CN109915570B - Power distribution device - Google Patents
Power distribution device Download PDFInfo
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- CN109915570B CN109915570B CN201811214612.5A CN201811214612A CN109915570B CN 109915570 B CN109915570 B CN 109915570B CN 201811214612 A CN201811214612 A CN 201811214612A CN 109915570 B CN109915570 B CN 109915570B
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Abstract
The invention provides a power distribution device, which shortens the axial length as much as possible, can be accommodated in a gearbox body, and can realize miniaturization and low cost. The power distribution device (1) of the present invention includes: a double pinion (14) including a 1 st pinion (P1) and a 2 nd pinion (P2); a pinion (P) meshed with the 1 st pinion (P1); a planet carrier member (13) which rotatably supports the double pinion (14) and the pinion (P); a sun gear (S) meshed with the pinion (P); a 1 st ring gear (R1) and a 2 nd ring gear (R2) which are engaged with a 1 st pinion (P1) and a 2 nd pinion (P2) and connected to a right output Shaft (SFR) and a left output Shaft (SFL); a 1 st brake (11) and a 2 nd brake (12) that brake the carrier member (13) and the sun gear (S); and a differential device (D). The 1 st pinion (P1) and the 2 nd pinion (P2) have different diameters and the same number of teeth, and the gear teeth (21a) and the gear teeth (22a) are integrally formed without a gap therebetween.
Description
Technical Field
The present invention relates to a power distribution device connected to a power source via a transmission for distributing power to two rotating shafts that can rotate in a differential manner.
Background
Conventionally, as such a power distribution device, for example, a power distribution device disclosed in patent document 1 is known. The conventional power distribution device is applied to a four-wheel vehicle, and includes: a differential device for distributing the torque of the internal combustion engine to the left and right output shafts, a carrier member rotatably provided around the left output shaft, a triple pinion gear rotatably supported by the carrier member, and a hydraulic clutch for acceleration and a hydraulic clutch for deceleration. The left and right output shafts are connected to left and right drive wheels, respectively. The triple pinion includes a 1 st pinion, a 2 nd pinion, and a 3 rd pinion having different pitch circle diameters, and the 1 st pinion, the 2 nd pinion, and the 3 rd pinion are integrally formed. The 1 st pinion gear meshes with a 1 st sun gear (sun gear) integral with the right output shaft, and the 2 nd pinion gear meshes with a 2 nd sun gear integral with the left output shaft. The 3 rd pinion gear meshes with a 3 rd sun gear provided rotatably. The 3 rd sun gear is connected to and disconnected from a stationary casing (casting) by an acceleration clutch, and the carrier member is connected to and disconnected from the casing by a deceleration clutch.
In the conventional power split device configured as described above, when the vehicle turns left and right, the torque distribution to the left and right output shafts is controlled by controlling the tightening force of the acceleration clutch and the deceleration clutch. For example, when the vehicle turns right, the 3 rd sun gear is disconnected from the case by releasing the acceleration clutch, and the carrier member is connected to the case by fastening the deceleration clutch, thereby decelerating the carrier member. As a result, a part of the torque of the right output shaft is transmitted to the left output shaft via the 1 st sun gear, the 1 st pinion, the 2 nd pinion, and the 2 nd sun gear, and as a result, the torque allocated to the left output shaft increases relative to the right output shaft. At this time, the torque distributed to the left output shaft is controlled by controlling the tightening degree of the speed reduction clutch.
[ Prior art documents ]
[ patent document ]
[ patent document 1] Japanese patent application laid-open No. Hei 8-114255
Disclosure of Invention
[ problems to be solved by the invention ]
As described above, in the conventional power split device, in order to control torque distribution to the left and right output shafts, triple pinions and three rows of sun gears are used, and the 1 st to 3 rd pinions of the triple pinions and the 1 st to 3 rd sun gears of the three rows of sun gears meshed with the 1 st to 3 rd pinions are arranged in the axial direction of the left and right output shafts (hereinafter, simply referred to as "axial direction").
Therefore, since the axial length (axial length) of the power split device is increased, a transmission case (transmission case) that houses the transmission may not house the power split device, and in this case, a separate case dedicated to the power split device is required. As a result, an oil pump (oil pump) or a filter (filter) for lubricating the power split device cannot be shared with the transmission, and a dedicated oil pump or filter is required, resulting in an increase in size and cost of the entire device.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power distribution device that can be housed in a transmission case by shortening the axial length as much as possible, and that can be reduced in size and cost.
[ means for solving problems ]
In order to achieve the above object, the invention according to claim 1 is a power distribution device 1 connected to a power source (an engine 3 in an embodiment (hereinafter, the same applies to the present description)) via a transmission 4 for distributing power to two rotating shafts (left and right output shafts SFL, SFR) that are capable of rotating in a differential manner, the power distribution device 1 including: a duplex pinion 14 including a 1 st pinion P1 and a 2 nd pinion P2 provided integrally with each other; a pinion gear P meshed with the 1 st pinion gear P1; a carrier member 13 rotatably supporting the double pinion 14 and the pinion P; a sun gear S freely rotating and meshed with the pinion gear P; a 1 st ring gear (ring gear) R1 which is engaged with the 1 st pinion P1 and is connected to one of the two rotation shafts (right output shaft SFR); a 2 nd ring gear R2 rotatably engaged with the 2 nd pinion P2 and connected to the other of the two rotation shafts (left output shaft SFL); a 1 st brake 11 to brake the carrier member 13; a 2 nd brake 12 for braking the sun gear S; and a differential device D having a 1 st rotation element (sun gear SD), a 2 nd rotation element (carrier CD), and a 3 RD rotation element (ring gear RD) that are capable of differential rotation with each other, the 1 st rotation element being connected to a power transmission path (flange)17) between the 1 st ring gear R1 and one of the rotation shafts (right output shaft SFR), the 2 nd rotation element being provided on the power transmission path between the 2 nd ring gear R2 and the other rotation shaft (left output shaft SFR), the 3 RD rotation element being connected to the transmission 4, the 1 st pinion P1 and the 2 nd pinion of the double pinion 14 having different diameters and the same number of teeth from each other, and the gear teeth 21a, the gear teeth 22a being integrally formed without a gap therebetween.
According to the configuration, the power split device has the double pinion including the 1 st pinion and the 2 nd pinion integrated with each other. The double pinion and pinion are rotatably supported by the carrier member, and the 1 st pinion of the double pinion is meshed with the pinion. The pinion is meshed with the sun gear, and a 1 st pinion and a 2 nd pinion of the duplex pinion are respectively meshed with the 1 st annular gear and the 2 nd annular gear. Also, the carrier member and the sun gear are braked by a 1 st brake and a 2 nd brake, respectively, and the 1 st ring gear and the 2 nd ring gear are connected to one and the other of the rotation shafts that are capable of differential rotation with each other, respectively.
The 1 st to 3 rd rotating elements of the differential device are configured to be capable of differential rotation with respect to each other. The 1 st rotating element is connected to a power transmission path between the 1 st ring gear and one of the rotation shafts, the 2 nd rotating element is provided on the power transmission path between the 2 nd ring gear and the other rotation shaft, and the 3 rd rotating element is connected to a power source via a transmission.
According to the above connection relationship, the rotation speeds of the carrier member, the 1 st ring gear, the 3 rd rotating element of the differential, the 2 nd ring gear, and the sun gear are in a so-called collinear relationship, and are aligned in a straight line on a collinear diagram. Also, on the collinear chart, the 3 rd rotating element of the differential apparatus is located at the center, the carrier member and the sun gear are located at both outer sides, respectively, and the 1 st ring gear and the 2 nd ring gear are located between the 3 rd rotating element and the carrier member, and between the 3 rd rotating element and the sun gear, respectively.
According to the above configuration, the power input from the power source to the differential device via the transmission and the 3 rd rotating element is transmitted to one and the other rotating shafts via the 1 st rotating element and the 2 nd rotating element, respectively, thereby driving both rotating shafts. Further, the 1 st brake and the 2 nd brake apply braking force to the carrier member and the sun gear, whereby the power distribution to the two rotary shafts can be appropriately controlled.
Further, the power split device of the present invention employs the double pinion gear having the smaller number of triple pinion gears than the conventional power split device, and therefore, the axial length can be shortened. Further, the 1 st pinion gear and the 2 nd pinion gear of the double pinion gear have different diameters and the same number of teeth from each other, and are integrally formed with no gap between the gear teeth. This can further shorten the axial length and reduce the size of the power distribution device. Further, since the 1 st brake and the 2 nd brake, which are relatively small, (compact) are used as the means (device) for applying the braking force to the carrier member and the sun gear, the power distribution device can be made smaller than the case of using an electric motor, for example.
Further, by downsizing the power distribution device as described above, the accommodation performance thereof is improved, and the power distribution device can be accommodated in the transmission case together with the transmission.
Further, since the gear teeth of the 1 st pinion gear and the 2 nd pinion gear of the double pinion gear are integrally formed without a gap, the bending load applied to each gear tooth can be supported favorably while relieving stress concentration due to the bending load by both gear teeth.
The invention of claim 2 is the power distribution device of claim 1, wherein the 1 st brake and the 2 nd brake are disposed in a state of overlapping (overlap) with each other in an axial direction of the rotary shaft.
According to the above configuration, the 1 st brake and the 2 nd brake overlap each other in the axial direction of the rotary shaft, so the axial length of the power split device can be further shortened in accordance with the overlap, and the downsizing of the power split device can be further promoted.
The invention of claim 3 is the power split device according to claim 1 or 2, characterized in that the power split device is entirely housed in a transmission case housing the transmission.
According to the above configuration, the power split device is housed in the transmission case together with the transmission as a whole, and a separate case for housing the power split device is not required. Also, an oil pump or a filter for lubricating the power split device can be shared with the transmission. As described above, the entire device including the transmission and the power split device can be reduced in size and cost.
Drawings
Fig. 1 is a diagram generally showing a power distribution device according to an embodiment of the present invention together with left and right drive wheels and the like of a vehicle to which the power distribution device according to the embodiment of the present invention is applied.
Fig. 2 is a block diagram showing an Electronic Control Unit (ECU) and the like that control the power distribution device.
Fig. 3 is an alignment chart showing a rotational speed relationship and a torque balance relationship between various rotary elements in the power split device in a vehicle straight-ahead state.
Fig. 4 is an alignment chart showing a rotational speed relationship and a torque balance relationship between various rotary elements in the power split device in a right turn state of the vehicle.
Fig. 5(a) is a plan view showing a duplex pinion used in the power split device.
Fig. 5(b) is a cross-sectional view taken along line X-X showing a double pinion used in the power split device.
Fig. 6(a) is a plan view showing a double pinion gear of the comparative example to fig. 5 (a).
Fig. 6(b) is a cross-sectional view along the Y-Y line of the double pinion gear of the comparative example to fig. 5 (b).
Description of the reference numerals
1: power distribution device
3: engine (Power source)
4: speed variator
11: 1 st brake
12: 2 nd brake
13: planet carrier member
14: duplex pinion
17: flange (power transmission path between the ring gear of the 1 st and one of the rotating shafts)
21 a: gear teeth of the 1 st pinion
22 a: gear teeth of the 2 nd pinion
SFR: right output shaft (one of two rotating shafts)
SFL: left output shaft (the other of the two rotating shafts)
P1: 1 st pinion
P2: 2 nd pinion
P: pinion gear
S: sun gear
R1: no. 1 ring gear
R2: no. 2 ring gear
D: differential gear
SD: sun gear (1 st rotating element)
CD: planet carrier (2 nd rotating element)
RD: inner gear ring (3 rd rotating element)
MC: gearbox casing
Detailed Description
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The power distribution device 1 shown in fig. 1 is mounted on the front of a four-wheeled vehicle (not shown) to distribute power to the left and right output shafts SFL, SFR. The left and right output shafts SFL, SFR are coaxially arranged with each other and are connected to left and right front wheels WFL, WFR, which are driving wheels, respectively. An internal combustion engine (hereinafter, referred to as "engine") 3 and a transmission 4 are mounted as power sources on a front portion of the vehicle, and power of the engine 3 is input to the power split device 1 via an output shaft 4a of the transmission 4 in a state of being shifted by the transmission 4.
The power distribution device 1 includes: gear unit GS, 1 st brake 11, 2 nd brake 12, and differential device D. The differential device D, the gear device GS, the 1 st brake 11, and the 2 nd brake 12 are arranged in order from the left side so as to be coaxial with the left and right output shafts SFL, SFR, and all of them are housed in a transmission case MC housing the transmission 4.
The gear device GS distributes the input power of the engine 3 to the left and right output shafts SFL, SFR, and includes a carrier member 13, a double pinion 14, a sun gear S, a pinion P, a 1 st ring gear R1, a 2 nd ring gear R2, and the like. These components are arranged coaxially with the left and right output shafts SFL, SFR.
The carrier member 13 includes a ring (doughmut) plate-shaped 1 st base portion 13a and a 2 nd base portion 13b, and, for example, four 1 st support shafts 13c and 2 nd support shafts 13d (only two of each are shown) provided between the base portions 13a and 13 b. Further, a first rotating shaft 15 and a right output shaft SFR, which will be described later, are relatively rotatably disposed inside the carrier member 13.
The 1 st base portion 13a and the 2 nd base portion 13b are disposed coaxially with each other, and face each other in the axial direction of the left and right output shafts SFL, SFR (hereinafter, simply referred to as "axial direction"). The 1 st support shaft 13c and the 2 nd support shaft 13d are provided integrally with the 1 st base portions 13a and 13b and extend in the axial direction. The 1 st support shaft 13c is disposed at the radially outer end of the 1 st base 13a, and the 2 nd support shaft 13d is disposed at the inner end. The four 1 st support shafts 13c are equally spaced from each other in the circumferential direction of the 1 st base 13a, as are the four 2 nd support shafts 13 d.
The double pinion 14 includes a 1 st pinion P1 and a 2 nd pinion P2 formed integrally with each other. The double pinion 14 is rotatably supported by each of the four first support shafts 13c (only two are shown). The 1 st pinion gear P1 and the 2 nd pinion gear P2 are disposed at the left and right portions of the 1 st fulcrum shaft 13c, respectively, and have different diameters (pitch circle diameters) from each other, and the 1 st pinion gear P1 is small in this example. Also, the numbers of teeth of the 1 st pinion gear P1 and the 2 nd pinion gear P2 are set to be identical to each other. The detailed structure of the double pinion 14 will be described later.
The sun gear S, the pinions P, and the 1 st pinion P1 of the double pinion 14 are arranged in this order from the radially inner side and mesh with each other, and the sun gear S is integrally attached to the hollow 1 st rotating shaft 15. The right output shaft SFR is disposed on the inner side of the 1 st rotating shaft 15 so as to be relatively rotatable, and the carrier member 13 is disposed on the outer side so as to be relatively rotatable. The pinion gears P are rotatably supported on each of four (only two) 2 nd support shafts 13d of the carrier member 13.
The 1 st ring gear R1 includes a so-called internal gear, is provided on the outer periphery of the sun gear S, and meshes with the 1 st pinion P1. The 1 st ring gear R1 is connected to the right output shaft SFR via the hollow 2 nd rotating shaft 16 and the flange 17, and is rotatable integrally with the right output shaft SFR. The carrier member 13 and the 1 st rotation shaft 15 are relatively rotatably disposed inside the 2 nd rotation shaft 16.
The 2 nd ring gear R2 includes the same internal gear as the 1 st ring gear R1, and a 2 nd pinion P2 meshed with the double pinion 14. The 2 nd ring gear R2 is connected to the left output shaft SFL via the hollow 3 rd rotating shaft 18 and the flange 19, and is rotatable integrally with the left output shaft SFL. The 2 nd rotation shaft 16, the carrier member 13, the 1 st rotation shaft 15, and the right output shaft SFR are relatively rotatably disposed inside the 3 rd rotation shaft 18.
The 1 st brake 11 includes, for example, a wet multiple disc clutch having an inner disc (inner)11a and an outer disc (outer)11b in a ring shape each including a plurality of clutch discs, an actuator (not shown) for driving the outer disc 11b, and the like, and the actuator is connected to an ECU (electronic control unit) 2. The plurality of clutch plates of the inner plate 11a and the plurality of clutch plates of the outer plate 11b are alternately arranged in the axial direction. The inner piece 11a is connected to the carrier member 13 and rotates integrally therewith. The outer piece 11b is provided in the stationary portion CA in the transmission case MC so as to be movable in the axial direction and unrotatable.
The 1 st brake 11 is controlled by the ECU 2 via an actuator to allow free rotation of the carrier member 13 in a released state (state of fig. 1) in which the inner and outer plates 11a and 11b are disconnected from each other, and to brake the carrier member 13 in a fastened state (not shown) in which they are fastened to each other. The braking torque at this time is controlled by adjusting the tightening degree of the 1 st brake 11.
The 2 nd brake 12 has the same configuration as the 1 st brake 11, and includes, for example, a wet multiple disc clutch, an annular inner disc 12a and an annular outer disc 12b each including a plurality of clutch discs, an actuator (not shown) for driving the outer disc 12b, and the like, and the actuator is connected to the ECU 2. The plurality of clutch plates of the inner plate 12a and the plurality of clutch plates of the outer plate 12b are arranged alternately in the axial direction. The inner piece 12a is connected to the sun gear S and rotates integrally therewith. The outer piece 12b is provided in the stationary portion CA in the transmission case MC so as to be movable in the axial direction and unrotatable.
The operation of the 2 nd brake 12 is controlled by the ECU 2 via an actuator, and in the released state (the state of fig. 1), the sun gear S is allowed to rotate freely, and in the fastened state (not shown), the sun gear S is braked. The braking torque at this time is controlled by adjusting the tightening degree of the 2 nd brake 12.
As shown in fig. 1, the 1 st brake 11 and the 2 nd brake 12 are disposed in a state of overlapping with each other in the axial direction.
The differential device D includes a planetary gear device of a so-called double pinion (double pinion) type, and includes a sun gear SD, a ring gear RD provided on an outer periphery of the sun gear SD, a plurality of 1 st pinion gears PD1 meshed with the sun gear SD, a plurality of 2 nd pinion gears PD2 meshed with the 1 st pinion gears PD1 and the ring gear RD, and a carrier CD rotatably supporting the 1 st pinion gears PD1 and the 2 nd pinion gears PD 2.
An external gear G that meshes with a gear 4b integrally provided on an output shaft 4a of the transmission 4 is formed on an outer peripheral portion of a ring gear RD of the differential device D. Thus, the power of the engine 3 is input to the differential device D via the output shaft 4a and the ring gear RD while being shifted by the transmission 4.
The sun gear SD of the differential device D is integrally connected to the 1 st ring gear R1 via the flange 17 and the 2 nd rotating shaft 16, and is integrally connected to the right output shaft SFR via the flange 17. In this way, the sun gear SD is connected to the power transmission path between the 1 st ring gear R1 and the right output shaft SFR.
The right end of the carrier CD of the differential device D is integrally connected to the 2 nd ring gear R2 via the flange 19 and the 3 rd rotating shaft 18, and the left end of the carrier CD is integrally connected to the left output shaft SFL. In this way, the carrier CD is provided on the power transmission path between the 2 nd ring gear R2 and the left output shaft SFL.
In the differential device D configured as described above, the torque transmitted from the engine 3 to the ring gear RD via the transmission 4 is distributed to the sun gear SD and the carrier CD at a torque distribution ratio of 1:1 via the 2 nd pinion PD2 and the 1 st pinion PD 1.
With the above configuration, the rotational speed relationship between the various rotational elements in the power split device 1 is as follows. First, the 2 nd ring gear R2 and the carrier CD are connected to each other via the 3 rd rotation shaft 18 and the flange 19, and the carrier CD is directly connected to the left output shaft SFL. Therefore, the rotational speeds of the 2 nd ring gear R2, the carrier CD, and the left output shaft SFL are equal to each other. The 1 st ring gear R1 is connected to the right output shaft SFR via the 2 nd rotation shaft 16 and the flange 17, and the sun gear SD of the differential device D is connected to the right output shaft SFR via the flange 17. Therefore, the rotational speeds of the 1 st ring gear R1, the sun gear SD, and the right output shaft SFR are equal to each other.
Also, the carrier member 13 and the inner plate 11a of the 1 st brake 11 are directly connected to each other, so the rotational speeds of the carrier member 13 and the inner plate 11a are equal to each other. The sun gear S and the inner plate 12a of the 2 nd brake 12 are directly connected to each other, so the rotational speeds of the sun gear S and the inner plate 12a are equal to each other.
Further, since the gear device GS is configured as described above and the differential device D is a planetary gear device of a double pinion type, the rotational speed relationship between the rotary elements in the power distribution device 1 is shown in a collinear chart shown in fig. 3, for example. That is, the sun gear S of the gear device GS, the 2 nd ring gear R2 (the carrier CD of the differential device D), the ring gear RD of the differential device D, the 1 st ring gear R1 (the sun gear SD of the differential device D), and the carrier member 13 constitute five rotational elements whose rotational speeds are collinear with each other. Further, as can be seen from fig. 3: the left and right output shafts SFL, SFR can perform differential rotation with each other.
In fig. 3, α and β are the 1 st lever (lever) ratio and the 2 nd lever ratio, respectively. In fig. 3, S, SD are indicated in parentheses to distinguish the sun gear S of the gear device GS from the sun gear SD of the differential device D.
As shown in fig. 2, the ECU 2 receives a detection signal indicating a steering angle θ of a steering wheel (handle) (not shown) of the vehicle from a steering angle sensor 31, a detection signal indicating a vehicle speed VP of the vehicle from a vehicle speed sensor 32, and a detection signal indicating an operation amount (hereinafter referred to as "accelerator pedal opening") AP of an accelerator pedal (not shown) of the vehicle from an accelerator pedal opening sensor 33, respectively.
The ECU 2 includes a microcomputer having an Input/Output (I/O) interface, a Central Processing Unit (CPU), a Random Access Memory (RAM), a Read Only Memory (ROM), and the like. The ECU 2 controls the 1 st brake 11 and the 2 nd brake 12 according to the detection signals from the steering angle sensor 31, the vehicle speed sensor 32, and the accelerator opening sensor 33, and a control program stored in the ROM. Thereby, the torque distribution operation of the power distribution device 1 is performed. The operation of the power distribution device 1 during straight traveling and during cornering of the vehicle will be described below.
When the vehicle travels straight, both the 1 st brake 11 and the 2 nd brake 12 are controlled to be released. Fig. 3 shows the rotational speed relationship and the torque balance relationship between the various rotating elements at this time. In fig. 3, TE is torque transmitted from the engine 3 to the ring gear RD via the transmission 4, and RLE and RRE are reaction torque acting on the left output shaft SFL and the right output shaft SFR, respectively, as the torque is transmitted from the engine 3 to the ring gear RD.
As described above, the torque transmitted to the ring gear RD is distributed to the carrier CD and the sun gear SD at the torque distribution ratio of 1: 1. Therefore, these reaction force torques RLE and RRE are equal to each other. At this time, the torque transmitted to the left output shaft SFL (hereinafter referred to as "left output shaft transmission torque") and the torque transmitted to the right output shaft SFR (hereinafter referred to as "right output shaft transmission torque") are represented by the reaction force torques RLE and RRE, respectively. As a result, the vehicle travels straight while the left output shaft transmission torque and the right output shaft transmission torque are equal to each other.
When the vehicle turns right, the 1 st brake 11 is controlled to a fastened state, and the degree of fastening thereof is controlled according to the detected steering angle θ or vehicle speed VP, and the like, and the 2 nd brake 12 is controlled to a released state. Fig. 4 shows the rotational speed relationship and the torque balance relationship between the various rotating elements at this time. In fig. 4, TG1 is the braking torque of the 1 st brake 11. RLG1 and RRG1 are reaction torques acting on the left output shaft SFL and the right output shaft SFR, respectively, in response to the braking of the 1 st brake 11.
At this time, the left output shaft transmission torque is represented by RLE + RLG1 and the right output shaft transmission torque is represented by RRE-RRG1, and the left output shaft transmission torque becomes larger than the right output shaft transmission torque. As a result, the right-turn running is performed in a state where the yaw moment (yaw moment) of the right turn of the vehicle is increased.
Further, although not shown, when the vehicle turns left, the 1 st brake 11 is controlled to be in a released state, and the 2 nd brake 12 is controlled to be in a fastened state, and the degree of fastening thereof is controlled, contrary to the right and left directions at the time of the right turn. At this time, the operation of the power split device 1 is in a completely reverse relationship to the right and left operation at the time of turning right as shown in fig. 4, and therefore, a detailed description thereof will be omitted.
Next, the structure of the double pinion 14 of the gear device GS will be described in detail with reference to fig. 5(a) and 5 (b). As described above, the 1 st pinion P1 and the 2 nd pinion P2 of the double pinion 14 have different diameters (pitch circle diameters) from each other and the same number of teeth as each other. The 1 st and 2 nd pinion gears P1 and P2 each include a spur gear having the same predetermined number of gear teeth 21a, 22a, gear grooves 21b, and 22 b.
As shown in fig. 5(a) and 5(b), the respective gear teeth 21a, 22a are arranged at the same positions as each other in the circumferential direction with their center positions aligned, and are formed integrally with each other without a gap. The gear teeth 21a of the 1 st pinion P1 have smaller tooth tips, smaller pitch circle diameters, and smaller tooth thicknesses than the gear teeth 22a of the 2 nd pinion P2. The duplex pinion 14 configured as described above is manufactured by, for example, precision forging.
Fig. 6(a) and 6(b) show a double pinion gear in which the diameters and the numbers of teeth of the 1 st pinion gear and the 2 nd pinion gear are different from each other as a comparative example with respect to the double pinion gear 14. At this time, since the number of teeth is different between the 1 st pinion gear P1 'and the 2 nd pinion gear P2', as shown in fig. 6(a), there are inevitably portions where the gear teeth 111a, the gear teeth 112a, and the gear grooves 111b, 112b are not aligned (shifted) with each other in the circumferential direction.
Therefore, since the gear teeth 111a and the gear teeth 112a need to be formed separately, it is difficult to use precision forging, and thus, for example, cutting work is required. In the above-described cutting process, the undercut 113 is formed over the entire outer peripheral surface of the double pinion gear, and then the gear teeth 111a and the gear teeth 112a are formed, respectively. As a result, since the undercut 113 remains between the produced gear teeth 111a and 112a, the entire width of the double pinion in the axial direction is increased by the width W of the undercut 113.
Since the gear teeth 111a and 112a are spaced apart from each other by the undercut 113, the bending loads F1 and F2 acting in opposite directions on the gear teeth 111a and 112a are supported by the gear teeth 111a and 112a, respectively, and stress concentration is likely to occur at the tooth bottoms (arrow B portion of fig. 6 (B)) of the gear teeth 111a and 112a, respectively, and adverse effects thereof cannot be avoided.
In contrast, in the double pinion 14 of the present embodiment, since the number of teeth of the 1 st pinion P1 and the 2 nd pinion P2 is the same as each other, and the gear teeth 21a and the gear teeth 22a are arranged at the same positions in the circumferential direction, the double pinion is manufactured by precision forging instead of cutting, and the gear teeth 21a and the gear teeth 22a are formed integrally with each other without a gap. Therefore, the undercut 113 in the case of the comparative example is no longer necessary, and the entire width of the double pinion 14 in the axial direction is shortened by the width W of the undercut 113.
Further, while being supported by the gear teeth 21a, 22a integrated with each other in such a manner as to cancel out the bending loads F1, F2 acting in opposite directions to the gear teeth 21a, 22a, the stress concentration at the boundary portion (arrow a portion of fig. 5 (b)) of the gear teeth 21a, 22a can be alleviated.
As described above, according to the power split device 1 of the present embodiment, the double pinion 14 having the smaller number of pinions than the triple pinion of the conventional power split device is used, and therefore the axial length can be reduced by that amount. Further, the 1 st pinion P1 and the 2 nd pinion P2 of the double pinion 14 have different diameters and the same number of teeth from each other, and the gear teeth 21a and the gear teeth 22a are integrally formed without gaps therebetween, so that the overall width of the double pinion 14 is shortened, and accordingly the axial direction length is further shortened. Since the 1 st brake 11 and the 2 nd brake 12 are disposed in a state of overlapping each other in the axial direction, the axial length is further shortened by the overlapping portion. By shortening the axial length as described above, the power distribution apparatus 1 can be downsized.
Further, since the 1 st brake 11 and the 2 nd brake 12, which are relatively small (compact), are used as the means (device) for applying the braking force to the carrier member 13 and the sun gear S, the power distribution device 1 can be made smaller than the case of using an electric motor, for example.
The entire power split device 1, which is miniaturized as described above, is housed in the transmission case MC together with the transmission 4. Thus, a separate case to house the power split device 1 is no longer required, and an oil pump or a filter to lubricate the power split device 1 can be shared with the transmission 4. As described above, the entire device including the transmission 4 and the power split device 1 can be reduced in size and cost.
The present invention is not limited to the embodiments described above, and can be implemented in various ways. For example, in the embodiment, the case where the 1 st pinion gear P1 and the 2 nd pinion gear P2 are integrally formed by precision forging has been described, but the present invention is not limited to this, and they may be formed separately from each other and then integrally connected.
In the embodiment, the 1 st brake 11 and the 2 nd brake 12 include wet multiplate clutches, but any other type of brake may be used as long as it can switch between tightening and releasing and can control the braking torque at the time of tightening.
In the embodiment, the 1 st ring gear R1 is connected to the right output shaft SFR and the 2 nd ring gear R2 is connected to the left output shaft SFR, but the 1 st ring gear R1 may be connected to the left output shaft SFR and the 2 nd ring gear R2 may be connected to the right output shaft SFR.
In the embodiment, a double-pinion planetary gear device is used as the differential device D, but other devices having the 1 st to 3 rd rotating elements that can rotate differentially with respect to each other, for example, a bevel-gear differential device or another type of differential device may be used. In the embodiment, the power distribution device 1 is configured to distribute power to the left and right output shafts SFL, SFR connected to the left and right drive wheels WFL, WFR of the vehicle, but may be configured to distribute power to the front and rear output shafts connected to the front and rear drive wheels of the vehicle.
Further, in the embodiment, the internal combustion engine 3 is used as the power source of the power split device 1, but other devices capable of outputting power, such as a rotating electrical machine or a hydraulic motor, may be used. Further, the embodiment is an example in which the present invention is applied to a vehicle, but the present invention is not limited to this, and may be applied to a ship, an airplane, or the like, for example. The configuration of the details may be appropriately modified within the scope of the present invention.
Claims (3)
1. A power split device that is connected to a power source via a transmission for splitting power to two rotating shafts that are capable of differential rotation with each other, characterized by comprising:
a double pinion including a 1 st pinion and a 2 nd pinion provided integrally with each other;
a pinion gear meshed with the 1 st pinion gear;
a rotatable carrier member that rotatably supports the double pinion gear and the pinion gear;
a sun gear which is freely rotatable and is meshed with the pinion;
a 1 st ring gear which is freely rotatable, is engaged with the 1 st pinion, and is connected to one of the two rotation shafts;
a 2 nd ring gear which is freely rotatable, is engaged with the 2 nd pinion gear, and is connected to the other of the two rotation shafts;
a 1 st brake for braking the carrier member;
a 2 nd brake for braking the sun gear; and
a differential device having a 1 st rotating element, a 2 nd rotating element and a 3 rd rotating element which can perform differential rotation with each other,
the 1 st rotating element is connected to a power transmission path between the 1 st ring gear and one of the two rotating shafts, the 2 nd rotating element is provided on a power transmission path between the 2 nd ring gear and the other of the two rotating shafts, the 3 rd rotating element is connected to the transmission,
the 1 st pinion gear and the 2 nd pinion gear of the double pinion gear have different diameters and the same number of teeth from each other, and gear teeth are integrally formed without a gap.
2. The power split device according to claim 1, wherein the 1 st brake and the 2 nd brake are arranged in a state of overlapping with each other in an axial direction of the two rotary shafts.
3. The power split device according to claim 1 or 2, characterized in that the power split device is entirely housed in a transmission case housing the transmission.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017238310A JP2019105311A (en) | 2017-12-13 | 2017-12-13 | Force distribution device |
| JP2017-238310 | 2017-12-13 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109915570A CN109915570A (en) | 2019-06-21 |
| CN109915570B true CN109915570B (en) | 2021-01-22 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811214612.5A Active CN109915570B (en) | 2017-12-13 | 2018-10-18 | Power distribution device |
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| Country | Link |
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| JP (1) | JP2019105311A (en) |
| CN (1) | CN109915570B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102019209465A1 (en) | 2019-06-28 | 2020-12-31 | Zf Friedrichshafen Ag | Gearbox with a differential locking unit |
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| DE19621380A1 (en) * | 1996-05-28 | 1997-12-04 | Voith Turbo Kg | Automotive gear box having hydrodynamic torque converter as constant=speed |
| US7503416B2 (en) * | 2005-06-28 | 2009-03-17 | Magna Powertrain Usa, Inc. | Torque distributing drive mechanism with limited slip |
| CN102362097A (en) * | 2009-03-31 | 2012-02-22 | 本田技研工业株式会社 | Drive device and vehicle with same |
| CN104185748A (en) * | 2012-03-27 | 2014-12-03 | 本田技研工业株式会社 | Motive power device |
| WO2016013380A1 (en) * | 2014-07-23 | 2016-01-28 | 株式会社ハーモニック・ドライブ・システムズ | Dual-type wave gear device |
| CN107387725A (en) * | 2017-08-10 | 2017-11-24 | 金明必 | Flexible gear and its component, decelerator and speed reducing ratio algorithm using the component |
-
2017
- 2017-12-13 JP JP2017238310A patent/JP2019105311A/en active Pending
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2018
- 2018-10-18 CN CN201811214612.5A patent/CN109915570B/en active Active
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| JPH08114255A (en) * | 1994-10-18 | 1996-05-07 | Honda Motor Co Ltd | Power transmitting apparatus for vehicle |
| DE19621380A1 (en) * | 1996-05-28 | 1997-12-04 | Voith Turbo Kg | Automotive gear box having hydrodynamic torque converter as constant=speed |
| US7503416B2 (en) * | 2005-06-28 | 2009-03-17 | Magna Powertrain Usa, Inc. | Torque distributing drive mechanism with limited slip |
| CN102362097A (en) * | 2009-03-31 | 2012-02-22 | 本田技研工业株式会社 | Drive device and vehicle with same |
| CN104185748A (en) * | 2012-03-27 | 2014-12-03 | 本田技研工业株式会社 | Motive power device |
| WO2016013380A1 (en) * | 2014-07-23 | 2016-01-28 | 株式会社ハーモニック・ドライブ・システムズ | Dual-type wave gear device |
| CN107387725A (en) * | 2017-08-10 | 2017-11-24 | 金明必 | Flexible gear and its component, decelerator and speed reducing ratio algorithm using the component |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2019105311A (en) | 2019-06-27 |
| CN109915570A (en) | 2019-06-21 |
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