Safety device, drive unit and valve

Abstract

The present application discloses a safety device, a drive unit and a valve. The safety device is for releasably locking an output member of a linear drive. The safety device comprises a coupling rod (12), a housing (13), a blocking unit (21), a spring device (28), a locking device (41) and an electromagnet device (18). The locking device (41) has support rollers (34a-34c) accommodated in the housing and a support sleeve (42) through which the coupling rod is linearly movably led, the support sleeve being movable between a support position (43) in which the support rollers are held in a locked position (45) locked radially outwardly with the blocking unit and a release position (44) in which the support rollers are retracted radially inwardly and no longer engage with the blocking unit. A plurality of support roller sets (50) are arranged around the circumference of the support sleeve, the support roller sets having a plurality of support rollers arranged one after the other in the radial direction.

Description

[0001] This divisional application is based on Chinese Invention Patent Application No. 201980069136.9 (International Application No. PCT / EP2019 / 078590), entitled "Safety Device", filed on October 21, 2019. Technical Field

[0002] The present invention relates to a safety device for releasably locking the output component of a linear driver. Background Technology

[0003] Such safety devices are well-known and have been used as fail-safe devices to hold the output component of a linear actuator (such as the stem of a process valve) in a defined position, i.e., to lock it in place, in the event of a power failure. In the case of a process valve, this defined position may be, for example, the open or closed position of the valve component connected to the stem.

[0004] For example, DE 10 2007 032 327 B3 discloses a valve regulating device with a safety function, wherein a safety device is connected between the actuator and valve member of a process valve. This safety device has an electromagnet that, when energized, locks a piston, thereby allowing the valve stem to operate normally to open, close, and freely (without spring) regulate a through-hole on the valve fitting through the valve member connected thereto. When de-energized, the electromagnet is deactivated, the locking of the piston is released, and the valve stem moves to a safe position, independent of the piston's position, which in this case is the closed position. Summary of the Invention

[0005] The object of the present invention is to provide a safety device for releasably locking the output component of a linear driver, by means of which the connected system can reliably enter a predetermined safety state.

[0006] The safety device for releasably locking the output component of a linear driver according to the present invention has the following components:

[0007] - A connecting rod that can be connected to the output component of a linear driver.

[0008] - The housing penetrated by the connecting rod in a linearly movable manner.

[0009] - A blocking unit, which is linearly movable and penetrated by the connecting rod, can move relative to the housing between a blocking position during the lifting of the connecting rod and a releasing position that enables the linear movement of the connecting rod.

[0010] - A spring mechanism for pre-tensioning the blocking device toward the blocking position.

[0011] - A locking device for locking the locking unit in a released position, wherein the locking device has a support rolling element housed in a housing and a support sleeve through which a connecting rod passes in a linearly movable manner, wherein the support sleeve is movable between a supported position and a disengaged position, wherein in the supported position the support rolling element is held in a locked position, radially outwardly engaged with the locking unit, and in the disengaged position the support rolling element is radially inwardly retracted and no longer engaged with the locking unit.

[0012] - An electromagnet device that, when energized, holds the support sleeve in a supported position against the adjusting force of at least one release spring of the release spring device, such that the holding function can be canceled in the event of power failure, and the support sleeve moves into a disengaged position by means of the at least one release spring, thereby allowing the locking unit to move into a locked position by means of the spring device.

[0013] In other words, the safety device operates based on the cooperation of an electromagnet, a locking device, and a supporting rolling element. In the released position, the locking device is locked and inactive, allowing free movement of the linear actuator's output member and its connected connecting rod within their range of motion. In the event of a power failure, the locking device is triggered by releasing the locking of the supporting rolling element. In this case, a spring mechanism brings the locking device into the locked position, where the lifting and lowering movement of the connecting rod is blocked. The safety device operates entirely mechanically, meaning it does not require electrical or other non-electrical energy sources, such as compressed air, for its function. This ensures reliable operation of the safety device in fault conditions.

[0014] In a further embodiment of the invention, a stop is formed on the connecting rod, and a mating stop is formed on the locking unit, which are spaced apart from each other by an axial distance in the released position, the axial distance determining the lift of the connecting rod, and the stop and the mating stop abut against each other in the locked position, thereby locking the output member.

[0015] Particularly preferably, the locking unit has a locking sleeve through which the connecting rod passes, which supports the rolling element in a radially outward direction in the released position and holds it in the locked position.

[0016] The locking sleeve advantageously has, in particular, an annular receiving space, into which the corresponding supporting rolling element is recessed in the locked position.

[0017] In a further embodiment of the invention, a plurality of support rolling element groups are provided around the circumference of the support sleeve, each having at least one support rolling element. Particularly preferably, each support rolling element group has a plurality of support rolling elements arranged radially in succession. This allows the support rolling elements to roll over each other when the locking device is released to enter the locking position, thereby quickly and technically easily canceling the lock. Furthermore, the support rolling elements of each support rolling element group can be easily brought into the locked position, thus preventing them from rolling over each other and locking the locking unit.

[0018] Preferably, the support rolling elements of each support rolling element assembly are stacked in a staggered manner in the vertical direction in the separated position of the support sleeve. Compared with the separated position of the support sleeve, in the locked position of the support sleeve, i.e., the locked position, the radial extension of the support rolling elements within the support rolling element assembly is greater, wherein the vertical staggering causes the radial extension to decrease.

[0019] In a further embodiment of the invention, the support sleeve has an outer wall on which a support sleeve receiving space is formed, which in a locked position cooperates with the receiving space of the locking device, wherein the support rolling element is inserted into the support sleeve receiving space in the locked position.

[0020] Particularly preferably, the supporting rolling element is cylindrical. That is, the supporting rolling element can be designed as a roller. However, alternatively, a ball can also be used as the rolling element.

[0021] In a further embodiment of the invention, the electromagnet device has a plurality of electromagnet groups surrounding the connecting rod, which, when energized, collectively hold the support sleeve in a supported position.

[0022] It is possible that each electromagnet is spring-loaded, particularly coupled to a return spring on the bottom side, which is compressed in the locked position of the locking unit and causes the electromagnets to move out of their original positions in the released position when the electromagnets are deactivated, wherein the corresponding position sensor is able to detect the position change.

[0023] Particularly preferably, the release spring device has multiple sets of release springs surrounding the connecting rod, which together move the support sleeve to the disengaged position when the electromagnet device is deactivated. The release springs and the electromagnet are advantageously arranged circumferentially staggered from each other.

[0024] In a further embodiment of the invention, the sealing sleeve has an inner sleeve portion forming a reverse stop, the inner sleeve portion concentrically surrounding the connecting rod and set into an annular gap between the cylindrical housing inner portion of the housing and the connecting rod, and wherein the sealing sleeve has an outer sleeve portion concentrically surrounding the housing inner portion, and a receiving space for supporting the rolling element is formed on the inner wall of the outer sleeve portion.

[0025] Particularly preferably, a reset element is provided to resist the elastic force of the spring device and reset the locking unit from the locked position to the released position. The reset element may have a mechanical, fluid, or electrical reset actuator for resetting the locking unit to the released position. For example, the reset actuator may be designed as a servo motor. However, other types of reset actuators, such as hydraulic or pneumatic actuators, may also be used.

[0026] A damping device may be provided to suppress the extension movement of the locking unit from the locked position to the released position when the safety function is triggered. Preferably, the damper is designed as an oil damper. The damper advantageously has two oil chambers interconnected by a throttle valve, wherein hydraulic oil is discharged from one oil chamber to the other to activate the damping function.

[0027] In a further embodiment of the invention, a retaining device is provided to hold the supporting rolling element in the locking position of the locking unit to prevent the supporting rolling element from moving radially outward. Since the receiving spaces of the locking sleeve are spaced a certain distance apart, and since the locking unit is triggered and in the released position, it is necessary to hold the supporting rolling element.

[0028] Particularly preferably, the retaining device has a retaining member corresponding specifically to the radially outermost support rolling element of the corresponding support rolling element group, which is movably supported between a retaining position holding the corresponding support rolling element and a non-use position. Preferably, the retaining member is spring-loaded and supported by a return spring that presses the retaining member against the radially outer support rolling element in the disengaged position of the support sleeve or the released position of the locking device.

[0029] The present invention also relates to a drive unit having a linear driver and a safety device.

[0030] The present invention also includes a valve having valve fittings and an actuation unit, particularly a process valve. Attached Figure Description

[0031] A preferred embodiment of the invention is illustrated in the accompanying drawings, which are described in detail below. Wherein:

[0032] Figure 1This is a longitudinal cross-sectional schematic diagram of a preferred embodiment of the safety device according to the present invention, wherein the locking unit is in the released position.

[0033] Figure 2 for Figure 1 A schematic diagram of a safety device, in which the blocking unit is in the blocked position when the safety function is triggered.

[0034] Figure 3 for Figure 1 A schematic diagram of detail X in the image.

[0035] Figure 4 In order to allow the support sleeve to return from the separated position to the supported position, Figure 1 A magnified view of detail X in the image.

[0036] Figure 5 for Figure 2 A magnified view of detail Y in the image, and

[0037] Figure 6 A circuit diagram of the electronic circuitry for an electrical interruption device (electronic safety solution). Detailed Implementation

[0038] Figures 1 to 6 A preferred embodiment of the safety device 11 according to the invention is shown. In the example shown, the safety device 11 is part of a valve (not shown), particularly a process valve, and is connected between a valve actuator (not shown) in the form of a linear actuator and a valve fitting (not shown). The valve actuator can be, for example, an electric or fluid, particularly pneumatic, linear actuator. The linear actuator has an output member (not shown), which, for example, in the case of a fluid linear actuator, can be the piston rod of a working cylinder, which is connected to a drive piston that can reciprocate within a cylinder housing due to the application of fluid pressure.

[0039] The output component of the linear actuator is connected to the connecting rod 12, which is part of the safety device 11. In the context of the process valve, the connecting rod 12 may also be referred to as the valve stem.

[0040] The valve also has a valve fitting (not shown), which may also be referred to as a valve body. A flow passage extends within the valve body between an inlet and an outlet. Within this flow passage, a flow opening is located between the inlet and outlet, which is surrounded by a valve seat. The valve seat corresponds to a valve member, which in turn is connected to a connecting rod 12.

[0041] The valve component can move between the closed position and the open position by adjusting the lift of the connecting rod 12. In the closed position, the valve component is fluid-tightly pressed against the valve seat, and in the open position, the valve component is detached from the valve.

[0042] The adjustment lift of the connecting rod 12 is generated by the valve actuator.

[0043] Accordingly, in this example, safety device 11 is connected between the valve actuator and the valve fitting.

[0044] Especially as Figure 1 and Figure 2 As shown, the safety device 11 has a housing 13 through which a connecting rod 12 is linearly movable.

[0045] The housing 13 has a sleeve-shaped outer housing portion 14, which is equipped with a lower fastening flange 15 at its lower end and an upper fastening flange 16 at its upper end. The lower fastening flange 15 of the housing 13 is fixed to a disc-shaped magnet housing 17, which also belongs to the housing 13 and houses the electromagnet device 18, which will be described in detail below. The magnet housing 17 is connected to a base flange 19, which is also penetrated by a connecting rod 12 in a linearly movable manner. The safety device 11 can be fixed, for example, to a fixed interface of the valve fitting (not shown) via the base flange 19.

[0046] The upper fastening flange 16, in particular, forms an upper stop 20 for the blocking unit 21, which will be described in detail below, with its annular inner shoulder, thereby preventing the blocking unit from extending out of the housing 13 when the safety function is triggered.

[0047] Especially as Figure 1 and Figure 2 As shown, the housing 13 has an inner housing portion 22, which is concentrically surrounded by an outer housing portion 14. The inner housing portion 22 is also designed as a sleeve. An annular gap 23 is formed between the outer wall of the inner housing portion 22 and the inner wall of the outer housing portion 14, in which the outer sleeve portion 24 of the sealing sleeve 25 of the sealing unit 21 is linearly movable.

[0048] The axial extension of the inner portion 22 of the housing is less than the axial extension of the outer portion 14 of the housing. An annular shoulder is formed on the outer surface of the inner portion 22 of the housing, which constitutes the stop surface 26 of the spring 27 for the spring device 28, which will be described in detail below.

[0049] The inner wall of the housing interior portion 22 jumps radially outward in its upper region, thereby forming the outer wall of the chamber 29, which will be described in detail below.

[0050] As described above, the safety device 11 includes a locking unit 21 through which the connecting rod 12 is linearly movable, the locking unit being positioned relative to the housing 13 in a locking position 30 that blocks the rise of the connecting rod 12. Figure 2 ) and the release position 31 that realizes the linear movement of the connecting rod 12 ( Figure 1 They move between ( ).

[0051] The main component of the sealing device 21 is the sealing sleeve 25, which has the aforementioned outer sleeve portion 24, which is received in a gap 23 between the inner housing portion 22 and the outer housing portion 14 via a linearly movable guide. The outer sleeve portion 24 has an annular shoulder on its outer surface, which forms an upper mating stop 32. When the safety function is triggered, the upper mating stop abuts against an upper stop 20 on the outer housing portion 14, thereby preventing the sealing sleeve 25 from extending out of the housing.

[0052] In the region at the lower end of the outer sleeve portion 24 of the sealing sleeve 25, there is an annular receiving space 33 on the inner wall, into which the supporting rolling element 34, which will be described and detailed in detail below, can at least partially sink.

[0053] On the top side of the sealing sleeve 25, a sleeve flange 35 is fixed to the outer portion 24 of the sleeve, to which the linear actuator can be connected. The sleeve flange 35 also establishes a connection with the inner portion 37 of the sealing sleeve 25. Another annular shoulder is formed on the inner side of the sleeve flange 35, which constitutes another stop surface 36 for the spring 27 of the spring device 28. The inner portion 37 is linearly movable and accommodated in an annular gap 38 formed by the inner wall of the housing inner portion 22 and the outer wall of the connecting rod 12.

[0054] Especially as Figure 1 and Figure 2 As shown, an annular shoulder constituting a stop 39 is provided on the connecting rod. The stop 39 on the connecting rod 12 corresponds to the mating stop 40 on the inner part 37 of the sleeve, which is formed by reducing the diameter of the through hole in the inner part 37 of the sleeve at the end side.

[0055] Will Figure 1 and Figure 2 In combination, it can be seen that the stop 39 and the mating stop are aligned with each other at a certain axial distance in the release position 31, thereby making the lifting and lowering movement of the connecting rod 12 possible. In such a way... Figure 2 In the blocking position 30 shown, the stop 39 on the connecting rod 12 and the mating stop on the inner part 37 of the sleeve come into contact with each other, thereby blocking the connecting rod 12 and preventing the lifting of the connecting rod 12.

[0056] Especially as Figure 1 and Figure 2 As shown, the outer wall of the inner portion 37 of the sleeve of the sealing sleeve 25 forms the inner wall of the chamber 29, which will be described below.

[0057] Safety device 11 also includes a locking device 41 for locking the locking unit 21 in the release position 31, wherein the locking device 41 has support rolling elements 34a, 34b, 34c housed in housing 13 and a support sleeve 42 through which the connecting rod 12 moves linearly.

[0058] Especially Figure 1 and Figure 2 ,as well as Figure 4 and Figure 5 Combining these findings, it can be seen that the support sleeve 42 is at the support position 43 ( Figure 1 ) and separation position 44 ( Figure 2 The support rolling elements 34a, 34b, and 34c are movably guided between each other. In the support position 43, the support rolling elements 34a, 34b, and 34c are held in the locked position 45, which is radially outward and locked with the locking unit 21, while in the disengaged position 44, the support rolling elements 34a, 34b, and 34c are radially inward and no longer locked with the locking unit 21.

[0059] The support sleeve 42 has an annular support sleeve receiving space 46 on its outer surface, which, in the released position, works in conjunction with a receiving space 33 on the outer sleeve portion 24 of the locking sleeve 25, such that the annular support sleeve receiving space 46 is opposite to the annular receiving space 33. The support sleeve 42 has a disc-shaped loading portion 47 or loading flange on its bottom side, the diameter of which is larger than the rest of the support sleeve 42, and works in conjunction with the release spring 48 of the release spring device 49, which will be described in detail below.

[0060] The locking device 41 has a plurality of support rolling element groups 50 surrounding the circumference of the support sleeve 42, each having a plurality of support rolling elements 34a-34c, in this example three support rolling elements 34a-34c each. In this example, the support rolling elements 34a-34c are designed as support rollers. The support rolling elements 34a-34c are arranged sequentially in the radial direction, thereby each support rolling element group 50 having an inner support rolling element 34a, a central support rolling element 34b, and an outer support rolling element 34c.

[0061] Especially as Figure 2 As shown, in the locked position, the support rolling elements 34a-34c are arranged in a staggered manner, both vertically and axially. In both the locked and released positions, the inner support rolling elements are embedded in the annular support sleeve receiving space 46. The outer support rolling element 34c, however, is embedded only in the annular receiving space located on the inner portion 37 of the locking sleeve 25 in the released position where locking occurs. Figure 2 In the blocked position shown, the external support rolling element is radially retracted inward.

[0062] The safety device 11 also includes an electromagnet device 18, which, when energized, resists the adjusting force of at least one release spring 48 to hold the support sleeve 42 in the support position 43, so that the holding function can be canceled in the event of power failure, and the support sleeve 42 enters the separation position 44 by means of the at least one release spring 48, thereby allowing the locking unit 21 to enter the locking position by means of the spring device 28.

[0063] In the example shown, a plurality of electromagnet assemblies 57 surrounding the connecting rod 12 are provided in the magnet housing 17, which together hold the support sleeve 42 in the support position 42 when energized. That is, when energized, the support sleeve 42 is held in the support position 43 against the elastic force of the release spring 48.

[0064] For this purpose, the release spring device 49 has a plurality of release spring groups 48 surrounding the connecting rod 12, which collectively move the support sleeve to the disengaged position 44 when the electromagnet device 18 is deactivated. Specifically, as Figure 1 As shown, a plurality of cylindrical receiving portions are formed in the magnet housing surrounding the connecting rod, and corresponding release springs 48 are housed in these receiving portions.

[0065] The safety device 11 also includes a retaining device 51 for retaining the supporting rolling elements 34a-34c in the blocking position 30 of the blocking unit 21, i.e., when the receiving space 33 on the sleeve outer portion 24 of the blocking sleeve 25 moves upward, to prevent them from moving radially outward.

[0066] Especially as Figures 3 to 5 As shown, the retaining device 51 has a retaining member 52 for each supporting rolling element group 50, which is movably supported between a retaining position 53 holding the corresponding supporting rolling element 34c and a non-use position 54. Each retaining member 52 corresponds to a return spring 55, one side of which is supported on the bottom side of the retaining member 52, and the other side is supported on the base flange 19. Specifically, as shown... Figure 3 and 5 As shown, the retaining member 52 has a radially outwardly protruding transmission member 56, for example, in the form of a screw. When the locking unit returns from the locking position 30 to the releasing position 31, the transmission member is forcefully applied by the outer portion 24 of the sleeve; that is, the lower edge of the outer portion of the sleeve contacts the transmission member 56, thus pushing the retaining member 52 back against the elastic force of the return spring 55. When the safety function is triggered, the locking unit 21 enters the locking position, so the locking sleeve 25 moves upward, and the return spring 55 thereby causes the retaining member 52 to abut against the outer support rolling element 34c. The top side of the retaining member 52 can match the shape of the corresponding support rolling element 34c, for example, the cylindrical shape of the support roller.

[0067] like Figure 6 As shown in the circuit diagram, a position detection device is provided to detect the position of the electromagnet 57 of the electromagnet device 18, thereby obtaining feedback on whether the electromagnet 57 is activated (i.e., energized or deactivated). For this purpose, the electromagnet 57 is movably supported in the magnet housing 17, and is further supported on its bottom side by means of a return spring 58. Figure 1 Support. With the electromagnet 57 activated, the support sleeve 42 is attracted and positioned in its supported position 43, thereby pushing the release spring 48 back, and the electromagnet 57 also pushes the return spring 58 back. After the safety function is triggered, the support sleeve 42 is removed from the electromagnet 57 because the release spring 48 presses the support sleeve 42 upward into the disengaged position 44. Herein, the return spring 58 is able to press the electromagnet 57 upward, where this position change is detected by a position sensor (not shown).

[0068] The safety device also includes a reset element that resists the spring force of the spring device 28 to reset the locking unit from the locked position 30 to the released position 31. In the example shown, the reset element includes an electrical reset actuator, for example in the form of a servo motor, which ensures that the locking sleeve 25 is pushed back against the spring force of the spring 27 of the spring device 28.

[0069] Safety device 11 also includes a damping device 59, which is designed as a hydraulic damping device 59 in this example.

[0070] As described above, a chamber 29 that can be filled with hydraulic oil is formed by the inner wall of the housing interior portion 22 and the outer wall of the sleeve interior portion 37.

[0071] like Figure 1 As shown, a smaller second chamber 60 is formed below the first chamber 29, specifically for the case where the sealing sleeve is in the released position, i.e., the sealing sleeve 25 is retracted and locked. These two chambers 60 are connected to each other via a throttle valve (not shown). Therefore, when the safety function is triggered, hydraulic oil is discharged from the second chamber 60 into the first chamber 29 through the throttle valve, thereby triggering the damping function. The hydraulic oil in the first chamber can then partially flow into a displacement chamber or compensation chamber (not shown).

[0072] During normal operation, the locking unit 21 retracts and locks in the release position 31, such as Figure 1 As shown. In the release position 31, the stop 39 and the mating stop 40 are axially spaced apart, thus allowing the connecting rod 12 to move up and down within the resulting lift. The locking of the locking unit 21 is achieved by energizing the electromagnet 57. If the electromagnet 57 is activated, i.e. energized, they collectively hold the support sleeve 42 in the support position 43.

[0073] Crucially, all the supporting rolling elements of the supporting rolling element assembly 50 are in the locked position 45. This is achieved by the annular supporting sleeve receiving space 46 and the annular receiving space 33 on the outer sleeve portion 34 of the locking sleeve 25 being opposite each other. In this position, the outer supporting rolling element 34c is embedded in the receiving space 33 on the locking sleeve 25. Simultaneously, the inner supporting rolling element 34a is embedded in the annular supporting sleeve receiving space 46. Although the spring 27 of the spring device 28 attempts to push the locking sleeve 25 out of the housing 13, this is impossible because the supporting rolling elements 34a-34c are locked together, and the outer supporting rolling element 34c prevents the locking sleeve from passing by it. Therefore, the restoring force of the spring 27 acts on the outer supporting rolling element 34c, then on the intermediate supporting rolling element 34a, and then on the inner supporting rolling element 34c, but it also gains support because the supporting sleeve is attracted and in the supported position 43.

[0074] When the power is off, the electromagnet 57 is deactivated, and thus loses its holding force on the support sleeve 42.

[0075] In this situation, the release spring 48 presses the support sleeve 42 upward into its separated position 44, as... Figure 2 As shown. Since the axial extension of the annular support sleeve receiving space 46 is greater than the axial extension of the inner support rolling element 34a, the support sleeve 42 can pass beside the inner support rolling element 34a. If the support sleeve 42 then contacts the inner support rolling element 34a with the lower annular shoulder of its support sleeve receiving space 46, this support rolling element moves upward with the support sleeve 42, thereby providing free space for the intermediate support sleeve rolling element 34b. Then, the intermediate support rolling element 34b can move radially inward to a certain extent, thereby providing space for the outer support rolling element 34c, which can also move radially inward. This cancels the locking of the locking unit, so the elastic force of the larger spring 27 of the spring device 28 presses the locking sleeve 25 upward from the housing until the upper mating stop 32 on the outer portion 24 of the sleeve abuts against the upper stop 20 on the outer portion 14 of the housing.

[0076] At the same time, the retaining device 41 is activated, and the retaining member 52 is brought upward into contact with the corresponding external support rolling element 34c by the return spring 55, thereby retaining the external support rolling element.

[0077] In addition, when the sealing sleeve extends, the hydraulic oil in the second chamber 60 is discharged into the first chamber, thereby triggering the damping function to prevent the sealing sleeve from suddenly popping out due to the high elasticity of the spring 27 of the spring device 28.

[0078] In such Figure 2In the shown locked position, the locking sleeve 25 is unlocked and extends from the housing 13. In this state, the mating stop 40 on the inner portion 37 of the locking sleeve 25 abuts against the stop 39 provided on the connecting rod 12, thereby preventing downward movement of the connecting rod 12. This allows, for example, the connected valve member to be moved into a defined open position.

[0079] Blockade Unit 21 from Figure 2 The blockade location shown is 30 to... Figure 1 The reset process of the release position 31 shown is as follows:

[0080] A servo motor applies force to the sealing sleeve 25, causing the sealing sleeve to retract into the housing 13 against the elastic force of the spring device 28. When the sealing sleeve retracts, the outer portion 24 and the inner portion 37 of the sleeve move downwards.

[0081] Especially as Figure 4 As shown, a height-adjustable loading element 61, for example in the form of a screw, is provided on the bottom side of the inner portion 37 of the sleeve. When the locking sleeve is retracted, the loading element contacts the upper end of the support sleeve, which is still in the separated position 44. Therefore, the loading element 61 resists the elastic force of the release spring 48 and presses the support sleeve 42 back to the support position 43, pressing it into the magnetic attraction region of the electromagnet 57. The electromagnet is activated and holds the support sleeve 42 in the support position 43. At the same time, due to the abutment of the inner edge of the outer portion of the sleeve, the retaining member 52 is pressed downward against the elastic force of the return spring 55, and the receiving space 33 in the region of the outer portion of the sleeve enters the region of the outer support rolling element 34c, which in this case is trapped in the annular receiving space 33.

[0082] After the support sleeve moves from its disengaged position 44 to its supported position 34, the locking sleeve 25 can move upward to a certain extent, thereby reaching the locked position 45 of the support rolling elements 34a-34c.

[0083] Figure 6 This is a schematic circuit diagram of electronic circuit 64 used to control an electronic interruption device (electronic safety solution). This circuit is part of safety device 11.

[0084] This is a single-transistor circuit powered by the quiescent current of an actuator motor in the form of a servo motor.

[0085] Electronic circuit 64 includes a circuit connected to electromagnet device 18. Two switches, in the form of transistors 65a and 65b, particularly npn transistors, are connected to this circuit. The first transistor 65a is connected to a higher-level controller, particularly a PLC controller. If its output is energized (i.e., high), the switch closes. The second transistor 65b is a redundant safety contact. If the output of the second transistor 65b is energized (i.e., high), the switch closes. Electromagnet 57 of electromagnet device 18 is activated only when both outputs of transistors 65a and 65b are high. Electromagnets 57 are connected in parallel, so they switch simultaneously.

[0086] These two output signals are controlled by current measurement and detection circuit 66. Generally, two cases can be distinguished. The first case is called SPIKE 67 or peak, and the other is called ALIVE 68 or fault. If a turn-on peak 69 is detected, especially a 0.5 s high-pulse turn-on peak, then the case is SPIKE 67. In principle, this is independent of the actual number of electromagnets 57 switched. Three electromagnets 57 are illustrated. Of course, the safety device can be operated by connecting more than three electromagnets 57 in parallel.

[0087] The peak current during switching is significantly higher than the rated current. That is, for example, if the current is much higher than the normal power consumption, the SPIKE output will go high within 0.5 seconds. The peak current 69 will only occur when the metal is in contact with the magnet, i.e., when the electromagnet 57 overcomes the spring force of the return spring 58 and is in contact with the metal base flange 19. When the blocking unit 21 is locked ( Figure 1 This is the situation.

[0088] If not all electromagnets 57 are energized, as shown in the circuit diagram by reference numerals 69 (one magnet not energized) and 70 (two magnets not energized), and only one or two electromagnets are energized, then the condition is ALIVE 68 (fault). However, it is also possible to identify a situation (reference numeral 71) where, although all three electromagnets 57 are energized, they are not pushed back to their basic position against the restoring force of the return spring. In this case, no metal is attached to the electromagnets 57, instead forming an air gap, causing a significant reduction in the measured current. In this case, the turn-on peak 69 does not occur.

Claims

1. A safety device for releasably locking an output member of a linear driver, the safety device comprising: - A connecting rod (12) is connected to the output member of the linear drive, thereby enabling the output member to move by means of the lifting motion of the connecting rod. - Housing (13), through which the connecting rod (12) extends in a manner capable of linear movement. -A blocking unit (21), through which the connecting rod (12) extends in a linearly movable manner, the blocking unit (21) being movable relative to the housing (13) between a blocking position (30) that blocks the rise of the connecting rod (12) and a releasing position (31) that allows linear movement of the connecting rod (12). - Spring device (28) for pre-tensioning the blocking unit (21) into the blocking position (30), - A locking device (41) for locking the locking unit (21) in a released position (31), wherein the locking device (41) has supporting rolling elements (34a-34c) and a supporting sleeve (42), the supporting rolling elements (34a-34c) being housed in a housing (13), and a connecting rod (12) extending through the supporting sleeve (42) in a linearly movable manner, wherein the supporting sleeve (42) is movable between a supported position (43) and a disengaged position (44), wherein in the supported position, the supporting rolling elements (34a-34c) are held radially outward in a locked position (45) with the locking unit (21), and in the disengaged position, the supporting rolling elements (34a-34c) are radially retracted inward and no longer engaged with the locking unit (21). - An electromagnet device (18) which, when energized, resists the adjusting force of at least one release spring (48) of a release spring device (49) to hold the support sleeve (42) in the support position (43), so that the holding function can be released when the power is off, and the support sleeve (42) moves into the separation position (44) by means of the at least one release spring (48), thereby allowing the locking unit (21) to move into the locking position (30) by means of the spring device (28). Its features are, A plurality of support rolling element groups (50) are provided around the circumference of the support sleeve (42), the support rolling element groups having a plurality of support rolling elements (34a-34c) arranged sequentially in the radial direction.

2. The safety device according to claim 1, characterized in that, Compared to the open position of the support sleeve (42), the support rolling elements (34a-34c) extend more radially within each support rolling element group (50) in the locked position (45).

3. The safety device according to claim 2, characterized in that, In the separated position (44) of the support sleeve (42), the support rolling elements (34a-34c) in each support rolling element group (50) are staggered in the vertical direction, wherein the staggering in the vertical direction causes the radial extension to decrease.

4. The safety device according to claim 1, characterized in that, The locking unit (21) has a locking sleeve (25) through which the connecting rod (12) passes, the locking sleeve (25) supporting the support rolling elements (34a-34c) in a radially outward direction in the release position (31) and holding the support rolling elements in the locked position (45).

5. The safety device according to claim 4, characterized in that, The locking sleeve (25) has an annular receiving space (33), and the external support rolling element is locked in the locking position (45) when the locking sleeve (25) is in the released position but not when the locking sleeve (25) is in the locked position.

6. The safety device according to any one of claims 1-5, characterized in that, The support sleeve (42) has an outer wall on which a support sleeve receiving space (46) is formed that interacts with the receiving space (33) of the blocking unit (21) in the support position (43), and the internal support rolling element is embedded in the support sleeve receiving space in the support position (43).

7. The safety device according to any one of claims 1-5, characterized in that, The supporting rolling elements (34a-34c) are cylindrical.

8. The safety device according to any one of claims 1-5, characterized in that, The electromagnet device (18) has a plurality of electromagnet groups (57) formed around the connecting rod (12), which together hold the support sleeve (42) in the support position (43) when energized.

9. The safety device according to any one of claims 1-5, characterized in that, The release spring device (49) has a plurality of release spring groups formed around the connecting rod (12), which together move the support sleeve (42) into the separation position (44) when the electromagnet device (18) is deactivated.

10. The safety device according to any one of claims 1-5, characterized in that, The sealing sleeve (25) has an inner sleeve portion (37) with a mating stop (40) formed therein, the inner sleeve portion concentrically surrounds the connecting rod (12) and is recessed into an annular gap (23) between the cylindrical housing inner portion (22) of the housing (13) and the connecting rod (12), and wherein the sealing sleeve (25) has an outer sleeve portion (24) with a concentrically surrounding the cylindrical housing inner portion (22) and a receiving space (33) for supporting the rolling elements (34a-34c) is formed on the inner wall of the outer sleeve portion.

11. The safety device according to any one of claims 1-5, characterized in that, A reset member is provided to resist the elastic force of the spring device (28) and reset the blocking unit (21) from the blocking position (30) to the releasing position (31).

12. The safety device according to claim 11, characterized in that, The reset element has a mechanical, fluid, or electrical reset actuator to reset the locking unit (21) to the release position (31), wherein the reset actuator is designed as a servo motor.

13. The safety device according to any one of claims 1-5, characterized in that, A retaining device (51) is provided to hold the support rolling elements (34a-34c) in the blocking position (30) of the blocking unit (21) to prevent the support rolling elements from moving radially outward.

14. The safety device according to claim 13, characterized in that, The retaining device (51) has a retaining member (52) corresponding to the corresponding support rolling element group (50), the retaining member corresponding to the radially outer support rolling element, the retaining member (52) being movable between a retaining position (53) and a non-use position (54) for retaining the corresponding outer support rolling element.

15. A drive unit having a linear driver and a safety device (11), characterized in that, The safety device (11) is formed according to any one of claims 1-14.

16. A valve, said valve being a process valve having valve fittings and an actuation unit, characterized in that, The drive unit is formed according to claim 15.

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