The present invention relates to a power transmitting apparatus with rotary electrical machine that integrates a power generation function and an engine start function of a vehicle's alternator and a vehicle's starter motor.
Conventionally, as a power generation apparatus for a vehicle, as shown in
Further, an apparatus in which the alternator 105 is additionally provided with a driving function to be capable of starting an internal combustion engine in a warm state (after a warm-up) (refer to integrated starter generators (ISGs) disclosed in JP 4782348 B2, JP 4787242 B2, and JP 2009-508464 A) and further performing a driving force assist while a vehicle is travelling, or the like is known.
However, the method for starting an internal combustion engine described above may fail to start the engine in a cold state. This is because in the cold state, a decrease in temperature of a lubricating oil in the internal combustion engine causes increases in viscosity of the lubricating oil and in agitating resistance during startup, and a decrease in friction coefficient between the V-belt 104 and the pulley 103 causes slippage to occur between the V-belt 104 and the pulley 103, thereby preventing a rotational driving force of the alternator 105 from being transmitted to the internal combustion engine 101.
To address such a problem, a vehicle equipped with such an apparatus includes, without exception, a starter motor 106 in addition to the alternator 105 for the cold start of an internal combustion engine. Note that, in
Accordingly, an object of the present invention, having been conceived to solve the problem, is to provide a power transmitting apparatus with rotary electrical machine in which an internal combustion engine and the rotary electrical machine coupled with each other without a V-belt and a pulley to enable a reliable cold start.
In order to achieve the above-described object, the present invention is constructed as below.
According to one aspect of the present invention, there is provided a power transmitting apparatus with rotary electrical machine disposed in a power transmission path from an output shaft of an internal combustion engine to a transmission in a vehicle, the power transmitting apparatus including:
a rotary electrical machine disposed coaxially with the output shaft; and
a transmission apparatus disposed adjacent to the power transmitting apparatus and the rotary electrical machine, the transmission apparatus being capable of mechanically switching at least two power transmission paths having different reduction ratios between one of an outer shell of the power transmitting apparatus and a synchronous rotation member that rotates synchronously with the outer shell and a rotor of the rotary electrical machine.
According to the aspect of the present invention, the transmission apparatus is disposed adjacent to the power transmitting apparatus and the rotary electrical machine, and the at least two power transmission paths having different reduction ratios between the outer shell of the power transmitting apparatus or the synchronous rotation member that rotates synchronously with the outer shell and the rotor of the rotary electrical machine can be mechanically switched, which enables, without a V-belt and a pulley, a rotational driving force of the rotary electrical machine to be reliably transmitted to the internal combustion engine even in a cold state and enables a reliable cold start of the internal combustion engine.
These and other aspects and features of the present invention will become clear from the following description taken in conjunction with the embodiments thereof with reference to the accompanying drawings, in which:
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. Note that, in description of each embodiment, the same components or portions are denoted by the same reference numeral, and redundant description will be omitted.
As shown in
Furthermore, in the embodiment of the present invention, when the rotary electrical machine 5 is disposed in combination with the power transmitting apparatus 3, a power generation function and an engine start function of an alternator and a starter motor are integrated to enable the rotary electrical machine 5 to perform both the functions in order to reduce the cost and space.
More specifically, as shown in
This power transmitting apparatus 3 includes at least the rotary electrical machine 5 disposed coaxially with the output shaft 7, and the transmission apparatus 9 that is disposed adjacent to the power transmitting apparatus 3 and the rotary electrical machine 5 and is capable of mechanically switching at least two power transmission paths having different reduction ratios between an outer shell of the power transmitting apparatus 3 or a synchronous rotation member 8 that rotates synchronously (rotates integrally) with the outer shell and a rotor 11 of the rotary electrical machine 5.
Such a configuration will be described in detail below.
The rotary electrical machine 5 includes a stator 12 fixed to a stationary end 13 such as a case and the rotor 11 that rotates relative to the stator 12. A rotation axis of the rotor 11 is coaxial with the output shaft 7.
The outer shell 8 of the power transmitting apparatus 3 can be constituted by an outer shell of a friction clutch (for example, a clutch cover), an outer shell of a torque converter, or an outer shell of a fluid coupling. Examples of the synchronous rotation member 8 that rotates synchronously (rotates integrally) with the outer shell 8 include a drive plate of the torque converter coupled with the output shaft of the engine 2 for synchronous rotation, a drive plate coupled on a side of the internal combustion engine of the fluid coupling, a flywheel coupled on a side of the internal combustion engine of the friction clutch, and a member coupled on a side of the internal combustion engine of an electromagnetic clutch.
As an example, the transmission apparatus 9 includes a planetary gear mechanism 15 disposed coaxially with the output shaft 7 of the engine 2 and the rotary electrical machine 5, and an engagement and disengagement mechanism 10 capable of restricting or allowing relative rotation between a sun gear 16 and a pinion carrier 19 of the planetary gear mechanism 15, or between the sun gear 16 and the stationary end 13.
The planetary gear mechanism 15 includes the sun gear 16, a plurality of pinion gears 17, a ring gear 18, and the pinion carrier 19.
Each of the pinion gears 17 is in mesh with the ring gear 18 and the sun gear 16.
The ring gear 18 is in mesh with the plurality of pinion gears 17. The ring gear 18 is connected to the rotor 11 and rotates integrally with the rotor 11.
The pinion carrier 19 supports the plurality of pinion gears 17 with the pinion gears 17 rotatable, and is connected to the outer shell of the power transmitting apparatus 3 or the synchronous rotation member 8 (hereinafter, referred to as a synchronous rotation member of the power transmitting apparatus 3) that rotates synchronously with the outer shell to rotate integrally with the outer shell or the synchronous rotation member 8.
The plurality of pinion gears 17 are arranged around and in mesh with the sun gear 16, and the engagement and disengagement mechanism 10 (to be described later) is configured to utilize a configuration where rotation of the sun gear 16 is reversed between a start mode and a power generation mode to automatically switch the paths.
Further, as shown in
The engaging ring 24 is inserted into and engaged with the hub ring 23 and is disposed between the first pawl ring 21 and the second pawl ring 22 to be rotatable integrally with the hub ring 23 in normal and reverse directions. The engaging ring 24 is further slidable on the hub ring 23 in an axial direction.
The first pawl ring 21 is disposed at one end (for example, a side of the engine) of the engagement and disengagement mechanism 10 in the axial direction of a rotational shaft 27 coaxial with the output shaft 7 and is connected to the pinion carrier 19 to rotate integrally with the pinion carrier 19 in the normal and reverse directions. The first pawl ring 21 includes, on one side portion thereof, a number of first protrusions 21a that are arranged at equal intervals along a circumferential direction and protruded from a first annular portion 21c toward the engaging ring 24, and a first depression 21b between first protrusions 21a adjacent to each other. Each of the first protrusions 21a is rectangle in plan view, for example.
The second pawl ring 22 is disposed at the other end (for example, a side of the transmission) of the engagement and disengagement mechanism 10 in the axial direction of the rotational shaft 27 and fixed to the stationary end 13. The second pawl ring 22 and the first pawl ring 21 are plane symmetrical, and the second pawl ring 22 includes, on one side portion thereof, a number of second protrusions 22a that are arranged at equal intervals along the circumferential direction and protruded from a second annular portion 22c toward the engaging ring 24, and a second depression 22b between second protrusions 22a adjacent to each other. Each of the second protrusions 22a is rectangle in plan view, for example.
The hub ring 23 is connected to the sun gear 16 to rotate integrally with the sun gear 16 in the normal and reverse directions between the first pawl ring 21 and the second pawl ring 22. The hub ring 23 includes a number of third protrusions 23a that are arranged at equal intervals along the circumferential direction and protruded from a third annular portion 23c toward a center in a radial direction of the hub ring 23, and a third depression 23b between third protrusions 23a adjacent to each other. Each of the third protrusions 23a is rectangle in plan view, for example.
The engaging ring 24 is disposed inside the hub ring 23 in the radial direction, engages with the hub ring 23 to rotate integrally with the hub ring 23 in the normal and reverse directions and to be movable forward and backward in the axial direction of the output shaft 7, and has engaging protrusions 24a that can alternately engage with the first protrusions 21a and the second protrusions 22a. Specifically, the engaging ring 24 includes a number of the engaging protrusions 24a that are arranged at equal intervals along the circumferential direction and protruded outward in the radial direction from a fourth annular portion 24c, and a fourth depression 24b between engaging protrusions 24a adjacent to each other. Each of the engaging protrusions 24a is rectangle in plan view, for example, and has a first inclined surface 24g and a second inclined surface 24h formed at a pair of opposite corners, for example, at an upper left corner and lower right corner by chamfering or the like. Each of the engaging protrusions 24a is longer in the axial direction than that of the engaging ring 24, and either the first inclined surface 24g or the second inclined surface 24h protrudes, without exception, from the engaging ring 24 in the axial direction to be engageable with the first protrusions 21a or the second protrusions 22a. The engaging protrusions 24a of the engaging ring 24 engage with the second depressions 23b of the hub ring 23 on a one-to-one basis, and the third protrusions 23a of the hub ring 23 engage with the fourth depressions 24b of the engaging ring 24 on a one-to-one basis, causing the hub ring 23 and the engaging ring 24 to engage with each other in a rotation direction to prevent relative rotation but allow integral rotation in the normal and reverse directions while allowing the engaging ring 24 to move forward and backward in the axial direction relative to the hub ring 23 between a first protruding position I (see
The engagement and disengagement mechanism 10 configured as described above operates as shown in
At the first protruding position I of the engaging protrusion 24a, as shown in
After a state shown in
On the other hand, after each of the engaging protrusions 24a moves to the second protruding position II and the engaging ring 24 stops rotating, the engaging ring 24 is rotated, via the sun gear 16 and the hub ring 23, in the reverse direction that is opposite to a previous direction, that is, in the reverse direction that is a downward direction (see an arrow 73) rather than an upward direction as shown in
Subsequently, as shown in
After a state shown in
Here, respective meanings of “engagement” and “disengagement” of the engagement and disengagement mechanism 10 do not indicate an absolute state but a relative state. That is, in the engagement and disengagement between the engaging ring 24 (including the hub ring 23) and the first pawl ring 21, and the engagement and disengagement between the engaging ring 24 (including the hub ring 23) and the second pawl ring 22, a state where the two rings are synchronized with each other is denoted by “engagement”, and a state where the two rings are not synchronized with each other (that is, a state where there is a difference in rotation, in other words, a state where relative rotation is allowed) is denoted by “disengagement”. The engagement and disengagement between the engaging ring 24 and the first pawl ring 21 and the engagement and disengagement between the engaging ring 24 and the second pawl ring 22 cooperate with each other to bring about mutually different engagement and disengagement states at all the time.
Specifically, as shown in
On the other hand, as shown in
In the start mode, the sun gear 16 stops with a rotation speed set to 0, and rotation reduced in speed is transmitted from the ring gear 18 to the pinion carrier 19.
In the power generation mode, the sun gear 16, the pinion carrier 19, and the ring gear 18 rotate integrally, and the reduction ratio is equal to 1.
A brake element BR between the sun gear 16 and the stationary end 13 and a clutch element CL between the sun gear 16 and the pinion carrier 19 shown in
That is, in the configuration of the first embodiment, as shown in
This is a state where the engagement and disengagement mechanism 10 allows the relative rotation between the sun gear 16 and the pinion carrier 19 and restricts the relative rotation between the sun gear 16 and the stationary end 13, and corresponds to a first path of the power transmission paths from the ring gear 18 to the pinion carrier 19 via the pinion gears 17.
On the other hand, after the start of the engine 2 is completed, when a shift is made to the power generation mode that requires characteristics of a low torque and a high rotation speed, the engagement and disengagement mechanism 10 restricts the relative rotation between the components of the planetary gear mechanism 15 to allow the torque and the rotation speed generated by the engine 2 to be transmitted to the rotary electrical machine 5 in a direct coupling state (at a reduction ratio of 1). Therefore, the rotation through the output shaft 7 of the engine 2 is transmitted from the outer shell of the power transmitting apparatus 3 or the member 8 that rotates synchronously with the outer shell to the rotor 11 of the rotary electrical machine 5 via the pinion carrier 19, the pinion gears 17, and the ring gear 18 of the planetary gear mechanism 15. At this time, in the engagement and disengagement mechanism 10, when the pinion gears 17 and the sun gear 16 rotate integrally along with the rotation of the pinion carrier 19, the engaging ring 24 starts to rotate in the downward direction (see the arrow 73) shown in
This is a state where the engagement and disengagement mechanism 10 restricts the relative rotation between the sun gear 16 and the pinion carrier 19 and allows the relative rotation between the sun gear 16 and the stationary end 13, and corresponds to a second path of the power transmission paths from the pinion carrier 19 to the ring gear 18 via the pinion gears 17.
As described above, the first embodiment in which the transmission apparatus 9 is disposed adjacent to the power transmitting apparatus 3 and the rotary electrical machine 5, and at least two power transmission paths having different reduction ratios between the outer shell of the power transmitting apparatus 3 or the synchronous rotation member 8 that rotates synchronously with the outer shell and the rotor 11 of the rotary electrical machine 5 can be mechanically switched, enables the engine 2 and the rotary electrical machine 5 to be coupled with each other without a V-belt and a pulley and accordingly enables a reliable cold start of the engine 2. Further, the first embodiment corresponds to a system that eliminates the need for a mechanism or signal to be controlled from the outside for switching the power transmission paths and utilizes the driving and driven relation that is reversed between the engine start mode and the power generation mode, and makes it possible to achieve the engagement and disengagement mechanism 10 having the other configuration made as simple configuration. Further, as compared with the conventional configuration, integrating the functions of an alternator and a starter motor into the configuration of the first embodiment makes it possible to eliminate the need for components such as a starter motor, a ring gear, a V-belt, and a pulley, and accordingly reduce cost. Further, with the transmission apparatus 9, the above-described integration makes it possible to achieve two characteristics of the low rotation speed and the high torque and the high rotation speed and the low torque that are contradictory to each other by using the one rotary electrical machine 5 and gear transmission in which slippage does not occur even under a low temperature condition, and eliminate the need for a space occupied by components by removing the components to achieve a reduction in size and weight. Further, normally, the planetary gear mechanism 15 is often used in a lubricating oil atmosphere, whereas, in the first embodiment, the planetary gear mechanism 15 is used in the power generation mode in the most part of a period of time during which the vehicle is in operation and is used in the start mode in a very short period of time, which makes it possible to implement the first embodiment even not in the lubricating oil atmosphere. That is, in the power generation mode, since the components of the planetary gear mechanism 15 rotate integrally, that is, there is no rolling occurring between the gears, it is possible to implement the first embodiment even not under the lubricating oil atmosphere. Such features make it possible to simplify a seal, a lubricating structure, and the like, which is excellent in terms of space and cost.
<Modification>
Note that the present invention is not limited to the embodiment and can be implemented in various other modes. For example, as a modification shown in
Further, the engagement and disengagement mechanism 10 is not limited to the mechanism of the first embodiment and can have a different configuration.
For example, as a second embodiment of the present invention, the engagement and disengagement mechanism 10 can include a friction brake 31, a friction clutch 32, and a control mechanism 33 for the friction brake 31 and the friction clutch 32.
For example, the control mechanism 33 can be constituted of, for example, a hydraulic piston or various actuators capable of driving the friction brake 31 and the friction clutch 32 separately based on a timing signal for starting the engine output from a signal circuit or the like.
The friction brake 31 is disposed between the sun gear 16 and the stationary end 13. Application of the friction brake 31 causes the sun gear 16 and the stationary end 13 to be integrated with each other to stop rotation of the sun gear 16 while release of the friction brake 31 allows the sun gear 16 to freely rotate in the normal and reverse directions relative to the stationary end 13. For example, the friction brake 31 is configured to press, in the axial direction, disks and driven plates alternately arranged to stop rotation, and the pressing operation is achieved by a direct push made by a hydraulic piston, or a pushing operation made by an electric actuator via bearings.
The friction clutch 32 is disposed between the sun gear 16 and the pinion carrier 19. The friction clutch 32 connects the sun gear 16 and the pinion carrier 19 to cause the sun gear 16 and the pinion carrier 19 to rotate integrally or releases the connection between the sun gear 16 and the pinion carrier 19 to cause the sun gear 16 and the pinion carrier 19 to rotate separately. For example, the friction clutch 32 is configured to press, in the axial direction, the disks and the driven plates alternately arranged to transmit torque, and the pressing operation is achieved by a direct push made by a hydraulic piston, or a pushing operation made by an electric actuator via bearings.
The control mechanism 33 drives and controls various actuators such as a hydraulic piston or an electric actuator based on a signal from a signal circuit or the like in order to operate the engagement and disengagement of the brake 31 and the clutch 32.
Even such a configuration can exhibit the action effect of the first embodiment.
Further, an engagement and disengagement mechanism having a different configuration according to a third embodiment of the present invention shown in
For example, the control mechanism 42 can be constituted of, for example, a hydraulic piston or various actuators capable of driving brake and clutch elements of the dog or synchronous clutch 41 based on a timing signal for starting the engine output from a signal circuit or the like.
A dog or synchromesh (dog or synchronous) brake element 44 is provided between the sun gear 16 and the stationary end 13, and a dog or synchromesh (dog or synchronous) clutch element 45 is provided between the sun gear 16 and the pinion carrier 19.
Further, the control mechanism 42 is provided to operate the engagement and disengagement of the brake element 44 and the clutch element 45.
Here, the synchronizing mechanism is capable of making the engagement and disengagement while absorbing, to some extent, a difference in relative rotation between members to be synchronized. On the other hand, the dog clutch makes the engagement and disengagement after the difference in relative rotation between the members to be synchronized becomes almost zero. The synchronizing mechanism and the dog clutch are different from each other in detailed function and mechanism, but essentially identical to each other in power transmission configuration where engagement is made on a tooth-to-tooth basis unlike a power transmission basis such as a friction clutch. Therefore, description will be collectively given herein with reference to either the dog clutch or the synchronizing mechanism.
An example of an actual shape of the synchronizing mechanism is shown in
When an operation member 41b such as a shift fork starts to move the sleeve 41a rightward in
That is, at an initial stage of the operation member 41b such as a shift fork, the sleeve 41a is in mesh with the protrusion 41g of the synchronizer key 41c, and the sleeve 41a is out of mesh with the spline 41j of the synchronizer ring 41d. At this time, friction is generated by the pressing action on the synchronizer ring 41d against the cone (circular cone) portion 41f of the gear 41e using the end surface of the synchronizer key 41c to start a synchronizing action.
At an intermediate stage of the operation member 41b such as a shift fork, the sleeve 41a and the protrusion 41g of the synchronizer key 41c is out of mesh with each other, the sleeve 41a and the spline 41j of the synchronizer ring 41d are in contact with each other at their respective tips, and the friction is generated by the synchronizer ring 41d that is pressed by the sleeve 41a to strongly come into pressure-contact with the cone portion 41f of the gear 41e to strengthen the synchronizing action. That is, such a strong pressure-contact operation means “engagement” in the engagement and disengagement mechanism, and a release operation opposite to these operations means “disengagement”.
Note that a main shaft connected to the pinion carrier 19 is denoted by 41m, and a clutch shaft fixed to the stationary end 13 is denoted by 41p.
Even such a configuration can exhibit the action effect of the first embodiment.
By appropriately combining arbitrary embodiments or modifications of the above various embodiments or modifications, respective effects can be produced. Additionally, combination between embodiments, combination between working examples, or combination between an embodiment(s) and a working example(s) is possible, and combination between characteristics in different embodiments or working examples is possible as well.
Although the present invention has been fully described in connection with the embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.
The power transmitting apparatus with rotary electrical machine according to the aspect of the present invention allows an increase in the degree of freedom in designing and an increase in the output performance, and is suitable for a power transmitting apparatus with rotary electrical machine that integrates the power generation function and the engine start function of a vehicle's alternator and a vehicle's starter motor.
Number | Date | Country | Kind |
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2017-014996 | Jan 2017 | JP | national |
This application is the National Phase in the United States of PCT/JP2018/002898, filed Jan. 30, 2018, which claims priority to Japanese Patent Application No. 2017-014996, filed Jan. 31, 2017. Those applications are incorporated by reference in their entireties.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2018/002898 | 1/30/2018 | WO | 00 |