HK1048844B - Pump for generating pressure or negative pressure - Google Patents

Description

Pump for generating pressure or vacuum

The invention relates to a pump for generating pressure or vacuum, comprising a pump chamber, two rotors with at least two blades, a transmission device arranged on one end face of the rotors, and a housing cover arranged on the other opposite side; the pump cavity has a high pressure interface and a low pressure interface, the two rotors are mounted on two parallel shafts which are relatively dislocated in the pump cavity, and the housing cover is formed into a basin shape, and the high pressure interface and the low pressure interface are combined with the housing cover into a whole.

In this type of pump, the blades of the rotor engage in one another in a non-contacting manner, so that lubricant-free operation is possible. The field of application of such pumps is therefore very diverse. Due to the numerous possible applications of such pumps, optimization is sought with regard to their structural size, weight and manufacturing costs.

From US 4057375, a positive displacement pump is known, which has two impellers, which rotate in opposite directions in synchronism with one another and whose vanes, due to their engagement with one another, form separate variable-volume spaces during the rotational movement, in which spaces the compressed flow medium is conveyed from the low-pressure side to the high-pressure side, wherein the flow medium is conveyed in a direction perpendicular to the two shafts.

Another hydraulic pump is disclosed in GB 2139287 a which has two meshing gears, each gear being located in a chamber, the input and output passages opening into the housing surface of the chamber.

In this pump, the rotors are supported on both sides, i.e., at each of the two shaft ends. The pump chamber is bounded on both ends by a portion of the housing. The suction channel and the discharge channel open into the housing surface of the pump chamber.

In EP 0389838 a2, which forms the latest prior art, a rotary piston pump in the form of a roots compressor is described, which has two rotors which are arranged in a cantilevered manner on two mutually parallel shafts and can continuously feed various uncompressed flow media. The rotors are located in a chamber which is delimited on the reducer side by a plate and on the side remote from the reducer by a housing cover, wherein the shafts of the two rotors pass through the plate in a fluid-tight manner, and connecting pipes which are radially open to the outside are provided on the housing surface of the housing cover for the supply and discharge.

The object of the invention is to provide a pump which, with a space-saving and simple construction, makes it possible to locate the high-pressure and low-pressure passage openings in the housing at the location of an end face.

The above object is achieved according to the invention in that the housing cover has two through-openings in its inner wall which delimits the pump chamber on the front side, for the high-pressure connection and the low-pressure connection, and each through-opening connects a channel which is integrated into the housing cover. A single component, namely the housing cover, thus has three functions: a delimitation of the end face of the pump chamber, a circumferential wall of the pump chamber and a receiving interface channel. The housing cover can be produced economically as a cast or molded part.

Further features and advantages of the invention result from the following description of an advantageous embodiment and the associated drawings. In the drawings:

fig. 1 shows a side view of a pump device, showing a section taken axially in the region of a pump section;

FIG. 2 shows a side view of the housing cover;

FIG. 3 shows a top view of the housing cover;

FIG. 4 shows another side view of the housing cover;

FIG. 5 shows a top view of the inside of the housing cover; and

FIG. 6 shows a cross-sectional view taken along line V1-V1 of FIG. 5.

The pump device shown in fig. 1 has an electric motor 10 as a transmission. The motor 10 is flange-mounted to the side of the fan cover 12. The motor 10 is connected to a fan wheel 16 inside the fan cover 12 via a coupling 14. The fan cover 12 is mounted on the reducer case 18. Two mutually parallel, oppositely offset shafts 20, 22 are mounted in the gear housing 18 at each end thereof. The shaft 20 is arranged in alignment with the axis of the motor 10 and is directly driven by the motor shaft. A first spur gear 24 is fixed to the shaft 20 and meshes with a second spur gear 26 fixed to the shaft 22.

The two-bladed rotors 28, 30 are fixed to the unsupported ends of the shafts 20, 22, respectively, away from the reducer case 18. The blades of the rotors 28, 30 are claw-shaped and their geometry is designed for internal compression. As is evident from fig. 1, the shafts 20, 22 are mounted in the gear housing 18 on ball bearings, in particular angular ball bearings, on both sides of the gears 24, 26. The shafts 20, 22 are thus reliably guided and supported with respect to the cantilevered mounting of the rotor.

The gear housing 18 forms with its plane facing the rotors 28, 30 a delimiting wall of the end face of the pump chamber 32, the remainder of which is delimited by a pot-shaped housing cover 34 mounted to the gear housing 18. The housing cover 34 delimits the pump chamber 32 with its planar inner wall on the side facing away from the gear housing 18 and forms with its housing a circumferential wall of the pump chamber 32.

Integrated with the housing cover 34 are channels which form the high-pressure and low-pressure connections of the pump. The structure and connection of these channels is evident from figures 2 to 6.

As is apparent in particular from fig. 2 to 6, projections 36, 38 are formed on the end face of the housing cover 34, by means of which projections the outer walls of two channels 40, 42 integrated into the housing cover are realized. Two through-holes 46, 48 are formed in the planar inner wall 44 of the housing cover 34. The channel 40 is initiated by a through hole 46. The channel 40 has a first channel section running parallel to the inner wall 44, a channel section adjoining it which is inclined obliquely to the transmission side and outwardly, and a channel section adjoining it which runs outwardly and parallel to the inner wall 44 and which opens onto the connecting flange 50 on the circumference of the housing cover 34. The channel 42 is connected to the through-opening 48, the channel 42 likewise having a first channel section parallel to the inner wall 44, a channel section connected thereto which is inclined outwardly toward the transmission and a channel section which is again parallel to the inner wall 44 and which opens onto the connecting flange 52 on the circumference of the housing cover 34. The connecting flanges 50, 52 are located at different heights on the sides of the housing cover remote from one another.

Due to the cantilevered mounting of the rotors 28, 30, a structural space is reserved in the region of the free ends of the shafts 22, 24, which space allows for an optimized design of the passages 40, 42. In particular, the channels 40, 42 can be designed for optimal flow conditions and advantageous connection conditions.

Claims (8)

1. Pump for generating pressure or vacuum, having: a pump chamber having a high pressure port and a low pressure port; two at least double-bladed rotors (28, 30) mounted on parallel, oppositely-displaced shafts (20, 22) within a pump chamber (32); a gear mechanism arranged at one end face of the rotor (28, 30) and a housing cover (34) arranged at the opposite side face, wherein the housing cover (34) is designed in a pot-shaped manner and the high-pressure connection and the low-pressure connection are integrated into the housing cover (34), wherein the housing cover (34) comprises two through-openings (46, 48) for the high-pressure connection and the low-pressure connection, respectively, and each through-opening (46, 48) is connected to a channel (40, 42) integrated into the body of the housing cover (34), characterized in that the through-openings (46, 48) are designed as axial through-openings in an inner wall (44) which delimits the pump chamber (32) with its end face, and in that the vane geometry of the rotor (28, 30) and the axial through-openings (46, 48) are designed such that an internal compression of the medium to be delivered by the pump is possible.

2. Pump according to claim 1, characterized in that the at least one channel (40, 42) opens onto the circumference of the housing cover (34) and opens there.

3. A pump according to claim 2, characterised in that the channel (40, 42) has a first channel portion extending parallel to the inner wall (44) of the housing cover, a channel portion connected thereto which is inclined away from the inner wall and outwardly, and a channel portion connected thereto which leads to the circumference of the housing cover (34) parallel to the inner wall thereof.

4. Pump according to one of the preceding claims, characterized in that on the circumference of the housing cover (34) two connecting flanges (50, 52) are formed on two sides remote from one another.

5. Pump according to claim 4, characterized in that the connecting flanges (50, 52) are facing away from each other and are at different levels.

6. A pump according to claim 1, characterised in that at least a major part of the circumferential wall of the pump chamber (32) is formed by the outer casing of the casing cover (34).

7. Pump according to claim 1, characterized in that the shafts (20, 22) are supported on the side facing the transmission (10).

8. Pump according to claim 7, characterized in that the shafts (20, 22) are supported on both sides of a gear wheel (24, 26), respectively.