JP2021001667A - Power transmission device - Google Patents

Abstract

To efficiently lubricate a chain and a sprocket.SOLUTION: A power transmission device 30 includes: a first sprocket 31; a chain 21 wrapped around the first sprocket 31; an oil supply hole 331 for supplying oil to a first engagement start part P1 that is part where the chain 21 engages with the first sprocket 31; a first bearing 34 for supporting the first sprocket 31; and a retainer 36 for holding the first bearing 34. The retainer 36 has a wall 366 for covering the first sprocket 31 from above.SELECTED DRAWING: Figure 4

Description

The present invention relates to a power transmission device.

Patent Document 1 discloses a transfer device provided with an oil injection nozzle for injecting lubricating oil between a sprocket and a chain.

Jikkenhei 4-5553

A power transmission device configured with a chain and a sprocket may be driven at high speed. In this case, since the chain is burnt and worn more severely, it is conceivable to increase the amount of oil supplied to the chain and the sprocket and increase the number of oil supply holes for forcibly lubricating the chain and the sprocket. However, in either case, the workload of the oil pump that supplies the oil increases, which may lead to deterioration of energy efficiency and the need to increase the size of the oil pump.

The present invention has been made in view of such problems, and an object of the present invention is to enable efficient lubrication of a chain and a sprocket.

A power transmission device according to an aspect of the present invention includes a sprocket, a chain wound around the sprocket, an oil supply hole for supplying oil to the chain and the meshing portion of the sprocket, and a bearing for supporting the sprocket. It has a retainer that holds the bearing, and the retainer has a wall that covers the sprocket from above.

According to this aspect, even if the oil supplied to the meshing portion of the sprocket and the chain is scattered by the centrifugal force, it can be captured by the wall provided in the retainer and used for lubrication of the chain and the sprocket. Therefore, according to this aspect, it becomes possible to efficiently lubricate the chain and the sprocket.

It is a schematic block diagram of a hybrid vehicle. It is a figure which shows the appearance of the power transmission device. It is a figure which shows the main part of the power transmission device in cross section. It is the first external view of the main part of the power transmission device. It is the figure which looked at the main part of the power transmission device from the back side. It is a second external view of the main part of a power transmission device. It is a figure which shows the movement path of the oil supplied from an oil supply hole. It is the whole view of the guide groove. It is an enlarged view of a guide groove. It is a figure which shows the guide path of oil by a guide groove. It is a figure which shows the comparative example.

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

FIG. 1 is a schematic configuration diagram of a hybrid vehicle 100 (hereinafter, referred to as “vehicle 100”) according to an embodiment of the present invention. The vehicle 100 includes a low-voltage battery 1 as a first battery, a high-voltage battery 2 as a second battery, an engine 3 as a driving drive source, a motor generator 4 (hereinafter referred to as "MG4"), and an engine. The starter motor 5 (hereinafter referred to as "SM5") as the first rotary electric machine used for starting the engine 3 and the starter generator 6 (hereinafter referred to as "SM5") as the second rotary electric machine used for power generation, assisting and starting the engine 3. (Referred to as "SG6"), a DC-DC converter 7, an inverter 8, a mechanical oil pump 9 and an electric oil pump 10 as hydraulic sources, a torque converter 11 constituting a transmission, a forward / backward switching mechanism 12, and a forward / backward switching mechanism 12. It includes a stepless speed change mechanism 13 (hereinafter, referred to as “CVT 13”), a differential mechanism 14, a drive wheel 18, and a controller 20.

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, 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 supply 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 rotational 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. In the CVT 13, the gear ratio can be changed 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 connected to the shaft of the primary pulley 13a via a chain 21 wound between the sprocket provided on the shaft of the MG4 and the sprocket provided on the shaft of the primary pulley 13a.

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 an 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 provided on the shaft of the MG4 and the sprocket 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 is decelerated. 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"), 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 into 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 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).

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 EV mode or idle stop state, and is stored in the oil pan in the same manner as the mechanical oil pump 9. The oil is sucked up and supplied 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 one 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 sets the engines 3 and MG 4 so that the selected driving mode is realized. Drive.

2 to 6 are views showing the power transmission device 30 according to the present embodiment. The vertical direction in FIG. 2 corresponds to the vertical direction. In addition to the chain 21, the power transmission device 30 includes a first sprocket 31, a second sprocket 32, a case 33, a first bearing 34, a second bearing 35, and a retainer 36.

The chain 21 is driven in the forward rotation direction and the reverse rotation direction. The chain 21 is driven in the forward rotation direction when driven by the MG 4, and is driven in the reverse rotation direction when driven by the drive wheels 18. The chain 21 is wound around the first sprocket 31 and the second sprocket 32.

The first sprocket 31 is the above-mentioned sprocket provided on the shaft of the MG 4, and the second sprocket 32 is the above-mentioned sprocket provided on the shaft of the primary pulley 13a. The second sprocket 32 constitutes another sprocket around which the chain 21 is wound together with the first sprocket 31.

When the rotation direction is the forward rotation direction, the first sprocket 31 constitutes the drive side sprocket, and the second sprocket 32 constitutes the driven side sprocket. When the rotation direction is the reverse direction, the first sprocket 31 constitutes the driven side sprocket, and the second sprocket 32 constitutes the driving side sprocket. That is, the first sprocket 31 and the second sprocket 32 are provided so that when one of the first sprocket 31 and the second 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 first sprocket 31 start meshing at the first meshing start portion P1. When the rotation direction is the reverse direction, the chain 21 and the first sprocket 31 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.

The case 33 is a case member of the power transmission device 30 and has an oil supply hole 331. The oil supply hole 331 supplies oil to the chain 21 and the first sprocket 31. The oil supply hole 331 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 331 is provided so as to open in the inner portion of the chain 21 in the case 33.

The first bearing 34 and the second bearing 35 support the first sprocket 31. The first bearing 34 is provided in the retainer 36 and the second bearing 35 is provided in the case 33.

The retainer 36 holds the first bearing 34. The retainer 36 has a bearing holding portion 361, a first side wall portion 362, a first flange portion 363, a second side wall portion 364, and a second flange portion 365.

The bearing holding portion 361 is a portion that holds the first bearing 34. The first side wall portion 362 and the first flange portion 363 are located outside the chain 21, and the second side wall portion 364 and the second flange portion 365 are located inside the chain 21. The first side wall portion 362 extends axially from the first flange portion 363 and connects to the bearing holding portion 361, and the second side wall portion 364 extends axially from the second flange portion 365 and connects to the bearing holding portion 361. To do.

A space for accommodating the first sprocket 31 is formed inside the retainer 36 provided in this way (the back side of the bearing holding portion 361). The retainer 36 is provided so that the second side wall portion 364 is located diagonally below the first side wall portion 362 (diagonally below in the vertical direction).

The retainer 36 further has a wall 366 that covers the first sprocket 31 from above (vertically above). The wall 366 is provided so as to extend above the first sprocket 31 from the first side wall portion 362. The wall 366 can be stretched with a convex bend upward and can be stretched within a range that does not interfere with the chain 21. The wall 366 further has a side wall that connects the stretched portion thus stretched with the bearing holding portion 361.

In the power transmission device 30 configured in this way, the oil injected from the oil supply hole 331 moves as described below.

FIG. 7 is a diagram showing an oil movement path. As shown in FIG. 7, the oil supply hole 331 injects oil into the first meshing start portion P1. The oil supplied to the first meshing start portion P1 scatters to the outside of the chain 21 while receiving centrifugal force. The scattered oil collides with the wall 366 and is guided to the inside of the retainer 36 along the wall 366. An oil guide groove G is provided on the inner wall surface of the retainer 36 as described below.

FIG. 8 is an overall view of the guide groove G. FIG. 9 is an enlarged view of the guide groove G. In FIG. 9, the guide groove G provided in the second side wall portion 364 is enlarged and shown.

The guide groove G is provided on the inner wall surface of the retainer 36, that is, on the inner wall surface of the first side wall portion 362, the bearing holding portion 361, and the second side wall portion 364. The guide groove G has a first guide groove G1, a second guide groove G2, and a third guide groove G3.

The first guide groove G1 is provided from the first side wall portion 362 to the bearing holding portion 361 and further to the second side wall portion 364. The first guide groove G1 has a plurality of (three in this case) grooves extending in the direction from the first side wall portion 362 toward the second side wall portion 364 in the first side wall portion 362. Further, the first guide groove G1 has a bypass groove in the bearing holding portion 361 that bypasses the bearing hole. Each of the plurality of grooves provided in the first side wall portion 362 extends to the bearing holding portion 361 and is connected to the bypass groove. The detour groove extends to the second side wall portion 364 and is connected to the third guide groove G3.

The second guide groove G2 is provided in the second side wall portion 364. The second guide groove G2 is provided so as to extend in the direction from the first side wall portion 362 toward the second side wall portion 364. A plurality of (three in this case) second guide grooves G2 are provided, and each of the plurality of second guide grooves G2 is connected to the third guide groove G3. The second guide groove G2, together with the first guide groove G1, constitutes a guide groove for guiding oil to the third guide groove G3.

The third guide groove G3 is provided in the second side wall portion 364, and the third guide groove G3 is provided so as to extend in the longitudinal direction of the second side wall portion 364. The third guide groove G3 is provided at an intermediate position of the second side wall portion 364 in the lateral direction of the second side wall portion 364. The intermediate position is set so that the lower end of the third guide groove G3 is located directly above the chain 21. The lateral direction of the second side wall portion 364 is the axial direction of the first sprocket 31 in the power transmission device 30, or a direction substantially along the axial direction.

In the guide groove G provided in this way, oil is guided as described below.

FIG. 9A is a diagram showing an oil guide path through the guide groove G. FIG. 9B is a diagram showing a comparative example. A comparative example shows a retainer 36'in which the guide groove G is not provided.

First, the case of the comparative example will be described. Since the guide groove G is not provided in the comparative example, most of the oil flows along the bent portion connecting the second side wall portion 364 and the bearing holding portion 361, and the retainer 36 It falls from ´. Since the bent portion is not located directly above the chain 21, the oil that has fallen from the retainer 36'will fall on the case 33 without falling on the chain 21. In the comparative example, the oil also drops from the first side wall portion 362 and the bearing holding portion 361 before reaching the second side wall portion 364.

In the case of the present embodiment, the first guide groove G1 and the second guide groove G2 guide the oil to the third guide groove G3. Further, since the lower end of the third guide groove G3 is located directly above the chain 21, the oil that has fallen from the third guide groove G3 falls on the chain 21.

The guide groove G is formed below the first meshing start portion P1 and the second meshing start portion P2 by dropping oil from the retainer 36 covering the first sprocket 31 onto the chain 21 in this way. 2 Oil is dropped to the position before meshing of the meshing start portion P2. As a result, the oil falling from the retainer 36 is used to lubricate the chain 21 and the first sprocket 31 that start meshing at the second meshing start portion P2 at the time of reversal. Further, the oil supplied to the first meshing start portion P1 by the first guide groove G1 and the second guide groove G2 and scattered is efficiently used for lubrication of the chain 21 and the first sprocket 31.

Next, the main effects of the present embodiment will be described.

The power transmission device 30 supplies oil to the first sprocket 31, the chain 21 wound around the first sprocket 31, and the first meshing start portion P1 which is the meshing portion of the chain 21 and the first sprocket 31. It has a supply hole 331, a first bearing 34 that supports the first sprocket 31, and a retainer 36 that holds the first bearing 34. The retainer 36 has a wall 366 that covers the first sprocket 31 from above.

According to such a configuration, even if the oil supplied to the first meshing start portion P1 which is the meshing portion of the first sprocket 31 and the chain 21 is scattered by centrifugal force, the wall 366 provided on the retainer 36 causes the oil to be scattered. It can be captured and used for lubrication of the chain 21 and the first sprocket 31. Therefore, the chain 21 and the first sprocket 31 can be efficiently lubricated (effect corresponding to claim 1).

In the power transmission device 30, the chain 21 is driven in the forward rotation direction and the reverse rotation direction. Further, the meshing portion of the first sprocket 31 and the chain 21 includes a first meshing start portion P1 formed in the forward rotation direction and a second meshing start portion P2 formed in the reverse rotation direction. The oil supply hole 331 supplies oil to the first meshing start portion P1 formed above the first meshing start portion P1 and the second meshing start portion P2. The retainer 36 has a guide groove G for dropping oil on the chain 21.

According to such a configuration, the oil falling from the retainer 36 can be used to lubricate the chain 21 and the first sprocket 31 that start meshing at the second meshing start portion P2 at the time of reversal (corresponding to claim 2). Effect).

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-described embodiment, the case where the oil supply hole 331 supplies oil to the first meshing start portion P1 has been described. However, the oil supply hole 331 is directly connected to the meshing portion of the chain 21 and the first sprocket 31 formed between the first meshing start portion P1 and the second meshing start portion P2, or via the chain 21 or the like. Oil may be supplied indirectly. Even in this case, the oil scattered to the outside of the chain 21 due to the centrifugal force can be captured by the wall 366 and used for lubrication of the chain 21 and the first sprocket 31.

In the above-described embodiment, the case where the oil supply hole 331 is provided in the case 33 has been described. However, the oil supply hole 331 may be, for example, a hole such as an oil supply pipe that is a member different from the case 33.

21: Chain 30: Power transmission device 31: First sprocket (sprocket)
32: 2nd sprocket 33: Case 331: Oil supply hole 34: 1st bearing (bearing)
35: 2nd bearing 36: Retainer 366: Wall P1: 1st meshing start part (meshing part)
P2: Second meshing start part (meshing part)
G: Guide groove

Claims (2)

With sprockets
The chain wrapped around the sprocket and
An oil supply hole for supplying oil to the meshing portion of the chain and the sprocket, and
Bearings that support the sprocket and
A retainer that holds the bearing and
Have,
The retainer has a wall that covers the sprocket from above.
A power transmission device characterized by that. The power transmission device according to claim 1.
The chain is driven in the forward rotation direction and the reverse rotation direction.
The meshing portion includes a first meshing start portion formed in the forward rotation direction and a second meshing start portion formed in the reverse rotation direction.
The oil supply hole supplies oil to the meshing start portion formed above the first meshing start portion and the second meshing start portion.
The retainer has a guide groove for dropping oil into the chain.
A power transmission device characterized by that.

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