LUBRICATION SYSTEM FOR AUTOMOTIVE TRANSMISSION POCKET BEARING

Abstract: The invention is directed to a transmission assembly comprising: a power output delivery end and a power input end; a pocket bearing operative between the power delivery end and the input end of the transmission; a lubricant con­ taining housing remote from the pocket bearing in the trans­ mission; a lubricant conduit system extending from said housing to said power input end of the transmission; a lubri­ cant pump in said housing responsive to transmission oper­ ation for throwing lubricant outwardly under pressure within said housing; and a lubricant collector in said housing in the part of the lubricant thrown out by said pump, said collector directing the lubricant under pressure into said conduit system for delivery into said power input end of the transmis­ sion for supplying lubricant under pressure to reach said pocket bearing.

Description: This invention is directed to a lubrication system for delivering lubricant to a transmission pocket bearing from a source of lubricant remote from the pocket bearing. It is known from the prior art to employ gear means to pump a lubricant into a lubricant guiding scoop where the lubricant is then directed from the scoop into a bearing that is not easily lubricated. Such an arrangement is seen in US-A- 2 011 559. In the automotive transmission art there is a known system of lubricating a pocket bearing by a lubricant splash collector that allows lubricant to drain into a passage that directs the lubricant into ports that feed a pocket bearing. This prior art arrangement is seen in US-A- 4 221 279, 4,227,427, and FR-A-2448656. In particular a transmission assembly according to the preamble of claim 1 is known from FR-A-2 448 656 The problem of obtaining adequate lubricant for a pocket bearing is magnified by the location of such a bearing in a pocket that is surrounded by structure required to sustain the torque during delivery of power from the engine output shaft to the input shaft of the transmission. Such a bearing is not susceptible of receiving lubricant by splash from the rotating gears because it is shielded by structure. In addition, there is the problem of getting lubricant to a forwardly located pocket bearing especially when the vehicle is moving up an incline where the lubricant shifts to the rear, away from the pocket bearing position. Some effort has been made to incorporate a dam to prevent lubricant shift in a transmission when in an inclined position of as much as 20°. The dam, however, is an impositive arrangement for overcoming the absence of pocket bearing lubricant. The object of the present invention is to provide means for adequately lubricating a pocket bearing in an automotive transmission. The present invention provides a transmission assembly with a pocket bearing lubricating system comprising a power delivery shaft having a drive gear thereon with an internal cavity; a transmission operating shaft having an end portion projecting into said internal cavity of said drive gear; bearing means operative between said drive gear and said transmission shaft end portion; and a lubricant collecting cavity having a connection with said internal cavity characterized by a lubricant containing housing remote from said cavities having a connection with said collecting cavity; pump means at said remote lubricant containing housing for forcing lubricant to flow through said connections and bearing cavity to said internal cavity for lubricating said bearing means; said pump means including gear means operating in said lubricant containing housing; and a lubricant gathering scoop mounted in said lubricant containing housing in position to receive lubricant forced by said gear means and direct said lubricant towards said connection; and said gear means and lubricant containing housing being placed at the power output end of the same said transmission assembly. A preferred embodiment of the present invention is illustrated in the accompanying drawings wherein: Fig. 1 is a longitudinal sectional view of the power input end of a typical automotive transmission to reveal the location of a pocket bearing; Fig. 2 is a perspective view of the power output end of an automotive transmission with cover structure removed to reveal a gear cluster that operates as a pump to supply an adjacent lubricant collector means; Fig. 3 is perspective view of the lubricant collecting means and outlet conduit; and Fig. 4 is a further view of the transmission showing the lubricant conducting means leading from the lubricant collecting means adjacent the gear cluster source to the power input end of the transmission for delivery to the pocket bearing. Fig. 1 is typical view of the power input end of an automotive transmission in which the power from the engine (not shown) is delivered to the output shaft 10. The enlarged end of the shaft 10 forms a drive gear 11 which meshes with a driven gear (not shown, but of well known character). The drive gear 11 encloses the power input end of a transmission shaft 12 which projects into the space in the drive gear 11. The pocket bearing assembly 13 is composed of an inner ring 13A on the shaft 12 and an outer race 13B in the gear 11 on the shaft 10, and between these shafts is a lubricant collecting cavity C. The input shaft adapter 14 is formed with suitable means to accommodate a further bearing assembly 15 for the shaft 10, as well as a seal 16. In the view of Fig. 1, there is the usual lubricant splash collection port 17 which opens from the interior of input shaft adapter 14 to a lubricant collecting space 18 which directs lubricant into the bearing cavity 19 adjacent other seal means 20 which prevents oil from entering bearing 15. The cavity 19 is in communication by drilled ports 21 with the pocket bearing 13 so that lubricant in the cavity furnishes bearing 13 with lubricant before it exits back to the transmission sump. Lubricant cannot be brought in from the transmission area beyond and to the right of the shaft 12 because of shifting mechanisms, synchronizers and other gears. The problem with this normal arrangement of lubricant for the pocket bearing 13 is that when the transmission is tilted up, as when the vehicle is moved up an incline, some inclines being of 20° or more, the pocket bearing is starved for lubricant at the worst possible operating condition when the torque demands of the drive are greatest. The preferred embodiment for solving the pocket bearing lubrication problem is seen in Figs. 1, 2, 3 and 4 where a source of lubricant under pressure or by force feed flow is associated with a conduit 22 connected into the cavity 19. Tracing that conduit 22 back toward the output end 23 of the transmission assembly, it can be appreciated that it enters the housing wall in the vicinity of the end housing 24 of the transmission (see Fig. 4). The details of the lubricant feed system are shown in Fig. 2, 3 and 4. The housing 24 has the rear end cover removed to show the lubricant pumping means in the nature of a gear cluster 25 in which a main gear 26 meshes with satellite gears 27 and 28 for a purpose that is not material to tis invention, except to forcefully deliver lubricant splash into the upper region of the housing 24. When the cover is in place on the housing 24 lubricant is retained therein regardless of the inclination of the vehicle. An important member of the lubricating system is seen in Fig. 3, and its position in the system is seen in Fig. 2. That member or collecting scoop is a curved pan 30 having sides 31 and 32 which confine the lubricant and direct it into the entrance end of the conduit 22. The spacing of the sides 31 and 32 is substantially the same as the width of the principal gear 26, and the entrance end of conduit 22 is partially confined by an overhanging lip 33 so that the lubricant thrown upwardly along the curved surface of the pan 30 is turned into the conduit 22 with considerable force sufficient to cause the lubricant to traverse the conduit 22 and reach the pocket bearing 13. The present disclosure shows the lubricant conducting conduit 22 to be partially separate from the housing wall of the transmission. However, it is understood that the wall may have an internal passage or series of connected passages for delivering lubricant to the pocket bearing. It is seen in Fig. 1 that the cavity C in front of the transmission shaft 12 receives and collects lubricant that will ultimately pass through the pocket bearing 13. When the clutch is engaged the principal pumping gear 26 is constantly rotating so lubricant will be delivered to the cavity C to assure adequate lubricant for the pocket bearing under transmission operating conditions. In Fig. 1 it can be seen that the usual arrangement of lubricant catch basin 18 is intended to supply the pocket bearing. The problem with that provision is that when the vehicle is moving up an incline or steep grade the lubricant migrates to the rear or away from the passage 17. The incline position is one in which the axis of the shaft 10 is tilted up from the left end. When that happens the gears in the front of the transmission do not dip into the lubricant and nothing reaches the passage 17 so the pocket bearing 13 is starved for lubricant. The present invention overcomes the problem of the prior provisions and delivers adequate lubricant to the pocket bearing 13 regardless of the position of the vehicle. Thus, there is increased pressure in and flow of lubricant to the pocket bearing in a significant amount.

Claims: 1. A transmission assembly with a pocket bearing lubricating system comprising a power delivery shaft (10) having a drive gear (11) thereon with an internal cavity (c); a transmission operating shaft (12) having an end portion projecting into said internal cavity (c) of said drive gear (11); bearing means (13) operative between said drive gear (11) and said transmission shaft end portion (12); and a lubricant collecting cavity (19) having a connection (21) with said internal cavity (c) characterized by a lubricant containing housing (24) remote from said cavities (c, 19) having a connection (22) with said collecting cavity (19); pump means (25) at said remote lubricant containing housing (24) for forcing lubricant to flow through said connections (21, 22) and bearing cavity (19) to said internal cavity (c) for lubricating said bearing means (13); said pump means (25) including gear means (26, 27, 28) operating in said lubricant containing housing (24); and a lubricant gathering scoop (30) mounted in said lubricant containing housing (24) in position to receive lubricant forced by said gear means and direct said lubricant towards said connection (22); and said gear means (26, 27, 28) and lubricant containing housing being placed at the power output end of the same said transmission assembly.

Inventors: CAMERON, ROBERT W., DRESSLER, GARY J., HARTLINE, JACK I.
Applicants: THE TIMKEN COMPANY
Application year: 1987
Main classification: F16C33
IPC codes: F16H57, F16N7, F16C33