HK1255359B - Belt-type traction means and method for fabricating the traction means as well as use of said traction means in an elevator and an elevator provided with said traction means - Google Patents

Description

Belt traction device, method of manufacturing the traction device, use of the traction device in an elevator and elevator provided with the traction device

Technical Field

The object of the invention is a belt traction arrangement according to the preamble of claim 1 and a method according to the preamble of claim 6 for manufacturing the aforementioned traction arrangement, as well as the use of a traction arrangement in an elevator according to claim 14 and an elevator provided with such a traction arrangement according to the preamble of claim 15.

Background

In the known solutions of the prior art, toothed belts are generally used as transmission means, i.e. as traction means, for rotating parts of machines and plants, the belts having, for example, spur teeth, helical teeth inclined in one direction, or so-called herringbone teeth inclined in two opposite directions. When a pulley, which is the drive wheel of a machine or equipment, pulls a toothed belt, different magnitudes of tooth force are exerted on the meshing teeth of the pulley at any given time. The distribution of the tooth forces is determined by the bending of longitudinal reinforcements, such as steel wires or corresponding means, in the tooth band in one space between the teeth. For example, when the spring constant of the teeth of the gear is about 5% of the spring constant of the belt reinforcement, the maximum tooth force, which may be about 20% of the corresponding belt force, is applied to the first traction tooth of the gear at any time. In this case, the three first traction teeth of the pulley bear almost half of the entire belt force. With softer gears, the tooth forces are of course distributed to more teeth, but at the same time the deformation of the teeth with greater load increases and the teeth are overloaded.

In document WO2013/075751a1, the carrier belt comprises a plurality of tensile elements enclosed in a casing, and a working side for contact with the pulley, said working side comprising: at least one row of tooth members projecting from the surface of the working side, thereby forming at least one toothed belt portion of the working side, and at least one toothless belt portion having a flat surface for contact with a pulley. In document WO2013/041759a1, a belt structure for transmitting a rotary motion generated by a drive machine into a linear motion comprises a housing provided with a rear portion, inside which a plurality of tensioning devices are provided, said tensioning devices being arranged in the length direction of the belt structure. The tensioning devices near the edges of the belt structure are more flexible than the tensioning devices near the longitudinal centerline of the belt structure.

Another problem with belts, such as herringbone toothed belts, which operate as traction means and are substantially as wide as their thickness, is that the belt must accommodate the axial tolerances of the wheels rotated by the belt, because the axles of the traction wheels and of the diverting pulleys rotated by the belt are not always sufficiently precise in the direction of rotation of the belt. In this case, the difference between the tension of the central part of the belt and the tension applied to the edges of the belt, which is not adapted to these tolerances, becomes too great and the belt wears too fast. The belt can be better adapted by making it flexible, for example by installing tensioning means, such as wires or braids or the like suitable for bending, as reinforcements of the belt, in which case the belt is prone to bending and buckling with respect to defects in the plane of rotation of the wheel. However, in a belt drive in which the belt length is long, for example, in the use of an elevator using the belt as a traction device, the belt which is easily elongated causes many problems, and therefore the elongation rate must be minimized. In this case, a more rigid reinforcement must be used than normally, but in these cases the problems arise that the tooth profile must be very precise and that the accuracy of the alignment of the traction sheave and diverting pulley must be very good, because otherwise the difference in tension of the central part of the belt and the tension exerted on the edges becomes too great and the belt will wear.

Disclosure of Invention

The object of the present invention is to eliminate the above-mentioned drawbacks and to achieve an inexpensive and easy-to-implement belt-type herringbone traction device, which device is capable of reducing the tooth forces in the teeth of the drive wheel driving the traction device, wherein in this case the teeth are subjected to a larger belt force than at present. This in turn enables the size of the components associated with the use of drive wheels and many other machines and equipment to be reduced, in which case the cost and often layout problems are also reduced. Accordingly, the better durability of the tooth forces of the drive wheel also enables the use of more efficient solutions, if desired. The pulling device according to the invention is characterized by what is disclosed in the characterization part of claim 1. Correspondingly, the method according to the invention for manufacturing a traction means is characterized by what is disclosed in the characterization part of claim 6, and the use of the traction means according to the invention in an elevator is characterized by what is disclosed in the characterization part of claim 14. The elevator of the invention is further characterized by what is disclosed in the characterization part of claim 15. Other embodiments of the invention are characterized by what is disclosed in the other claims.

Some inventive embodiments are also discussed in the descriptive section of the present application. The inventive content of the application can also differ from the definitions in the claims presented below. The inventive content may also consist of several separate inventions, especially if the invention is considered in the light of expressions or implicit sub-tasks or from the point of view of advantages or categories of advantages achieved. In this case, some of the attributes contained in the claims below may be superfluous from the point of view of separate inventive concepts. Similarly, the different details presented in connection with each embodiment may also be applied in other embodiments. It may furthermore be stated that at least some of the dependent claims may at least in some cases be regarded as inventive.

By using the traction means according to the invention it is advantageous to implement an elevator solution in which the suspension ropes of the elevator car and the counterweight or compensating weight are separate from the traction means. In this case, the elevator machine is usually located in the bottom part of the elevator shaft, e.g. at or near the base of the elevator shaft. This type of elevator solution provided with a traction means according to the invention is very suitable for low and medium-rise buildings and, due to the small tooth forces exerted by the traction means, is even suitable for elevators intended for very high buildings. The traction means according to the invention are also suitable for new elevators in low-rise buildings which previously had no elevator. Furthermore, the traction means according to the invention are very suitable for modernization of old elevators.

The traction means according to the invention preferably comprise a toothed belt having two edge parts side by side in the width direction and a central part between and connecting the edge parts, the spring constant of the central part in the transverse direction of the toothed belt being smaller than the corresponding spring constant of the edge parts. In this case, the central part, which is more flexible than the edge parts, allows a slight widening of the toothed belt at the meshing teeth and thus a more even distribution of the belt forces to the teeth of the drive wheel driving the traction means.

In addition to this, one advantage of the solution according to the invention is that the belt forces exerted on the teeth of the drive wheel driving the herringbone toothed belt are more evenly distributed to several successive meshing teeth of the drive gear, since the toothed belt is better bent in the lateral direction. In this case the teeth together are subjected to a much greater belt force than the solutions known in the prior art. This further allows the size of the machine and all components to be reduced without, however, losing the power required. In this case, costs are reduced and there is better control over space requirements. Accordingly, the power used can be increased if desired without unduly compromising the durability of the teeth of the drive wheel. Another advantage is better durability and less wear of the toothed belt. This increases the service life of the toothed belt and enables the use of a long toothed belt without excessive internal tension being exerted on the belt due to dimensional inaccuracies in the alignment of the traction sheave and the diverting pulley. A herringbone toothed belt having better lateral flexibility than before can also reduce the noise generated by tooth contact.

In addition to this, one advantage of using the traction means according to the invention is that it enables in particular to achieve a reliably operating elevator solution with a machine in which the elevator car and the counterweight or the suspension means of the compensating weight and the traction means are separated from each other. A further advantage is that with the solution according to the invention the rope lay-out and the elevator lay-out can be made diversified, which makes the lay-out design easier. Another advantage is that the installation of the elevator is faster and easier because the dimensional accuracy requirements for the alignment of the traction sheave and the diverting pulley are lower. The solution according to the invention enables much smaller moving masses to be achieved compared to elevators according to the prior art. In this case, less acceleration force is required, whereby smaller machines, lighter structures, smaller guide rails, etc. can be used. Furthermore, the diameter of the traction wheel used as driving wheel may be approximately 1/4 of the diameter of the traction wheel required in solutions according to the prior art. It follows that the sufficient torque of the machine is also only approximately 1/4 of the torque required in the solutions according to the prior art. In this case, the efficiency of the machine is much better than in the prior art, since the speed of rotation is approximately four times faster. The above-mentioned characteristics also reduce costs and, in addition, the solution according to the invention makes it possible to save space in the height, width and depth direction of the elevator shaft.

Drawings

In the following, the invention will be described in more detail by means of some examples of its embodiments with reference to the appended simplified and schematic drawings, in which

Figure 1 shows an oblique view of the top and sides of a short section part of a towing installation according to the invention.

Figure 2 shows an end view of another cross-sectional traction device according to the present invention.

FIG. 3 shows an end view of a third cross-sectional traction device according to the invention, an

Fig. 4 presents a simplified and diagrammatic side view of an elevator arrangement in which a traction means according to the invention is used and in which the hoisting machine of the elevator is arranged in the bottom part of the elevator shaft.

Detailed Description

Fig. 1 to 3 show simplified cross-sectional views of various herringbone toothed belts according to the invention, which are used as traction means 1. What all the different toothed belts 1 have in common is that in the cross-sectional direction of the toothed belt 1, i.e. in the width direction, the edge part 2 with the teeth 2b is reinforced to withstand forces in the longitudinal and transverse directions of the toothed belt 1, while in the cross-sectional direction the toothless central part 4 in the centre of the toothed belt 1 between the side edges 2 is arranged to bend more than the edge part 2 of the toothed belt 1 at least in the transverse direction of the toothed belt 1. In this case, the spring constant of the central part 4 between the edge parts 2 and connecting the edge parts 2 in the transverse direction of the toothed belt 1 is smaller than the corresponding spring constant of the edge parts 2.

There are no teeth 2b at the central part 4 and therefore in cross section at the central part 4 there are grooves 2c, the length of which is the length of the toothed belt 1, the depth of which is substantially the height of the teeth 2b or more. The teeth 2b on the two edge parts 2 are similar to each other and, seen from above, they form angles of the same order of magnitude as each other with respect to the longitudinal centre line of the toothed belt 1 but on opposite sides of the longitudinal centre line.

Fig. 1 shows an oblique top view of a shorter section of a herringbone toothed belt 1 according to the invention, which section is composed of three parts side by side in cross section, namely a first edge part 2 and a second edge part 2 and, between them, a central part 4 in the center of the toothed belt 1 in the cross-sectional direction of the toothed belt 1, which central part is, for example, glued or otherwise fastened at its sides to a back support structure 2a serving as an edge part 2. In the structure according to fig. 1, the thickness of the central part 4 is smaller than the thickness of the support structure 2a of the edge part 2, in which case the bending properties of the central part 4 are improved.

The two edge members 2 are constituted by a support structure 2a provided with teeth 2b in an inclined attitude with respect to the direction of travel of the toothed belt 1. Inside the support structure 2, a plurality of load-bearing reinforcing means 3, for example wires or corresponding means in the longitudinal direction of the toothed belt 1, are arranged side by side. The reinforcing devices 3 are arranged side by side at regular intervals in the support structure 2 and they are arranged in the longitudinal direction of the toothed belt 1 substantially on a plane in the plane direction of the support structure 2a of the toothed belt 1.

The support structure 2a of the edge part 2 as well as the teeth 2b are of a strong and wear resistant and substantially hard material, for example of an elastomer suitable for the purpose. Correspondingly, the central part 4 has a softer material than the support structure 2a of the edge part 2, for example with some elastomer suitable for the purpose, and is arranged to act as a transverse spring in the toothed belt 1, the spring constant of which is smaller than the spring constant of the support structure 2a of the edge part 2, and in this case allows the toothed belt 1 to widen in its transverse direction at the heavily loaded engaging tooth 2 b. In this case the belt force is distributed over several teeth 2b and the reinforcement means 3 in the support structure 2a can be somewhat elongated without the tooth force becoming too great.

Fig. 2 shows an end view of a toothed belt 1 according to the invention of a second cross section, which belt serves as a traction means 1. The toothed belt 1 is otherwise similar to the toothed belt shown in fig. 1, but in this construction the thickness of the central part 4, which is of a different material, is substantially the same as the thickness of the support structure 2a of the edge part 2. In other respects, however, the belt solution is substantially similar in structure and function to the solution according to fig. 1.

Fig. 3 shows an end view of a third sectional toothed belt 1 according to the invention, which belt is used as a traction means. The toothed belt 1 is otherwise similar to the toothed belt shown in fig. 1, but in this construction the central part 4 is of the same material as the support structure 2a of the edge part 2, which support structure in this solution is essentially the width of the entire toothed belt 1. The central part 4 differs from the edge part 2 of the toothed belt 1, however, in that there are no reinforcing means 3 in the central part 4 and the thickness of the central part 4 is substantially smaller than the thickness of the support structure 2a of the edge part 2 of the toothed belt 1, because in the central part 4 there is a thinning groove 5 thinning the support structure 2 a. The groove 2c between the teeth 2b at the centre of the toothed belt 1 is in this solution now deeper with the depth of the thinned groove 5 and the base of the groove 2c extends inside the support structure 2a below the bottom plane of the teeth 2 b. The thinning groove 5 can be on the front surface of the support structure 2a of the toothed belt 1, i.e. on the side of the teeth 2b, or on the rear surface of the support structure 2a of the toothed belt, i.e. on the opposite side of the teeth 2 b. The thinner central part 4 without the reinforcing means 3 now forms, in the lateral direction of the toothed belt 1, i.e. in the width direction, a region which is more flexible than the edge parts 2 and whose spring constant in the width direction of the toothed belt 1 is smaller than the spring constant of the thicker edge parts 2.

The toothed belt 1 according to the invention is manufactured using the method according to the invention, for example in such a way that, in the case where a support structure 2a and a tooth 2b are provided on each edge of the toothed belt 1 and a central part 4 is formed between the edge parts 2 in the centre of the toothed belt 1, which central part has a spring constant in the width direction of the toothed belt 1 that is smaller than the corresponding spring constant of the edge parts 2, in the cross section of the edge parts 2, the central part 4 is arranged to bend more in the transverse direction of the toothed belt 1 than the edge parts 2 of the toothed belt 1.

In the solution according to fig. 1 and 2, the toothed belt 1 is manufactured in such a way that a central part 4, which is substantially more flexible than the edge parts 2, consists of a different material with respect to the edge parts 2 and has a spring constant smaller than that of the edge parts 2, is fastened at its sides to the mutually opposite side surfaces of the support structures 2a of the edge parts 2 between the support structures 2 a. Fastening is accomplished by, for example, gluing, vulcanization, or by other methods suitable for fastening elastomers.

Accordingly, in the solution according to fig. 3, the toothed belt 1 is produced in such a way that a thinning groove 5 is formed in the cross section of the toothed belt 1 in the center of the toothed belt 1 in the support structure 2a of the toothed belt 1 in the longitudinal direction of the toothed belt 1, at which thinning groove the support structure 2a is thinner than at the edge part 2 of the toothed belt 1. The thinning groove 5 can be made on the front surface of the supporting structure 2a of the toothed belt 1, i.e. on one side of the teeth 2b, or on the rear surface of the supporting structure 2a of the toothed belt 1, i.e. on the opposite side of the teeth 2 b. If the thinning groove 5 is formed on the side of the teeth 2b, the groove 2c between the teeth 2b can be made together with the thinning groove. The thinning groove 5 is either formed together with the profile forming the toothed belt 1, for example by casting or moulding, or is formed afterwards, for example by cutting or milling.

The dimensions, strength characteristics, spring constants and materials of the central part 4 and the edge parts 2 of the toothed belt 1 can be varied in many different ways in order to effectively adjust the transverse bending of the central part 4 and the edge parts 2 of the toothed belt 1.

Fig. 4 presents a simplified partially sectioned side view of an elevator arrangement, in which a herringbone toothed belt according to the invention is used, which functions as traction means 1. The elevator car 6 and the compensating weight or counterweight 7, hereinafter for simplicity only referred to as compensating weight 7, are suspended at 1:1, so that the suspension ropes 8 of the elevator car 6 are guided on their own guide rails from the elevator car 6 via diverting pulley 9 to the compensating counterweight 7, the second ends of the suspension ropes 8 being fastened to the compensating weight.

In the solution using the traction means 1 according to the invention, the suspension and movement of the elevator car 6 and the compensating weight 7 are separated from each other, in which case the movement is effected by means of a separate traction means 1, which traction means 1 is fixed at a first end to a fixing point 14 of the bottom part of the elevator car 6 and at a second end to a fixing point 15 of the bottom part of the compensating weight 7. The traction means 1 is guided from its first end fixing point 14 below the bottom end of the herringbone traction sheave 10 of the elevator machine 11 in the bottom end part of the elevator shaft, e.g. at floor 13 of the elevator shaft, to the diverting pulley 12, and after passing around the bottom of the diverting pulley 12 the traction means 1 is guided to the second section fixing point 15 on the bottom part of the compensating weight 7. The contact between the traction wheel and the traction means transmits the force moving the traction means to the traction means mainly through the teeth of the traction means. The traction means deflect on the traction sheave the value of the contact angle between them. The elevator machine 11 may be geared or gearless.

The purpose of the towing arrangement 1, in respect of the fixing point 14 of the first end of the towing arrangement 1, is to keep the towing arrangement 1 sufficiently tight from the operating function point of view, also the tension means 14a of the towing arrangement 1. The tensioning device 14a can be connected only to the fixing point 15 of the second end of the pulling device 1 or also at both ends of the pulling device 1.

The traction means 1 is in this elevator embodiment a herringbone toothed belt, which receives its kinetic energy from the traction sheave 10 by shape locking. Furthermore, the traction means 1 is constructed such that the central part 4, which is arranged to be more curved in the transverse direction of the traction means 1, i.e. in the width direction, than the edge parts 2 of the traction means 1, is located in the center of the traction means 1 in the cross-section of the traction means 1, in which case the belt forces acting in the traction means 1 are more evenly distributed over the herringbone gearing of the traction wheel 10.

The use of the traction means 1 according to the invention is not limited to the use of the elevator solution presented above, but the same traction means 1 can also be used in very different elevator solutions. In addition to one traction means 1 and the other components connected thereto, there may be, for example, two side-by-side components and also two side-by-side compensation weights 7. Furthermore, the suspension ratio and the traction ratio may also be other than 1:1, for example 2: 1.

The elevator of fig. 4 can also be implemented in other ways, e.g. so that the traction sheave instead of the diverting pulleys is located in the top part of the elevator shaft.

Fig. 4 shows the traction sheave and the diverting pulley arrangement such that their contact angle is 90 degrees. The elevator according to the invention can also be implemented using another contact angle. By arranging the mutual passage of the belt and the traction sheave additionally, e.g. by means of a single diverting pulley or a plurality of diverting pulleys, a contact angle of 180 degrees or even more can easily be achieved.

It must also be noted that the different solutions and features presented above may be characteristic of the invention as well as one or more other features of the invention.

It is obvious to the person skilled in the art that the invention is not limited solely to the examples described above, but that it may be varied within the scope of the claims presented below. Thus, for example, the attitude and shape of the teeth may be different from that shown above, and the structure, shape, size, number, location and material of the stiffening means may be different from that described above. Thus, for example, the material of the reinforcement means may not be iron, but for example carbon fibre, glass fibre, Kevlar, an artificial substance, preferably Aramid (Aramid), or a combination of one or more of the above, or some other metal or non-metal suitable for the purpose, and the reinforcement means may be a braid, an article of manufacture, a bundle of fibres, a wire bundle, a metal or non-metal tension rod or a composite structure receiving tension.

Claims (18)

1. A belt traction device comprising a herringbone toothed belt (1) having at least one toothed element (1a) and a support structure (2a) supporting the toothed element (1a), which support structure (2a) comprises a plurality of reinforcing means (3) in the longitudinal direction of the toothed belt (1), characterized in that the toothed belt (1) comprises two edge elements (2) side by side in the transverse direction of the toothed belt (1), and a central element (4) between the edge elements (2) and connecting the edge elements (2), the spring constant of which central element in the transverse direction of the toothed belt (1) is smaller than the corresponding spring constant of the edge elements (2).

2. Traction means according to claim 1, characterized in that the thickness of the central part (4) is equal to or less than the thickness of the support structure (2a) of the edge part (2).

3. Traction means according to claim 1 or 2, characterized in that the central part (4) is of a different material than the edge parts (2), and that the material of the central part (4) is softer and more flexible than the material of the edge parts (2).

4. Traction means according to claim 1 or 2, characterized in that in the centre of the toothed belt (1), between two edge parts (2) positioned side by side, in the direction of the cross section of the toothed belt (1), the central part (4) is fastened at its sides to the side surface toothed belt of the support structure (2a) of each edge part (2).

5. Traction means according to claim 1 or 2, characterized in that the thickness of the central part (4) is smaller than the thickness of the support structure (2a) at the edge parts (2).

6. Traction means according to claim 1 or 2, characterized in that the central part (4), which is more flexible than the edge parts (2), is adapted to allow widening of the toothed belt (1) at the meshing teeth.

7. A method for manufacturing a belt type traction device, which comprises a herringbone toothed belt (1) having at least one tooth member (1a) and a support structure (2a) supporting the tooth member (1a), which support structure (2a) comprises a plurality of reinforcing means (3) in the longitudinal direction of the toothed belt (1), characterized in that, in the width direction of the toothed belt (1), an edge member (2) having a support structure (2a) and teeth (2b) is provided on each edge of the toothed belt (1), and a central member (4) is formed between the edge members (2) in the center of the toothed belt (1), which central member has a spring constant in the width direction of the toothed belt (1) that is smaller than the respective spring constant of the edge members (2).

8. A method according to claim 7, characterized in that the central part (4), which is substantially more flexible than the edge parts (2), consists of a different material than the edge parts (2), and has a spring constant smaller than the spring constant of the edge parts (2), is fastened at its sides to mutually opposite side surfaces of the support structure (2a) of the edge parts (2).

9. Method according to claim 8, characterized in that the central part (4) is fastened at its sides to the mutually opposite side surfaces of the support structures (2a) of the edge parts (2) by gluing, welding, vulcanization or other suitable fixing method.

10. A method according to claim 7, characterised in that the support structure (2a) of the toothed belt (1) is made essentially the width of the entire toothed belt (1), and that the central part (4) is formed in such a way that, in the longitudinal direction of the toothed belt (1), in the cross-section of the toothed belt (1), at the centre of the toothed belt (1), a thinning groove (5) is formed in the support structure (2a) of the toothed belt (1), where the other solid support structure (2a) is thinner than at the edge parts (2) of the toothed belt (1).

11. Method according to claim 10, characterized in that the thinning groove (5) is formed on the front surface of the support structure (2a), i.e. on the side of the tooth (2 b).

12. Method according to claim 11, characterized in that when forming the thinned groove (5) on the front surface of the support structure (2a), i.e. on the side of the teeth (2b), a groove (2c) is formed simultaneously between the teeth (2 b).

13. Method according to claim 10, characterized in that the thinning groove (5) is formed on the rear surface of the support structure (2a), i.e. on the opposite side of the tooth (2 b).

14. Method according to any of the preceding claims 10 to 13, characterized in that the thinning groove (5) is formed in the support structure (2a) either by casting or moulding together with the forming of the profile of the toothed belt (1) or afterwards by cutting or milling.

15. Method according to any of the preceding claims 10-13, characterized in that the central part (4), which is more flexible than the edge parts (2), is adapted to allow widening of the toothed belt (1) at the meshing teeth.

16. Use of a herringbone toothed belt (1) as a traction means according to any of the preceding claims 1 to 6 for moving an elevator car (6) separate from the suspension means and at least one compensating weight (7) in an elevator.

17. Elevator, which comprises at least one elevator car (6), a drive machine (11) supported in its position relative to the elevator hoistway for effecting movement of the elevator car (6), and a herringbone toothed belt (1) used as a belt traction device according to claim 1 for transmitting the rotary movement produced by the drive machine (11) into the movement of the elevator car (6).

18. Elevator according to claim 17, characterized in that the central part (4), which is more flexible than the edge parts (2), is adapted to allow widening of the toothed belt (1) at the meshing teeth.