous rotary electric machine, which is connected to the crankshaft of the engine 3 via a V-belt 22 and functions as a generator when receiving rotational energy from the engine 3. The electric power generated in this way is charged to the high voltage battery 2 through the inverter 8. Further, the SG 6 operates as an electric motor that is rotationally driven by receiving electric power supplied from the high-voltage battery 2, and assists the driving force of the engine 3. Further, the SG6 is used to rotationally drive the crankshaft of the engine 3 to restart the engine 3 when the engine 3 is restarted from the idling stop state.

The mechanical oil pump 9 is an oil pump that operates by transmitting the rotation of the engine 3 via the chain 23. The mechanical oil pump 9 sucks up hydraulic oil stored in an oil pan (not shown) and supplies the oil to the lockup clutch 11a, the forward / backward switching mechanism 12, and the CVT 13 via a hydraulic circuit (not shown).

The electric oil pump 10 is an oil pump operated by electric power supplied from the high voltage battery 2. The electric oil pump 10 operates when the engine 3 is stopped and the mechanical oil pump 9 cannot be driven by the engine 3, such as in the EV mode or the idling stop state. Like the mechanical oil pump 9, the electric oil pump 10 sucks up the hydraulic oil stored in the oil pan and supplies the oil to the lockup clutch 11a, the forward / backward switching mechanism 12, and the CVT 13 via a hydraulic circuit (not shown). .. In particular, by securing the necessary flood pressure in the CVT 13, the slip of the belt 13c is suppressed.

The controller 20 is composed of a single or a plurality of microcomputers including a central arithmetic unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface). The controller 20 corresponds to the control unit, and by executing the program stored in the ROM or RAM by the CPU, the engine 3, the inverter 8 (MG4, SG6, the electric oil pump 10), the DC-DC converter 7, the SM5, The lockup clutch 11a, the forward / backward switching mechanism 12, the CVT 13, and the like are controlled in an integrated manner.

As the operation mode of the vehicle 100, the controller 20 drives the MG4 with the electric power supplied from the high-voltage battery 2 and travels by the driving force of the MG4 only, and the engine traveling mode of traveling by the driving force of the engine 3 only. And the HEV mode in which the vehicle travels according to the driving force of the engine 3 and the driving force of the MG 4.

In the EV mode, the vehicle 100 travels by driving only the MG4 with the electric power from the high-voltage battery 2 in a state where the forward clutch 12b and the reverse brake 12c are released (hereinafter, this state is referred to as "EV travel"). .. The EV mode is selected when the required output of the vehicle 100 is low and the remaining capacity of the high voltage battery 2 is sufficient.

In the engine running mode, the vehicle 100 runs by driving only the engine 3 with either the forward clutch 12b or the reverse brake 12c engaged. The engine running mode is selected when the required output of the vehicle 100 is relatively high.

In the HEV mode, the vehicle 100 runs by driving the engine 3 and the MG 4 with either the forward clutch 12b or the reverse brake 12c engaged. The HEV mode is selected when the required output of the vehicle 100 is high, specifically, when the required output of the vehicle 100 cannot be supplemented only by the output of the engine 3.

The controller 20 selects a driving mode based on the accelerator opening, the pedal effort of the brake pedal, and the vehicle speed in consideration of a driving mode selection map (not shown), and drives the engines 3 and MG 4 so that the selected driving mode is realized. To control.

Hereinafter, the power transmission device 30 will be described with reference to FIGS. 2 to 4.

First, the configuration of the power transmission device 30 will be described with reference to FIGS. 2 and 3.

FIG. 2 is a diagram showing the appearance of the power transmission device 30. The vertical direction in FIG. 2 corresponds to the vertical direction, the left-right direction corresponds to the front-rear direction of the vehicle 100 (the left direction is the front direction), and the vertical direction of the paper surface is the left-right direction of the vehicle 100 (the depth direction of the paper surface is the right direction). ) Corresponds. FIG. 3 is a perspective view of the gap filling member 50 in the power transmission device 30.

As shown in FIG. 2, the power transmission device 30 includes a chain 21, a sprocket 31, a sprocket 32, a case 40, and a gap filling member 50 as a gap filling portion. The chain 21, the sprocket 31, and the sprocket 32 form a power transmission mechanism 30a.

The chain 21 is wound around the sprocket 31 and the sprocket 32. The chain 21 transmits power between the sprocket 31 and the sprocket 32. The chain 21 is driven in the forward rotation direction and the reverse rotation direction. When the vehicle 100 moves forward, the chain 21 is driven in the forward rotation direction (counterclockwise direction in FIG. 2). On the other hand, when the vehicle 100 moves backward, the chain 21 is driven in the reverse direction (clockwise in FIG. 2).

The sprocket 31 is provided on the shaft of the primary pulley 13a (see FIG. 1), and the sprocket 32 is provided on the shaft of the MG 4 (see FIG. 1). When the MG 4 operates as an electric motor, the sprocket 32 constitutes a drive-side sprocket, and the sprocket 31 constitutes a driven-side sprocket. When the MG 4 functions as a generator, the sprocket 31 constitutes a drive-side sprocket, and the sprocket 32 constitutes a driven-side sprocket. That is, when one of the sprocket 31 and the sprocket 32 constitutes the driving side sprocket, the other constitutes the driven side sprocket.

When the rotation direction is the forward rotation direction, the chain 21 and the sprocket 32 start meshing at the first meshing start portion P1. When the rotation direction is the reverse direction, the chain 21 and the sprocket 32 start meshing at the second meshing start portion P2. The first meshing start portion P1 at the time of normal rotation is located above the second meshing start portion P2 at the time of reverse rotation.

When the rotation direction is the forward rotation direction, the chain 21 and the sprocket 31 start meshing at the third meshing start portion P3 and end meshing at the fourth meshing start portion P4. When the rotation direction is the reverse direction, the chain 21 and the sprocket 31 start meshing at the fourth meshing start portion P4 and end meshing at the third meshing start portion P3.

The case 40 is a case member of the power transmission device 30. The case 40 forms an oil bath 41 in which lubricating oil is stored. The case 40 has an oil supply hole 42 as a supply hole and an oil discharge hole 43 as a discharge hole.

The oil supply hole 42 supplies the lubricating oil from the mechanical oil pump 9 or the electric oil pump 10 to the chain 21 and the sprocket 32. The oil supply hole 42 supplies oil to the first meshing start portion P1 which is the meshing start portion formed above the first meshing start portion P1 and the second meshing start portion P2. The oil supply hole 42 is provided so as to open in the inner portion of the chain 21 in the case 40.

The oil discharge hole 43 is formed on the wall surface 40a of the case 40. The oil discharge hole 43 discharges the lubricating oil to the outside when the oil level height of the lubricating oil in the oil bath 41 exceeds the set height. Specifically, when the height of the oil level O reaches the oil discharge hole 43, the lubricating oil is discharged to the outside (for example, an oil pan). That is, the height of the oil level O is maintained at the same height (set height) as the lower end of the oil discharge hole 43. Hereinafter, the oil level O will be described as being horizontal as shown in FIG.

The gap filling member 50 is a member mounted in the case 40. In the present embodiment, the gap filling member 50 is made of resin. The gap filling member 50 is provided in the gap between the sprocket 31 and the case 40. Specifically, the gap filling member 50 includes a portion from the third meshing start portion P3 to the fourth meshing start portion P4 where the sprocket 31 and the chain 21 mesh with each other (hereinafter, the portion is referred to as a meshing portion) and a case. It is provided in a space between 40 and above the set height.

As shown in FIGS. 2 and 3, the gap filling member 50 has a gap filling portion 51 and an extending portion 52. As shown in FIG. 2, the gap filling portion 51 includes a portion of the meshing portion from the oil level O to the fourth meshing start portion P4 (hereinafter, the portion is referred to as a first meshing portion) and the case 40. The gap between them is filled with a clearance that allows the sprocket 31 and the chain 21 to rotate. Here, since the first meshing portion is a portion where the vibration and rattling of the chain 21 during driving of the power transmission mechanism 30a are small, the clearance can be minimized. The bottom surface 51a of the oil level O side end of the gap filling portion 51 is in contact with the oil level O at the set height.

As shown in FIG. 2, the extending portion 52 extends from the outer peripheral side of the chain 21 to the inner peripheral side of the chain 21 along the horizontal oil level O at the same height (set height) as the lower end of the oil discharge hole 43. Extend towards. The extending portion 52 extends over the range of the oil level O where the lubricating oil is scraped up as the chain 21 and the sprocket 31 rotate in the normal direction. The bottom surface 52a of the extending portion 52 on the oil level O side comes into contact with the oil level O at the set height. One end of the extending portion 52 is connected to the oil level O side end portion of the gap filling portion 51. That is, the bottom surface 51a and the bottom surface 52a are continuous surfaces and are surfaces in contact with the oil surface O at the set height.

Next, the action and effect of the gap filling member 50 will be described with reference to FIG.

FIG. 4 is an enlarged perspective view of the power transmission device 30 when the sprocket 31 and the chain 21 are rotating in the forward rotation direction (counterclockwise direction in FIG. 4).

In the present embodiment, there is a space between the meshing portion and the case 40 above the set height, in other words, a space where the lubricating oil is scattered from the oil level O as the sprocket 31 and the chain 21 rotate in the normal direction. It is filled with the bottom surfaces 51a and 52a of the gap filling member 50. Therefore, even if the lubricating oil is scraped up in the forward rotation direction along with the sprocket 31 and the chain 21, the lubricating oil does not scatter from the oil level O and is returned to the oil bath 41.

Explaining the flow of the lubricating oil in detail, the lubricating oil in the oil bath 41 is scraped up in the direction of arrow A (the direction in which it scatters beyond the oil level O) by the forward rotation direction rotation of the sprocket 31 and the chain 21. To go. The lubricating oil scraped up in the direction of arrow A eventually comes into contact with the bottom surfaces 51a and 52a. Specifically, of the lubricating oil flowing in the direction of arrow A, the lubricating oil on the outer peripheral side of the chain 21 mainly comes into contact with the bottom surface 51a of the gap filling member 50. Further, of the lubricating oil flowing in the direction of arrow A, the lubricating oil on the inner peripheral side of the chain 21 mainly comes into contact with the bottom surface 52a of the gap filling member 50. After that, the lubricating oil flows in the direction of arrow B. That is, the lubricating oil does not scatter from the oil level O and is returned to the oil bath 41.

As described above, in the present embodiment, by providing the gap filling member 50, the scattering of the lubricating oil from the oil level O itself is suppressed. Specifically, the scattering of the lubricating oil from the oil level O on the outer peripheral side of the chain 21 is suppressed by the bottom surface 51a of the gap filling portion 51, and the scattering of the lubricating oil from the oil level O on the inner peripheral side of the chain 21 is extended. It is suppressed by the bottom surface 52a of the portion 52. As a result, the scattering of the lubricating oil into the case 40 of the lubricating oil is suppressed, so that the change in the oil level O of the oil bath 41 can be suppressed.

Here, when the gap filling member 50 is not provided, the lubricating oil of the oil bath 41 is scraped up by the chain 21 during high-speed rotation of the power transmission mechanism 30a, so that the lubricating oil adheres to the wall surface 40a. As a result, the height of the oil level O of the oil bath 41 is lowered. When the height of the oil level O decreases, the height of the oil level O becomes less than the set height of the oil discharge hole 43, and the lubricating oil of the oil bath 41 is not discharged from the oil discharge hole 43.

After that, when the rotation speed of the power transmission mechanism 30a changes from high-speed rotation to low-speed rotation, the amount of the lubricating oil scraped up by the chain 21 decreases. Here, when the lubricating oil adhering to the wall surface 40a returns to the oil bath 41, the total amount of the lubricating oil in the oil bath 41 may increase and the height of the oil level O may rise. As the amount of lubricating oil in the oil bath 41 increases, the amount of air that can be contained in the oil bath 41 increases relatively. As a result, when the lubricating oil of the oil bath 41 is agitated by the rotating chain 21, the air content of the lubricating oil increases. If the air content of the lubricating oil increases, the pump pressure in the mechanical oil pump 9 and the electric oil pump 10 may decrease, the pulley 13a (13b) pressure may decrease, and the like.

On the other hand, in the present embodiment, by having the gap filling member 50, it is possible to suppress the scattering of the lubricating oil from the oil level O. As a result, the change in the height of the oil level O of the oil bath 41 is suppressed, and the scattered lubricating oil is suppressed from adhering to the inside of the case. This suppresses an increase in the total amount of lubricating oil in the case 40. As a result, it is possible to suppress an increase in the height of the oil level O and suppress an increase in the air content of the lubricating oil.

By the way, a clearance is provided between the sprocket 31 and the chain 21 and the gap filling portion 51 to the extent that the sprocket 31 and the chain 21 can rotate. Therefore, the lubricating oil that has entered the clearance from the oil bath 41 and the lubricating oil that has adhered to the outer periphery of the chain 21 may exceed the oil level O.

However, in the present embodiment, since the gap filling member 50 (gap filling portion 51) is arranged in the first meshing portion where the vibration and rattling of the chain 21 during driving of the power transmission mechanism 30a are small, the clearance is minimized. Can be limited. That is, it is possible to suppress the intrusion of the lubricating oil into the clearance.

Further, as shown in FIG. 2, since the gap filling portion 51 is widely provided from the oil level O to the fourth meshing start portion P4, the fourth meshing start even if the lubricating oil enters the clearance. It cannot rise to the part P4 and does not scatter in the case 40. Further, even if the lubricating oil adhering to the outer peripheral surface of the chain 21 is scattered from the outer peripheral surface of the chain 21 by centrifugal force, the lubricating oil is collected by the inner wall surface of the gap filling portion 51 and returned to the oil bath 41. Therefore, it does not scatter in the case 40. In this way, the gap filling member 50 can prevent the lubricating oil from scattering into the case 40 even if the lubricating oil enters the clearance.

According to the above embodiment, the following effects are exhibited.

The power transmission device 30 is a chain wound between the case 40 forming the oil bath 41 in which the lubricating oil is stored, the sprocket 31 in which at least a part of the lubricating oil in the oil bath 41 is immersed, and the sprocket 31. Lubricating oil from the oil bath 41 due to the rotation of the chain 21 provided in the gap between the power transmission mechanism 30a having the sprocket 32 and the sprocket 32 in which the power is transmitted to and from the sprocket 31 by 21 and the sprocket 31 and the case 40. A gap filling member 50 that suppresses the scattering of the sprocket is provided.

According to this configuration, the scattering of the lubricating oil from the oil surface O on the outer peripheral side of the chain 21 is suppressed by the gap filling portion 51 (bottom surface 51a). As a result, by suppressing the scattering of the lubricating oil from the oil level O, the scattering of the lubricating oil into the case 40 of the lubricating oil is suppressed, so that the change in the oil level O of the oil bath 41 can be suppressed. (Effects corresponding to claims 1 and 4).

Further, according to this configuration, by suppressing the lubricating oil from adhering to the inside of the case 40, it is possible to suppress an increase in the total amount of the lubricating oil in the case 40. As a result, it is possible to suppress an increase in the height of the oil level O and suppress an increase in the air content of the lubricating oil (effects corresponding to claims 1 and 4).

Further, the case 40 is provided with an oil discharge hole 43 formed on the wall surface 40a of the case 40 and discharges the lubricating oil to the outside when the oil level height of the lubricating oil in the oil bath 41 exceeds the set height, and is provided with a gap filling portion. Reference numeral 50 denotes a space above the set height between the meshing portion where the sprocket 31 and the chain 21 mesh with each other and the case 40.

According to this configuration, the clearance between the sprocket 31 and the chain 21 and the gap filling member 50 can be minimized. As a result, the intrusion of the lubricating oil into the clearance can be suppressed, and the scattering of the lubricating oil from the oil level O can be suppressed (effect corresponding to claim 2).

Further, the gap filling portion 50 extends from the outer peripheral side of the chain 21 toward the inner peripheral side of the chain 21 along the oil level O when the oil level height of the lubricating oil of the oil bath 41 is the set height. It has an extension 52 to be used.

According to this configuration, the scattering of the lubricating oil from the oil surface O on the inner peripheral side of the chain 21 is suppressed by the extending portion 52 (bottom surface 52a). As a result, the scattering of the lubricating oil into the case 40 of the lubricating oil is suppressed, so that the change in the oil level O of the oil bath 41 can be suppressed (effect corresponding to claim 3).

Although the embodiments of the present invention have been described above, the above embodiments are only a part of the application examples of the present invention, and the technical scope of the present invention is limited to the specific configurations of the above embodiments. Absent.

In the above embodiment, the gap filling member 50 has been described as an independent member, but the gap filling member 50 may be provided integrally with the case 40.

5 to 7 are an enlarged view of a main part and a schematic view of a main part of the power transmission device 30 according to a modified example of the embodiment of the present invention. In this embodiment, as shown in FIG. 5, the case 40 has a case cover 44 that covers the case 40.

As shown in FIGS. 6 and 7, the case 40 has gap filling portions 61a and 61b integrally provided with the case 40. Further, the case cover 44 has a gap filling portion 61c, 61d and an extending portion 62 integrally provided with the case cover 44. Since the positions where the gap filling portions 61a to 61d and the extending portions 62 are provided are the same as the positions where the gap filling portions 51 and the extending portions 52 are provided, the description thereof will be omitted.

According to the present embodiment, since the gap filling portions 61a to 61d and the extending portion 62 are integrally provided in the case 40, the scattering of the lubricating oil is suppressed without increasing the number of parts, and the oil level O of the oil bath 41 is suppressed. (Effect corresponding to claim 5).

100 Vehicle 21 Chain 30 Power transmission device 30a Power transmission mechanism 31 Sprocket (1st sprocket)
32 sprocket (second sprocket)
40 Case 50 Gap filling member (gap filling part)

Claims (5)

It is a power transmission device
A case that forms an oil bath in which lubricating oil is stored, and
A first sprocket in which at least a part is immersed in the lubricating oil in the oil bath, and a second sprocket in which power is transmitted between the first sprocket by a chain wound between the first sprocket and the first sprocket. With a power transmission mechanism that has,
A gap filling portion provided in the gap between the first sprocket and the case to prevent the lubricating oil from scattering from the oil bath due to the rotation of the chain.
To prepare
A power transmission device characterized by that. The power transmission device according to claim 1.
The case is provided with a discharge hole formed on the wall surface of the case and discharging the lubricating oil to the outside when the oil level height of the lubricating oil in the oil bath exceeds the set height.
The gap filling portion is provided in a space above the set height between the meshing portion where the first sprocket and the chain mesh with each other and the case.
A power transmission device characterized by that. The power transmission device according to claim 1 or 2.
The case is provided with a discharge hole formed on the wall surface of the case and discharging the lubricating oil to the outside when the oil level height of the lubricating oil in the oil bath exceeds the set height.
The gap filling portion extends from the outer peripheral side of the chain toward the inner peripheral side of the chain along the oil level when the oil level of the lubricating oil of the oil bath is the set height. Has a protrusion,
A power transmission device characterized by that. The power transmission device according to any one of claims 1 to 3.
The gap filling portion is an independent member mounted in the case.
A power transmission device characterized by that. The power transmission device according to any one of claims 1 to 3.
The gap filling portion is provided integrally with the case.
A power transmission device characterized by that.

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