Description

Manifolded Multiple Hydraulic Pump Structure

Technical Field

This invention relates to a manifolded, multiple hydraulic pump structure which may be used wherever two or more rotary pumps may be driven by a single drive shaft. It is expressly disclosed herein as applied to a heavy vehicle having a hydraulic trans¬ mission and a hydraulic torque converter; but is not limited to such application.

Background Art \

There are numerous situations in which a hydraulic power circuit requires a plurality of rotary pumps to supply fluid to various power elements in the system. Commonly such pumps are completely independent of one another, which requires plural mountings and a substantial number of conduits of varying length/ all of which are subject to possible leakage at their various connections and to breakage under operating stress. The arrangement of separate pumps, separately mounted, gives very poor space utilization and requires a separate drive train to each of the pumps.

Typical of such hydraulic systems are those in heavy vehicles, such as crawler tractors, wheel loaders, and large capacity dump trucks. Such vehicles commonly have a hydraulic transmission and a hydraulic torque converter. The hydraulic system for such a vehicle requires a charging pump for the hydraulic trans¬ mission, a fluid conduit from the pump to the trans- mission, a charging pump for the torque converter, a fluid conduit from the torque converter charging pump to the torque converter, scavenging pumps, scavenging con¬ duits from the transmission and the torque converter to

O PI /JI. ^WIPO _* v

the scavenging pumps, fluid delivery lines to both - charging pumps, and return lines from the scavenging pumps to the sump.

Disclosure of Invention The present invention is directed to overcoming one or more of the problems as set forth above.

According to the present invention, an improved pump structure has a pump casing assembly consisting of a plurality of rotary pump casing elements disposed in face abutting relationship, with sealing means between the casing elements and means detachably securing the casing elements in- assembled, face abutting relation¬ ship. The casing elements cooperate to define a first pump cavity and a second pump cavity, with a single drive shaft extending through an opening in a drive end plate of the casing elements and through both pump cavities in each of which it carries a rotary pump member. The cas¬ ing elements also are provided with a plurality of mani¬ fold passages including a first fluid inlet passage for admitting fluid to the first pump, a first fluid deliv¬ ery passage from the first pump which has a port in a fluid delivery end plate of the casing elements, a second fluid inlet passage and a second fluid outlet passage. When the invention is applied to a heavy vehicle which has a hydraulic transmission and a hy¬ draulic torque converter, the pump casing elements de¬ fine a transmission charging pump cavity and a torque converter charging pump cavity with the drive shaft extending through both cavities and a rotary charging pump member in each cavity, the charging, fluid inlet passage also supplies the torque converter pump cavity, there is a torque converter charging fluid delivery passage from that pump to a charging fluid port in the fluid delivery end plate, and a second scavenging pump which also has a pump member on the drive shaft.

OMPI IPO

Brief Description of Drawings

Fig. 1 is a side elevational view of the im¬ proved hydraulic pump structure of the present invention, mounted upon a gear housing wall of a heavy vehicle, with parts broken away and illustrated in section;

Fig. 2 is an end elevational view illustrating the fluid delivery end of the pump structure, taken sub¬ stantially as indicated along the line II-II of Fig. 1; Fig. 3 is an elevational view taken substan- tially as indicated along the line III-III of Fig. 1;

Fig. 4 is a horizontal sectional view taken substantially as indicated _# along the line IV-IV of Fig. 2;

Fig. 5 is a sectional view taken substantially as indicated along the line V-V of Fig. 4;

Fig. 6 is a fragmentary sectional view taken substantially as indicated along the line VI-VI of Fig. 5;

Fig. 7 is a sectional view taken substantially as indicated along the line VII-VII of Fig. 6;

Fig. 8 is a fragmentary sectional view taken substantially as indicated along the line VIII-VIII of Fig. 7;

^' Fig. 9 is a fragmentary sectional view taken substantially as indicated along the line IX-IX of Fig. 2;

Fig. 10 is a fragmentary sectional view taken substantially as indicated along the line X-X of Fig. 9; and Fig. 11 is a diagrammatic view illustrating the operative relationship between the pump structure of the present invention and functionally related parts of a heavy vehicle power train and hydraulic system.

Best Mode for Carrying Out the Invention

Referring to Figs. 1-4 of the drawings, the improved pump structure of the present invention com-

OMPI

_/ .- wIiPrOu . _.ΛΛ^

prises a pump casing assembly, indicated generally at 20, which includes a charging pump subassembly, indicated generally at 21, and a scavenging pump subassembly, indi¬ cated generally at 22. The pump casing elements forming the charging pump subassembly include a drive end plate 23 and a first set of casing elements consisting of a torque converter charging pump element 24, a transmission charging pump casing element 25, and a charging subassem¬ bly transition casing element 26. The scavenging pump subassembly 22 consists of a second set of casing ele¬ ments including a scavenging inlet casing element 27, a scavenging pump casing element 28, and a fluid delivery end plate 29.

The casing elements 23-26 of the charging pump subassembly 21 are aligned by means of a pair of align¬ ment pins 30 which make a snug sliding fit in alignment sleeves 31 and screw into threaded bores 32 in the transition casing element 26. Assembly of the charging pump subassembly 21 is by means of four long machine screws 33 which have their heads seated in counterbores 34 in a transition face 35 of the transition casing ele¬ ment 26, and the machine screws 33 extend through aligned bores 36 in the casing elements 24, 25 and 26, and screw into threaded bosses 37 which project from the outer surface of the drive end plate 23.

The three casing elements of the scavenging pump subassembly 22 are aligned with one another and with the charging pump subassembly 21 by means of guide pins 38 in the scavenging inlet casing element 27 and the fluid delivery end plate 29 which seat in sockets 39 in the scavenging pump casing element 28 and in the transi¬ tion face 35 of the transition casing element 26. The three casing elements of the scavenging pump subassembly 22 are assembled by means of four long machine screws 40 which have their heads recessed in counterbores 41 formed in a front face 42 of the subassembly 22, and the machine

O PI IPO r

5 -

screws 40 extend through aligned bores 43 in the casing elements 27 and 28 and screw into threaded bores 44 in the fluid delivery end plate 29.

As best seen in Figs. 1 and 2, the fluid delivery end plate 29 is provided with mounting flanges 45 in which there are bolt holes 46; and there are also four peripheral mounting bosses 47 on the transitional pump casing element 26, and aligned with the bosses 47 on the pump casing elements 27, 28 and 29 are mounting bosses 48, and continuous bolt holes 49 extend through the aligned bosses 47 and 48. The bolt holes 46 and the bolt holes 49 receive mounting bolts 50 and 51, respectively, by means of which the subassemblies 21 and 22 are inde¬ pendently secured to a housing wall H of a bevel gear housing which is a part of the vehicle drive. The housing wall H has threaded holes HI into which the mounting bolts 50 are screwedto secure the scavenging pump subassembly 22 to the wall H and there are also threaded bolt holes H2 in the wall H which receive the mounting bolts 51 that secure the charging pump subassembly 21 to the wall. In addition to securing the charging pump subassembly 21 to the housing wall H, the threaded bolts 51 also detachably secure the two subassemblies 21 and 22 in face abutting relationship as illustrated in Fig. 1. In addition to the mounting bolts 50, guide pins 52 which are aligned with the guide pins 38 in the fluid delivery end plate 29 seat in holes H3 in the housing wall H.

Referring now to Fig. 4, the pump casing ele¬ ments 23 and 24 cooperate to define a torque converter charging pump cavity 53; and the casing element 24 also cooperates with casing elements 25 and 26 to define a transmission charging pump cavity 54. The three casing elements of the subassembly 22 cooperate to define scavenging pump cavities 55 and 55a. The pump casing elements of the charging pump subassembly 21 are pro¬ vided with a series of aligned pump drive shaft openings

O PI

56, 57 and 58 which are provided with respective sleeve bearings 56a, 57a and 58a; and in the scavenging pump subassembly 22 are aligned pump drive shaft openings 59, 60 and 61 which are provided, respectively, with sleeve bearings 59a, 60a and 61a. A charging pump drive shaft segment 62 is journalled in the sleeve bearings 56a-58a, while a scavenging pump drive shaft segment 63 is jour¬ nalled in the bearings 59-61; and the two drive shaft segments have an axially interfitting drive connection provided by a slot 62a at the inner end of the drive shaft segment 62 and a lug 63a at an end of the drive shaft segment 63 which makes a sliding fit in the slot 62a. The drive shaft segment 62 has an end portion 62b which extends through the drive shaft opening 56 in the drive end plate 23 which is adapted for operative con¬ nection to driving means through a drive pulley assembly, indicated generally at 64, by means of which a drive pulley 65 is mounted upon the drive shaft segment 62 through a splined connection 62c. The drive pulley as- sembly forms no part of the novel subject matter of the present invention, so it is not described in detail.

Alongside the drive shaft openings 56-58 in the charging pump subassembly 21 are idler shaft openings 66, 67 and 68 which are provided with respective sleeve bearings 66a-68a; and alongside the drive shaft openings 59, 60 and 61 in the subassembly 22 are idler shaft openings 69, 70 and 71 which are provided, respectively, with sleeve bearings 69a-71a. A charging pump idler shaft 72 is journalled in the sleeve bearings 66a-68a, while an idler shaft 73 is journalled in the sleeve bearings 69a-71a.

Keyed to the drive shaft segment 62 and to the idler shaft 72 in the torque converter charging pump cavity 53 are meshing gear pump members 74 and 75 which form a rotary, gear type torque converter charging pump; and on said shafts 62 and 72 in the transmission charging

O PI WIPO

- -

pump cavity 54 are inter eshing gear pump members 76 and 77 which provide a rotary transmission charging pump. Similarly, on the drive shaft segment 63 and the idler shaft 73, in the scavenging pump cavity 55 are inter- meshing gear pump members 78 and 79 which provide a first rotary scavenging pump; while intermeshing gear pump members 80 and 81 in the scavenging pump cavity 55a pro¬ vide a second rotary scavenging pump. The first rotary scavenging pump 78-79 scavenges fluid from a torque con- verter C, while, the second rotary scavenging pump 80-81 scavenges fluid from a transmission T.

Referring now particularly to Figs. 1, 2 and 5-10, the present hydraulic pump structure 20 is mani¬ folded to provide a charging fluid inlet passage 82 (Figs. 1, 5, 6 and 8); a torque converter charging delivery passage 83 (Figs. 3, 5, 6 and 7); a transmission charging fluid delivery passage 84 (Figs. 2, 7 and 8) ; a torque converter scavenging inlet passage 85 (Figs. 1, 2, 9 and 10) ; a transmission scavenging fluid inlet passage 86 (Figs. 2 and 9); and a scavenging fluid outlet passage 87 (Figs. 2 and 9) .

Because of the fact that the pump structure is mounted on the gear housing wall H with the fluid deliv¬ ery end plate 29 abutting the wall, the wall is provided with holes which are seen in Figs. 2 and 3 to be in register with the ports for the passages 83, 84, 86 and 87, and said holes are identified in Fig. 3 by the respec-* tive numerals H4, H5, H6 and H7.

When the structure 20 is assembled, annular seals 88, which are mounted in grooves in certain of the casing element faces in abutment with the adjacent casing element faces and with the wall H, seal the entire struc¬ ture against leakage from the pump cavities. In addi¬ tion, leakage from the charging delivery passages 83 and 84 is minimized or provided by means of annular seals 89 (see Figs. 6 and 8) at the abutting faces between the casing elements through which those passages pass.

OMPI

"

8 -

Industrial Applicability

The improved pump structure 20 of the present invention can be used in any hydraulic system having two rotary pumps that can be driven off the same shaft. A particularly advantageous use is illustrated in Fig. 11, where the pump structure 20 is mounted on a housing wall H of a gear housing G that is in direct communication with the housing for the hydraulic transmission T of a heavy vehicle. This permits a transmission charging con- duit 90 to conduct fluid from the transmission charging delivery passage 84 to the transmission through the gear housing and also permits a transmission scavenging con¬ duit 91 to extend through the gear housing. This pro¬ tects such conduits from damage that could result from their being mounted in exposed locations, and also causes any leakage from the conduits to remain inside the housing. Furthermore, the entrance to the charging fluid inlet passage 82 is very close to, and directly in line with the outlet from a screen F which is also mount- ed upon the wall H, so that a charging fluid conduit 92 may be straight and only a few inches long. Likewise, although the torque converter charging fluid conduit 93 must go outside the gear housing, its connection to the pump through the hole H4 is inside the housing, and thus more protected than would otherwise be the case. A por¬ tion of the gear housing G provides a sump S to receive scavenged fluid from the passage 87 through the conduit 94, for return to the pump through the screen F. 95 is a scavenging fluid conduit which connects the torque converter to the scavenging inlet passage 85 of the scavenging pump subassembly 22.

Other aspects, objects and advantages of this invention can be obtained from a study of the drawings, the disclosure and the appended claims. The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should

OMPI WIPO

be un _d erstoo _d therefrom as modifications will be obvious to those skilled in the art.

^• ^OREXCΓ

O PI /.. WIPO \. K VS