JP2559829Y2 - Magnetic coupling - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION This invention relates to a magnetic coupling.

[0002]

2. Description of the Related Art An example of a conventional magnetic coupling is shown in FIG.

In FIG. 2, a shaft (2) is coaxially inserted into the center of a cylindrical housing (1). housing
Although (1) is made of a non-magnetic material and not shown, the magnetic coupling is rotatably supported by a suitable bearing on a fixed portion of the device to be used so as not to move in the axial direction by a suitable bearing, and is rotated by a suitable rotary driving device. It is made to be made. Shaft (2)
Is supported by a non-contact type bearing (not shown) such as a magnetic bearing so as to be rotatable and axially movable with respect to the housing (1). A permanent magnet device comprising a plurality of pairs of permanent magnet groups (3) (4) and magnetic pole members (6) (7) on one axially opposed peripheral surface of the housing (1) and the shaft (2). (5) is provided. The permanent magnet group (3) on the housing (1) side is composed of three permanent magnets (3a) (3b) (3c) arranged in the axial direction, and these are magnetic poles provided on the inner peripheral portion of the housing (1). It is arranged between the members (6). The permanent magnet group (4) on the shaft (2) side also consists of three permanent magnets (4a) (4b) (4c) arranged in the axial direction.
These are arranged between magnetic pole members (7) provided on the outer periphery of the shaft (2). Each permanent magnet (3a) (3b) (3c), (4a) (4b)
The thick solid arrow drawn in (4c) indicates the direction of magnetization. The magnetic path of the permanent magnet device (5) is indicated by a thin broken arrow. Three permanent magnets (3a) (3b) on the housing (1) side
The magnetic pole member (6) sandwiching (3c) and the magnetic pole member (7) sandwiching the three permanent magnets (4a) (4b) and (4c) on the shaft (2) side are opposed to each other. Permanent magnets (3a), (3b), (3c), (4a), (4b), and (4c) are arranged so that competitors attract each other. The permanent magnet groups (3) and (4) and the magnetic pole members (6) and (7) forming a pair are provided at a plurality of locations that equally divide the housing (1) and the shaft (2) in the circumferential direction. A pair of permanent magnet units (3) and (4) and magnetic pole members (6) and (7) constitute a set of permanent magnet devices (5).

In this magnetic coupling, a housing (1), a permanent magnet group (3) and a magnetic pole member (6) provided on the housing (1) are provided.
When the shaft rotates, the shaft (2) and the permanent magnet group (4) and the magnetic pole member (7) provided on the shaft (2) are caused by an attractive force generated between the magnetic pole member (6) and the magnetic pole member (7) facing each other. The shaft (2) is supported in the axial direction while rotating in synchronization with the housing (1).

[0005]

[Problem to be Solved by the Invention] As described above, in the conventional magnetic coupling in which the permanent magnet device (5) is provided at one position in the axial direction, the magnetic pole member (7) on the shaft (2) side has an axial direction. In the neutral position where the position matches the axial position of the magnetic pole member (6) on the housing (1) side, the magnetic pole member on the housing (1) side
No axial attractive force acts on the magnetic pole member (7) on the shaft (2) side from (6). When the shaft (2) shifts from the neutral position, an axial suction force acts on the shaft (2), and the shaft (2) is held at a position where the load acting on the shaft (2) balances the suction force. Is done. However, if the load acting on the shaft (2) fluctuates, for example, due to the temporary disappearance of the load due to the occurrence of a descent acceleration, the shaft (2) generates an axial vibration. Also,
When the ambient temperature of the magnetic joint changes, the magnetic flux density of the permanent magnet changes, and the relationship between the axial displacement of the shaft (2) and the attractive force changes. Therefore, even if the load acting on the shaft (2) is constant, there is a problem that the axial position of the shaft (2) changes due to a temperature change.

[0006] The purpose of this invention is to solve the above problems,
An object of the present invention is to provide a magnetic joint which can provide a supporting force at a neutral position, suppress vibration due to a load change, and is less affected by a temperature change.

[0007]

The magnetic coupling according to the present invention is coaxially inserted into the center of the hollow first coupling member so that the second shaft-like coupling member can relatively rotate and move in the axial direction. In a magnetic joint in which a permanent magnet device composed of a plurality of pairs of permanent magnets and magnetic pole members facing each other is provided on opposing peripheral surfaces of these two joint members, two sets of permanent magnet devices are connected to the shafts of the two joint members. In the state in which the two joint members are relatively in the neutral position, the opposing magnetic pole members of each set of permanent magnet devices are out of phase with each other in the axial direction. It is characterized in that the direction of displacement is reversed between the two sets of permanent magnet devices.

[0008]

In the neutral position, the axial phases of the magnetic pole members facing each other of the two sets of permanent magnet devices are shifted from each other, so that an axial attractive force acts between the sets of permanent magnet devices. In addition, since the direction of this phase shift is reversed in the two sets of permanent magnet devices, the direction of the attractive force in each set of permanent magnet devices is reversed. For this reason, in the neutral position, an axial supporting force is generated between the two joint members, and the axial vibration due to the load fluctuation is suppressed. When the ambient temperature of the magnetic joint changes, the relationship between the displacement between the magnetic pole members of each permanent magnet device and the attractive force in the axial direction changes.
Since the overall axial support force between the two joint members is a composite of the attractive forces of the two permanent magnet devices, the variation in the attractive force of each permanent magnet device due to temperature is offset,
Even if the temperature changes, the relationship between the displacement of the two joint members and the overall supporting force does not change. Therefore, if the load is constant, the two joint members are supported at fixed positions even when the temperature changes.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In the following description, the upper and lower parts of FIG.

In FIG. 1, a first joint member (10) and a second joint member (11) are the same as the housing (1) and the shaft (2) of the conventional example of FIG. And two joint members
(10) The conventional permanent magnet device shown in FIG.
Two sets of permanent magnet units (12) and (13) similar to (5)
(10) They are provided at intervals in the axial direction of (11). The upper permanent magnet device (12) includes a permanent magnet group (14), a magnetic pole member (16), and a second joint member (1) on the first joint member (10) facing each other.
It consists of a permanent magnet group (15) on the 1) side and a magnetic pole member (17),
Each of the permanent magnet groups (14) and (15) includes three permanent magnets (14a) (14b) (14c) and (15a) disposed between the magnetic pole members (16) and (17).
(15b) (15c). The permanent magnet group (18) and the magnetic pole member (20) on the side of the first joint member (10) and the permanent magnet group (19) and the magnetic pole on the side of the second joint member (11) also oppose the lower permanent magnet device (13). (21), and each of the permanent magnet groups (18) and (19) includes three permanent magnets (18a) (18b) (18c) and (19a) disposed between the magnetic pole members (20) and (21). ) (19b) and (19c). Each permanent magnet (14a) (14b) (14c), (15a) (15b) (15c), (18a) (18
b) Thick solid arrows written in (18c), (19a), (19b) and (19c) indicate the directions of magnetization. In addition, each permanent magnet device (1
2) The magnetic path of (13) is indicated by a thin broken arrow.

FIG. 1 shows a state in which the second joint member (11) is at a neutral position (origin position) with respect to the first joint member (10). When the second joint member (11) is in the neutral position, the axial middle point of the upper and lower magnetic pole members (17) and (21) on the second joint member (11) side is closer to the first joint member (10) side. It coincides with the axial middle point of the upper and lower magnetic pole members (16, 20). And at this time, the magnetic pole members (16) (17) facing each other of the upper permanent magnet device (12)
Of the lower permanent magnet device (1
The phase of the magnetic pole members (20) and (21) opposed to each other in (3) is shifted in the axial direction, and the directions in which the phases are shifted are reversed between the two sets of permanent magnet devices (12) and (13). That is, as shown in FIG. 1, in the upper permanent magnet device (12), the magnetic pole member (17) on the second joint member (11) side is lower than the magnetic pole member (16) on the first joint member (10) side. These phases are shifted so that the magnetic pole member (21) on the side of the second joint member (11) becomes the first permanent magnet device (13) in the lower permanent magnet device (13).
These phases are shifted so as to be higher than the magnetic pole member (20) on the joint member (10) side.

When the second joint member (11) is in the neutral position,
Opposing magnetic pole members of two sets of permanent magnet devices (12, 13)
(16) Since the phases in the axial direction of (17), (20) and (21) are shifted from each other, an attractive force in the axial direction acts between the permanent magnet devices (12) and (13) of each set. Moreover, since the direction of the phase shift is reversed in the two sets of permanent magnet devices (12) and (13), the direction of the attraction force of each set of permanent magnet devices (12) and (13) is reversed. That is,
The second joint member (11) is attracted upward by the upper permanent magnet device (12) and downward by the lower permanent magnet device (13). Therefore, in the neutral position, an axial supporting force is generated in the second joint member (11), and the axial vibration of the second joint member (11) due to a load change is suppressed. When the ambient temperature of the magnetic joint changes, each permanent magnet device (12, (1)
The relationship between the mutual displacement and the axial attraction force of the magnetic pole members (16), (17), (20), (21) of (3) changes, but the entire axis between the two joint members (10) (11) changes. The supporting force in the direction is two permanent magnet devices (12) (1
Since the attraction force in 3) is synthesized, fluctuations in the attraction force of each of the permanent magnet devices (12) and (13) due to the temperature are offset, and even if the temperature changes, the second joint member (11) can be used. The relationship between displacement and overall bearing capacity remains unchanged. Therefore, if the load is constant, the second joint member (11) is supported at a constant position even if the temperature changes.

[0013]

According to the magnetic coupling of the present invention, as described above, an axial supporting force can be generated between the two coupling members at the neutral position, and vibration due to load fluctuation can be suppressed. Can. Further, the influence of the temperature change can be reduced, and the change in the position of the two joint members due to the temperature change can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a magnetic coupling showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a main part of a magnetic coupling showing a conventional example.

[Explanation of symbols]

 (10) First joint member (11) Second joint member (12) Upper permanent magnet device (13) Lower permanent magnet device (14) Permanent magnet group (14a) (14b) (14c) Permanent magnet (15) Permanent magnet Group (15a) (15b) (15c) Permanent magnet (16) (17) Magnetic pole member (18) Permanent magnet group (18a) (18b) (18c) Permanent magnet (19) Permanent magnet group (19a) (19b) ( 19c) Permanent magnet (20) (21) Magnetic pole member

Claims (1)

(57) [Scope of request for utility model registration] An axial second center member is provided at a center of a hollow first joint member.
A permanent magnet device comprising a plurality of pairs of permanent magnets and magnetic pole members opposed to each other is provided on the opposing peripheral surfaces of the two joint members so that the joint members can be relatively rotated and axially moved. A magnetic coupling, wherein two sets of permanent magnet devices are provided at intervals in the axial direction of the two joint members, and with the two joint members being in a relatively neutral position, each set of permanent magnet devices is A magnetic coupling characterized in that the magnetic pole members facing each other are out of phase with each other in the axial direction, and the directions in which the phases are shifted are reversed between the two sets of permanent magnet devices.