A closed electromagnetic brake

Abstract

The present invention relates to the technical field of brakes, and proposes a closed electromagnetic brake, in which a clutch plate and a friction disc are coaxially arranged in a space enclosed by a casing and a tail casing, a first clutch surface of the clutch plate is used for being attracted to the casing, and a second clutch surface of the clutch plate is used for engaging and rubbing with the friction disc, and at least one annular groove is provided on the second clutch surface to accommodate friction particles on the friction disc, and the annular groove is coaxially arranged with the clutch plate and the friction disc, so that iron-containing debris or dust worn out inside the closed electromagnetic brake enters the annular groove under the adsorption effect of the magnetic field on the clutch plate, thereby reducing the debris and dust entering the air gap between the clutch plate and the casing, improving the functional reliability of the electromagnetic brake and extending its service life; on the other hand, the press-fit method simplifies the assembly method of the casing and the tail casing, increases the utilization rate of the internal space of the brake, and makes the torque of the brake have room for further improvement, thereby improving the braking performance.

Description

Technical Field

[0001] The present invention relates to the technical field of brakes, and more specifically, to a closed electromagnetic brake. Background Art

[0002] The power-off electromagnetic brake is a mechanical device that uses power and spring as power sources to brake the friction disc, and transmits torque through the sleeve or directly connected to the motor shaft to brake the motor. Its structure includes components such as the housing, excitation coil, clutch plate, friction disc, tail housing, and sleeve. The working principle of the power-off electromagnetic brake is: when the excitation coil is energized to generate a magnetic field, the magnetic lines of force pass through the housing and the clutch plate, and through the air gap between the housing and the clutch plate, so that the housing and the clutch plate are attracted, so that the clutch plate is separated from the friction disc, and the hole in the friction disc is connected to the motor shaft through the sleeve or directly and rotates freely; when the excitation disappears, the spring in the housing pushes the clutch plate to make it contact with the friction surface of the friction disc, so that the rotating friction disc is braked, thereby connecting with the motor shaft through the sleeve to transmit torque, and the motor is braked. Power-off electromagnetic brakes are usually divided into open electromagnetic brakes and closed electromagnetic brakes. Closed electromagnetic brakes have been widely used due to their good sealing and high safety. However, precisely because of their good sealing, when the friction disc of the existing closed electromagnetic brake is in use, the iron-containing debris or dust that is worn away is not easy to be discharged from the brake, but is easily accumulated in the air gap formed between the clutch plate and the housing. With the use of the brake, more and more debris or dust enters the air gap, resulting in a decline in the brake function or even failure. Summary of the invention

[0003] The purpose of the present invention is to provide a closed electromagnetic brake, aiming to solve the technical problem in the prior art that iron-containing debris or dust worn off the friction disc easily enters the air gap formed between the clutch plate and the housing, resulting in a decrease in brake function or even failure.

[0004] In order to solve the above technical problems, the present invention provides a closed electromagnetic brake, which is sleeved on the motor shaft for braking, including a coaxially arranged housing, a tail housing and a shaft sleeve, and a coil and a spring arranged inside the housing, the housing and the tail housing are fixedly combined by press-fitting, and a clutch plate and a friction disk are coaxially arranged in the space enclosed by the housing and the tail housing, the first clutch surface of the clutch plate is used to engage with the housing, and the second clutch surface of the clutch plate is used to engage and rub with the friction disk, and at least one annular groove for accommodating friction particles on the friction disk is provided on the second clutch surface, and the annular groove is coaxial with the clutch plate.

[0005] Furthermore, annular friction plates matching the size of the friction plate are respectively arranged on both side surfaces of the friction plate, and the annular grooves are respectively provided on the second clutch surface at positions corresponding to the inner diameter and outer diameter of the annular friction plate.

[0006] Furthermore, the annular groove is provided in a region of the second clutch surface where the magnetic field is saturated.

[0007] Furthermore, the housing and the tail housing are fixedly combined by at least one of interference fit, gluing and welding.

[0008] Furthermore, the brake also includes a plurality of user-installed screws arranged along the circumference of the end surface of the tail housing, the user-installed screws are used to connect the motor flange, and the nuts of the plurality of user-installed screws are built into the tail housing.

[0009] Furthermore, the outer diameter of the friction disk is greater than or equal to the circumferential diameter of the plurality of user installation screws.

[0010] Furthermore, the tail shell is provided with a countersunk hole corresponding to the position of the nut of the user installation screw, and the nut is embedded in the countersunk hole.

[0011] Furthermore, through holes are provided in the housing, the clutch plate and the friction plate at positions corresponding to the nut, and the through holes are used to provide installation channels for the user to install the screws.

[0012] Furthermore, the two annular friction plates are respectively fixed on the tail housing and the clutch plate, and the friction disc is located in the middle of the two annular friction plates.

[0013] Furthermore, there is an air gap with a fixed distance between the housing and the clutch plate.

[0014] The beneficial effect of the closed electromagnetic brake provided by the present invention is that: compared with the prior art, the casing and tail casing of the closed electromagnetic brake of the present invention are fixedly combined by press-fitting, and a clutch plate and a friction disc are coaxially arranged in the space enclosed by the casing and the tail casing, the first clutch surface of the clutch plate is used to engage with the casing, and the second clutch surface of the clutch plate is used to engage and rub with the friction disc, and at least one annular groove is provided on the second clutch surface to accommodate friction particles on the friction disc, and the annular groove is coaxially arranged with the clutch plate and the friction disc, so that iron-containing debris or dust worn out of the friction material inside the closed electromagnetic brake enters the annular groove under the adsorption action of the magnetic field on the clutch plate, thereby reducing the debris and dust entering the air gap between the clutch plate and the casing, improving the functional reliability of the electromagnetic brake, and extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the prior art description. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0016] Figure 1 is a schematic diagram of the overall structure of a closed electromagnetic brake in one embodiment of the present invention;

[0017] Figure 2 yes Figure 1 Schematic diagram of the splitting;

[0018] Figure 3 yes Figure 2 Schematic diagram of the second clutch surface of the middle clutch plate;

[0019] Figure 4 is a top view schematic diagram of a closed electromagnetic brake in one embodiment (the tail shell is processed with a countersunk hole or the tail shell is not processed with a countersunk hole);

[0020] Figure 5 yes Figure 4 AA section view (unprocessed countersunk hole of tail shell);

[0021] Figure 6 yes Figure 4 BB cross-section (the tail shell is machined with a countersunk hole);

[0022] Figure 7 yes Figure 6 A partial enlarged view of

[0023] Figure 8 It is a schematic diagram of the assembly of a closed electromagnetic brake according to an embodiment of the present invention.

[0024] Description of reference numerals:

[0025] 1. Casing; 11. Coil; 12. Spring; 13. Through hole; 14. Elastic pin; 2. Tail housing; 21. User mounting screw; 22. Countersunk hole; 3. Bushing; 4. Clutch plate; 41. First clutch surface; 42. Second clutch surface; 421. Annular groove; 43. Notch; 5. Friction disc; 51. Annular friction plate; 6. Bottom clamp; 7. Press head clamp. DETAILED DESCRIPTION

[0026] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but are not to be construed as limiting the present invention.

[0027] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms such as "installation", "connection", "combination" and the like should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The preferred embodiments of the present invention are described below with reference to the accompanying drawings:

[0031] The technical solution of the present invention is applicable to electromagnetic brakes, especially closed electromagnetic brakes, and can also be applied to other similar brake structures in the field of electromagnetic brakes. There is no sole limitation on the specific application scenarios. The following is an explanation using a closed power-off electromagnetic brake as an example.

[0032] like Figure 1 , Figure 2 , Figure 5 , Figure 6 and Figure 7 As shown, in this embodiment, the closed electromagnetic brake is sleeved on the motor shaft for braking, and the closed electromagnetic brake includes a coaxially arranged housing 1, a tail housing 2 and a sleeve 3, and a coil 11 and a spring 12 arranged inside the housing 1. The housing 1 and the tail housing 2 are fixedly combined by press-fitting. A clutch plate 4 and a friction disc 5 are coaxially arranged in the space enclosed by the housing 1 and the tail housing 2. The first clutch surface 41 of the clutch plate 4 is used for attracting the housing 1, and the second clutch surface 42 of the clutch plate 4 is used for engaging and rubbing with the friction disc 5. At least one annular groove 421 is provided on the second clutch surface 42 for accommodating friction particles on the friction disc 5, and the annular groove 421 is coaxial with the clutch plate 4.

[0033] Specifically, in this embodiment, the housing 1 and the tail housing 2 of the electromagnetic brake do not need screws or other parts for assembly, but are fixedly combined by a simple press-fit method, which is simple to install and can increase the space utilization of the housing 1. By providing at least one annular groove 421 on the second clutch surface 42 where the clutch plate 4 and the friction disc 5 are engaged to accommodate the friction particles, the adsorption effect of the magnetic field on the clutch plate 4 is utilized to adsorb the worn friction particles into the annular groove 421, thereby reducing the entry of debris and dust into the air gap between the clutch plate 4 and the housing 1, improving the functional reliability of the electromagnetic brake and extending its service life.

[0034] In the above embodiment, preferably, the friction material contains ferromagnetic components, and the ferromagnetic material debris in the friction material is attracted by the magnetic field on the clutch plate 4 and gathers into the annular groove 421 to achieve the effect of dust accumulation. According to different brake structures and different properties of friction materials, different numbers of annular grooves 421 can be set, and the size of the annular groove 421 can be selected according to actual conditions, which is not limited here.

[0035] like Figure 2 and Figure 3 As shown, in this embodiment, annular friction plates 51 matching the size of the friction plate 5 are respectively provided on both sides of the friction plate 5, and annular grooves 421 are respectively provided on the second clutch surface 42 at positions corresponding to the inner diameter and outer diameter of the annular friction plate 51.

[0036] Specifically, if Figure 3 As shown, in the present embodiment, during the use of the annular friction plate 51, more friction particles will usually appear at the positions of the inner diameter and outer diameter thereof. Preferably, annular grooves 421 are respectively provided on the second clutch surface 42 at the positions corresponding to the inner diameter and outer diameter of the annular friction plate 51, so as to improve the adsorption effect of the friction particles and enable more friction particles to enter the annular grooves 421.

[0037] Specifically, in another embodiment, the annular friction plate 51 may be a friction block distributed in an annular shape.

[0038] Preferably, in this embodiment, an annular groove 421 is provided in the area where the magnetic field is saturated on the second clutch surface 42. That is, the dust accumulation groove is usually provided in a place where the magnetic field is saturated or the magnetic field saturation is relatively large, so that the leakage magnetic field can be used to the maximum extent to absorb the friction particles produced by wear. In practical applications, the magnetic field saturation distribution on the clutch plate 4 can be obtained by experimental or simulation calculation methods, and then the specific position and size of the annular groove 421 can be designed based on the obtained magnetic field saturation distribution results.

[0039] Preferably, in this embodiment, the depth dimension of the annular groove 421 can be determined according to the wear resistance of the annular friction plate 51. Through simulation calculation, the dimension of the annular groove 421 will affect the magnetic field around the groove. The increase in the depth of the annular groove 421 will cause the magnetic field near the groove to be close to saturation, and the magnetic field close to saturation can maximize the use of leakage magnetic field to absorb the friction particles worn out. Therefore, determining the depth dimension of the annular groove 421 in combination with the wear resistance of the annular friction plate 51 will help improve the adsorption effect of the friction particles. For example, under the premise that the brake space structure allows, when the wear resistance of the annular friction plate 51 is poor, it means that the annular friction plate 51 will wear away more friction particles during the use of the brake. At this time, it is necessary to enhance the dust accumulation effect of the annular groove 421. On the one hand, the annular groove 421 can be set at a place where the magnetic field is saturated or the magnetic field saturation is large. On the other hand, the depth dimension of the annular groove 421 can be appropriately deepened to make the magnetic field near the annular groove 421 close to saturation, thereby maximally utilizing leakage magnetic field to absorb the friction particles worn out, and obtain a stronger adsorption effect. When the wear resistance of the annular friction plate 51 is good, the friction particles worn out by the annular friction plate 51 are very few during the use of the brake. At this time, a shallow annular groove 421 can be set according to the situation to meet the dust accumulation requirements.

[0040] Specifically, in the present embodiment, the housing 1 and the tail housing 2 are fixedly combined by at least one of interference fit, glue bonding, and welding. In the case of high sealing requirements, two or three of the fixing methods in the above schemes can be combined to connect the housing 1 and the tail housing 2. The above press-fit combination method not only eliminates the process of assembling the brake with screws, which simplifies the assembly method of the housing 1 and the tail housing 2; at the same time, after eliminating the screw assembly, the utilization rate of the housing 1 space is increased, and the radial size of the coil 11 can be increased according to actual needs, so as to effectively reduce the power of the coil 11, reduce the heat generated by the brake coil, or increase the electromagnetic force, thereby improving the braking performance of the brake; the press-fit combination method can also achieve a good sealing effect without adding sealing materials.

[0041] like Figure 2 , Figure 4 and Figure 6 As shown, the brake further includes a plurality of user-installed screws 21 arranged along the circumference of the end surface of the tail housing 2 , the user-installed screws 21 are used to connect the motor flange, and the nuts of the plurality of user-installed screws 21 are built into the tail housing 2 .

[0042] Specifically, in this embodiment, the user installation screw 21 is built-in, and its nut is built-in in the tail housing 2. The user installation screw 21 does not need to pass through the entire brake, but is directly fixed and installed through the tail housing 2. The built-in user installation screw 21 can make the installation process simple and convenient; and can provide enough space to expand the outer diameter of the friction disc 5 according to actual needs, thereby facilitating the improvement of the torque of the brake and improving its braking performance.

[0043] Preferably, in one embodiment, the outer diameter of the friction disc 5 is greater than or equal to the circumferential diameter of the circle where the plurality of user mounting screws 21 are located.

[0044] Specifically, since the brake torque is proportional to the spring force and the radius or diameter of the friction disc 5, when the elastic force of the spring 12 remains unchanged, the brake torque can be increased by increasing the size of the friction disc 5. For example, under the premise that the user installation screw 21 is built into the tail housing 2, the outer diameter of the friction disc 5 can exceed the pitch circle of the user installation screw 21. In order to allow the user installation screw 21 to pass smoothly, slots can be opened around the friction disc 5. In this way, the brake torque can be significantly increased under the same size of the brake structure, and the braking performance of the brake can be significantly improved.

[0045] Preferably, in one embodiment, Figure 6 As shown, the tail housing 2 is provided with a countersunk hole 22 corresponding to the position of the nut of the screw 21 installed by the user, and the nut is embedded in the countersunk hole 22 .

[0046] When the user installs the screw 21 inside the brake, if the outer diameter of the friction disc 5 exceeds the pitch circle of the user installing the screw 21, during the actual assembly process of the brake, the nut of the user installing the screw 21 is likely to hit the friction disc 5. By processing the countersunk hole 22 on the tail shell 2, the nut is embedded in the countersunk hole 22, thereby ensuring that the nut of the user installing the screw 21 will not hit the friction disc 5, thereby not affecting the normal braking of the brake.

[0047] like Figure 6 As shown, through holes 13 are provided at positions of the housing 1 , the clutch plate 4 and the friction plate 5 corresponding to the nut, and the through holes 13 are used to provide installation channels for users to install screws 21 .

[0048] Specifically, through holes 13 (or slots) are provided on the housing 1, the clutch plate 4 and the friction plate 5 at positions corresponding to the nuts, and are aligned so that the user's screwdriver can easily pass through the through holes 13 to complete the installation connection between the user's installation screws 21 and the motor flange.

[0049] Specifically, if Figure 5As shown, in another embodiment, if the countersunk hole 22 is not processed on the tail housing 2, and in order to prevent the nut of the user installing the screw 21 from hitting the friction disc 5, two annular friction plates 51 or friction blocks distributed in an annular shape can be fixed on the tail housing 2 and the clutch plate 4 respectively, and the friction disc 5 is located in the middle of the two annular friction plates 51 or friction blocks distributed in an annular shape. In this way, it is not necessary to retain the thickness of the countersunk hole on the tail housing. Under the premise of ensuring good braking performance, the overall thickness of the brake can be reduced, and the processing steps can be reduced, simplifying the processing and installation process of the brake. In this embodiment, the two annular friction plates 51 can be fixedly combined with the tail housing 2 and the clutch plate 4 in a variety of ways, which are not limited here. Preferably, adhesives can be used for fixed combination. Compared with mechanical installation, adhesives are simple and quick, reduce processing steps, and can ensure the same braking reliability.

[0050] Specifically, in the enclosed brake of any of the above-mentioned embodiments, there is an air gap with a fixed spacing between the housing 1 and the clutch plate 4. Since the housing 1 and the tail housing 2 are fixedly combined by a press-fit method, during the installation and connection process by the press-fit method, the air gap between the housing 1 and the clutch plate 4 is controlled by the assembly process. After the installation is completed, the air gap spacing is fixed and does not need to be adaptively adjusted. Compared with the existing brakes whose air gaps need to be adjusted or the brakes that require high-precision parts to ensure the air gap spacing, the fixed air gap spacing in the present invention can make the brake structure simple, easy to assemble, with good assembly consistency and high precision, improve the assembly efficiency and performance of the brake, reduce the air gap adjustment process during use, and improve the overall use experience of the brake.

[0051] like Figure 4 and Figure 5 As shown, in this embodiment, a plurality of elastic pins 14 are arranged along the circumferential direction on the end surface of the housing 1 in contact with the clutch plate 4, and the elastic pins 14 are used to limit the circumferential rotation of the clutch plate 4. Preferably, an elastic cylindrical pin can be used, which is embedded in the housing 1, and the end is exposed from the end surface of the housing 1 in contact with the clutch plate 4. A plurality of notches 43 are provided on the edge of the clutch plate 4 corresponding to the position of the elastic cylindrical pin, and the plurality of notches 43 are sleeved on the elastic cylindrical pin, thereby limiting the circumferential rotation of the clutch plate 4 and ensuring the normal braking of the brake.

[0052] The following provides a production and installation step of the brake of the present invention, such as Figure 8 As shown:

[0053] Place the housing 1 on a bottom fixture 6 with several guide steel needles, and the guide steel needles pass through the through holes 13 on the housing 1;

[0054] Install the wound coil 11, elastic pin 14 and spring 12 to the corresponding positions in the housing 1 in sequence;

[0055] Place the first clutch surface 41 of the clutch plate 4 on the magnetic pole surface of the housing 1, and align the notch 43 of the clutch plate 4 with the elastic pin 14;

[0056] Place the friction disc 5 on the second clutch surface 42 of the clutch plate 4, and align the notch 43 of the friction disc 5 with the notch 43 on the clutch plate 4, and let the guide steel needle of the bottom fixture 6 pass through the notch 43 of the friction disc 5 and the notch 43 of the clutch plate 4 at the same time;

[0057] Place the user installation screw 21 in the notch 43 of the friction disc 5 (the nut is placed on the guide steel pin of the bottom fixture 6), and at the same time, cover the friction disc 5 with the tail housing 2, and allow the user installation screw 21 to pass through the countersunk hole 22 on the tail housing 2;

[0058] Align the pressure head fixture 7 with the middle hole of the tail housing 2 and the friction plate 5. At the same time, the pressure head fixture 7 is aligned with the countersunk hole 22 of the tail housing 2 and the middle guide column of the pressure head fixture 7 contacts the clutch plate 4, and the tail housing 2 is pressed onto the casing 1 by pressure. The matching surfaces of the tail housing 2 and the casing 1 are combined together by interference connection or the like.

[0059] The air gap spacing of the brake is controlled by the assembly process. After installation, the air gap is fixed and no adaptive adjustment is required. Specifically, the air gap AG is equal to the length L1 of the middle guide post of the pressure head fixture 7 minus the thickness T1 of the tail shell 2, and then minus the thickness T2 of the friction disc 5 (including the annular friction plate 51), that is, AG=L1-T1-T2.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A closed electromagnetic brake, sleeved on the motor shaft for braking, comprising a coaxially arranged housing, a tail housing and a sleeve, and a coil and a spring arranged inside the housing, characterized in that: The housing and the tail housing are fixedly combined by press-fitting, a clutch plate and a friction disc are coaxially arranged in the space enclosed by the housing and the tail housing, a first clutch surface of the clutch plate is used to be attracted to the housing, a second clutch surface of the clutch plate is used to engage and rub with the friction disc, at least one annular groove for accommodating friction particles on the friction disc is provided on the second clutch surface, and the annular groove is coaxial with the clutch plate; Annular friction plates matching the size of the friction plate are respectively arranged on the two side surfaces of the friction plate, and the annular grooves are respectively arranged on the second clutch surface at positions corresponding to the inner diameter and outer diameter of the annular friction plate; The diameter of the annular groove located on the outside is larger than the outer diameter of the annular friction plate, and the diameter of the annular groove located on the inside is smaller than the inner diameter of the annular friction plate; There is an air gap AG with a fixed spacing between the housing and the clutch plate; when installing the brake, align the pressure head fixture with the middle hole of the tail housing and the friction plate, so that the middle guide post of the pressure head fixture contacts the clutch plate, and the tail housing is pressed onto the housing by pressure. The mating surfaces of the tail housing and the housing are interference connected, and the air gap AG is equal to the length L1 of the middle guide post of the pressure head fixture minus the thickness T1 of the tail housing, and then minus the thickness T2 of the friction plate containing the annular friction plate, and the air gap AG=L1-T1-T2.

2. The enclosed electromagnetic brake according to claim 1, characterized in that: The annular groove is provided in the area of ​​the second clutch surface where the magnetic field is saturated.

3. The enclosed electromagnetic brake according to claim 1, characterized in that: The housing and the tail housing are fixedly combined by at least one of interference fit, glue bonding and welding.

4. The enclosed electromagnetic brake according to claim 1, characterized in that: The brake further comprises a plurality of user-mounted screws arranged along the circumference of the end surface of the tail housing, the user-mounted screws being used to connect the motor flange, and the nuts of the plurality of user-mounted screws are built into the tail housing.

5. The enclosed electromagnetic brake according to claim 4, characterized in that: The outer diameter of the friction disk is greater than or equal to the circumferential diameter of the plurality of user mounting screws.

6. The enclosed electromagnetic brake according to claim 5, characterized in that: The tail shell is provided with a countersunk hole corresponding to the position of the nut of the user installing the screw, and the nut is embedded in the countersunk hole.

7. The enclosed electromagnetic brake according to claim 6, characterized in that: The housing, the clutch plate and the friction plate are all provided with through holes at positions corresponding to the nut, and the through holes are used to provide installation channels for the user to install the screws.

8. The enclosed electromagnetic brake according to claim 1, characterized in that: The two annular friction plates are respectively fixed on the tail housing and the clutch plate, and the friction disc is located in the middle of the two annular friction plates.

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