US 3751191 A
An arrangement of a hydraulic pump and cooler unit for a hydrostatic drive mechanism, the unit comprises pump means, blower means, duct means, and heat exchanger means. The pump means and blower means are mounted on a single shaft so that they are coaxial and have common drive means. The heat exchanger means is located within the duct means, and both of said means are located directly above the blower means. The unit may include a reservoir means arranged side-by-side with the duct means and above the pump means. Said reservoir means may also include filtering means therein.
Claims available in
Description (OCR text may contain errors)
United States Patent n 1 Mott, Jr. et a1.
1 1 Aug. 7, 1973 HYDRAULIC PUMP AND COOLER UNIT  Inventors: Carl W. Mott, Jr., La Grange Park; Tommy A. Middlesworth, Hinsdale,
21 App1.No.: 111,954
 US. Cl. 417/313, 60/52 US, 60/52 HE,
165/122  Int. Cl. F04b 39/12  Field of Search 417/313, 360;
60/52 HE, 52 US, DIG. 5, 52 HD; 184/104 R; 165/107, 121,122,41'5/121, 121G; 180/53 1,762,028 6/1930 Phclps..... 415/121 2,672,000 3/1954 Speiscr 56/7 3,429,110 2/1969 Straser 56/7 FORElGN PATENTS OR APPLICATIONS 650,815 3/1951 Great Britain 415/121 G Primary Examiner-Carlton R. Croyle Assistant Examiner--R. .1. Sher Att0rney-Hibben, Noycs & Bicknell  ABSTRACT An arrangement of a hydraulic pump and cooler unit for a hydrostatic drive mechanism, the unit comprises pump means, blower means, duet means, and heat exchanger means. The pump means and blower means are mounted on a single shaft so that they are coaxial and have common drive means. The heat exchanger means is located within the duct means, and both of said means are located directly above the blower means. The unit may include a reservoir means arranged side-by-side with the duct means and above the pump means. Said reservoir means may also include filtering means therein.
12 Claims, 5 Drawing Figures PATENTEDAUB I ma mum's Inue CO/TZ IMMot 22919. If Mil/071111,
PATENFED M15 7 W3 SHEU 3 0f 3 HYDRAULIC PUMP AND COOLER UNIT This invention relates to a hydrostatic drive mechanism having a compact hydraulic pump and cooler unit.
Heretofore, it has been known to use a hydrostatic drive mechanism to operate various types of equipment. Such a mechanism usually includes a hydraulic pump for supplying pressure fluid for driving a hydraulic motor. Frequently, because of the large amount of heat transferred to the hydraulic fluid, cooling means, usually in the form of a fan and radiator, are also pro= vided for cooling the hydraulic fluid. Attempts have been made to achieve a compact assembly of these components, but such attempts have been only partially successful.
The present invention eliminates the foregoing disadvantages by providing a hydrostatic drive mechanism having a hydraulic pump and cooler unit with compactly arranged components. Such unit comprises hydraulic pump means and cooler means, and the cooler means further comprises duct means having heat exchanger means therein, and blower means for dissipat-- ing heat from the fluid. The hydraulic pump means and blower means are coaxially arranged and mounted on a single shaft, and drive means is provided for simultaneously driving the pump means and blower means. In addition, reservoir means having filter means therein, may be connected to the hydraulic pump means and heat exhanger means. The reservoir means and duct means are located side-by-side and may also be adjacent the coaxially arranged hydraulic pump means, drive means and blower means. Thus, the duct means extends radically from the blower means.
Accordingly, it is the primary object of the present invention to provide a hydrostatic drive mechanism having a compact hydraulic pump and cooler unit.
Another important object of the present invention is to provide a hydrostatic drive mechanism of the foregoing character suitable for being mounted on a vehicle for driving various types of equipment carried by the vehicle.
Still another object of the present invention is to provide a hydraulic pump and cooler unit having pump means and blower means coaxially aligned and having a common drive means, reservoir means attached to said pump means, and duct means extending radially from the blower means and arranged in side-by-side relation with said reservoir means and having a heat exchanger therein. w
Theseafl'dnier' objects of the present invention will become apparent from the following description and accompanying figures of the drawings in which:
FIG. 1 is a perspective view of a tractor equipped with three mowers, two of which are driven by two hydrostatic drive mechanisms each utilizing a hydraulic pump and cooler unit embodying the features of the present invention;
FIG. 2 is an enlarged vertical sectional view of one of the hydraulic pump and cooler units shown in FIG. 1;
FIG. 3 is a sectional view taken along the line 33 of FIG. 2;
FIG. 4 is a sectional view taken along the line 4--4 of FIG. 2; and
FIG. 5 is it reduced. top plan view of the unit shown in FIG. 2.
In FIG. I a vehicle or tractor I0 is illustrated, to which are secured a rear m'ower 12 and two side mowers 14. The rear mower I2 is, in this instance, mechanically driven from the rear power take-off of the tractor 10. The side mowers 14 are pivotally mounted on the outer ends of a pair of frames 13, the inner ends of the frames 13 also being pivotally connected to the sides of .the tractor 10. Thus, the side mowers 14 can be moved,
upwardly or downwardly, from their illustrated horizontal position, and can be pivoted. Such movements may be effected by conventional hydraulic cylinders (not shown) which receive hydraulic fluid under pressure from the hydraulic system of the tractor under the control of a multi-section control valve 15. The mowers l2 and 14 have rotatable mower shafts 17 to which cutting elements 19 are secured.
For convenience of installation, reduction in size, and increased operating efficiency, a separate hydrostatic drive mechanism embodying the features of the present invention, is utilized to drive each side mower 14. It will be understood that the hydrostatic mechanism to be hereinafter described could be used to drive other types of associated devices while located either on or off a vehicle. The provision of a separate hydrostatic drive mechanism for each associated device to be driven results in smaller, more easily handled components, and eliminates the pressure losses due to division of the fluid to drive two or more devices.
Each hydrostatic drive mechanism, in this instance, comprises a hydraulic motor 16 secured to one of the mowers l4 and driving the shaft 17 thereof, and a hydraulic pump and cooler unit 18. The motor 16 and unit 18 are connected together by conduit means in the form of flexible hoses 20 and 22.
The two units 18 are preferably mounted on the respective sides of the tractor l0 and at one end thereof, preferably the front end. The units may thus be driven by a power take-off shaft at the front of the tractor. The units may be selectively connected to or disconnected from .the power take-off shaft by manual controls 24.
As shown in FIG. 2, each hydraulic pump and cooler unit 18 comprises pump means, such as a hydraulic pump 28, and cooler means indicated generally at 30 The cooler means 30 includes a blower means 32, and a heat exchanger means 34 mounted within duct means 36. In this instance, reservoir means-38 having filtering means 40 therein, is also provided. The components are arranged with the pump means 28 closely adjacent and in coaxial alignment with the blower means 32, the duct means 36 extending radially from the blower means 32 and having the heat exchanger means 34 therein. The reservoir means 38 is arranged in close side-by-side relation with the duct means and adjacent the pump means 28.
The hydraulic pump 28 is conventional and has an outer housing 42, a fluid inlet pipe 44, a fluid outlet pipe 46, and a shaft 48 rotatably mounted in the housing 42 and extending from one end thereof. When driven, the pump 28 draws hydraulic fluid from the reservoir 38 and supplies hydraulic fluid under pressure to the motor 16.
Drive means is secured to the shaft 48 and, in this instance, comprises a pulley 50 having an inner or hub portion 52 keyed to the shaft 48, and an outer portion 54 secured to the hub portion 52 as by bolts 56. The pulley 50, in the present instance, is driven by two V- belts 58 which extend around another pulley 60 (FIG. I) mounted on the-front power take-off shaft of the tractor 10. Since the blower 3 2'a'nd pump 28 are connected to a single shaft 48, both may utilize the same drive means, i.e., the pulley 50.
The blower means 32, preferably comprises a squirrel cage rotor 62, and an enclosing housing 80. The rotor 62 includes a rear disk or plate 64 secured to the hub portion 52 of the pulley 50 by the bolts 56. An adapter 66 is located between the plate 64 and hub portion 52 so that the pulley 50 clears the rotor 62. The rear plate 64 is piloted on a portion 68 of the adapter 66 which serves to align the rotor 62 with the bore in the hub 52. Blades 70 are carried by the rear plate 64 and an annular front disk 72 forming part of the rotor. The axial center opening 73 of the front disk 72 forms the blower inlet and is covered by a screen 74 held in place on the rotor 62 by screws 76 and an outer annular disk 78. The screen 74 thus rotates with the rotor.
The rotor 62 rotates in the blower housing 80 which, except for an opening 82 in its rear wall, an opening 84 in its front wall, and a blower outlet or opening 86 at its top and connected to the heat exchanger 34, is completely closed. The housing 80 has a flange 88 surrounding the opening 86 and is secured to the lower end of the duct 36 surrounding the heat exchanger. The front opening 84 and, in this instance, the rear opening 82, are larger than the diameter of the rotor 62 so that some of the air delivered by the rotor bleeds out through the annular clearances between the housing 80 and the rotor 62 constituting positions of the opening 82 and 84. This air bleed eliminates the need for seals or the like, and insures that all air enters the blower through the screen 74 covering the blower inlet. The air bleed also prevents debris or other material from'entering the blower or from accumulating on the portion of the unit adjacent the blower. Debris and other materials are also centrifully prevented from accumulating on the screen 74.
The heat exchanger 34 comprises two headers 90 and 92 connected by a plurality of transverse tubes 94 having thin heat transfer fins 96 secured thereto. The header 90 has an inlet 98, and the header 92 has an outlet 100. The heat exchanger 34 is mounted in the duct 36 provided by a bottom wall 102, side walls 104, 106, 108, and a side wall 110 which also forms part of the reservoir 38, the top of the duct 36 being open. An opening 1 12 in the lower wall 102 aligns with the opening 86 in the blower housing 80 and permits passage of air from the blower 32 through the duct 36 to the heat exchanger 34.
The reservoir 38 is in side-by-side relation with the duct 36 and is also directly above the pump means 28. The reservoir 38 comprises the wall 110 which is common to the duct 36, side walls 128, 130 and 132, a bottom wall 134, and a top wall 136. The reservoir 38 is adapted to be filled with hydraulic fluid to a surface or level indicated by the broken line 109 in FIG. 2.
Fluid conducting'structure is provided to supply hydraulic fluid to the heat exchanger 34 and to transmit the fluid from the heat exchanger to the reservoir. To this end the one means, i.e., the heat exchanger 34 is interposed in the fluid conducting structure. The fluid conducting structure includes an inlet connection 137 which at one end is connected to the hose 22, an inlet pipe 138 which extends into the reservoir through an opening 139 (FIG. 4) in the reservoir wall 128, a pipe 140 extending into the duct 36 through an opening 141 (FIG. 3) in the common wall 110, and a hose 142 exrect hydraulic fluid away from the hydraulic fluid level' 109 in the reservoir 38, so that aeration of the fluid in the reservoir is minimized.
For flow from the heat exchanger 34 to the reservoir 38, the fluid conducting structure includes a hose 144 extending from the outlet of the heat exchanger 34, a pipe 145 located in a second opening 146 (FIG. 3) in the common wall 110, and a transfer pipe 147. The transfer pipe 147 extends through a second opening 148 (FIG. 4) in the reservoir wall 128, and the end of the pipe 147 is closed by a pipe cap 149 which may be fitted with a gauge, such as a temperature gauge 150. The pipe 147 has openings 151 within the reservoir downstream of the heat exchanger which are also oriented so that hydraulic fluid discharging through these openings is directed away from the upper surface 109 of the hydraulic fluid in the reservoir to likewise minimize aeration. All of the fluid flowing through the heat exchanger is discharged into the reservoir through the openings 151.
The pump inlet pipe 44 extendsfrom the pump 28 through an opening 152 in the lower wall 134 of the reservoir 38 and is threaded into the lower end of a larger diameter pipe 154 positioned within the reservoir. The lower wall 134 of the reservoir 38 is clamped between the end of the pipe 154 and an annular boss 156 secured to the inlet pipe 44, as by welding, to retain and support the reservoir 38 above the pump 28. An O-ring 158 is provided in a groove in the boss 156 to form a seal. In this instance, a removable cover 160 has been provided in the top wall 136 of the reservoir. The cover 160 has a groove and O-ring 162 on its outer edge to seal the cover 160 to the wall 136. A removable filler plug 164 having a vent opening 166 therein, is threaded into the cover 160. The cover 160 is held in place by a single center bolt 168 which engages a threaded member 170 welded to the upper end of the pipe 154, the member 170 closing the upper end of the pipe 154. The cover 160 permits replacement The filter means 40 is contained within the reservoir 38, is placed directly above and connected to the pump 28 through the pipe 154 and the inlet pipe 44, and comprises a conventional cylindrical filter element 172 having a center passage 174. The filter element 172 is held in place by a spring 176 which abuts the cover 160 and the element, and is centered by the pipe 154. The spring 176 is positioned by a tube 178 secured to the cover 160. The ends of the filter element 172 are sealed by engagement with seal washers 182. Openings 184 in the pipe 154 permit fluid to flow from the reservoir 38 through the filter element 172 to the pump 28.
In operation of the hydraulic pump and cooler unit, the drive means i.e., the pulley 50 is driven by a tractor power take off shaft, and in turn drives the pump 28 and blower rotor 62. Hydraulic fluid is pumped from the reservoir 38 by the pump 28, through the outlet pipe 46, and the hose 20, to the hydraulic motor 16, which drives the mower 14. The hydraulic fluid returns from the motor 16 through the hose 22 and the pipe 138. A portion of this fluid flows directly into the reservoir 38 through the bypass openings 143 in the pipe 138 to be recirculated by the pump. The remainder of the fluid flows through the pipe 138 and enters the heat exchanger 34, is cooled therein, and is returned to the reservoir through the hose 144 and the holes 151 in the transfer pipe 147. Fluid from the reservoir 38 is then drawn through the filter element 172 and the pipe 154 and the inlet pipe 44 by the pump 28 to again be supplied to the motor 16.
The blower rotor 62 draws air through the rotating screen 74. A small portion of this air is bled off through the clearances between the rotor 62 and the opening 82 and 84 of the blower housing 80. Most of the air, however, passes through the duct 36 and then passes through the heat exchanger 34 to the hydraulic fluid.
it is apparent from the foregoing that a hydrostatic drive mechanism having a compact hydraulic pump and cooler unit has been provided, whereinahydraulic pump means and blower means are closely adjacent to each other and in coaxial alignment, duct means havinga heat exchanger means therein is so as to extend radically from the blower means. Reservoir means may be located in close side-by-side relation with said duct means and adjacent said pump means, and filter means may be located within said'reservoir means.
We claim: v
1. A hydraulic pump and cooler unit, comprising hydraulic pump means, cooler means comprising blower means, duct means connected to and extending radially from said blower means for receiving air discharged from said blower means, and heat exchanger means in said duct means, said heat exchanger means being operable to cool hydraulic fluid pumped by said pump means, and reservoir means communicating with said heat exchanger means and said pump means and adapted to contain hydraulic fluid pumped by said pump means, said pump means and said blower means being arranged in coaxial relation with and close to each other and said reservoir means being located adjacent said pump means and arranged in side-by-side contiguous relation with said duct means, whereby the components of said unit are compactly arranged and the overall size of said unit is minimized.
2. The combination of claim 1, wherein drive means is provided for driving said pump means and said blower means, and said reservoir means is adapted to receive hydraulic fluid from said heat exchanger means and to supply hydraulic fluid to said pump means.
3. The combination of claim 2, in' which said pump means includes a shaft, said blower means includes a 6. The combination of claim 1, in which said reservoir means and said duct means are elongated and have a common wall, said pump means is connected to one end of said reservoir means, and said blower means is connected to the corresponding end of said duct means.
7. The combination of claim 6, in which said reservoir means and said duct means are arranged in an upright position, and said pump means and said blower means are respectively connected to the lower ends of said reservoir means and said duct means.
8. The combination of claim 7, in which said duct means is open at its upper end, said blower means including a rotor having an axial inlet and a housing having an upwardly opening outlet, and said blower outlet is connected to the lower end of said duct means.
9. In a hydraulic pump and cooler unit including reservoir means adapted to contain a supply of hydraulic fluid and heat exchanger means adapted to cool hydraulic fluid, the improvement comprising fluid conducting structure having spaced ends, one of said ends being adapted to be connected to a source of hydraulic fluid, said heat exchanger means being interposed between said ends of said structure, said structure having at least one opening therein upstream from said heat exchanger means for discharging hydraulic fluid into said reservoir means, and said structure downstream from said heat exchanger means communicating with said reservoir means.
10. The combination of claim 9, wherein said opening in said structure directs hydraulic fluid flowing therethrough away from the surface of hydraulic fluid in said reservoir means to minimize aeration thereof.
11. The combination of claim 9, wherein said structure is closed at its other end, and said structure downstream of said heat exchanger means has at least one otheropening therein for discharging hydraulic fluid into said reservoir means.
12. The combination of claim 11, wherein said other opening directs hydraulic fluid flowing therethrough away from the surface of hydraulic fluid in said reservoir means to minimize aeration.
$239,? UNITED STATES PATENT OFFICE (IECR'IH'FECATE (W comuzmmw Patent No. 3 I 191 Dated August I, 1973 Inventor(s) Carl W. Mott, Jr. et al It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below: 7
Col. 1, line 33, "radically" should read "radially".
Col. 3, line 29, "positions" should read "portions"; line 36, "centrifully. should read "centrifugally".
Col. 5, line 12, "opening" should read "openings",- line 22, after "is" should appear -loca1f;ed--,-- line 23, "radically' should read "radially".
Signed and sealed this 27th day of November 1973.
EDWARD M..FLETCI'IER,JR. RENE D. TEGTNEYER Attesting Officer Acting Commissioner of Patents