US1164105A - Means for deaerating and cooling the driving medium of hydraulic gears. - Google Patents

Description

H. LENTZ.

MEANS FOR DEAERATING AND COOLING THE DRIVING MEDIUM 0F HYDRAULIC GEARS.

APPLICATION FILED OCT-28,1?I3- I 1,164,1U5 R I Q. I Patented Doc. 14, 1915.

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llNltlllD b TATd PATENT @FFICE HUGO LENTZ, 0F HALENSEE, NEAR BERLIN, GERMANY.

MEANS FOR DEAERATING AND COOLING THE DRIVING MEDIUM 0]? HYDRAULIC GEARS.

Application filed October 28, 1913.

To all whom it may concern:

Be it known that I, HUGO Lnx'rz, a citizen of the German Empire, and residing at Halensee, near Berlin, Germany, have invented certain ;new and useful Improvements in Means for Deaerating and Cooling the Driving Medium of Hydraulic Gears, of which the following is a specification.

My invention relates to apparatus for cooling and removing the air from the driving medium of hydraulic gears.

It has already been attempted to remove the air from the driving medium of hydraulic gears by connecting the suction chamber of the pumps by two pipes with an elevated tank, the oil mixed with air being contained in the one pipe and the oil free from air in the other pipe, so that in consequence of the excess weight of the column of oil free from air the oil circulates between the suction chamber of the pump and the tank. As, in this apparatus, the circulation of the oil depends solely on the small difference in weight of the two columns of liquid, the circulation of oil can only be exceedingly weak. Therefore with this apparatus it is not possible to remove sutlicient air, and still less simultaneously to cool the driving medium, because only an exceedingly small part of the entire operative quantity of oil is conveyed into the tank; the greater part of the oil remains, on the contrary, uncooled inside the gear, Particularly, such an apparatus cannot be employed for motor-cars and the like, because in such vehicles there are no appreciable differences of level at all at disposal and, further, the jerks caused during travel are so severe that they entirely negative any such action due to difference of height. a

A -orimary object of my invention is ellectively to remove the air from the fluid medium and also to cool the latter in an improved manner.

To this end, li cause powerful circulation of oil by connecting by means of a bypass pipe having a tank connected therein two chambers in which different pressures exist, namely the suction chamber, and an exhaust chamber which is separated therefrom by a regulating member and in which a pressure is produced owing to the fluid being dammed back. The entire chamber of the gear is subdivided into three cham- -i bers, namely, the suction chamber of the pumps, the delivery chamber which supplies Specification of Letters Patent.

Patented Dec. 14, EH5.

Serial No. 797,846.

the working liquid from the pumps to the motors and in which the working pressure for the time being exists, and an exhaust chamber arranged directly behind the outlets of the motor and separated from the suction chamber by a regulating member, valve, or the like. In the exhaust chamber a pressure is produced on the one hand by the resistance of the said regulating member, and, on the other hand, by the conveying action ofthe motors, while the ordinary suction pressure exists in the suction chamber of the pumps. Now instead of connecting, as heretofore, two places at different elevations in one and the same chamber (2'. c. the suction chamber) which receives the driving liquid relieved of pressure, I connect together two difierent chambers, namely the suction chamber, which receives the discharged driving liquid relieved of pressure, and the exhaust chamber which receives the discharged driving liquid under pressure, and consequently a more powerful circulation of the liquid is produced in the by-pass pipe, so that all the driving liquid has the air removed from it and is cooled in a short time. It is not necessary, as in apparatus known heretofore, to arrange the tank high above the gear, for the purpose of producing a height of fluid premure produced solely by the difierence of weight, but the tankmust be located only a little or not at all above the gear, because the difference of pressure which is produced always brings about a powerful circulation of oil inclependently of the elevation of the tank.

One illustrative embodiment of the invention is represented by way of example in the accompanying drawing, wherein Figure 1 is a longitudinal section through hydraulic gear, and Fig. 2 is a section through the hydraulic pumps of the gear taken on the line ill-ll in Fig. 1.

Referring to the drawing, the gear comprises the twin pump 7; driven by any prime mover and. connected by the delivery cham-- her (7 to the hydraulic motors c. from which the fluid passes into an exhaust chamber 6 which is separated by the member 7, used for example, for reversing, from the suction :lxr-t 0 connected directly to the set of pumps Z. i by-pass pipe 7:, 2' branches oil from t exhaust chamber 6 and the suction duct a. mto which pipe is connected a tank 8 which ma v be in connection with the atmosphere. Now as this reversing member 7,

which must be provided, has an ap reciable unavoidable resistance, in consequence of the conveying action of the motors 0 a pressure is produced in the exhaust chamber 0 which is'far higher than the pressure in the suction duct 0. Owing to this difierence of pressure a powerful circulation of the oil is caused in the direction of the arrows shown in Fig. 1, so that the particles of air separate out in the tank and the oil can effectively cool. The circulation of the driving medium is regulated by the valve f and the damper or throttle valve 9. Preferably the one branch pipe 2' branching ofl from the suction duct 0 opens directly in front of the reversing valve 7, while the second branch pipe 70 branched off from the exhaust chamber 6 opens at the highest point of the gear close behind the exhaust port of the motors 0.

The apparatus operates as 'follows:- When the gear is stationary all the three said chambers are at the same pressure. WVhen the gear is driven a difference of pressure is produced between the two outlets m and n because the one outlet m opens directly into the suction duct of the pump where the low suction pressure exists, while the other outlet 11. is located behind the valve 7 in the exhaust chamber e at the highest point of the gear where the hydraulic pressure is far greater thanin the suction duct, as it has to overcome, in addition, the frictional resistance up to the valve and the resistances in the valve itself. In consequence of this difference of pressure a part of the driving medium is constantly powerfully circulated in the by-pass pipe; it issues out of the highest part of the gear, takes with it the air there collected and flows through the branch pipe is into the tank, here allows the air to escape into the open and is then sucked free from air and cooled through the branch pipe 27 into the gear.

The apparatus can be readily employed for filling the gear with oil. It is only neces sary to fill the tank with oil and to slowly start the motor and the pump of the gear. The oil is then sucked into the suction chamber, while the air can escape out of the exhaust'chamber through the pipe is until the gear is filled with oil.

I claim 1. The combination with hydraulic gear comprising a suction chamber, an exhaust chamber in direct communication with the suction chamber and a valve between the chambers, of an auxiliary circulating system comprising a pipe opening at one end into the suction chamber and at the other end into the exhaust chamber, and a tank connected into said pipe.

2. The combination with hydraulic gear comprising a casing containing a suction chamber and an exhaust chamber in communication with the suction chamber, a pump connected to the suction chamber, a motor connected to the exhaust chamber and reversing valves between the suction chamber and the exhaust chamber, of an auxiliary circulating system comprising a by-pass pipe opening at one end into the suction chamber and at the other end into the exhaust chamber, and a tank connected into said pipe.

In testimony whereof, I aflix my signature in the presence of two witnesses.

HUGO LENTZ.

W'itnesses:

HENRY HASPER, WOLDEMAR HAUPT.

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