WO2005093928A1

WO2005093928A1 - Rotor for a permanent-magnet synchronous motor with reduced load pulsation, and lift drive unit comprising one such motor

Info

Publication number: WO2005093928A1
Application number: PCT/EP2005/003109
Authority: WO
Inventors: Dirk Schmidt; Frank Gerber
Original assignee: Ina Drives & Mechatronics Gmbh & Co. Ohg
Priority date: 2004-03-25
Filing date: 2005-03-23
Publication date: 2005-10-06
Also published as: DE102004030111A1

Abstract

The invention relates to a rotor for a permanent-magnet synchronous motor. Said rotor comprises a base body (1), numerous bearing surfaces (2) that are arranged on the periphery of the base body (1) and have longitudinal axes (4) that are parallel to the rotational axis of the rotor, and a plurality of permanent magnet elements (3) that are applied to the bearing surfaces (2) and act as magnetic poles of the rotor. Each pole comprises at least three butt-mounted permanent magnet elements (3u, 3m, 3o). The permanent magnet elements (3) of each pole are sequentially staggered in relation to each other on the associated bearing surface (2) in such a way that the load pulsation of the synchronous motor is reduced in relation to the non-staggered arrangement. The invention also relates to a lift drive unit comprising one such rotor.

Description

Rotor for a permanently excited synchronous motor with reduced load pulsation and elevator drive unit with such a motor

The present invention relates to a rotor for a permanently excited synchronous motor, this rotor having a base body which has numerous, essentially planar support surfaces arranged on the circumference, to which permanent magnet elements are attached, which act as poles of the rotor. The invention further relates to a gearless elevator drive unit which uses such a synchronous motor with such a rotor and can advantageously be used as a drive for goods or passenger lifts. In addition to the motor mentioned, such an elevator drive unit also has at least one bearing block, a traction sheave and a brake unit.

In general, permanent-magnet synchronous motors have a stator and a rotor, with electrical windings usually being attached to the stator and the rotor having permanent magnet elements which provide a permanent magnetic field for exciting the motor. Permanently excited synchronous motors are built both as inner rotors and as outer rotors (stator arranged on the inside), in order to achieve the best possible synchronism properties, the electrical windings of the stator are divided into numerous winding sections, which are arranged in succession according to the current phases used in the circumferential direction. Modern synchronous motors are often operated in an electrical 3-phase network, whereby high torques can be made available. In this case, the number of electrical partial windings is a multiple of three. The one on the rotor The number of magnetic poles formed is adapted to the winding type of the electrical coils on the stator. The ratio between the number of poles on the rotor and the number of electrical poles on the stator also influences the synchronism properties of the motor. Two adjacent poles on the rotor each form a so-called pair of poles.

Due to the acting magnetic forces, the permanent-magnet synchronous motor in the de-energized state has a noticeable detent behavior when the rotor is rotated manually, which is also referred to as "cogging" in English. However, a similar effect is more problematic for the running properties of such a synchronous motor energized state occurs under load and is referred to in this context as load pulsation, torque fluctuation or "ripple torque". The load pulsation can hardly be determined when the engine is idling (if no or only a low torque is tapped) with a sufficiently high number of poles. However, if the engine is operated with a high torque decrease, the load pulsation can be clearly determined as a periodic torque fluctuation. The torque fluctuation usually follows a sine wave which corresponds to a higher harmonic of the torque change occurring at a pole pair.

Since a load pulsation has a disruptive effect in many applications, especially when high synchronous properties are required for precision drives, there are different approaches in the prior art to reduce the load pulsation. For example, attempts are made to counteract the load pulsation by varying the current values fed into the motor in opposite directions. Such an electronic See control can lead to a reduction in the load pulsation with relatively slow running motors and constant load decrease with very fast acting control circuits. If, however, the engine control system has to compensate for rapidly changing load conditions at high speeds, conventional control circuits are no longer able to regulate the load pulsation at a reasonable cost.

Another approach pursued in practical implementations is to reduce the load pulsation by inclining the poles of the rotor with respect to the poles of the stator. In the case of permanently excited synchronous motors, the permanent magnets arranged on the rotor are tilted with respect to the axis of rotation. This inclination means that the entire cross-sectional area of the poles is never opposed, which on the one hand leads to a reduction in the maximum torque but on the other hand also leads to a leveling effect in relation to the load pulsation. The problem with this solution is above all that the iron surfaces of the rotor, which form the contact surfaces for permanent magnet elements, can no longer run parallel to the axis of rotation or at least several steps that cause a lateral offset in the longitudinal direction. Usually, the contact surfaces to which the permanent magnet elements are attached are produced by a milling process on the outside of a cylindrical base body. If it is necessary to form support surfaces that are oblique to the axis of rotation or staggered in the longitudinal direction, the milling process is complicated and expensive.

A comparable previously known solution consists in the inclination of the poles of the stator and rotor by a Achieve set in the stator laminated core. The permanent magnet poles are kept axially parallel, while the electrical poles run obliquely to the axis of rotation. However, this poses considerable problems when introducing the electrical winding. All known solutions pursue the goal of ensuring that the cross section for the magnetic flux is as undisturbed as possible despite the desired inclination of the poles on the stator and rotor.

The synchronism properties of a motor are of particular importance if it is used as a drive for elevators, in particular if it is part of a gearless elevator drive unit. Since load pulsations, which are clearly noticeable in the event of a load, are transferred directly to the traction sheave and the suspension cables, this results in a restless elevator ride, which is perceived as uncomfortable by users in passenger elevators.

Gearless elevator drives are generally known. For example, EP 1 216 949 A2 describes a traction sheave elevator with a backpack-style elevator car. A motor is used, which is connected to a traction sheave via which the carrying cables of the elevator are guided without the interposition of a transmission. The traction sheave is flanged directly to the motor shaft and has only one-sided bearing. The motor forms the load-bearing element of the drive unit and is attached with its housing to the building or to the special supports provided there. In addition to the undesirably high load pulsation, the force acting on the traction sheave on the traction sheave leads to a further disadvantage. Due to the asymmetrical introduction of force with respect to the motor housing fastening, this inevitably results in an inclination with respect to the suspension cable level stationary traction sheave, which results in increased frictional forces between the suspension cable and traction sheave. In addition, the suspension cables are subject to increased wear due to this inclination. The only one-sided mounting of the traction sheave (so-called flying mounting) leads to a high load on the motor shaft due to the resulting bending moments, which result in increased wear on the motor and poor running properties.

The load pulsation and the associated torque fluctuations can also lead to undesirable vibrations of the traction sheave, which in the event of resonance cause excessive material loading. To prevent the transmission of such vibrations into the building, fastenings of drive motors usually have to be equipped with damping elements. Due to the asymmetrical force acting on the fastening points, this also leads to an additional tilting between the suspension cable and the traction sheave.

The object of the present invention is therefore to provide an improved rotor for a permanently excited synchronous motor, in which the load pulsation is reduced or completely canceled out, without the production expenditure being increased compared to rotors with high load pulsation. In addition, the aim is to integrate a corresponding motor into an improved elevator drive unit, which also works under load conditions without disturbing load pulsation. Finally, it is a sub-task of the present invention to provide a compact elevator drive unit in which all the necessary structural units are integrated and which thus allows quick assembly in elevator shafts. This object is achieved according to the invention in that, on the one hand, the longitudinal axes of the contact surfaces for the permanent magnet elements continue to lie parallel to the axis of rotation of the rotor, each magnetic pole assigned to such a contact surface being composed of at least three permanent magnet elements lined up in series and the permanent magnet elements of each pole in the longitudinal direction as far as possible are attached sequentially offset to one another on the associated support surface, so that the load pulsation of the synchronous motor is reduced or completely canceled compared to the non-offset arrangement.

An important advantage of the invention is that no oblique or stepped contact surfaces have to be attached to the base body when manufacturing the rotor. The expensive manufacture of parallelogram magnets with radius on the contact surfaces is also eliminated. Surprisingly, it has been shown that a significant reduction in the load pulsation can be achieved simply by the offset of the permanent magnet elements on the contact surfaces. Although the non-conforming course between the contact surface and the permanent magnet elements does not permit full-surface contact of the permanent magnet elements on the iron material of the base body at all points, this does not have a negative effect on the running properties and the achievable torques. Instead, the torque fluctuation referred to as load pulsation is drastically reduced when the synchronous motor is in the energized state.

The permanent magnet elements are preferably displaced by the same amount on all contact surfaces. The permanent magnet elements adjacent to one another in the circumferential direction are thus evenly spaced apart from one another in comparison with that in FIG Axial direction adjacent annular chain of permanent magnet elements.

In a particularly advantageous embodiment, three permanent magnet elements of essentially the same size are attached to each support surface. These three permanent magnet elements are mutually offset in each case by approximately one-eighth of the circumferential section occupied by two adjacent poles (corresponds to a pair of poles). It has been shown that the load pulsation essentially follows the sixth harmonic of the torque change that is directly dependent on the pole pair angle. Furthermore, the invention is based on the knowledge that the load pulsation can be reduced or completely canceled out by a phase shift of at least three partial oscillations.

To generalize this finding, the pole pair angle, the absolute amount of which depends on the number of poles or pole pairs arranged on the rotor, is set equal to 360 ° in relation to the torque change. The torque-related state in a synchronous motor repeats itself after rotation after each angle segment comprising a pole pair, so that this assumption is justified. Investigations have shown that the load pulsation follows the sixth harmonic within such an angle segment, ie a period of the load pulsation takes an angle of electrically 60 ° within the pole pair angle calibrated to electrically 360 °. The load pulsation can be minimized or completely extinguished by assigning a separate phase to each permanent magnet element of a pole and shifting these partial phases relative to one another by the phase shift that is achieved across all permanent magnet elements of a pole to bring summed load pulsation essentially to zero.

For example, if three permanent magnet elements are used per pole (i.e. six elements in the pole pair), a shift of the phase assigned to each individual permanent magnet element by 120 ° within a full period of the load pulsation will result in the sixth harmonic being canceled. Relative to the period length of the load pulsation within the pole pair angle (electrical 60 °), this leads to a phase shift of electrical 20 ° of each permanent magnet element within the pole pair angle assumed to be electrical 360 °.

If, in an assumed example, the rotor has 20 pole pairs (number of pole pairs zρ = 20), an electrical pole pair angle of 360 ° corresponds to an absolute angle of 18 ° with respect to the full rotor circle. The electrical 60 ° within the pole pair angle, which describe the period of the sixth harmonic, would correspond to 3 ° of the full rotor circle in this case. Since the phase shift must be carried out within this period to eliminate the load pulsation, this leads to an offset of 1 ° of the full rotor circle when using three permanent magnet elements per pole. This means that the three permanent magnet elements assigned to a pole or a bearing surface on the rotor each have an offset of 1 ° of the full rotor circle in sequence.

The relationship found can be mathematically described as follows for different numbers of permanent magnet elements per pole and any number of pole pairs: 360 ° CCy = z _p -6n

where n is the number of permanent magnet elements per pole and zp is the number of pole pairs of the rotor.

According to a preferred embodiment of the rotor according to the invention, the permanent magnet elements are glued to the bearing surfaces. In the case of modified versions, the permanent magnet elements can also be soldered to the support surfaces or attached and fixed in some other suitable way. Since the width of the permanent magnet elements is preferably less than or equal to the width of the contact surfaces, this leads to a slight lateral projection of the permanent magnet elements over the contact surface, at least in the region of the ends of the rotor. The gaps between the magnets of adjacent poles remaining between the adjacent contact surfaces can be chosen so large that the offset permanent magnet elements do not come into contact with the adjacent permanent magnets.

The synchronous motor explained with the rotor according to the invention can be used particularly advantageously in a gearless elevator drive unit. A major advantage of this elevator drive unit is that the drastically reduced load pulsation enables the elevator to run at high speed.

In a preferred embodiment, the traction sheave of the elevator drive unit is arranged in a bearing block which provides the mounting of the entire unit. Furthermore, it is advantageous that the traction sheave is fixedly positioned in the bearing block by its two-sided mounting, so that the over the forces applied to the suspension cables cannot lead to an inclined position of the traction sheave in relation to the suspension cable level. Since the pedestal is directly attached to a support, for example a building wall in the elevator shaft, via its foot surface, there is no change in the position of the traction sheave or undesired vibration behavior during elevator operation, even when the load fluctuates.

The preferred attachment of the synchronous motor and the brake unit to the bearing block not only lead to a compact construction of the elevator drive unit, by means of which the required assembly work is reduced to a minimum, but also to a very stable construction in which occurring forces and moments do not cause increased wear of the engine or the brake unit.

It is particularly advantageous if the side walls of the bearing block, together with its foot surface and a top surface, form a self-contained frame which surrounds the traction sheave in a ring. This frame-shaped bearing block is preferably designed as a cast part and therefore has high rigidity. Since this rigid frame can absorb forces from different directions with appropriate dimensioning, the bearing block can be attached to the support or the structure in any installation position, which means that a wide variety of applications can be realized. The bearing block can therefore be fixed upright, overhead or laterally to the walls of the building or supports provided by the customer.

The bearing block is expediently dimensioned such that the traction sheave is arranged essentially centrally in the bearing block. is net and the occurring forces are introduced almost symmetrically into the attachment points of the foot surface.

Fastening the motor housing to the bearing block results in a flying suspension of the motor, since advantageously no additional fastening of the motor to the structure is required. This eliminates overdeterminations with regard to the mounting of the motor shaft, so that only low frictional forces occur in the corresponding bearings. The motor-side bearing of the traction sheave shaft is arranged in the first side wall of the bearing block and at the same time serves to mount the motor shaft. Additional support elements for fastening the bearing can thereby be avoided.

It is particularly advantageous if the brake-side bearing of the traction sheave shaft is arranged in the brake unit, which in turn is attached to the second side wall of the bearing block. It is particularly useful if a spring-applied multi-disc brake is used, such as that offered by the Ortlinghaus company. The overall size of the entire elevator drive unit can be kept small if the brake drum of the brake unit is integrated directly into the traction sheave. The Bremsklötzer the brake unit engage in this case by the second side wall of the bearing block and into the brake drum one to the braking force immediately ^• on the traction sheave be effective to make. This direct coupling between the brake unit and the traction sheave also meets the highest safety requirements, which are set in particular when the elevator drive unit is used on passenger elevators. Finally, it is expedient to equip the elevator drive unit with a measuring system which determines relevant values, such as the speed of rotation and the current position of the suspension cable. Such a measuring system can be installed both on the side of the traction sheave facing the motor and on the opposite side, which is directed towards the brake unit.

Further advantages, details and developments of the invention result from the following description of a preferred embodiment, with reference to the drawings. Show it:

Figure 1 is a perspective view of a simplified body of a rotor of a permanent magnet synchronous motor.

2 shows a side view of the base body equipped with permanent magnet elements;

3 shows a perspective detailed illustration of a section of the rotor;

4 shows a side sectional view of a first embodiment of an elevator drive unit using the permanently excited synchronous motor with the rotor according to FIG. 3;

5 shows a sectional side detailed view of a second embodiment of the elevator drive unit with the rotor and with a second brake drum; Fig. 6 is a schematic diagram of various installation variants of the elevator drive unit.

1 shows a perspective view of a simplified basic body 1 of a rotor. The base body consists of a magnetically conductive material and essentially has a cylindrical shape. In the interior of the base body, stiffening and bearing elements are usually arranged (not shown), with which the rotor is stiffened and can be attached to a motor shaft or can be attached to other elements (transmitted light drives, ring motors). The torque generated is tapped via the motor shaft or a similar element. In order to attach permanent magnets to the base body 1 to provide permanent excitation, numerous contact surfaces 2 are formed on the outside of the base body 1. For the rotor according to the invention, these contact surfaces can run parallel to the axis of rotation of the rotor, as in the case of conventional rotors, in which no reduction in the load pulsation is achieved in a constructive manner. The contact surfaces 2 are produced, for example, by milling, grinding, etc. on the longitudinal side. The number of contact surfaces corresponds to the number of magnetic poles.

2, the rotor is shown in a side view. Numerous permanent magnet elements 3 are attached to the base body 1. For example, this attachment is carried out by gluing, screwing or the like of the permanent magnet elements 3 onto the support surfaces 2. In the example shown, three individual permanent magnet elements 3 are attached to each support surface 2, so that three rings of permanent magnet elements which alternate with respect to their polarity direction arise. Two contact surfaces lying next to each other form a so-called pole pair with their permanent magnet elements. The magnetic polarity of the permanent magnet elements along the contact surface remains constant parallel to the longitudinal axis of the rotor. Currently common permanent magnet synchronous motors, which are used to provide higher torques, include, for example, between 30 and 200 individual poles.

To illustrate the position of the permanent magnet elements on the contact surfaces, in Fig. 2 shows a center line 4 of a selected surface. It can be seen that the permanent magnet element arranged in the middle row of rings rests 3m in the center on the contact surface. The permanent magnet element 3u arranged in the lower row of rings is shifted to the left with respect to the center line 4, so that its left side edge projects beyond the left edge of the associated contact surface. In contrast, the permanent magnet element 3o arranged in the upper row of rings is shifted to the right relative to the center line 4, so that its right side projects beyond the contact surface. The permanent magnet elements of a support surface thus lie in one plane. The resulting offset between the permanent magnet elements immediately following one another in the longitudinal direction corresponds to the offset angle <x _v explained above. The offset is carried out in the same way on each bearing surface 2, so that there is a regular arrangement of the permanent magnet elements lying in a row of rings. Depending on the number of pole pairs, the offset carried out can also result in a slight overlap between the permanent magnet elements of adjacent bearing surfaces, but this must be kept small in order not to unnecessarily weaken the resulting total torque. 3 shows a perspective detailed view of the base body 1 equipped with the permanent magnet elements 3. From this view it can be clearly seen again that the offset permanent magnet elements 3 project laterally over the contact surfaces 2 on the longitudinal ends of the base body 1. In the case of modified embodiments, however, it would also be possible for the permanent magnet elements to have a smaller width than the contact surfaces 2, so that this overhang is reduced or completely eliminated. However, this would result in a reduction in the effective cross-sectional area available for the magnetic flux between the stator and rotor, as a result of which the maximum torque of the motor would decrease. In contrast, it has been shown that the slight protrusion of the permanent magnet elements over the contact surfaces has hardly any noticeable effects on the maximum torques. Nevertheless, the load pulsation is significantly reduced and, with a suitable lateral offset, is almost completely eliminated in accordance with the procedure described above.

It is again pointed out that the principles of operation according to the invention can also be applied to rotors with differing numbers in terms of the pole pairs and the permanent magnet elements provided for each bearing surface.

FIG. 4 shows a sectional side view of a first embodiment of an elevator drive unit which is equipped with a rotor 40 of the construction described above, which is part of a permanently excited synchronous motor 41. The elevator drive unit comprises, as further main elements, a bearing block 42, a traction sheave 43 and a brake unit 44. The rotor 40 provides the generated torque to a motor shaft 46. In a preferred embodiment, the motor shaft 46 may be integral with a drive Disk shaft 47 may be formed on which the traction sheave 43 is fastened. Motor shaft and traction sheave shaft can also be individual components that are firmly connected to each other for torque transmission.

A housing 48 of the motor 41 is fastened to a first side wall 49 of the bearing block 42. In the side wall 49 there is also a motor-side bearing 50, in which the motor shaft 46 and the drive pulley shaft 47 are mounted. By fastening the motor housing 48 to the bearing block 42, the motor shaft 46 is only "floating" mounted on the side facing the traction sheave. In a modified embodiment, however, it is also conceivable that the opposite side of the motor shaft 46 is mounted in a further bearing , which is attached for example in the housing of the engine.

In the embodiment shown, the housing 48 of the motor has cooling fins 51 on its outside, which are arranged essentially parallel to the traction sheave 43. The inside of the housing 48 is coupled to the electrical winding of the motor with good thermal conductivity in order to dissipate the heat generated there. The cooling effect of the cooling fins 51 is increased when the motor protrudes at least in sections into the air flow which is generated in the elevator shaft by the elevator moved by the elevator drive unit.

The traction sheave 43 has a running surface 52 with cable grooves arranged therein in a conventional manner, in which a carrying cable is guided and driven. The suspension cable can be connected directly or via pulleys to an elevator car or a counterweight (not shown). The traction sheave 43 is between the first side wall 49 and a second side wall 53 of the bearing block 42 is arranged. The bearing block also has a foot surface 54 with a plurality of fastening points 55. In the embodiment shown, the bearing block 42 is produced as a frame-shaped cast part, the two side walls 49, 53 merging into the foot surface 54 in the lower region and a cover surface 56 in the upper surface, so that this framework is self-contained. A high rigidity of the bearing block 42 is achieved by this design. A transport eyelet 57 can be attached to the top surface 56.

The brake unit 44 is fastened to the second side wall 53 of the bearing block 42. In the embodiment shown, a brake-side bearing 58 is integrated in the brake unit 44, in which the end of the traction sheave shaft 47 facing away from the motor is mounted. In this way, the traction sheave shaft 47 is supported on both sides, so that the tensile forces transmitted from the support cable to the traction sheave do not lead to a tilting of the traction sheave with respect to the plane of the support cable. Due to the essentially central arrangement of the traction sheave 43 with respect to the fastening points 55 of the foot surface 54, the forces impressed by the supporting cable are derived almost symmetrically, so that damping elements (rubber buffers or the like) provided at the foot points have no negative effects on the aligned position of the traction sheave to have.

The brake unit 44 has a plurality of brake pads 59 which engage in a brake drum 60 to generate the required braking force. The brake drum 60 is an integral part of the traction sheave 43 in the embodiment shown if necessary, provided with suitable coatings. When the brake unit 44 is actuated, the brake pads 59 are pressed into the brake drum 60, so that the rotation of the traction sheave 43 is braked or blocked.

FIG. 5 shows a laterally sectioned detailed view of a second embodiment of the elevator drive unit, in which again the rotor 40 described above is used as part of the synchronous motor 41. The decisive difference from the previously described embodiment is that the brake unit 44 has a second brake drum 61 which is arranged outside the bearing block 42. This is necessary if the elevator drive unit moves larger loads that require an increased braking force. Depending on the application, the elevator drive unit is therefore equipped with different braking units, so that a modular system can meet a wide variety of requirements.

The flexibility of such a modular system is further increased in that traction sheaves with different diameters are available, which are arranged as required in the bearing block described. The traction sheave diameter is selected taking into account the required torque, the desired speed and the mounting space available in the elevator shaft. In addition, it is possible to provide differently sized or powerful motors which, depending on the application, are attached to the bearing block in the manner described in order to provide a suitable elevator drive unit.

Through the use of the stable bearing block and the attachment of the motor and the brake unit to this bearing block it is sufficient for the use of the elevator drive unit if the bearing block is fastened with its base 54 to a support in a manner which allows the carrying cable to be led away in the desired direction. Since the traction sheave 43 is only gripped in a frame-like manner by the bearing block 42, the supporting cable can be removed from the traction sheave in almost any direction.

6 shows some possible installation variants for the elevator drive unit, which are intended to illustrate the flexibility of this unit. The elevator drive unit is only shown in simplified form in a view of the rear of the motor. In addition, two arrows each symbolize the direction in which the support cable guided over the traction sheave is led away. In Figure a), the elevator drive unit is mounted with the foot surface of the bearing block 42 on a ceiling support 65a, which is located, for example ^, at the upper end of an elevator shaft. The suspension cable is guided downwards perpendicular to the base of the pedestal.

The high stability of the bearing block also allows tensile forces to be introduced, so that an assembly of the elevator drive unit in the base region of an elevator shaft can also be considered, as is shown in FIG. 6 b. In this mounting variant, the bearing block is fastened on a bottom surface 65b.

Overhead mounting of the elevator drive unit is also easily possible, as shown in FIG. 6, Figure c). The bracket can be attached to a ceiling surface 65c or below a ceiling bracket. Finally, FIG. 6 also shows an operating variant in FIG. D), in which the bearing block is mounted on a side wall 65d of an elevator shaft. The arrows drawn in this figure to symbolize the suspension cable guide also make it clear that the suspension cable can also be removed at an angle. The dimensions of the bearing block 42 are to be suitably adapted so that the suspension cable does not come into contact with the bearing block.

Any other mounting variants and suspension cable guides are conceivable. It is also pointed out that the elevator drive unit explained can also be constructed with other motors, in particular rotors of different construction.

Reference 3 character list 1 base body 2 contact surfaces 3 permanent magnet elements 4 longitudinal axis of the contact surface

40 rotor 41 motor 42 bearing block 43 traction sheave 44 brake unit

46 Motor shaft 47 Drive pulley shaft 48 Motor housing 49 First side wall of the pedestal 50 Motor-side housing 51 Cooling fins 52 Tread 53 Second side wall of the pedestal 54 Foot surface of the pedestal 55 Fastening points 56 Top surface 57 Transport eye 58 Brake-side bearing 59 Brake pads 60 Brake drum 61 Second brake drum

65a ceiling support 65b floor surface 65c ceiling surface 65d side wall

Claims

claims

A rotor for a permanent magnet synchronous motor, comprising: a base body (1); numerous support surfaces (2) arranged on the circumferential side of the base body (1), the longitudinal axes (4) of which lie parallel to the axis of rotation of the rotor; a plurality of permanent magnet elements (3), which are attached to the bearing surfaces (2) and act as magnetic poles of the rotor; wherein each pole comprises at least three permanent magnet elements (3u, 3m, 3o) lined up, and wherein the permanent magnet elements (3) of each pole are attached in the longitudinal direction so far sequentially to the associated support surface (2) that the load pulsation of the synchronous motor compared to the non-offset Arrangement is reduced.

2. Rotor according to claim 1, characterized in that the permanent magnet elements (3) on all bearing surfaces (2) are offset by the same amount, so that the adjacent permanent magnet elements (3) in the circumferential direction are evenly spaced apart.

3. Rotor according to claim 1 or 2, characterized in that on each bearing surface (2) three permanent magnet elements (3u, 3m, 3o) of substantially the same size are attached, which sequentially each one another by an eighteenth of the two lying side by side Pole-forming poles occupying the circumferential section are offset.

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4. Rotor according to claim 1 or 2, characterized in that the displacement angle a _v in the circumferential direction between two successive permanent magnet elements (3) of a 360 ° pole is determined according to the following formula: a _v =, where z _p - 6n zp is the number of Pole pairs of the rotor and n is the number of permanent magnet elements per contact surface.

5. Rotor according to one of claims 1 to 4, characterized in that the width of the permanent magnet elements (3) is substantially equal to the width of the contact surfaces (2), at least the permanent magnet elements (3u) arranged at the ends of the contact surfaces (2). 3o) protrude laterally in mirror image over the contact surfaces.

6. Rotor according to one of claims 1 to 5, characterized in that the permanent magnet elements (3) are glued, soldered or screwed onto the support surfaces (2).

7. Rotor according to one of claims 1 to 6, characterized in that the surfaces of the permanent magnet elements (3u, 3m, 3o) which face the stator of the synchronous motor and which are attached to a common bearing surface (2) lie in a common plane.

8. Rotor according to one of claims 1 to 7, characterized in that the bearing surfaces (2) are formed by a milling or grinding process on a cylindrical base body (1), the milling or grinding direction being parallel to the axis of symmetry of the base body (1) ,

9. Rotor according to one of claims 1 to 8, characterized in that it is designed as an inner rotor or as an outer rotor of a synchronous motor.

10. Rotor according to one of claims 1 to 9, characterized in that it is used in a synchronous motor of an elevator drive unit.

11. Elevator drive unit comprising a bearing block (42), a motor, a traction sheave (43) and a brake unit (44), characterized in that the motor is a permanently excited synchronous motor (41) which has a rotor (40) which according to one of claims 1 to 9 is formed.

12. Elevator drive unit according to claim 11, characterized in that • the bearing block (42) has a foot surface (54) for attachment to a carrier, and has a first (49) and a second side wall (53); • The motor (41) has a housing (48) which is attached to the first side wall (49) of the bearing block (42); • the traction sheave (43) is arranged between the two side walls (49, 53) of the bearing block (42), has a running surface (52) for driving one or more suspension cables and is fastened to a traction sheave shaft (47) mounted on both sides of the traction sheave, which gearlessly coupled to a motor shaft (46) of the rotor (40); and • the brake unit (44) is fastened to the second side wall (53) of the bearing block (42) and, when activated, brakes the traction sheave (43).

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13. Elevator drive unit according to claim 12, characterized in that the foot surface (54) and the two side walls (49, 53) of the bearing block (42) together with a cover surface (56) form a closed, the traction sheave (43) encompassing frame, which is manufactured as a casting.

14. Elevator drive unit according to claim 12 or 13, characterized in that the bearing of the traction sheave shaft (47) in a motor-side bearing (50), which is arranged in the first side wall (49) of the bearing block, and in a brake-side bearing (58), which is arranged in the brake unit (44).

15. Elevator drive unit according to one of claims 12 to 14, characterized in that a brake drum (60) is formed on the side surface of the traction sheave (43) facing the brake unit (44), in which a plurality of brake blocks (59) of the brake unit are brought into brake engagement can.

16. Elevator drive unit according to claim 15, characterized in that the brake unit (44) receives a second brake drum (61) which is positioned on the side of the second side wall (53) of the bearing block (42) facing away from the traction sheave (43).

17. Elevator drive unit according to one of claims 12 to 16, characterized in that the brake unit (44) is designed as a spring-applied multi-disk brake.

18. Elevator drive unit according to one of claims 12 to 17, characterized in that the dimensions of the bearing block (42) are adapted to the diameter of the traction sheave (43) in such a way that the support rope or ropes are guided unhindered to the running surface of the traction sheave at different angles can.

19. Elevator drive unit according to one of claims 12 to 18, characterized in that it can be equipped with traction sheaves of different diameters.

20. Elevator drive unit according to one of claims 12 to 19, characterized in that it also has a measuring system for detecting the rotation of the traction sheave, its speed of rotation and / or the moving length of the suspension cable.

21. Elevator drive unit according to one of claims 12 to 20, characterized in that the motor (41) and brake unit (44) are coupled to the carrier only via the bearing block (42).

22. Elevator drive unit according to one of claims 12 to 21, characterized in that the housing (48) of the motor is coupled to the electrical winding of the motor with good thermal conductivity and carries cooling fins (51) on its outside which are essentially parallel to the traction sheave (43 ) run, the elevator drive unit being arranged such that the motor (41) projects into the air flow generated by the movement of the coupled elevator.

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