Lubricant distributor for dispensing lubricant to at least one lubrication point, and method for operating said lubricant distributor

Abstract

A lubricant distributor for delivering lubricant to at least one lubrication point includes a lubricant distributor housing with a cylinder bore, a metering piston mounted for reciprocal movement in the cylinder bore, and a detector connected at an end of the cylinder bore, the detector including an entry bore configured to receive a portion of the metering piston, and the entry bore being in fluid communication with the cylinder bore, and the detector including an interior space separated from the entry bore by a wall and a Hall sensor in the interior space. The detector is configured to output a detection signal in response to detecting the portion of the metering piston in the entry bore. Also a method of operating the lubricant distributor.

Claims

1. A lubricant distributor for the delivery of lubricant to at least one lubrication point, wherein the lubricant distributor includes a lubricant distributor housing, wherein a metering piston is disposed movably back-and-forth in a cylinder bore in the housing, wherein a detector device is mounted at the bore and, using the detector device, a position of the metering piston can be detected in at least one piston position, wherein the detector device comprises a Hall sensor disposed in a space in an adapter piece, wherein the adapter piece is disposed on the lubricant distributor housing such that the Hall sensor can detect the metering piston when the metering piston is located in a first end position in the cylinder bore, wherein the adapter piece includes an entry bore facing the metering piston, the entry bore being configured to receive a portion of the metering piston, and wherein the space is separated from the entry bore by a continuous base.

2. The lubricant distributor according to claim 1, wherein a threaded section connects axially to the cylinder bore in at least one axial end region of the cylindrical bore, in which threaded section a screw section of the adapter piece is screwed-in.

3. The lubricant distributor according to claim 2, wherein a diameter of the cylinder bore is less than a diameter of the threaded section.

4. A method of operating the lubricant distributor according to claim 1 comprising: a) prior to operating the lubricant distributor, defining a temporal duration (T) of a lubrication cycle and defining a time proportion (t.sub.Soll) of the lubrication cycle during which the metering piston should be located in the entry bore of the detector during proper operation of the lubricant distributor; b) during operation of the lubricant distributor, measuring a time proportion (t.sub.Ist) during which the metering piston is located in the entry bore by evaluating a signal produced by the Hall sensor; c) comparing the measured time proportion (t.sub.Ist) to the defined time proportion (t.sub.Soll); and d) outputting an alarm signal if the measured time proportion is greater than the defined time proportion (t.sub.Soll) by a first predetermined amount or less than the defined time proportion (t.sub.Soll) by a second predetermined amount.

5. The lubricant distributor according to claim 1, wherein a screw section of the adapter piece is screwed into an axial threaded section of the housing at an end of the cylinder bore, and a diameter of the threaded section is greater than a diameter of the cylinder bore.

6. The lubricant distributor according to claim 1, wherein, when the metering piston is located in the first end position, the portion of the metering piston is located in the entry bore of the adapter piece.

7. A method for operating a lubricant distributor for the delivery of lubricant to at least one lubrication point, wherein the lubricant distributor includes a lubricant distributor housing wherein a metering piston is disposed movably back-and-forth in a cylinder bore in the housing, wherein a detector device is mounted at the bore and using which a position of the metering piston can be detected in at least one piston position, wherein the detector comprises a Hall sensor disposed in a space in an adapter piece, wherein the adapter piece is disposed on the lubricant distributor housing such that the Hall sensor can detect the metering piston when the metering piston is located in a first end position in the cylinder bore, wherein the method includes: a) prior to the operation of the lubricant distributor defining a temporal duration (T) of a lubrication cycle and a time proportion (t.sub.Soll) of the lubrication cycle within which the metering piston should be located in the first end position of the cylindrical bore during proper operation of the lubricant distributor; b) during the operation of the lubricant distributor: measuring a time proportion (t.sub.Ist), during which the metering piston is located in the first end position by evaluating a signal produced by the Hall sensor; c) comparing the measured time proportion (t.sub.Ist) to the defined time proportion (t.sub.Soll); and d) outputting a first alarm signal indicative of a line tear if the measured time proportion is greater than the defined time proportion (t.sub.Soll) by a predetermined amount.

8. The method according to claim 7, wherein steps b) to d) are carried out in a periodically repeating manner.

9. The method according to claim 7, including outputting a second signal, different from the first signal, indicative of a line blockage if the measured time proportion (t.sub.Ist) is less than the defined time proportion (t.sub.Soll) by more than the predetermined amount.

10. The method according to claim 7, including redefining the temporal duration and the time proportion based on changing external environmental conditions.

11. A lubricant distributor for delivering lubricant to at least one lubrication point, the lubricant distributor comprising: a lubricant distributor housing including a cylinder bore; a metering piston mounted for reciprocal movement in the cylinder bore; a detector connected at an end of the cylinder bore, the detector including an entry bore configured to receive a portion of the metering piston, the entry bore being in fluid communication with the cylinder bore, and the detector including an interior space separated from the entry bore by a wall and the detector including a Hall sensor in the interior space, wherein the detector is configured to output a detection signal in response to detecting the portion of the metering piston in the entry bore.

12. The lubricant distributor according to claim 11, wherein the cylinder bore includes an enlarged end portion, wherein the detector includes an adapter portion sealingly mounted in the enlarged end portion of the cylinder bore, and wherein the entry bore is located in the adapter portion.

13. The lubricant distributor according to claim 11, wherein the metering piston extends through a first portion of the cylinder bore into the enlarged end portion of the cylinder bore and into the entry bore of the detector.

14. A method of operating the lubricant distributor according to claim 11 comprising: a) prior to operating the lubricant distributor, defining a temporal duration (T) of a lubrication cycle and defining a time proportion (t.sub.Soll) of the lubrication cycle during which the portion of the metering piston should be located in the entry bore of the detector during proper operation of the lubricant distributor; b) during operation of the lubricant distributor, measuring a time proportion (t.sub.Ist) during which the portion of the metering piston is located in the entry bore by evaluating the detection signal; c) comparing the measured time proportion (t.sub.Ist) to the defined time proportion (t.sub.Soll); and d) outputting an alarm signal if the measured time proportion is greater than the defined time proportion (t.sub.Soll) by a first predetermined amount or is less than the defined time proportion (t.sub.Soll) by a second predetermined amount.

15. The method according to claim 14, wherein outputting an alarm comprises outputting a first alarm signal if the measured time proportion is greater than the defined time proportion (t.sub.Soll) by the first predetermined amount and outputting a second alarm signal if the measured time proportion is less than the defined time proportion (t.sub.Soll) by the second predetermined amount.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) An exemplary embodiment of the invention is depicted in the drawings:

(2) FIG. 1 schematically shows a lubricant supply system for lubrication points, in particular for bearing points,

(3) FIG. 2 shows a lubricant distributor in section A-A according to FIG. 3,

(4) FIG. 3 shows the lubricant distributor according to FIG. 2 in front view,

(5) FIG. 4 shows an adapter piece of the lubricant distributor in partially sectioned side view, and

(6) FIG. 5 shows a time diagram wherein a number of lubrication cycles are reproduced wherein the signal detected by a Hall sensor and the pressure of the lubricant in the lubricant outlet is recorded for the lubrication cycles.

DETAILED DESCRIPTION

(7) In FIG. 1 a lubricant supply system is seen, using which lubrication points 2 in the form of bearing points are supplied with lubricant, e.g. lubricating oil. For this purpose the lubricant is pumped via two main lines, wherein in this respect reference is made to the embodiments in the above-mentioned publications, wherein details thereof are explained.

(8) Lubricant distributors 1 are connected by their inputs to the two main lines 15. The lubricant distributor 1 supplies the lubrication point (bearing point) 2 out from a lubricant outlet 14 via a line 13. Here the lubricant distributor 1 comprises detector device, using which the position of a metering piston or of its presence at a defined point of its cylinder bore can be detected.

(9) The construction of the lubricant distributor 1 and of a specific part thereof, namely an adapter piece 8, is apparent from FIGS. 2 to 4.

(10) Accordingly the lubricant distributor 1 includes a lubricant distributor housing 3, whereinand the following embodiments relate only to the elements that in the present case are relevant for the inventive concepta cylinder bore 5 is introduced wherein a metering piston 4 is disposed in a translationally movable manner. In this regard reference is made to the mentioned previously-known solutions.

(11) It is essential that a detector device 6 is disposed, namely screwed, on the one axial end of the cylinder bore 5. The detector device 6 is provided with a Hall sensor 7, using which it can be determined when the metering piston has reached its axial end position in the cylinder bore 5. The Hall sensor according delivers a signal when, and only when, the metering piston is located in its one axial end position. The detector device 6 is configured as a sleeve-shaped adapter piece 8, which (see FIG. 4) includes a screw section 10 on its one axial end. Using this screw section 10 the adapter piece 8 is screwed in a threaded section 9, which is incorporated in the axial end region of the cylinder bore 5.

(12) As is apparent from FIG. 2 and from FIG. 4, in the axial end region that faces the cylinder bore 5 the adapter piece 8 includes an entry bore 11 that has a slightly larger diameter than the metering piston 4. The metering piston 4 can thus enter into said entry bore 11 in order to reach its axial end position.

(13) The receiving space wherein the Hall sensor 7 is disposed and the space that is formed by the entry bore 11 are separated from each other by a base 12. This ensures the impermeability of the system in a simple manner.

(14) For the operation of the proposed monitoring method reference is made to FIG. 5. Here the case is schematically indicated that initially there is a proper lubrication operation.

(15) Then, however, a tear occurs of a line 13, which leads to a no-longer-proper operation, which is determined using the proposed method. In FIG. 5 the time t is plotted on the abscissa. Said tear of the line occurs at the time that is marked by Ab.

(16) For the applied pressure p it can be provided that before the tear this is present regularly with a course that is marked by p0. Starting from the tear there is a (fallen) pressure course, which is marked by pAb.

(17) While the temporal duration T of a lubrication cycle always remains constant, i.e., namely is the same before the tear and after the tear, the time proportion changes wherein the metering pistondetected by Hall sensor 7is located in its end position.

(18) As long as there is proper operation, the intact line 13 opposes the lubricant with a certain resistance, so that the metering piston 4 requires its time to arrive into the end position. Accordingly the time proportion tIst 0 (see FIG. 5, top) is relatively short; this is the period of time that is between the reaching of the axial end position of the metering piston 4 and the rerouting of the lubricant in the main lines 15.

(19) However, if the line 13 tears, it results now that the metering piston 4, as a consequence of the reduced line resistance, reaches the axial end position faster. Accordingly the time proportion increases to a value tIst A, which is significantly longer than the value tIst 0.

(20) By monitoring the actual time proportion tIst it is thus managed, by comparison to a typical and stored target value tSoll for proper operation, to conclude whether proper lubrication operation is performed or not.

(21) According to the invention a functional control of the lubricant distributor 1 thus occurs using a Hall sensor. The Hall sensor 7 is screwed into the adapter piece 8, which is preferably comprised of stainless steel. The end position of the metering piston 4 in the lubricant distributor 1 can be reliably detected by the sleeve-shaped adapter 8.

(22) Different thread connections on the lubricant distributor housing 3 can thus be adapted to. The lubricant distributor 1 is thus completely closed; an exchange of the Hall sensor 7 is also possible during operation of the lubricant distributor 1. The sealing problems in the pressure region or sensor region occurring in the previously known solutions are advantageously omitted.

(23) The Hall sensor or the detector device(s) can be designed as a universal sensor.

(24) Using the proposed Hall sensor a detection can thus be effected, at which times the metering piston 4 is located in the axial end position.

(25) In this way it is also possible to compare the respective most-recent movement diagrams with newly recorded measured values in current lubrication cycles, in order to test whether there is proper operation. In a two-line distributor, if the diagram course changes significantlyi.e. the time proportion tSoll increaseswith respect to the previously stored diagram coursesa line break of the connected lubricant line can be deduced. Of course this also analogously applies in the case of a progressive distributor instead of a two-line distributor.

(26) It correspondingly holds that with a shortening of the time proportion tSoll in a two-line distributor an incipient blockage can be assumed.

(27) The Hall sensor 7 or the adapter piece 8 can be designed such that, for example, the alarm output is output to the switch output, which indicates that the lubricant line is defective or an incipient blockage threatens.

REFERENCE NUMBER LIST

(28) 1 Lubricant distributor 2 Lubrication point 3 Lubricant distributor housing 4 Metering piston 5 Cylinder bore 6 Detector device 7 Hall sensor 8 Adapter piece 9 Threaded section 10 Screw section 11 Entry bore 12 Base 13 Line 14 Lubricant outlet 15 Main line T Temporal duration (period of a lubrication cycle) t Time tSoll Target time proportion tIst Actual time proportion Ab Time of the line tear p Pressure p0 regular pressure course pAb pressure course with line tear