WO2004069416A1

WO2004069416A1 - Combination of crusher rotor and counter blade structure thereof

Info

Publication number: WO2004069416A1
Application number: PCT/FI2004/000050
Authority: WO
Inventors: Pentti Jarkko; Jarkko Nurmi
Original assignee: Bmh Wood Technology Oy
Priority date: 2003-02-03
Filing date: 2004-02-02
Publication date: 2004-08-19
Also published as: FI20030159A; FI20030159A0

Abstract

The invention relates to a combination of a crusher rotor and a c ounter blade structure thereof, in which a crusher blade structure (2) comprising crusher teeth (2a) extending in the lateral direction is fastened to the periphery of a rotor (1) that crushes material, and in which a counter blade structure (3) comprises counter teeth (3a) that crush and cut material together with the crusher teeth (2a) of the crusher rotor (1). In order to achieve an effective, cutting crushing the contact surfaces of the crusher tooth (2a) and the counter tooth (3a) thereof deviate from a flat surface.

Description

COMBINATION OF CRUSHER ROTOR AND COUNTER BLADE STRUCTURE THEREOF

BACKGROUND OF THE INVENTION

[0001] The invention relates to a combination of a crusher rotor and a counter blade structure thereof, in which a crusher blade structure comprising crusher teeth extending in the lateral direction is fastened to the periphery of a rotor that crushes material, and in which a counter blade structure comprises counter teeth that crush and cut material together with the crusher teeth of the crusher rotor, and whereby contact surfaces of the crusher tooth and the counter tooth placed against one another deviate from a flat surface.

[0002] The crusher arrangement described above is typical when for instance recycled waste is processed into a utilizable form. In spite of a possible sorting the material contains hard un-crushable fractions that often cause malfunction in the crushing process.

[0003] When materials are being crushed by slowly rotating rotor crushers, the capacity is intensified by pushing the material to be crushed with a press against the surface of the crusher rotor. Thus, the first crushing procedure follows already when the material is being ground between the rotor and the press, while the actual crushing takes place by cutting later at the counter blade structure. The slowly rotating crushers reduce the particle size of the material by means of crushing. This is typical when the flank clearance of the crusher tooth and the counter tooth exceeds 1 to 5 mm. When the clearance is less than 1 mm, the portion of the cutting procedure increases when the crusher tooth and the counter tooth meet. The smaller the clearance the greater the cut becomes. Rounding the flank edges of the crusher tooth and the counter tooth increases the crushing portion and reduces the cutting portion. Absolute values depend on the material to be processed.

[0004] Combinations of crusher blade structures and counter blade structures are known in the art, in which the form of the crusher teeth and the counter teeth is triangular. Thus, when observing the crusher tooth on the surface of the rotor from the direction of the tangent of the rotor, it resembles a triangle with a tip pointing upwards. In order for the blade costs to remain fairly low, a quadratic crusher tooth is typically used, whose diagonal is in the direction of the radius of the rotor. Then the tooth can be turned four times, in which case all four sharp angles can be utilized. It is known that a counter tooth pro- vided with a similar profile is used as the counter element of such a crusher tooth, and a structure as the crusher tooth, in which the crushing surface is provided with a middle part that is deeper than the sides, thus intensifying the crushing process. The counter blade structure is usually provided with a flat surface and is typically an elongated piece, which functions as the counter surface of several crusher teeth.

BRIEF DESCRIPTION OF THE INVENTION

[0005] It is an object of the present invention to provide and especially to improve the counter blade structure. This object is achieved with a counter blade arrangement, mainly characterized in that the junction of the adjacent crusher teeth of the rotor is placed higher than the surface of the rotor.

[0006] The advantages achieved with the invention are presented in the following detailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In the following the invention is explained in greater detail by means of a preferred embodiment with reference to the accompanying drawings, in which

Figure 1 shows a combination of a crusher rotor and a counter blade thereof in co-operation seen from the axial direction of the rotor;

Figure 2 shows an arrangement shown in Figure 1 from direction 2- 2 in Figure 1 ; and

Figure 3 shows the co-operation of the arrangement illustrated in the previous Figures step by step.

DETAILED DESCRIPTION OF THE INVENTION

[0008] The Figures show a part of a crusher rotor 1 and a crusher blade structure 2 extending in the lateral direction (typically in the axial direction of the rotor 1) and fastened to the periphery of the crusher rotor 1 , and a counter blade structure 3 that crushes and cuts material together with the crusher blade structure 2 of the crusher rotor 1.

[0009] Typically, the crusher and the counter blade structure 2, 3 comprise individual replaceable blade parts, or teeth 2a, 3a, which are always fastened to a corresponding body part, or the rotor 3, and to a counter blade body 4.

[0010] The teeth 2a and 3a are quadratic parts placed on the tips thereof, both of which being provided with middle parts that are placed deeper than the sides; in other words the teeth 2a and 3a are concave. Thus, the cutting surfaces of the teeth 2a and 3a facing one another during cutting diverge as much as possible. The cutting surfaces move efficiently in relation to one another, meaning that they perform a cutting motion. As regards both teeth 2a and 3a, the concave surfaces prevent the material to be reduced from escaping. The cutting has an advantageous effect in relation to the required power.

[0011] What is shown particularly in Figure 2 is the preferable location of the teeth 2a and 3a. The teeth 2a on the surface of the rotor 1 are thought to form a cross-sectional surface that resembles a saw blade in cross section when the rotor 1 rotates. The innermost point of such a surface is placed substantially outside the surface cylinder of the rotor 1 (distance X) and the tips of the counter teeth 3a move a distance that equals the running clearance outside said surface.

[0012] When material is pressed towards the surface of the rotor 1 , the cutting process takes place clearly outside the surface of the rotor 1 , thus reducing the resting of the material against the rotor 1. The material is provided with sufficient space to approach the rotor 1 and the cutting takes place in the form of slices from the material bed to be pushed. The slicing is preferable in view of the crusher's capacity and reduces the formation of heat created by the abrasive operation of the surface of the rotor 1.

[0013] The above description of the invention is merely intended to illustrate the basic idea of the invention. However, those skilled in the art may implement the details of the invention in various ways within the scope of the accompanying claims.

Claims

1. A combination of a crusher rotor and a counter blade structure thereof, in which a crusher blade structure (2) comprising crusher teeth (2a) extending in the lateral direction is fastened to the periphery of a rotor (1) that crushes material, and in which a counter blade structure (3) comprises counter teeth (3a) that crush and cut material together with the crusher teeth (2a) of the crusher rotor (1), whereby contact surfaces of the crusher tooth (2a) and the counter tooth (3a) placed against one another deviate from a flat surface, characterized in that the junction of the adjacent crusher teeth (2a) of the rotor (1) is placed higher (distance X) than the surface of the rotor.

2. A counter blade structure as claimed in claim 1 , characterized in that the contact surfaces of the teeth (2a, 3a) are concave.

3. A counter blade structure as claimed in claim 1, characterized in that the teeth (2a, 3a) are formed of individual blade parts.