GB2076472A

GB2076472A - A vane-type rotary pump

Info

Publication number: GB2076472A
Application number: GB8115405A
Authority: GB
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1980-05-22
Filing date: 1981-05-20
Publication date: 1981-12-02
Also published as: JPS5716294A

Abstract

A pump, which may be a vacuum pump, has in a housing (1) a bore (2) within which is received a rotor (5) carrying sliding vanes (6, 7, 8, 9). In order to effect lubrication, sealing and cooling the pump is provided with a flow-through of oil, a suction port (19) for the oil being located at a point between bottom- dead-centre (UT) and an inlet passage (14) for the working fluid. In this manner, the oil throughput is made dependent upon rotational speed so that adequate cooling and lubrication is ensured even at high rotational speeds. <IMAGE>

Description

SPECIFICATION A vane-type pump The invention relates to a vane-type pump and in particular to a vane-type vacuum pump.

A vane-type vacuum pump having an eccentrically mounted rotor, is known from the published patent application of German Offenlegungsschrift 26 12 024. Known vacuum pumps of this kind involve the problem of making sufficient oil available to the pump for lubrication and for cooling. Known pumps frequently run dry or become too hot.

According to the present invention there is provided a vane-type pump having a housing bore in the wall of which are disposed an inlet passage and an outlet passage and in which an eccentrically mounted rotor rotates, the pump being provided with a flow-through of oil which serves as a sealing agent and lubricant and which is drawn in by the pump itself, and that a suction port for the oil intersects the housing bore at a point located in the vicinity of the inlet passage.

In contrast to the known pumps, the vane-type vacuum pump according to the invention has the advantage that the throughput of oil is also increased at higher rotational speeds for the purpose of improving lubrication and cooling, that is to say, the throughout of oil is proportionally variable in dependence upon rotational speed. In detail, a pump is provided in which the throughput of oil is dependent upon the vacuum produced in the pump. A portion which is speed-proportional to this oil throughput is superimposed on the oil throughput effected by vacuum. With corresponding design, it is possible to determine the corresponding time phases by the position of the inlet control edge or the position of the suction port.

An advantageous development of the invention is provided if the point of intersection for the intake line is located between bottom dead centre and the inlet passage.

One embodiment of the present invention will now be described further, by way of example only, with reference to the accompanying drawing which is a sectional view of a vane-type vacuum pump.

A pump housing 1 has a housing bore 2 having a central axis 3. A rotor 5 is disposed eccentrically in the housing bore 2, that is to say, the rotor has the central axis 4. The shortest distance between the rotor 5 and the housing bore 2 is designated bottom dead centre UT, and the largest distance is designated top dead centre OT.

Four vanes 6, 7, 8, 9 are mounted crosswise in the rotor 5 and, together with the rotor 5, form cells 10, 11, 12, 13 on the wall of the housing bore 2.

The wall of the housing bore 2 incorporates an inlet passage 14 and an outlet passage 1 5 which is located approximately diametrically opposite the inlet passage 1 4. The two passages have a respective widened recess 1 6 and 1 7 at the housing bore 2. An inlet control edge is designated 1 8.

An intake line 20 is connected to an oil suction port 1 9 which is provided at a predetermined distance in advance of the inlet passage 14 in the direction of rotation (arrow), which distance can be zero when the inlet passage 1 4 and the oil suction port 1 9 coincide with one another. In the illustrated embodiment, a corresponding distance is provided between the inlet control edge 1 8 and the oil suction port 1 9. The intake line 20 leads from an oil reservoir (not illustrated) which is preferably identical with the oil sump of an internal combustion engine, such as a diesel engine, which drives the vacuum pump.

The mode of operation of the embodiment illustrated in the drawing is as follows: The cell 12 located between the vane 8 and the bottom dead centre UT is enlarged during rotation of the rotor 1 5 in the direction of the arrow, so that oil is drawn in through the suction line 20 and the port 1 9. The suction port 1 9 is located such that, after the vane 8 has passed over the inlet control edge 18, the following vane 7 has not yet reached the suction port 1 9. The volume of oil delivered between UT, rotor 5, housing bore 2 and the vane 8 at the instant of passing over the inlet control edge 1 8 is directly proportional to the rotational speed of the rotor.After passing over the inlet control edge 18, the oil suction port 20 is directly subjected to the vacuum prevailing in the intake line 14. This continues until the following vane 7 has passed over the oil suction port 20.

The quantity of oil drawn in during this period of time is directly dependent upon the vacuum produced. The time phases for the speedproportional or vacuum-dependent intake of oil can be determined by the position of the inlet control edge 1 8 and by the position of the suction port 19.

Preferably, the pump is usable as a vacuum pump for vehicles in which the internal combustion engine is a diesel engine.

1. A vane-type pump having a housing bore in the wall of which are disposed an inlet passage and an outlet passage and in which an eccentrically mounted rotor rotates, the pump being provided with a flow-through of oil which serves as a sealing agent and lubricant and which is drawn in by the pump itself, and that a suction port for the oil intersects the housing bore at a point located in the vicinity of the inlet passage.

2. A vane-type pump as claimed in claim 1, in which the inlet passage has a widened recess at the housing bore, and that the distance of the suction port from the inlet passage is selectively measurable by a control edge, facing the suction port, of the inlet passage recess.

3. A vane-type pump as claimed in claim 1, in which the point of intersection for the intake line is

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A vane-type pump The invention relates to a vane-type pump and in particular to a vane-type vacuum pump. A vane-type vacuum pump having an eccentrically mounted rotor, is known from the published patent application of German Offenlegungsschrift 26 12 024. Known vacuum pumps of this kind involve the problem of making sufficient oil available to the pump for lubrication and for cooling. Known pumps frequently run dry or become too hot. According to the present invention there is provided a vane-type pump having a housing bore in the wall of which are disposed an inlet passage and an outlet passage and in which an eccentrically mounted rotor rotates, the pump being provided with a flow-through of oil which serves as a sealing agent and lubricant and which is drawn in by the pump itself, and that a suction port for the oil intersects the housing bore at a point located in the vicinity of the inlet passage. In contrast to the known pumps, the vane-type vacuum pump according to the invention has the advantage that the throughput of oil is also increased at higher rotational speeds for the purpose of improving lubrication and cooling, that is to say, the throughout of oil is proportionally variable in dependence upon rotational speed. In detail, a pump is provided in which the throughput of oil is dependent upon the vacuum produced in the pump. A portion which is speed-proportional to this oil throughput is superimposed on the oil throughput effected by vacuum. With corresponding design, it is possible to determine the corresponding time phases by the position of the inlet control edge or the position of the suction port. An advantageous development of the invention is provided if the point of intersection for the intake line is located between bottom dead centre and the inlet passage. One embodiment of the present invention will now be described further, by way of example only, with reference to the accompanying drawing which is a sectional view of a vane-type vacuum pump. A pump housing 1 has a housing bore 2 having a central axis 3. A rotor 5 is disposed eccentrically in the housing bore 2, that is to say, the rotor has the central axis 4. The shortest distance between the rotor 5 and the housing bore 2 is designated bottom dead centre UT, and the largest distance is designated top dead centre OT. Four vanes 6, 7, 8, 9 are mounted crosswise in the rotor 5 and, together with the rotor 5, form cells 10, 11, 12, 13 on the wall of the housing bore 2. The wall of the housing bore 2 incorporates an inlet passage 14 and an outlet passage 1 5 which is located approximately diametrically opposite the inlet passage 1 4. The two passages have a respective widened recess 1 6 and 1 7 at the housing bore 2. An inlet control edge is designated 1 8. An intake line 20 is connected to an oil suction port 1 9 which is provided at a predetermined distance in advance of the inlet passage 14 in the direction of rotation (arrow), which distance can be zero when the inlet passage 1 4 and the oil suction port 1 9 coincide with one another. In the illustrated embodiment, a corresponding distance is provided between the inlet control edge 1 8 and the oil suction port 1 9. The intake line 20 leads from an oil reservoir (not illustrated) which is preferably identical with the oil sump of an internal combustion engine, such as a diesel engine, which drives the vacuum pump. The mode of operation of the embodiment illustrated in the drawing is as follows: The cell 12 located between the vane 8 and the bottom dead centre UT is enlarged during rotation of the rotor 1 5 in the direction of the arrow, so that oil is drawn in through the suction line 20 and the port 1 9. The suction port 1 9 is located such that, after the vane 8 has passed over the inlet control edge 18, the following vane 7 has not yet reached the suction port 1 9. The volume of oil delivered between UT, rotor 5, housing bore 2 and the vane 8 at the instant of passing over the inlet control edge 1 8 is directly proportional to the rotational speed of the rotor.After passing over the inlet control edge 18, the oil suction port 20 is directly subjected to the vacuum prevailing in the intake line 14. This continues until the following vane 7 has passed over the oil suction port 20. The quantity of oil drawn in during this period of time is directly dependent upon the vacuum produced. The time phases for the speedproportional or vacuum-dependent intake of oil can be determined by the position of the inlet control edge 1 8 and by the position of the suction port 19. Preferably, the pump is usable as a vacuum pump for vehicles in which the internal combustion engine is a diesel engine. CLAIMS

3. A vane-type pump as claimed in claim 1, in which the point of intersection for the intake line is located between the bottom dead centre and the inlet passage.

4. A vane-type pump constructed and arranged and adapted to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.