1. A lubrication structure of a cranking rotational force transmission mechanism for an internal combustion engine, the cranking rotational force transmission mechanism having an outer race member that is coupled with a rotational output shaft of the internal combustion engine; a ring gear to which a rotational drive force is transmitted from a starter motor and a portion of which faces the outer race member from a side of the internal combustion engine; and a one-way clutch that is provided in a position across which the portion of the ring gear faces the outer race member and that transmits a rotational force of the starter motor in one rotational direction from the ring gear to the outer race member and interrupts transmission of a rotational force of the starter motor in the other rotational direction from the ring gear to the outer race member, the lubrication structure comprising:
a sealing member that is provided to oil-seal a gap between the ring gear and the outer race member so that the one-way clutch is in an oil-sealed area in the internal combustion engine side; and
a lubricant-return hole that is formed in a portion of the ring gear between a portion of the ring gear at which the one-way clutch is provided and a portion of the ring gear at which the sealing member is provided, the lubricant-return hole penetrating the ring gear from a first side to a second side;
wherein the ring gear has a spoke portion which is provided on the radially outer side of the sealing member and in which spokes and openings are alternately provided in a peripheral direction of the ring gear, and
wherein phase positions of the lubricant-return holes are arranged so as not to overlap phase positions at which the radial dimensions of the openings are maximum.
2. The lubrication structure according to claim 1, wherein
a sectional area A1 of a lubricant passage upstream of the one-way clutch, a sectional area A2 of a lubricant passage downstream of the one-way clutch, and a sectional area A3 of a lubricant passage in the lubricant-return hole are set such that A1\u2266A2\u2266A3 is true at any rotational phase of the ring gear.
3. The lubrication structure according to claim 1, further comprising a wall which is provided on the side of an oil pan of the internal combustion engine the wall having a lubricant outlet hole formed therein, wherein lubricant that has been returned from the lubricant-return hole falls to the side of a lubricant storage of the oil pan through the lubricant outlet hole, wherein
the lubricant outlet hole is shaped and positioned such that when the internal combustion engine is running in a steady manner, the level of a surface of lubricant stagnating between the ring gear and the outer race member does not exceed a horizontal line that is drawn tangent to the lower side of the outer periphery of the outer race member.
4. The lubrication structure according to claim 3, wherein
V14\u2266Cf\xb7A15\u221a{square root over ( )}(2 gH) is true where V14 is a flow rate of lubricant flowing to the lubricant outlet hole, A15 is the sectional area of a lubricant passage in the lubricant outlet hole, H is the height from the lubricant outlet hole to a sealed slide surface of the sealing member at which the sealing member slidably contacts the outer race member, g is a gravitational acceleration, and cf is a flow rate coefficient of lubricant.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A reworkable passive element embedded PCB (printed circuit board) comprising:
a board member comprising first and second through holes spaced apart from each other;
first and second fillings buried in the first and second through holes, respectively, said first and second fillings formed of a reflowable conductive material that melts in a reflow process;
a removable first passive element having first and second electrodes; and
a first insertion groove formed in an upper surface of the board member between the first and second through holes and between portions of the first and second fillings,
wherein said first passive element is mounted in the first insertion groove, the first passive element having a bottom surface contacting the board member, the first electrode having a bottom surface and a side contacting the first filling, and said second electrode having a bottom surface and a side contacting the second filling, the first and second fillings at least partially embedding the removable first passive element in the PCB, and
wherein the first passive element has an exposed upper surface that is not in contact with another structure, enabling removal of the first passive element upon melting of the reflowable conductive material in response to the reflow process.
2. The reworkable passive element embedded PCB of claim 1, further comprising:
a plurality of first distribution patterns arranged on the upper surface of the board member; and
first and second distribution layers formed on sidewalls of the first and second through holes, respectively, wherein the first distribution layer is connected to corresponding one of the plurality of first distribution patterns and directly contacts the bottom surface of the first electrode of the first passive element, the second distribution layer connected to corresponding one of a plurality of pins arranged in a terminal part of said PCB and directly contacts the bottom surface of the second electrode of the first passive element.
3. The reworkable passive element embedded PCB of claim 1, wherein the first and second through holes penetrate the board member.
4. The reworkable passive element embedded PCB of claim 3, further comprising:
a second insertion groove formed in a bottom surface of the board member opposite from said upper surface and between the first and second through holes and between portions of the first and second fillings; and
a removable second passive element mounted on the second insertion groove, the second passive element having third and fourth electrodes, and an upper surface contacting the board member;
wherein the third electrode of the second passive element has an upper surface and a side contacting the first filling, and the fourth electrode has an upper surface and a side contacting the second filling, the first and second fillings at least partially embedding the removable second passive element in the PCB, and
wherein the second passive element has an exposed bottom surface that is not in contact with another structure, enabling removal of the second passive element upon melting of the reflowable conductive material in response to the reflow process.
5. The reworkable passive element embedded PCB of claim 4, further comprising:
a plurality of first distribution patterns arranged on the upper surface of the board member;
a plurality of second distribution patterns arranged on the bottom surface of the board member; and
first and second distribution layers respectively formed on sidewalls of the first and second through holes, wherein the first distribution layer is connected to a corresponding one of the plurality of first distribution patterns and corresponding one of the plurality of second distribution patterns and directly contacts the bottom surface of the first electrode of the first passive element and the upper surface of the third electrode of the second passive element, the second distribution layer is connected to a corresponding one of the plurality of pins arranged in the terminal part of the board member and directly contacts the bottom surface of the second electrode of the first passive element and the upper surface of the fourth electrode of the second passive element.
6. A semiconductor module comprising:
a PCB having a board member with first and second through holes spaced apart from each other, first and second fillings buried in the first and second through holes and formed of reflowable conductive materials that melt in a reflow process, a first insertion groove formed in an upper surface of the board member between the first and second through holes and between portions of the first and second fillings, and a terminal part having a plurality of pins;
a first passive element having first and second electrodes and mounted in the first insertion groove of the PCB, wherein the first passive element has a bottom surface contacting the board member, the first electrode has a bottom surface and a side contacting the first filling, and the second electrode has a bottom surface and a side contacting the second filling, the first and second fillings at least partially embedding the removable first passive element in the PCB; and
a first semiconductor package having a plurality of first connection terminals,
wherein the first passive element has an exposed upper surface that is not in contact with another structure, enabling removal of the first passive element upon melting of the reflowable conductive materials in response to the reflow process.
7. The semiconductor module of claim 6, wherein the first and second fillings comprise solders.
8. The semiconductor module of claim 6, wherein the PCB further comprises:
a plurality of first distribution patterns arranged on the upper surface of the board member and connected to the plurality of the first connection terminals of the first semiconductor package; and
first and second distribution layers respectively formed on sidewalls of the first and second through holes, wherein the first distribution layer is connected to a corresponding one of the plurality of first distribution patterns and directly contacts the bottom surface of the first electrode of the first passive element, and the second distribution layer is connected to a corresponding one of the plurality of pins of the terminal part and directly contacts the bottom surface of the second electrode of the first passive element.
9. The semiconductor module of claim 8, wherein the first and second through holes penetrate the board member.
10. The semiconductor module of claim 9, further comprising:
a second insertion groove formed in a bottom surface of the board member, between portions of the first and second distribution layers and between the first and second fillings; and
a removable second passive element having third and fourth electrodes mounted in the second insertion groove, the second passive element having an upper surface contacting the board member, the third electrode having an upper surface and a side contacting the first filling, and the fourth electrode having an upper surface and a side contacting the second filling, the first and second fillings at least partially embedding the removable second passive element in the PCB,
wherein the second passive element has an exposed bottom surface that is not in contact with another structure, enabling removal of the second passive element upon melting of the reflowable conductive materials in response to the reflow process.
11. The semiconductor module of claim 10, wherein the PCB further comprises:
a plurality of first distribution patterns arranged on the upper surface of the board member and connected to the plurality of the first connection terminals of the first semiconductor package; and
first and second distribution layers respectively formed on sidewalls of the first and second through holes, wherein the first distribution layer is connected to a corresponding one of the plurality of first distribution patterns and directly contacts the bottom surface of the first electrode of the first passive element and the upper surface of the third electrode of the second passive element, and wherein the second distribution layer is connected to a corresponding one of the plurality of pins of the terminal part and directly contacts the bottom surface of the second electrode of the second passive element and the upper surface of the fourth electrode of the second passive element.
12. A reworkable passive element embedded printed circuit board (PCB) comprising:
a board member comprising first and second through holes spaced apart from each other;
first and second insertion grooves formed on opposite surfaces of the board member between the first and second through holes;
a removable first passive element having first and second electrodes mounted in the first insertion groove;
a removable second passive element having third and fourth electrodes mounted in the second insertion groove; and
first and second fillings that fill the first and second through holes and portions of the first and second insertion grooves, respectively, to at least partially embed the removable first and second passive elements in the PCB, the first and second fillings being formed of a reflowable conductive material that melts in a reflow process,
wherein a bottom surface of the first passive element and a top surface of the second passive element contact the board member, the first and second electrodes contact the first and second fillings, and the third and fourth electrodes contact the first and second filling, respectively, and
wherein the first passive element has an exposed upper surface that is not in contact with another structure, and the second passive element has an exposed bottom surface that is not in contact with another structure, enabling removal of at least one of the first passive element and the second element upon melting of the reflowable conductive material of the first and second filling in response to the reflow process.
13. The reworkable passive element embedded PCB of claim 1, further comprising:
a plurality of first distribution patterns connected to a plurality of first connection terminals, the plurality of first distribution patterns being arranged on the upper surface of the board member; and
a plurality of second distribution patterns connected to a plurality of second connection terminals, the plurality of second distribution patterns being arranged on a bottom surface of the board member;
wherein the first and second through holes penetrate the board member from the upper surface of the board member to the bottom surface of the board member.
14. The semiconductor module of claim 6, wherein the PCB further comprising:
a plurality of first distribution patterns connected to a plurality of first connection terminals, the plurality of first distribution patterns being arranged on the upper surface of the board member; and
a plurality of second distribution patterns connected to a plurality of second connection terminals, the plurality of second distribution patterns being arranged on a bottom surface of the board member;
wherein the first and second through holes penetrate the board member from the upper surface of the board member to the bottom surface of the board member.
15. The reworkable passive element embedded PCB of claim 12, further comprising:
a plurality of first distribution patterns connected to a plurality of first connection terminals, the plurality of first distribution patterns being arranged on an upper surface of the board member; and
a plurality of second distribution patterns connected to a plurality of second connection terminals, the plurality of second distribution patterns being arranged on a bottom surface of the board member;
wherein the first and second through holes penetrate the board member from the upper surface of the board member to the bottom surface of the board member.