ELEVATOR HAVING A BRAKING DEVICE

Abstract

An elevator may include a braking device such as a safety gear system or a service brake, for instance. The braking device may include a hydraulically-acting brake for braking an elevator car of the elevator. The braking device may further include a hydraulic unit with a pump assembly, a brake cylinder assembly, and a valve assembly for ventilating the brake. Further, the hydraulic unit may be fastened to the braking device.

Claims

1.-11. (canceled)

12. An elevator including a braking device that comprises: a hydraulically-acting brake for braking an elevator car of the elevator; and a hydraulic unit that is fastened to the braking device and includes a pump assembly, a brake cylinder assembly, and a valve assembly for ventilating the hydraulically-acting brake, wherein the brake cylinder assembly includes a piston that is displaceable in a cylinder, wherein the piston is prestressed in a sprung fashion by a spring, wherein the valve assembly includes a valve such that in a switched state the valve ventilates the brake, wherein the piston divides an interior space of the cylinder into a first chamber and a second chamber, with the spring being received in the first chamber, wherein in the switched state of the valve the first chamber of the cylinder is connected to the pump assembly so as to deliver hydraulic oil.

13. The elevator of claim 12 further comprising a common housing that receives the pump assembly, the brake cylinder assembly, and the valve assembly.

14. The elevator of claim 12 wherein the braking device further comprises a base body to which the hydraulic unit is fastened.

15. The elevator of claim 12 wherein the pump assembly includes a submersible pump.

16. The elevator of claim 12 wherein the switch state is a first switched state, wherein in a second switched state of the valve the second chamber is connected to the pump assembly so as to deliver hydraulic oil.

17. The elevator of claim 12 wherein the valve of the valve assembly is a 3/2-way valve.

18. The elevator of claim 12 wherein the valve assembly includes at least two valves that are connected in parallel.

19. The elevator of claim 12 wherein the hydraulic unit includes a closed hydraulic oil circuit.

20. The elevator of claim 19 wherein the hydraulic circuit is configured to conduct hydraulic oil that escapes from the cylinder of the brake cylinder assembly to the pump assembly.

21. A hydraulic unit for ventilating a brake of a braking device, the hydraulic unit comprising a pump assembly, a brake cylinder assembly, and a valve assembly for ventilating the brake, wherein the hydraulic unit is fastened to the braking device.

22. The hydraulic unit of claim 21 wherein the brake cylinder assembly comprises a piston that is displaceable in a cylinder, wherein the piston is prestressed in a sprung fashion by a spring, wherein the valve assembly includes at least one valve, wherein in a switched state the valve ventilates the brake, wherein in the switched state of the valve a chamber of the cylinder is connected to the pump assembly so as to deliver hydraulic oil.

Description

DESCRIPTION OF THE FIGURES

[0025] FIG. 1 shows in schematic form a preferred embodiment of an elevator according to the invention having a braking device and having a hydraulic unit,

[0026] FIG. 2 shows a schematic perspective view of a preferred embodiment of a hydraulic unit according to the invention,

[0027] FIG. 3 shows a schematic sectional illustration of the hydraulic unit according to FIG. 2, connected to the braking device, and

[0028] FIG. 4 shows a schematic view of a hydraulic circuit of the hydraulic unit.

[0029] In FIG. 1, an elevator 2 is illustrated in schematic form as a preferred embodiment of an elevator system according to the invention.

[0030] The elevator 2 has in the present exemplary embodiment an elevator car 4 for transporting persons and/or loads, which elevator car 4 is mounted so as to be movable in or counter to the direction of gravity g in an elevator shaft on two guide rails 6 running parallel to one another. In contrast to the present exemplary embodiment, the elevator car 4 can, however, be mounted so as to be movable, e.g. on a single guide rail.

[0031] In order to move the elevator car 4, a drive is provided which is embodied in the present exemplary embodiment as a traction sheave drive. The elevator car 4 can therefore have a cabin and a safety frame (both not illustrated). In the present exemplary embodiment, the drive has a suspension rope 8 which is fastened to the roof of the elevator car 4. The suspension rope 8 runs over a traction sheave 12, which can be motor-driven by means of a motor (not illustrated), in order to move the elevator car 4. Provided at the other end, lying opposite the elevator car 4, of the suspension rope 8 is a counterweight 10 which reduces the expenditure of force to move the elevator car 4 through the equalization of weight. In contrast to the present exemplary embodiment, the elevator can be embodied as an elevator without a supporting medium. An elevator without a supporting medium is an elevator system which does not use any cables or belts which are driven by a traction sheave 12. The drive of these elevators is located directly on the elevator car 4. For example rack and pinion drives and linear drives are used here.

[0032] In order to brake the elevator car 4 to a standstill if excessive speeds and/or uncontrolled travel movements of the elevator car 4 occur, a braking device 14 is provided which in the present exemplary embodiment is embodied as safety gear and/or a service brake. In the present exemplary embodiment a hydraulic unit 16 is provided for hydraulically venting the braking device 14.

[0033] FIG. 2 shows the hydraulic unit 16 in detail.

[0034] In the present exemplary embodiment, the hydraulic unit 16 has a pump assembly 20, a brake cylinder assembly 24 and a valve assembly 26.

[0035] The pump assembly 20, the brake cylinder assembly 24 and the valve assembly 26 are accommodated in a common housing 18 to form one integrated component. In the present exemplary embodiment, the housing 18 is a metal housing. The housing 18 can also be an injection molded plastic housing.

[0036] In the present exemplary embodiment, the pump assembly 20 has a submersible pump 22. In addition, the valve assembly 26 has two valves 28 which, as will be explained later, are connected in parallel, in order to provide redundancy.

[0037] FIG. 3 shows the hydraulic unit 16 connected to the braking device 14. In this context, the hydraulic unit 16 is connected directly to a base body 46 of the braking device 14. In the present exemplary embodiment, the braking device 14 has a brake 30 which is fastened to the base body 46 and has brake linings of flat design. When a brake 30 is vented, the brake linings lie against the guide rail 6 in order to brake the elevator car 4.

[0038] FIG. 4 shows the hydraulic unit with a closed hydraulic circuit 44.

[0039] The hydraulic circuit 44 connects the pump assembly 20, the brake cylinder assembly 24 and the valve assembly 26 to one another in such a way as to conduct hydraulic oil.

[0040] In the present exemplary embodiment, the two valves 28 of the valve assembly 26 are embodied as 3/2-way valves.

[0041] Furthermore, further details of the brake cylinder assembly 24 can be seen in FIG. 4. The brake cylinder assembly 24 has a piston 34 which can be moved in a cylinder 32. The piston 34 divides a cylinder interior space of the cylinder 32 into a first chamber 36 and a second chamber 38. In this context, the piston 34 is prestressed in a sprung fashion. For this purpose, a spring 40 is provided in the interior of the piston 34. In the present exemplary embodiment, the spring 40 is a disk spring packet 42. The spring 40 or the disk spring packet 42 are accommodated in the first chamber 36.

[0042] On the input side, each of the valves 28 of the valve assembly 26 is connected to the pump assembly 20, while a respective first outlet of the valves 28 is connected to the first chamber 36 so as to conduct hydraulic oil, and a respective second outlet of the valves 28 is connected to the second chamber 38 in such a way as to conduct hydraulic oil.

[0043] Therefore, the first chamber 36 and/or the second chamber 38 are connected to the two valves 28 of the valve assembly 26 in such a way as to conduct hydraulic oil.

[0044] In addition, in the present exemplary embodiment a sensor assembly (not illustrated) is provided with which a movement of the piston 34 in the cylinder 32 can be detected, e.g. on the basis of a pressure loss in the hydraulic circuit 44.

[0045] The pump assembly 20 can have, in addition to the submersible pump 22 provided in the present exemplary embodiment, in addition a non-return valve (not illustrated) and/or an overpressure valve (not illustrated).

[0046] During the normal operation, i.e. when the braking device 14 is not active, the pump assembly 20 pumps hydraulic oil through the valves 28 of the valve assembly 26 which are in a first switched state, and delivers said hydraulic oil into the first chamber 36 of the brake cylinder assembly 24. There, the hydraulic oil which is under pressure brings about ventilation of the brake 30. At the same time, in the present exemplary embodiment the first chamber 36 additionally has the function of an accumulator for the hydraulic oil. In addition, the hydraulic oil brings about lubrication of the spring 40 there.

[0047] If the braking device 14 is then activated on the basis of e.g. an excessive speed of the elevator car 4, at least one of the two valves 28 changes from its first switched state into its second switched state. The valve assembly 26 then disconnects the first chamber 36 from the hydraulic circuit 44. In this way, there is no force counteracting the spring force of the spring 40 available in the first chamber 36, with the result that the spring 40 relaxes and the brake 30 of the braking device 14 is no longer vented. In this case, a first control signal of e.g. 24 volts is assigned to the first switched state, and a second control signal e.g. 0 volts is assigned to the second switched state.

[0048] If, on the other hand, just one of the two valves 28 is intact, the spring force of the spring 40 acts in this case, with the result that the brake 30 is activated, which brings about venting of the brake 30. The valve groups 26 and therefore the hydraulic unit 16 therefore have redundancy which increases the safety of the system.

[0049] In contrast with the above, the brake cylinder assembly 24 can be embodied in the double-acting fashion. If both valves 28 are then intact in the second switched state the valve assembly 26 conducts the hydraulic oil which is under pressure into the second chamber 38 of the brake cylinder assembly 24 and at the same time disconnects the first chamber 36 from the hydraulic circuit 44. The hydraulic oil pressure present in the second chamber 38 then additionally acts on the piston 34 in order to move the braking device 14 from the vented switched state into the non-vented switched state. The brake cylinder assembly 24 is therefore embodied in a double-acting fashion.

[0050] Hydraulic oil flowing through the brake cylinder assembly 24 is collected in a collecting container 46 and fed back to the pump 22. In contrast with the present exemplary embodiment, the first chamber 36 or the collecting container 46 can be embodied as a pressure accumulator. A valve (not illustrated) which is arranged between the brake cylinder assembly 24 and the collecting container 46 is then opened.

[0051] For the elevator 2 to be put into service after the braking device 14 has been activated and service personnel have been deployed requires the pump 22 to build up a necessary operating pressure in the hydraulic circuit 44 again in order to be able to vent the brake 30.

LIST OF REFERENCE SYMBOLS

[0052] 2 Elevator [0053] 4 Elevator car [0054] 6 Guide rails [0055] 8 Suspension rope [0056] 10 Counterweight [0057] 12 Traction sheave [0058] 14 Braking device [0059] 16 Hydraulic unit [0060] 18 Housing [0061] 20 Pump assembly [0062] 22 Submersible pump [0063] 24 Brake cylinder assembly [0064] 26 Valve assembly [0065] 28 Valve [0066] 30 Brake [0067] 32 Cylinder [0068] 34 Piston [0069] 36 first chamber [0070] 38 second chamber [0071] 40 Spring [0072] 42 Disk spring packet [0073] 44 Hydraulic circuit [0074] 46 Base body [0075] g Direction of force of gravity