Pumps – With muffler acting on pump fluid
Patent
1995-07-05
1998-03-10
Thorpe, Timothy
Pumps
With muffler acting on pump fluid
417313, 181198, F04B 3900
Patent
active
057253617
DESCRIPTION:
BRIEF SUMMARY
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic unit the essential parts of which are an oil container and a pump unit, wherein the container has an internal and an external outer wall with an oil receiving space between the walls. The oil container is hollow and has a receiving space for oil between an external outer wall and an internal outer wall. The pump unit comprises an electric motor and a pump which can be driven by the electric motor.
Such a hydraulic unit in which, furthermore, the electric motor is air cooled, is known from Federal Republic of Germany Utility Model 82 07 794. In that hydraulic unit, a hollow cylindrical oil container and the pump unit are arranged vertically. The oil container is substantially shorter than the pump unit and is spaced from the feet of a frame which supports the oil container and the pump unit. Below the oil container, a pipeline which is connected to the discharge connection of the pump is wound so as to form three pipe coils lying radially above one another. The inner space between the internal outer wall of the oil container and the pipe coils is hermetically closed in the vicinity of the bottom while it is covered on top by a ventilation grid. A fan wheel is arranged on the side of the electric motor opposite the pump between the electric motor and the ventilation grid. It is intended, in operation, to force outward through the ventilation grid air which it has drawn in from the outside through the pipe coils. It may be that the hydraulic oil flowing in the pipe coils can be cooled in this manner. However, it appears disadvantageous that the air which is heated upon flowing through the pipe coils passes along the electric motor to the fan wheel. Sufficient cooling of the electric motor does not appear to be assured by this. In addition to the problem of the production of heat and the cooling of the hydraulic oil as well as of the electric motor forming a part of the pump unit which is thereby necessary, the problem of the production of noise and of the damping of the noise has for some time come more and more into the foreground in connection with hydraulic units, under the slogan of the humanizing of work stations.
SUMMARY OF THE INVENTION
The object of the present invention is so to improve a hydraulic unit having the features set forth above so that its noise level is low. Furthermore, sufficient cooling of the hydraulic oil and of the pump unit, and particularly of the electric motor of the pump unit, is to be assured by a further development. The ease of assembly of the hydraulic unit is also to be the subject of attention.
The goal of a low emission of noise is obtained for a hydraulic unit of the foregoing type by providing a sound damping element. By means of the oil container and one or more sound-damping elements, the pump or pump unit is encapsulated so that the hydraulic unit has only a low noise level.
Advantageous embodiments of a hydraulic unit in accordance with the invention can be noted herein.
Primarily two principles are applied for the cooling of the electric motor of a hydraulic unit which drive a hydraulic pump. One of them is the principle of air cooling. In that case, there is associated with the electric motor a fan wheel which is generally driven by the electric motor itself and which, by means of a baffle plate, produces a flow of air which passes over cooling ribs on the outside of the motor housing. The second principle is liquid cooling of the electric motor by the oil present in an oil container of a hydraulic unit. For this type of cooling, the electric motor together with the pump is immersed in the oil present in the oil container. The unit consisting of electric motor and pump is then referred to as an under-oil unit. Due to the fact that the pump unit is immersed in the oil contained within an oil container, the emission of noise is already reduced as compared with a hydraulic unit in which the pump unit is located outside the oil container. A further reduction in noise is obtained if
REFERENCES:
patent: 3723027 (1973-03-01), Montelius
patent: 4201523 (1980-05-01), Olofsson
patent: 4569637 (1986-02-01), Tuckey
patent: 4585398 (1986-04-01), Drake
patent: 5169531 (1992-12-01), Shiraga et al.
patent: 5211547 (1993-05-01), Gaston et al.
patent: 5407330 (1995-04-01), Rimington et al.
Book: Grundlagen und Komponenten der Fluid-Technik Hydraulik (Principles and Components of Fluid Hydraulics) vol. 1, 1991, published by Mannesmann Rexroth GmbH, p. 295 et seq., Exner et al.
Farber Martin A.
Korytnyk Peter G.
Mannesmann Rexroth GmbH
Thorpe Timothy
LandOfFree
Hydraulic unit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydraulic unit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydraulic unit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-134035