Centrifuge

Abstract

The invention relates to a centrifuge (10), having a drive shaft (12), a rotor (14), which is mounted on the drive shaft (12) and is axially removable in a removal direction (26), a quick closure (20), which operates between the rotor (14) and the drive shaft (12) and by means of which the rotor (14) can be fixed relative to the drive shaft (12) in the removal direction (26), a thrust bearing (44) connected to the drive shaft (12), a locking bearing (24) connected to the rotor (14), at least one blocking element (38), which, when activated, fixes the rotor (14) relative to the drive shaft (12) and operates between the locking bearing (24) of the rotor (14) and the thrust bearing (44) of the drive shaft (12). The pivot axis (38b) is aligned perpendicular to a straight line parallel to the drive shaft (12) and the blocking element (38) has a cardan shaft (38a), which is rotatable about the pivot axis (38b), and is connected to a bearing (40) via the cardan shaft (38a).

Claims

1-23. (canceled)

24. Centrifuge (10), comprising: a drive shaft (12), a rotor (14) which is mounted on the drive shaft (12) and is axially removable in a removal direction (26), a quick-acting closure (20) which operates between the rotor (14) and the drive shaft (12) and by means of which the rotor (14) can be fixed relative to the drive shaft (12) in the removal direction (26), a thrust bearing (44) connected to the drive shaft (12), a locking bearing (24) connected to the rotor (14), at least one blocking element (38), which, when activated, fixes the rotor (14) relative to the drive shaft (12) and operates between the locking bearing (24) of the rotor (14) and the thrust bearing (44) of the drive shaft (12), wherein the quick-acting closure (20) has an actuating element (52) and the blocking element (38) is operatively connected to the actuating element (52) such that the quick-acting closure (20) is unlocked by a movement of the actuating element (52) in a direction parallel to the longitudinal axis of the drive shaft (12) and a movement of the blocking element (38) in a direction parallel to longitudinal axis of the drive shaft (12) relative to the locking bearing (24) and/or relative to the thrust bearing (44) and that during locking, a relative movement of the blocking element (38), on the one hand, and of the locking bearing (24) and/or of the thrust bearing (44), on the other hand, toward each other occurs in a direction parallel to longitudinal axis of the drive shaft (12), with the blocking element (38) being adapted to pivot about a pivot axis at least between a blocking position and an unlocking position, said pivot axis (38b) is aligned perpendicular to a straight line parallel to the drive shaft (12) and that the blocking element (38) has a cardan shaft (38a), adapted to be pivoted about the pivot axis (38b), or a bearing (40), with said cardan shaft (38a) engaging in a bearing (40) or said bearing (40) engaging around a cardan shaft (38a).

25. Centrifuge according to claim 24, characterized in that the cardan shaft (38a) extends transversely to the longitudinal extent of the blocking element (38) and along the pivot axis (38b) of the blocking element (38), about which the blocking element (38) is pivotally connected to the bearing (40), and that a movement of the blocking element (38) about the pivot axis (38b) results in a relative movement of the blocking element (38) with its cardan shaft (38a) and the bearing (40).

26. Centrifuge according to claim 24, characterized in that the bearing (40) is part of a force transmission element (60) which is operatively connected to the actuating element (52).

27. Centrifuge according to claim 24, characterized in that the bearing (40) is a radial bearing.

28. Centrifuge according to claim 24, characterized in that the blocking element (38) has, perpendicular to its longitudinal extent, two cardan shaft areas (38a) that extend laterally to the longitudinal extent, which are each associated with an area of the bearing (40).

29. Centrifuge according to claim 24, characterized in that the blocking element (38) has a blocking area (38e) on one side with respect to the drive shaft area (38a) and a blocking mass (38c) on the other side.

30. Centrifuge according to claim 28, characterized in that the blocking mass (38c) is heavier than the blocking area (38e).

31. Centrifuge according to claim 29, characterized in that the blocking mass (38c) urges the blocking area (38e) of the blocking element (38) into the blocking position during operation of the centrifuge.

32. Centrifuge according to claim 28, characterized in that the center of gravity (S) of the blocking element (38) is located within the locking mass (38c) and is located outside the point of intersection of an axis along the longitudinal extent by the pivot axis (38b) such that, during unlocking, a torque will act on the blocking area (38e) of the blocking element (38) in the direction of the unlocking position.

33. Centrifuge according to claim 28, characterized in that the blocking area (38e) of the blocking element (38) is curved.

34. Centrifuge according to claim 28, characterized in that the blocking area (38e) matches the shape of the thrust bearing and/or of the locking bearing.

35. Centrifuge according to claim 24, characterized in that the mass element (38c) of the blocking element (38) has a U-shaped guide recess (38d) on the side remote from the free end.

36. Centrifuge according to claim 25, characterized in that the force transmission element (60) has a guide projection (62a) that engages in the recess.

37. Centrifuge according to claim 24, characterized in that the blocking element (38) is produced by metal powder injection molding (MIM), by precision casting, by pressure die casting, by cold forming, by plastic injection molding or by sintering.

38. Centrifuge according to claim 24, characterized in that at least three blocking elements (38) are provided, with all blocking elements (38) being identical and each being arranged at a uniform distance from the respective adjacent blocking element.

39. Centrifuge according to claim 25, characterized in that the force transmission element (60) is spring-loaded in the direction of the locking position.

40. Centrifuge according to claim 24, characterized in that the force transmission element (60) is a cylindrical piston which is guided in a cylinder.

41. Centrifuge according to claim 40, characterized in that the cylindrical piston (60) consists of several piston segments (54, 56, 58) which are mounted so as to be movable relative to one another about a cylinder axis.

42. Centrifuge according to claim 40, characterized in that a spring (42) is provided which acts on the cylindrical piston (60)

43. Centrifuge according to claim 40, characterized in that several springs are provided, with one spring acting on a piston segment (54, 56, 58).

44. Centrifuge according to claim 38, characterized in that the cylinder (30) is connected to the drive shaft (12) so as to support the power transmission element (60) on the drive shaft side.

45. Centrifuge according to claim 38, characterized in that the cylinder (30) is connected to the rotor (14) so as to support the power transmission element (60) on the rotor side.

46. Centrifuge according to claim 38, characterized in that during unlocking, the actuating element (52) is moved in a direction towards the drive shaft (12) or in a direction away from the drive shaft (12).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In the drawings,

[0030] FIG. 1 is a sectional view of an angle rotor with a cover and a drive shaft taken along the center axis of the centrifuge, according to a first embodiment of the invention;

[0031] FIG. 2a is a first lateral view, in perspective, of a power transmission element with three blocking elements, according to a first embodiment of the invention;

[0032] FIG. 2b is a second lateral view, in perspective, of the power transmission element with the three blocking elements, according to a first embodiment of the invention;

[0033] FIG. 2c is a third perspective view, taken at an angle from above, of the power transmission element with the three blocking elements, according to a first embodiment of the invention;

[0034] FIG. 2d is a top view of the power transmission element with the three blocking elements, according to a first embodiment of the invention;

[0035] FIG. 3 is a lateral view, in perspective, partially cut with respect to FIG. 2a;

[0036] FIG. 4a is a sectional detail view of the power transmission element with the blocking element, according to the first embodiment of the invention;

[0037] FIG. 4b is a lateral view of the part of the power transmission element of FIG. 4a;

[0038] FIG. 4c is a perspective view, taken at an angle from above, of the part of the power transmission element of FIG. 4a;

[0039] FIG. 4d is a top view of the part of the power transmission element of FIG. 4a;

[0040] FIG. 5a is a lateral view of the blocking element according to the first embodiment of the invention;

[0041] FIG. 5b is a front view of the blocking element of FIG. 5a;

[0042] FIG. 5c is a top view, in perspective, of the blocking element of FIG. 5a;

[0043] FIG. 5d a top view of the blocking element of FIG. 5a;

[0044] FIG. 6a is a lateral view of the part of the power transmission element without the blocking element, of FIG. 5a;

[0045] FIG. 6b is a front view of the part of the power transmission element of FIG. 6a;

[0046] FIG. 6c is a perspective view, taken at an angle from above, of the part of the power transmission element of FIG. 6a;

[0047] FIG. 6d is a top view of the part of the power transmission element of FIG. 6a;

[0048] FIG. 7 is a sectional view of the installed power transmission element with blocking elements according to a first embodiment, in its unlocking position, and

[0049] FIG. 8 is a sectional view according to FIG. 7, illustrating the locking position.

DESCRIPTION OF THE INVENTION

[0050] The view of FIG. 1 schematically illustrates a vertical section of a centrifuge of the invention, which in its entirety is designated by reference numeral 10, having an angle rotor according to a first embodiment of the invention. For the sake of clarity, the substructure is not shown; only the upper portion of a drive shaft 12 is indicated schematically. A rotor 14 is arranged on the drive shaft 12.

[0051] According to the embodiment shown in the figures, the centrifuge 10 comprises the vertically aligned cylindrical drive shaft 12 and the adapter 16 arranged on the drive shaft 12 and non-rotatably connected to the drive shaft 12. A concentrically arranged rotor hub 18 of rotor 14 is mounted on the adapter 16. The adapter 16 and the rotor hub 18 and thus the drive shaft 12 and the rotor 14 are non-rotatably connected in a manner explained below. The rotor 14 is equipped with a quick-acting closure 20 which connects the rotor 14 with the adapter 16 and thus with the drive shaft 12.

[0052] The adapter 16 can also be designed to form a constructive unit with the drive shaft 12 and can thus be adapted to the rotor hub 18. Otherwise, the adapter 16 is optional. Alternatively, the drive shaft 12 can also be designed to directly accommodate the rotor hub 18.

[0053] The outer contour 16a, 16b of the adapter 16 is essentially adapted to the inner profile of the rotor hub 18 and, viewed from a shoulder 16c, initially extends in the form of an upwardly tapering cone 16a, then in the form of a cylinder 16b.

[0054] The inner profile of the rotor hub 18 extends upwards beyond the free end of the cylindrical part of the outer contour 16b of the adapter 16 and then merges into a rotor central area 22 that is non-rotatably connected to the rotor hub 18.

[0055] For axially fixing the rotor 14 on the adapter 16 and thus on the drive shaft 12, the rotor central area 22 has a locking part 24 that projects into the adapter 16 and has an outer contour of a diameter which, as viewed against the removal direction 26, first increases up to its widest point 24a and from there then decreases. The area of the outer contour in which the circumference decreases as viewed against the removal direction 26 forms a control surface 24b, the function of which will be explained below. The locking part 24 is spaced from the inner contour of the adapter 16. The locking part 24 has a bore 24c made in it, which bore 24c is concentric to a drive axis 28.

[0056] The adapter 16 is provided with a first central cylindrical recess 30 and a second central cylindrical recess 30 immediately following thereafter in the upward direction and having a wider diameter, resulting in an inner contour 32. The inner contour 32 has a longer higher section 32a, followed by a shoulder 32b at its rotor-side end. A shorter lower section 32c having a wider inner diameter than the longer section 32a adjoins this shoulder 32b.

[0057] The base of the recess 30 rests on the drive shaft 12. A threaded screw 34 and pins (not shown) connect the base to the drive shaft 12 at its front end. In this manner, the drive shaft 12 and the adapter 16 are non-rotatably connected to each other.

[0058] Located within the adapter 16, above the base of the recess 30, is the shaft-side part of the quick-acting closure 20. This part comprises a blocking unit 36 shown in FIGS. 2 to 6, in which three blocking elements 38 are each mounted in a radial bearing 40 and arranged at an equal distance from each other. The blocking unit 36 forms a piston 60 which is acted upon in the removal direction 26 by a spring 42 resting on the bottom of the recess 30. The piston 60 can be moved along the longitudinal axis of the drive shaft 12, as will be explained below.

[0059] A thrust bearing insert 44 is screwed into section 32c of the adapter 16. This insert extends upwards over the free end of section 32c, and its outer contour above section 32c is adapted to the inner contour of the rotor central area 22. The thrust bearing insert 44 has a bore 44a, the upper end of which is dimensioned such that the widest point 24a of locking part 24 can pass therethrough. Bore 44a then widens conically towards the bottom and forms an abutment surface 44b, the function of which will be explained below.

[0060] The inner contour 32a, 32b, 32c of adapter 16, together with the abutment surface 44b of the thrust bearing insert 44 and, with the rotor 14 in place on the drive shaft 12, the outer contour of the locking part 24, between them delimit a locking chamber within which the rotor 14 is locked and unlocked and thus fixed axially on the drive shaft 12.

[0061] Arranged above the rotor 14 is a removable cover 46 that forms a non-detachable unit with a handle 48. Handle 48 is mounted concentrically relative to the drive axis 28 on the top of cover 46, with a housing 50 of handle 48 having a rotationally symmetrical outer contour and a cylindrical inner contour and a centrally arranged recess 46a of cover 46, which recess 46a extends through the cover 46.

[0062] The rotor-side part of the quick-acting closure 20 is essentially arranged inside the handle 48. It comprises an actuating pin 52 that is longer in length than the axial extent of the handle 48 and which on the shaft side passes through the locking part 24 in bore 24c and comes into contact with a base area 36a of blocking unit 36. The free end of actuating pin 52 has an actuating knob 52a. The rotor is unlocked as a result of the interaction of handle 48 and actuation knob 52a. Actuation knob 52a must be depressed, with the handle 48 serving as a counter bearing for the user, then the rotor 14 can be removed, especially via the handle 48.

[0063] The view of FIG. 7 is an enlarged detail of a cross-section taken along the center axis of the centrifuge 10 of FIG. 1, showing the quick-acting closure 20 in its unlocked state, with rotor 14 still mounted on adapter 16. Actuating pin 52 is depressed. As a result, the piston-shaped locking unit 36, which has the actuating pin 52 in abutment with its base area on the shaft side, is displaced in the locking chamber against the removal direction 26 that is parallel to the longitudinal axis of the drive shaft 12, against the action of the spring 42. In the fully unlocked position of the blocking elements 38, their free ends abut on the control surface 24b of locking part 24, i.e. the blocking elements 38 are then outside their blocking position between locking part 24 and abutment surface 44b.

[0064] For locking, see FIG. 8, the pressure on actuating pin 52 is released against the removal direction 26. In doing so, the rotor 14 is brought into its locked position. The weight of the rotor 14 may be sufficient to cause the rotor 14 to move into its locked position. For light-weight rotors 14, the rotor may have to be pushed slightly into its locked position. Mounting the rotor 14 causes the locking unit 36 and thus also the blocking elements 38 mounted in the locking unit 36 to be displaced in the removal direction 26, i.e. along the longitudinal axis, due to the action of spring 42, or causes these components to counteract the weight of the rotor 14. The blocking elements 38 slide along the control surface 24b of the locking part 24 of the rotor 14, past its widest point 24a, into their blocking position between the outer contour of the locking part 24 and the abutment surface 44b. The weight of the rotor 14 counteracts the blocking elements 38 of the locking unit 36 sliding over the control surface 24b.

[0065] For locking, the blocking elements 38 are deflected laterally, i.e. pivoted about a horizontally extending pivot axis 38b, so as to enable them to pass the widest point 47a, after which, due to the center of gravity of the blocking elements 38, they will not fully resume their original orientation, as will be explained in more detail below, but will again bear against the outer contour of the locking part 24 and the abutment surface 44b. This results in the rotor 14 being fixed in centrifuge 10 in the axial direction, i.e. both in the removal direction and in the direction opposite thereto.

[0066] The view of FIG. 8 is an enlarged detail of a cross-section taken along the center axis of the centrifuge 10 of FIG. 1, showing the quick-acting closure 20 in its locked state. In contrast to the view of FIG. 7, this view shows the actuating pin 52 in the position into which it is automatically moved by the indirect action of the spring 42 when no external pressure is exerted on the pin 52 in the direction of the longitudinal axis of the drive shaft 12. The locking unit 36 and the blocking elements 38 mounted on the locking unit 36 are located in the area of the locking chamber near the rotor, due to the action of the spring 42 and the absence of any pressure exerted by the actuating pin 52 in the direction of the drive shaft 12. In their locking position, the blocking elements 38 are located between the outer contour of the locking part 24 and the abutment surface 44b. The quick-acting closure 20 is thus locked.

[0067] As is seen in particular in the views of FIGS. 2 to 6, the locking unit 36 consists of three piston segments 54, 56 and 58. All three piston segments 54, 56, 58 are of identical design and form a piston 60 as a force transmission element. The piston 60 is mounted in the cylindrical recess 30 of the adapter 16. The spring 42 acts on the piston 60. The piston segments 54, 56, 58 are mounted so as to be movable relative to each other along the drive axis 28. This allows manufacturing tolerances to be compensated and it is ensured that all the blocking elements 38 are operative in the locking position. This also ensures that all the blocking elements 38 are arranged at the same distance from each other.

[0068] Each piston segment 54, 56, 58 is equipped with a radial bearing 40 in order to allow pivoting about the horizontal pivot axis 38b and thus perpendicularly about a straight line parallel to the longitudinal axis of the drive shaft 12. The radial bearing 40 is formed by two bearing arms 40a and 40b, which in some areas engage around a cardan shaft 38a that extends transversely to the longitudinal extent of the blocking element 38. The cardan shaft 38a extends along the horizontally extending pivot axis 38b of the blocking element 38 and has two cardan shaft areas on each side. The blocking element 38 is adapted to pivot about this pivot axis 38b between an unlocking position, as shown in FIG. 7, and a locking position, as shown in FIG. 8. Below the cardan shaft 38a, the blocking element 38 is provided with a substantially rectangular mass element 38c, above the cardan shaft 38a, it is provided with the blocking area 38e. The pivot shaft 38b extends perpendicularly to a straight line parallel to the longitudinal axis of the drive shaft 12 and is therefore horizontally aligned when the longitudinal axis of the drive shaft 12 is vertical.

[0069] The piston segments 54, 56, 58 each have a recess 62 made in them that matches the outer contour of the mass element 38c. The recess 62 is designed in such a way that the mass element 38c is always located within the envelope of the piston 60, regardless of the pivotal position of the blocking element 38. This ensures that the piston 60 will not be impeded as it moves along the drive axis 28 in the recess 30 in the adapter 16, regardless of the pivotal position of the blocking element 38.

[0070] The recess 62 has a rectangular projection 62a in its lower area, which projection 62a extends into recess 62. Correspondingly, the mass element 38c has an associated U-shaped recess 38d designed to match the shape of the projection 62a.

[0071] The blocking area 38e is curved and designed to match the outer contour of the locking part 24.

[0072] The blocking mass 38c is heavier than the blocking area 38e. The center of gravity S of the blocking element 38 is located within the blocking mass 38c and is thus outside the point of intersection of an axis along the longitudinal extent of the blocking element 38 by the pivot axis 38b. This means that during unlocking, a torque acts on the blocking area 38e of the blocking element 38 in the direction of the unlocking position. During unlocking, i.e. when the actuating pin 52 is actuated and the piston 60 is moved against the force of the spring 42, the torque applied will thus cause the blocking element 38 to pivot about the horizontal pivot axis 38b from the locking position into the unlocking position.

[0073] The piston segment 54, 56, 58 is provided with a centrally arranged strut 64 which, together with the other piston segments 54, 56, 58 resting against each other, forms a cylindrical receptacle 66 for the actuating pin 52, see FIG. 6 in particular. A horizontal strut 68, which is connected to the vertical strut 64 and terminates within projection 62a, forms the contact surface 68a of the spring 42. In addition, the struts 64 and 68 act to stabilize the piston segment in 54, 56, 58. The vertical strut 64, together with the side surfaces of the piston segment 54, 56, 58, serves as a guide surface with respect to the other adjacent piston segments 54, 56, 58, which together form the piston 60, so as to enable the piston segments 54, 56, 58 to move relative to each other.

[0074] The blocking element 38 is manufactured by powder injection molding, in particular metal powder injection molding, by precision casting, by pressure die casting, by cold forming, by plastic injection molding or by sintering.

[0075] In an alternative embodiment not shown here, the blocking element 38 engages around the bearing 40, and the piston segments 54, 56 and 58 engage around the cardan shaft 38a. The blocking element 38 with the bearing 40 is adapted to be pivoted relative to the cardan shaft of the piston segment. Otherwise, the design of the piston segments 54, 56 is the same as in the embodiment described above.

LIST OF REFERENCE SIGNS

[0076] 10 centrifuge [0077] 12 drive shaft [0078] 14 rotor [0079] 16 adapter [0080] 16a conical part of the outer contour of adapter 16 [0081] 16b cylindrical part of the outer contour of adapter 16 [0082] 16c shoulder of the outer contour of adapter 16 [0083] 18 rotor hub [0084] 20 quick-acting closure [0085] 22 rotor central area [0086] 24 locking part [0087] 24a widest part of the outer contour of locking part 24 [0088] 24b control surface of the outer contour of locking part 24 [0089] 24c central bore in locking part 24 [0090] 26 removal direction [0091] 28 drive axis [0092] 30 recess in adapter 16 [0093] 32 Inner contour within adapter 16 [0094] 34 threaded screw [0095] 36 control unit [0096] 38 blocking element [0097] 38a cardan shaft [0098] 38b pivot axis [0099] 38c mass element [0100] 38d recess in mass element 38c [0101] 38e blocking area of blocking element 38 [0102] 40 radial bearing [0103] 40a left-side bearing arm [0104] 40b right-side bearing arm [0105] 42 spring [0106] 44 thrust bearing insert [0107] 44a bore in thrust bearing insert [0108] 44b abutment surface [0109] 46 removable cover [0110] 46a recess in cover 46 [0111] 48 handle [0112] 50 housing of handle 48 [0113] 52 actuating pin [0114] 52a actuating knob of actuating pin 52 [0115] 54 first piston segment [0116] 56 second piston segment [0117] 58 third piston segment [0118] 60 piston [0119] 62 recess [0120] 62a projection in recess 62 [0121] 64 strut [0122] 66 cylindrical receptacle [0123] 68 horizontal strut [0124] 68a contact surface [0125] S center of gravity of blocking element 38