JP6456540B2 - Transmission case - Google Patents

Description

  The present invention relates to a transmission case.

  In a vehicle such as an automobile, power from a drive source is input to an input shaft of a transmission (transmission), and power shifted by the transmission is transmitted from an output shaft to a drive wheel via a differential gear or the like.

  As a transmission mounted on a vehicle, a continuously variable transmission mechanism that continuously changes engine power, a gear mechanism that transmits engine power without going through a continuously variable transmission mechanism, and power from the continuously variable transmission mechanism And a planetary gear mechanism for synthesizing power from the gear mechanism have been proposed. In this transmission, the power from the engine can be divided into a continuously variable transmission mechanism and a gear mechanism, and the divided powers can be combined by the planetary gear mechanism and transmitted to the wheels.

JP 2004-176890 A

  The applicant has also proposed a transmission capable of dividing and transmitting the power of the drive source into two systems as a power split type continuously variable transmission.

  The power split type continuously variable transmission according to the proposal includes a continuously variable transmission mechanism, a parallel shaft gear mechanism, and a planetary gear mechanism. The continuously variable transmission mechanism has the same configuration as a known belt-type continuously variable transmission (CVT). Engine power input to the input shaft is transmitted to the primary shaft of the continuously variable transmission mechanism. The secondary shaft of the continuously variable transmission mechanism is connected to the sun gear of the planetary gear mechanism. The parallel shaft gear mechanism includes a split drive gear that transmits / cuts off the power of the input shaft, and a split driven gear that forms a gear train with the split drive gear and rotates integrally with the carrier of the planetary gear mechanism. An output shaft is connected to the ring gear of the planetary gear mechanism. The rotation of the output shaft is transmitted to the differential gear, and is transmitted from the differential gear to the left and right drive wheels.

  In this power split type continuously variable transmission, a belt mode and a split mode are provided as power transmission modes during forward traveling.

  In the belt mode, the sun gear and the ring gear of the planetary gear mechanism are directly connected by the engagement of the clutch. Further, the transmission of power from the input shaft to the split drive gear is interrupted, so that the split drive gear is in a free rotation state (free), and the carrier of the planetary gear mechanism is in a free rotation state. Therefore, the sun gear and the ring gear rotate integrally with the power output from the continuously variable transmission mechanism, and the output shaft rotates integrally with the ring gear. Therefore, in the belt mode, the gear ratio (unit gear ratio) of the power split continuously variable transmission matches the gear ratio (belt gear ratio) of the continuously variable transmission mechanism.

  In the split mode, the direct connection between the sun gear and the ring gear of the planetary gear mechanism is released by releasing the clutch. Therefore, the sun gear is rotated by the power output from the continuously variable transmission mechanism. On the other hand, power is transmitted from the input shaft to the split drive gear, and the power is shifted from the split drive gear via the split driven gear at a constant split gear ratio and input to the carrier of the planetary gear mechanism. Therefore, in the split mode, the larger the belt speed ratio, the smaller the unit speed ratio, and a speed ratio that is less than or equal to the split speed ratio can be realized.

  Further, in the reverse mode during reverse travel, the carrier of the planetary gear mechanism is braked by the engagement of the brake while the direct connection between the sun gear and the ring gear of the planetary gear mechanism is released. As a result, when the sun gear is rotated by the power output from the continuously variable transmission mechanism, the ring gear rotates in the opposite direction to the sun gear, and the output shaft rotates in the opposite direction integrally with the ring gear during forward travel.

  The brake engaged in the reverse mode is released in the split mode. Therefore, in the split mode, the differential rotation between the brake plate fixed to the case (transmission case) of the power split type continuously variable transmission and the brake disc provided on the carrier is large, and drag loss in the brake is reduced. large. In addition, when oil (lubricating oil) accumulates in the brake portion, the shear resistance that the brake disk receives from the oil increases, and drag loss further increases. The drag loss is a factor that deteriorates the running fuel consumption of the vehicle.

  An object of the present invention is to provide a transmission case that can reduce drag loss in a brake.

  In order to achieve the above object, a transmission case according to the present invention (one aspect) shifts power between an input shaft and an output shaft and is provided on the output shaft or the output shaft. A transmission case used in a transmission having a brake for braking / permitting rotation of the motor, and in this transmission case, a circumferential surface surrounding the periphery of the output shaft is formed, and the circumferential surface is included in the brake A plurality of spline grooves are formed in the circumferential direction to fit the brake plate to be splined, and one of the spline grooves is located at a position facing the oil pan attached to the transmission case in the vertical direction from above. , A discharge hole is formed to discharge oil toward the oil pan, Utoputto axis is located above the input shaft, the discharge hole extends in a vertical direction to a position lower than the position of the axis of the input shaft spline groove is open in the vertical direction.

  According to this configuration, the transmission case is formed with a circumferential surface surrounding the periphery of the output shaft, and the spline for fitting the brake plate to the spline is formed on the circumferential surface where the brake is provided. Grooves are formed side by side in the circumferential direction. A drain hole is formed in one of the spline grooves, and oil (lubricating oil) supplied to the brake portion passes through the drain hole to an oil pan that is opposed to the drain hole in the vertical direction from below. It is discharged towards. Therefore, it is possible to suppress oil from being accumulated in the portion where the brake is provided. As a result, the shear resistance that the brake disc receives from the oil can be reduced, and drag loss in the brake can be reduced.

  Moreover, the part which becomes a peak with respect to a spline groove is formed in the both sides of a spline groove. Therefore, the oil flowing along with the rotation of the brake disk can be dammed up at the crest portion located downstream in the rotation direction with respect to the discharge hole, and the oil can be collected in the spline groove in which the discharge hole is formed. . Therefore, the effect which suppresses that oil accumulates in the part in which the brake is provided can be heightened.

  According to the present invention, drag loss in the brake can be reduced, so that the torque transmission efficiency of the transmission can be improved, and as a result, the fuel efficiency improvement effect of the vehicle on which the transmission is mounted can be exhibited.

It is sectional drawing which shows the structure of the drive system of a vehicle. It is a figure which shows the state of the engagement element contained in a power division type continuously variable transmission. FIG. 5 is a collinear diagram showing a relationship among rotation speeds (rotational speeds) of a sun gear, a carrier, and a ring gear of a planetary gear mechanism included in a power split continuously variable transmission. It is a perspective view of the 2nd case of a transmission case. It is a side view of the 2nd case. It is a bottom view of the 2nd case.

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

<Vehicle drive system>
FIG. 1 is a cross-sectional view showing a configuration of a vehicle drive system 1. In FIG. 1, the hatching indicating the cross section is omitted.

  The drive system 1 is mounted on, for example, a vehicle that uses an engine as a drive source. The engine output is input to a power split type continuously variable transmission (CVT) 4 via a torque converter 3.

  The torque converter 3 includes a pump impeller 31, a turbine runner 32, and a lockup clutch 33. An engine output shaft 21 is connected to the pump impeller 31, and the pump impeller 31 is provided so as to be integrally rotatable about the same rotation axis as the output shaft 21. The turbine runner 32 is provided to be rotatable about the same rotation axis as the pump impeller 31. The lockup clutch 33 is provided to directly connect / separate the pump impeller 31 and the turbine runner 32. When the lockup clutch 33 is engaged, the pump impeller 31 and the turbine runner 32 are directly connected, and when the lockup clutch 33 is released, the pump impeller 31 and the turbine runner 32 are separated.

  When the output shaft 21 of the engine rotates in a state where the lockup clutch 33 is released, the pump impeller 31 rotates. When the pump impeller 31 rotates, an oil flow from the pump impeller 31 toward the turbine runner 32 is generated. This oil flow is received by the turbine runner 32 and the turbine runner 32 rotates. At this time, the amplifying action of the torque converter 3 occurs, and the turbine runner 32 generates a power larger than the power (torque) of the engine output shaft 21.

  When the lockup clutch 33 is engaged, when the engine output shaft 21 rotates, the pump impeller 31 and the turbine runner 32 rotate together.

  The power split type continuously variable transmission 4 transmits the power input from the torque converter 3 to the differential gear 6. The power split type continuously variable transmission 4 includes an input shaft 41, an output shaft 42, a continuously variable transmission mechanism 43, a reverse gear mechanism 44, a planetary gear mechanism 45, a split drive gear 46 and a split driven gear 47.

  The input shaft 41 is connected to the turbine runner 32 of the torque converter 3 and is provided so as to be integrally rotatable about the same rotation axis as the turbine runner 32.

  The output shaft 42 is provided in parallel with the input shaft 41. An output gear 48 is formed integrally with the output shaft 42. The output gear 48 meshes with the differential gear 6 (the input gear of the differential gear 6).

  The continuously variable transmission mechanism 43 has the same configuration as a known belt-type continuously variable transmission (CVT). Specifically, the continuously variable transmission mechanism 43 includes a primary shaft 51, a secondary shaft 52 provided in parallel with the primary shaft 51, a primary pulley 53 supported by the primary shaft 51 so as not to be relatively rotatable, and a secondary shaft 52. And a secondary pulley 54 supported so as not to rotate relative thereto, and a primary pulley 53 and a belt 55 wound around the secondary pulley 54.

  The primary pulley 53 is disposed so as to face the fixed sheave 61 fixed to the primary shaft 51 with the belt 55 sandwiched between the fixed sheave 61 and is supported by the primary shaft 51 so as to be movable in the axial direction but not to be relatively rotatable. (Primary sheave) 62. A cylinder 63 fixed to the primary shaft 51 is provided on the opposite side of the movable sheave 62 from the fixed sheave 61, and a piston chamber (oil chamber) 64 is formed between the movable sheave 62 and the cylinder 63. Yes.

  The secondary pulley 54 is arranged so as to be opposed to the fixed sheave 65 fixed to the secondary shaft 52 with the belt 55 sandwiched between the fixed sheave 65 and supported on the secondary shaft 52 so as to be movable in the axial direction but not to be relatively rotatable. (Secondary sheave) 66. A cylinder 67 fixed to the secondary shaft 52 is provided on the opposite side of the movable sheave 66 from the fixed sheave 65, and a piston chamber (oil chamber) 68 is formed between the movable sheave 66 and the cylinder 67. Yes. In the rotational axis direction, the positional relationship between the fixed sheave 65 and the movable sheave 66 is reversed from the positional relationship between the fixed sheave 61 and the movable sheave 62 of the primary pulley 53.

  In the continuously variable transmission mechanism 43, the hydraulic pressure supplied to the piston chambers 64 and 68 of the primary pulley 53 and the secondary pulley 54 is controlled, and the groove widths of the primary pulley 53 and the secondary pulley 54 are changed, so that the primary The pulley ratio between the pulley 53 and the secondary pulley 54 is continuously changed steplessly.

  Specifically, when the pulley ratio is decreased, the hydraulic pressure supplied to the piston chamber 64 of the primary pulley 53 is increased. As a result, the movable sheave 62 of the primary pulley 53 moves to the fixed sheave 61 side, and the interval (groove width) between the fixed sheave 61 and the movable sheave 62 is reduced. Accordingly, the winding diameter of the belt 55 around the primary pulley 53 is increased, and the interval (groove width) between the fixed sheave 65 and the movable sheave 66 of the secondary pulley 54 is increased. As a result, the pulley ratio between the primary pulley 53 and the secondary pulley 54 is reduced.

  When the pulley ratio is increased, the hydraulic pressure supplied to the piston chamber 64 of the primary pulley 53 is lowered. Thereby, the thrust of the secondary pulley 54 with respect to the belt 55 becomes larger than the thrust of the primary pulley 53 with respect to the belt 55, the interval between the fixed sheave 65 and the movable sheave 66 of the secondary pulley 54 is reduced, and the fixed sheave 61 and the movable sheave The distance from 62 increases. As a result, the pulley ratio between the primary pulley 53 and the secondary pulley 54 is increased.

  On the other hand, the thrust of the primary pulley 53 and the secondary pulley 54 needs to be large enough to prevent slippage between the primary pulley 53 and the secondary pulley 54 and the belt 55. Therefore, the hydraulic pressure supplied to the piston chamber 68 of the secondary pulley 54 is controlled so that a thrust according to the magnitude of the torque input to the input shaft 41 is obtained.

  The reverse gear mechanism 44 is configured to transmit the power input to the input shaft 41 to the primary shaft 51 by reversely rotating and decelerating. Specifically, the reverse gear mechanism 44 includes an input shaft gear 71 formed integrally with the input shaft 41, a larger diameter and a larger number of teeth than the input shaft gear 71, and a rotation axis line by spline fitting to the primary shaft 51. And a primary shaft gear 72 that is supported so as to be movable in the direction and not to be relatively rotatable, and meshes with the input shaft gear 71.

  The planetary gear mechanism 45 includes a sun gear 81, a carrier 82, and a ring gear 83. The sun gear 81 is supported by the secondary shaft 52 so as to be movable in the rotational axis direction and not relatively rotatable by spline fitting. The carrier 82 is fitted on the output shaft 42 so as to be relatively rotatable. The carrier 82 rotatably supports a plurality of pinion gears 84. The plurality of pinion gears 84 are arranged on the circumference and mesh with the sun gear 81. The ring gear 83 has an annular shape that collectively surrounds the plurality of pinion gears 84, and meshes with the pinion gears 84 from the outside in the rotational radial direction of the secondary shaft 52. The ring gear 83 is fixed to the output shaft 42, and the ring gear 83 is provided so as to be integrally rotatable about the same rotational axis as the output shaft 42.

  The split drive gear 46 is fitted on the input shaft 41 so as to be relatively rotatable.

  The split driven gear 47 is provided so as to be integrally rotatable about the same rotation axis as the carrier 82 of the planetary gear mechanism 45. The split driven gear 47 is formed with a smaller diameter than the split drive gear 46 and has fewer teeth than the split drive gear 46.

  The power split type continuously variable transmission 4 includes clutches C1 and C2 and a brake B1.

  The clutch C1 is switched between an engaged state in which the input shaft 41 and the split drive gear 46 are directly coupled (coupled so as to be integrally rotatable) and a released state in which the direct coupling is released.

  The clutch C2 is switched between an engaged state in which the sun gear 81 and the ring gear 83 of the planetary gear mechanism 45 are directly coupled (coupled so as to be integrally rotatable) and a released state in which the direct coupling is released.

  The brake B1 is switched between an engagement state in which the carrier 82 of the planetary gear mechanism 45 is braked and a release state in which the rotation of the carrier 82 is allowed.

<Transmission mode>
FIG. 2 is a diagram illustrating states of the clutches C1 and C2 and the brake B1 when the vehicle is moving forward and backward. In FIG. 2, “◯” indicates that the clutches C1 and C2 and the brake B1 are engaged. “X” indicates that the clutches C1 and C2 and the brake B1 are in the released state. FIG. 3 is a collinear diagram showing the relationship between the rotational speeds (rotational speeds) of the sun gear 81, the carrier 82, and the ring gear 83 of the planetary gear mechanism 45.

  The power split type continuously variable transmission 4 has a belt mode and a split mode as shift modes in the forward range.

  In the belt mode, as shown in FIG. 2, the clutch C1 and the brake B1 are released, and the clutch C2 is engaged. As a result, the split drive gear 46 is disconnected from the input shaft 41, the carrier 82 of the planetary gear mechanism 45 becomes free (free rotation state), and the sun gear 81 and the ring gear 83 of the planetary gear mechanism 45 are directly connected.

  The power input to the input shaft 41 is reversed and decelerated by the reverse gear mechanism 44 and transmitted to the primary shaft 51 of the continuously variable transmission mechanism 43 to rotate the primary shaft 51 and the primary pulley 53. The rotation of the primary pulley 53 is transmitted to the secondary pulley 54 via the belt 55 to rotate the secondary pulley 54 and the secondary shaft 52. Since the sun gear 81 and the ring gear 83 of the planetary gear mechanism 45 are directly connected, the sun gear 81, the ring gear 83, and the output shaft 42 rotate together with the secondary shaft 52. Therefore, in the belt mode, as shown in FIG. 3, the gear ratio (unit gear ratio) of the power split type continuously variable transmission 4 matches the pulley ratio.

  In the split mode, as shown in FIG. 2, the clutch C1 is engaged, and the clutch C2 and the brake B1 are released. Thereby, the input shaft 41 and the split drive gear 46 are directly connected, the carrier 82 of the planetary gear mechanism 45 becomes free, and the sun gear 81 and the ring gear 83 of the planetary gear mechanism 45 are disconnected.

  The power input to the input shaft 41 is reversed and decelerated by the reverse gear mechanism 44 and transmitted to the primary shaft 51 of the continuously variable transmission mechanism 43, and is transmitted from the primary shaft 51 via the primary pulley 53, the belt 55 and the secondary pulley 54. Is transmitted to the secondary shaft 52 and transmitted to the sun gear 81 of the planetary gear mechanism 45. On the other hand, the power input to the input shaft 41 is accelerated and transmitted from the split drive gear 46 to the carrier 82 of the planetary gear mechanism 45 through the split driven gear 47.

  Since the gear ratio between the split drive gear 46 and the split driven gear 47 is constant and unchanged (fixed), in the split mode, if the power input to the input shaft 41 is constant, the carrier 82 of the planetary gear mechanism 45 rotates. Is maintained at a constant speed. For this reason, when the pulley ratio is increased, the rotational speed of the sun gear 81 of the planetary gear mechanism 45 decreases, so that the rotational speed of the ring gear 83 (output shaft 42) of the planetary gear mechanism 45 is reduced as shown by a broken line in FIG. Go up. As a result, in the split mode, the gear ratio of the continuously variable transmission mechanism 43 decreases as the pulley ratio increases.

  The rotation of the output shaft 42 in the belt mode and the split mode is transmitted to the differential gear 6 via the output gear 48. As a result, the drive shafts 7 and 8 of the vehicle rotate in the forward direction.

  In the reverse range, the reverse mode is set, and the clutches C1 and C2 are engaged and the brake B1 is released as shown in FIG. Thereby, the split drive gear 46 is disconnected from the input shaft 41, the sun gear 81 and the ring gear 83 of the planetary gear mechanism 45 are disconnected, and the carrier 82 of the planetary gear mechanism 45 is braked.

  The power input to the input shaft 41 is reversed and decelerated by the reverse gear mechanism 44 and transmitted to the primary shaft 51 of the continuously variable transmission mechanism 43, and is transmitted from the primary shaft 51 via the primary pulley 53, the belt 55 and the secondary pulley 54. Then, the sun gear 81 of the planetary gear mechanism 45 is rotated integrally with the secondary shaft 52. Since the carrier 82 of the planetary gear mechanism 45 is braked, when the sun gear 81 rotates, the ring gear 83 of the planetary gear mechanism 45 rotates in the opposite direction to the sun gear 81. The rotation direction of the ring gear 83 is opposite to the rotation direction of the ring gear 83 during forward movement (belt mode and split mode). Then, the output shaft 42 rotates integrally with the ring gear 83. The rotation of the output shaft 42 is transmitted to the differential gear 6 via the output gear 48. Thereby, the drive shafts 7 and 8 of the vehicle rotate in the reverse direction.

<Transmission case>
The torque converter 3, the power split type continuously variable transmission 4, and the differential gear 6 are accommodated in a transmission case (transaxle case) 101 as shown in FIG.

  The transmission case 101 is divided into a first case 102, a second case 103, and a third case 104. The first case 102, the second case 103, and the third case 104 are arranged in this order from the engine side of the vehicle.

  FIG. 4 is a perspective view of the second case 103. FIG. 5 is a side view of the second case 103 (viewed from the engine side). FIG. 6 is a bottom view of the second case 103.

  The second case 103 includes an outer wall portion 111 that forms an outer shell, and a partition wall portion 112 that is formed so as to divide a space inside the outer wall portion 111 into two in the rotation axis direction.

  In the space surrounded by the outer wall 111 on the engine side with respect to the partition wall 112, the first arrangement portion 113 in which the split drive gear 46 and the clutch C <b> 1 are arranged, the output shaft 42, the planetary gear mechanism 45, and the split driven gear 47. A second placement portion 114 where the clutch C2 and the brake B1 are placed and a third placement portion 115 where the differential gear 6 is placed are provided.

  A continuously variable transmission mechanism 43 is disposed in a space surrounded by the outer wall 111 on the side opposite to the engine side with respect to the partition wall 112.

  In the partition wall 112, a first insertion hole 116 through which the input shaft 41 is inserted is formed at a position facing the first arrangement portion 113. Further, the partition wall portion 112 is formed with a second insertion hole 117 through which the secondary shaft 52 is inserted at a position facing the second arrangement portion 114. Further, the partition wall portion 112 is formed with a third insertion hole 118 through which the drive shaft 7 is inserted at a position facing the third arrangement portion 115.

  The second case 103 has a circumferential surface 121 surrounding the output shaft 42 in the second arrangement portion 114. A plurality of spline grooves 122 are formed in the circumferential surface 121 side by side in the circumferential direction.

  The spline groove 122 is a groove for fitting the brake plate 123 (see FIG. 1) of the brake B1 with a spline. The brake B1 has the same configuration as a known wet multi-plate clutch, and has a configuration in which a plurality of brake plates 123 and a plurality of brake disks 124 are alternately arranged in the rotation axis direction as shown in FIG. doing.

  As shown in FIGS. 4 and 5, one of the plurality of spline grooves 122 is located downstream of the lowermost spline groove 122 in the rotational direction of the brake disk 124 (counterclockwise in FIG. 5). The adjacent spline groove 122A is formed longer in the circumferential direction than the other spline grooves 122. An oil discharge hole 125 is formed on the bottom surface of the spline groove 122A. The oil discharge hole 125 extends in the vertical direction, and is opened in the vertical direction as shown in FIG. As shown in FIG. 5, the lower end opening of the oil discharge hole 125 faces the oil pan 126 connected to the bottom surface of the transmission case 101 in the vertical direction from above.

  From another point of view, the oil discharge hole 125 is below the center of the line segment connecting the rotation axis of the input shaft 41 and the rotation axis of the secondary shaft 52 in the side view shown in FIG. It is formed at a position facing the arrangement portion 113 in the rotation axis direction.

<Effect>
As described above, the transmission case 101 (second case 103) is formed with a circumferential surface 121 that surrounds the output shaft 42, and a portion of the circumferential surface 121 where the brake B1 is provided includes Spline grooves 122 for spline fitting the brake plate 123 are formed side by side in the circumferential direction. An oil discharge hole 125 is formed in the spline groove 122A, which is one of the spline grooves 122, and oil (lubricating oil) supplied to the brake B1 portion passes through the oil discharge hole 125 and passes through the oil discharge hole 125. The oil is discharged from below toward the oil pan 126 facing in the vertical direction. Therefore, oil can be prevented from being accumulated on the portion where the brake B1 is provided, that is, on the circumferential surface 121. As a result, the shear resistance that the brake B1 disc receives from the oil can be reduced, and the drag loss in the brake B1 can be reduced.

  Further, on both sides of the spline groove 122A, a portion 127 that is a mountain with respect to the spline groove 122A is formed. Therefore, the oil flowing along with the rotation of the brake disk 124 is blocked by a crest portion 127 located on the downstream side in the rotation direction with respect to the oil discharge hole 125, and the spline groove 122A in which the oil discharge hole 125 is formed. You can collect the oil. Therefore, the effect which suppresses that oil accumulates in the part in which brake B1 is provided can be heightened.

<Modification>
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  For example, although the power split type continuously variable transmission 4 is taken up as an example of the transmission, the transmission to which the transmission case according to the present invention can be applied is not limited to the power split type continuously variable transmission 4, but a known continuously variable transmission. (CVT: Continuously Variable Transmission) or a stepped automatic transmission (AT) may be used.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

4 Power split type continuously variable transmission (transmission)
41 Input shaft 42 Output shaft 82 Carrier (Rotating body)
101 Transmission case 103 Second case 121 Circumferential surface 122 Spline groove 122A Spline groove 123 Brake plate 125 Oil discharge hole (discharge hole)
126 Oil pan B1 Brake

Claims (1)

A transmission case used in a transmission having a brake that shifts power between an input shaft and an output shaft and brakes / allows rotation of the output shaft or a rotating body provided on the output shaft. And
A circumferential surface surrounding the periphery of the output shaft is formed;
On the circumferential surface, a plurality of spline grooves for spline fitting a brake plate included in the brake are formed side by side in the circumferential direction,
In one of the spline grooves, a discharge hole for discharging oil toward the oil pan is formed at a position facing the oil pan attached to the transmission case in the vertical direction from above.
The output shaft is positioned above the input shaft;
The transmission case, wherein the discharge hole extends linearly in the vertical direction from the spline groove to a position below the axis of the input shaft, and is open in the vertical direction.