Intermittent coupling oiling

Abstract

A pump, particularly a vacuum pump for boosting braking power on a motor vehicle, including a housing, a rotor mounted in the housing so as to be rotatable, an oil riser groove arranged in the housing in the area of the rotor mounting, and a transverse bore arranged in the rotor transverse to the longitudinal axis of the rotor and which can be connected to the oil riser groove. The rotor mounting area is connected to an oil supply bore. The transverse bore interacts with an axial bore in the rotor which leads to a coupling section within the rotor, in which a coupling is arranged which can be engaged by a fastener having a central bore running parallel to the longitudinal axis of the rotor.

Claims

1. A vacuum pump for brake boosting in a motor vehicle, having a housing, a rotor which is mounted rotatably therein, at least one oil riser groove formed in the housing in the region of a rotor bearing section of the rotor, and a transverse bore which is arranged in the rotor bearing section transversely with respect to a longitudinal axis of the rotor and which is connected to the at least one oil riser groove, the rotor bearing section being connected to an oil feed bore formed in the housing, wherein the transverse bore interacts with an axial bore in the rotor bearing section, which the axial bore leads to a rotor coupling section of the rotor, in which rotor coupling section a coupling is arranged and engaged by a fastening means having a central bore which runs parallel to the longitudinal axis of the rotor for guiding oil from the oil feed bore to the rotor coupling section of the rotor through the transverse bore, the axial bore and the central bore of the fastening means.

2. The pump as claimed in claim 1, wherein the transverse bore is configured to run as far as the middle of the rotor bearing section of the rotor.

3. The pump as claimed in claim 1, wherein the transverse bore is configured to run all the way through the rotor bearing section of the rotor.

4. The pump as claimed in claim 1, wherein the oil feed bore is adapted to be connected to an engine oil circuit of an internal combustion engine.

5. The pump as claimed in claim 1, wherein the rotor includes a radial groove, and wherein the oil feed bore opens into the rotor bearing section of the rotor in the region of the radial groove.

6. The pump as claimed in claim 5, wherein the oil riser groove is connected to a pump interior space and via the radial groove to the oil feed bore.

7. The pump as claimed in claim 1, wherein the pump is ventilated via grooves formed in the rotor bearing section of the rotor.

8. The pump as claimed in claim 1, wherein a volume delivered via the transverse bore and one or more lubricating grooves into the rotor coupling section is determined based on the width of the oil riser groove.

9. A vacuum pump for use in a motor vehicle, comprising: a housing defining a pump interior space and having a bearing portion that is connected to an oil feed bore, wherein the bearing portion of the housing is formed to include at least one oil riser groove; a rotor disposed for rotation in the housing about a longitudinal rotary axis, the rotor having a rotor section disposed in the pump interior space of the housing, a rotor bearing section disposed in the bearing portion of the housing, a rotor coupling section formed at an end of the rotor bearing section, an axial bore extending from the rotor coupling section into the rotor bearing section and which is aligned with the longitudinal axis, and a transverse bore communicating with the axial bore and which communicates with the at least one oil riser groove in response to rotation of the rotor; a coupling installed in the rotor coupling section of the rotor and having a throughbore aligned with the axial bore formed in the rotor bearing section of the rotor; and a fastener extending through the throughbore in the coupling and into the axial bore in the rotor bearing section for securing the coupling to the rotor, the fastener having a central bore aligned with the longitudinal axis of the rotor and which is in communication with the transverse bore formed in the rotor bearing section of the rotor for guiding oil from the oil feed bore to the rotor coupling section of the rotor through the transverse bore, the axial bore and the central bore of the fastener.

10. The vacuum pump as claimed in claim 9, wherein the transverse bore is configured to sweep over the at least one oil riser groove once per revolution of the rotor.

11. The vacuum pump as claimed in claim 9, wherein the transverse bore is configured to sweep over the at least one oil riser groove twice per revolution of the rotor.

12. The vacuum pump as claimed in claim 9, wherein the oil feed bore is formed in the housing, and wherein an engine oil supply from an engine oil circuit is supplied through the oil feed bore to the at least one oil riser groove.

13. The vacuum pump as claimed in claim 12, wherein the at least one oil riser groove communicates with the pump interior space of the housing.

14. The vacuum pump as claimed in claim 12, wherein the oil feed bore opens into a rotor bearing interface between the bearing portion of the housing and the rotor bearing section of the rotor, wherein a radial groove is formed in the rotor bearing section of the rotor which is generally aligned with the oil feed bore and assists in distributing the engine oil supply to the rotor bearing interface and the at least one oil riser groove, and wherein the oil riser grooves supplies a majority of the engine oil supply to the pump interior region while a small portion of the engine oil supply is routed through the transverse bore and the central bore in the fastener into the coupling.

15. The vacuum pump as claimed in claim 14, wherein the axial bore formed in the rotor bearing section of the rotor includes at least one lubrication groove for conveying oil into the rotor coupling section of the rotor.

16. A vacuum pump for brake boosting in a motor vehicle, comprising: a housing including a bearing portion connected to an oil feed bore and having an oil riser groove; a rotor having a rotor bearing section rotatably mounted in the bearing portion of the housing for rotation about a longitudinal axis, the rotor bearing section having a transverse bore oriented transversely to the longitudinal bore and which communicates with the oil riser groove in response to rotation of the rotor, wherein the transverse bore interacts with an axial bore formed in the rotor bearing section and which leads to a rotor coupling section of the rotor; a coupling drivingly engaged with the rotor coupling section of the rotor; and a fastener retained in the axial bore for securing the coupling to the rotor coupling section of the rotor, the fastener having a central bore communicating with the transverse bore for guiding oil from the oil feed bore to the rotor coupling section of the rotor through the transverse bore, the axial bore and the central bore of the fastener.

Description

DRAWINGS

(1) The invention will now be described using one exemplary embodiment which is shown in FIGS. 1 to 3, in which:

(2) FIG. 1 shows a cross section through the vacuum pump according to the invention with the illustration of the oil feed bore, and with the oil feed bore connected to a schematically illustrated internal combustion engine with an engine oil supply and an engine oil circuit,

(3) FIG. 2 shows a cross section of the vacuum pump according to the invention with an illustration of the transverse bore and the position of the oil riser groove,

(4) FIG. 3a shows a first section A-A through the rotor according to the invention,

(5) FIG. 3b shows a second section B-B through the rotor according to the invention, and

(6) FIG. 3c shows a plan view of the coupling side of the rotor.

DETAILED DESCRIPTION

(7) FIG. 1 shows a vacuum pump 1 with a rotor 5 having a rotor bearing section 6 rotatably supported in a bearing portion 3a of a housing 3. An oil feed bore 9 is arranged in the housing 3 of the pump 1, which oil feed bore 9 is connected to a supply connector 10 and opens into the rotor bearing section 6. The rotor 5 has at least one radial groove 8 which serves for improved distribution of the lubricating oil which is introduced through the oil feed bore 9. The oil feed bore 9 ideally opens into the rotor bearing section 6 in the region of the radial groove 8, in order to achieve an optimum lubricating oil supply. Moreover, the rotor 5 has a transverse bore 13a which is configured to run as far as the middle of the rotor bearing section 6. A bore 15 is provided in the axial direction of the rotor 5, into which bore 15 a fastening means 17 is installed for connecting a coupling 27 to the rotor 5. Bore 15 terminates in a conical cavity 15a. The fastening means 17 likewise has a central bore 18 in the axial direction. As a result of the rotational movement of the rotor 5, the transverse bore 13a sweeps over an oil riser groove 7 formed in housing 3 once per revolution. In this way, a part quantity of the engine oil introduced via supply connector 10 and oil feed bore 9 is removed and is guided through transverse bore 13a, bore cavity 15a and the central bore 18 of the fastening means 17 into a rotor coupling section 25 of the rotor 5 which is shown in FIG. 3. In this way, oiling of an underside 24 of the rotor coupling section 25 which is likewise shown in FIG. 3 and also of the coupling 27 takes place.

(8) FIG. 2 shows a different view of the vacuum pump 1 according to the invention with a transverse bore 13b in the rotor bearing section 6 of the rotor 5, which transverse bore 13b reaches over the entire diameter of the rotor bearing section 6. Furthermore, FIG. 2 shows the oil riser groove 7 formed in housing 3 which extends axially in the rotor bearing section 6 as far as into the pump interior space 19. The oil riser groove 7 can be manufactured by means of a material-removing production method, such as milling or drilling. As an alternative, the oil riser groove 7 can also be produced by way of a primary forming method. The final shape then arises from the subsequent final machining. This results in a cross section which is dependent on the production method and can be, for example, rectangular or semicircular.

(9) It can be seen from the consideration of FIGS. 1 and 2 that there is an uninterrupted connection to the pump interior space 19 starting from the supply connector 10 via the oil feed bore 9, the radial groove 8 and the oil riser groove 7, and continuous oiling of the pump interior space 19 therefore takes place via the lubricating oil pressure of the internal combustion engine. On account of the fact that the rotor bearing section 6 of the rotor 5 of the exemplary embodiment which is shown in FIG. 2 has a transverse bore 13b which runs all the way through, the transverse bore 13b sweeps over the oil riser groove 7 twice per revolution of the rotor 5. As a result, twice the quantity of engine oil per rotor revolution is delivered into the coupling section 25 of the rotor 5 which can be seen in FIG. 3.

(10) The oil quantity which is to be used for oiling the coupling section 25 of the rotor 5 which is shown in FIGS. 3a to 3c can additionally be varied by way of further parameter variables such as the diameter of the transverse bore 13, the width and depth of the oil riser groove 7, the cross section of the oil feed bore 9 and engine oil pressure in addition to the structural configuration of the transverse bore (ending in the middle or running all the way through) and can therefore be adapted to the required properties.

(11) The abovementioned low pressure pulsation during oil feed into the vacuum pump 1 results from the fact that the oil flow which is guided via the supply connector 10 and the oil feed bore 9 into the rotor bearing section 6 can pass as it were unimpeded via the oil riser groove 7 into the pump interior space 19. In the embodiment according to the invention, the transverse bore 13a or 13b transports only a small part quantity of the lubricating oil, since the greatest part flows into the pump interior space 19. As a result of this method of operation, the discharge jolts are not additionally reinforced by way of the large chamber volume of the pump interior space 19 of the vacuum pump 1, since oiling is carried out continuously. The discharge jolts which are caused by way of the small part quantity for intermittent oiling of the coupling section 25 of the rotor 5 are negligibly small.

(12) In the embodiment according to the invention of the vacuum pump 1 according to FIGS. 1 and 2, there is a continuous connection from the engine oil circuit 32 via the supply connector 10 and the oil feed bore 9, via the radial groove 8 and the oil riser groove 7 into the pump interior space 19. The bearing tolerances here result in the formation of a gap which makes rapid ventilating of the pump during switching off of the engine possible. As a result of the formation of a gap at the interfaces, the lubricating grooves 21 and 22 of the rotor 5 which is shown in FIGS. 3a to 3c and via the transverse bore 13a and 13b and the oil riser groove 7 of the vacuum pump 1 which is shown in FIGS. 1 and 2, said vacuum pump 1 is ventilated from the outside. This has the advantage that the remaining vacuum in the vacuum pump 1 is dissipated during switching off of the internal combustion engine 29 and therefore when the vacuum pump 1 is at a standstill and therefore no oil is sucked into said vacuum pump 1, which oil would have to be displaced with great effort during restarting and can lead to overloading and to destruction of the vacuum pump 1.

LIST OF DESIGNATIONS

(13) 1 Pump 3 Housing 5 Rotor 6 Rotor bearing section 7 Oil riser groove 8 Radial groove 9 Oil feed bore 10 Supply connector 11 Longitudinal axis 13 Transverse bore 15 Axial bore 17 Fastening means 18 Oil bore 19 Pump interior space 21 Lubricating groove 22 Lubricating groove 24 Coupling underside 25 Rotor Coupling section 27 Coupling 29 Internal combustion engine 30 Engine oil supply 32 Engine oil circuit