Electric grinding spindle

Abstract

The utility model relates to the technical field of grinding machine motorized spindles, in particular to a grinding motorized spindle. Comprising a shell, a core shaft is supported in a cavity in the shell through a first bearing, a second bearing and a permanent magnet bearing set, the front end of the core shaft is connected with a grinding wheel disc in a conical surface contact mode, the grinding wheel disc and the front end of the core shaft are fixed through a screw, a first step face is arranged at the tail end of the core shaft, and a rotor is installed on the first step face in a heat fit mode. And a motor stator is coaxially and correspondingly arranged in the shell, and the stator and the cooling shell are arranged at the rear end of the shell in an interference fit manner. The grinding motorized spindle solves the problem that heating of a motor of the grinding motorized spindle affects a spindle shaft system, the precise angular contact bearings are arranged at the front end of the spindle in multiple rows, the spindle is high in rigidity, heating of the motor has small influence on the bearings, vibration of the spindle can be restrained under the action of magnetic force due to the arrangement of the permanent magnet bearing sets, and the grinding motorized spindle is stable and reliable. The spindle is small in vibration and high in rotation precision.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of grinding machine electric main shaft, in particular to a grinding electric main shaft. BACKGROUND

[0002] The grinding machine electric main shaft can improve the efficiency and quality of grinding due to high speed, and especially for precision parts, the grinding machine can guarantee high precision size and surface quality of the parts. The configuration of the grinding electric main shaft is usually that the motor stator and rotor are built-in and arranged at the middle position of the front and rear bearings. When high speed is needed to improve the surface grinding quality, spring pre-tightening is adopted, and when high rigidity is needed to improve the feeding efficiency, rigid pre-tightening is adopted. Since the motor generates a lot of heat during operation, even if the motor cooling system is used, heat will be conducted to the bearings, resulting in poor bearing precision and reduced service life. The heat generated by the motor also affects the mandrel of the grinding main shaft, causing the mandrel to elongate during the grinding process and affecting the grinding quality of the main shaft.

[0003] The current grinding main shaft has the following shortcomings:

[0004] 1. The existing grinding main shaft is a mechanical shaft driven by a belt, which has low speed, large vibration, low grinding efficiency and cannot guarantee the quality.

[0005] 2. Some use electric main shafts with a long rod connected to the front end, which has low rigidity.

[0006] 3. The motor stator and rotor of the current electric main shaft are of a nested structure, and a large amount of heat generated by the motor cannot be completely removed by cooling, which has a great impact on the main shaft bearing, the rotor core utilization rate is low, and the bearing stiffness is poor.

[0007] In view of the above defects, the designer actively researches and innovates to create a grinding electric main shaft, which has more industrial utilization value. CONTENT OF THE UTILITY MODEL

[0008] To solve the above technical problems, the purpose of the utility model is to provide an electric machine stator and rotor rear-mounted grinding electric main shaft with permanent magnetic bearing auxiliary support.

[0009] The utility model relates to a grinding electric main shaft, which comprises a shell, a cavity in the shell, a mandrel movably installed in the cavity through bearing group one, bearing group two and permanent magnetic bearing group three, a grinding disc installed at the front end of the mandrel through conical surface contact, a grinding wheel fixed disc connected to the front end of the grinding disc, a first step surface at the tail end of the mandrel, a rotor installed on the first step surface through thermal fitting, a cooling jacket fixed to the tail end of the shell, and a stator installed in the cooling jacket.

[0010] The grinding electric spindle, which is provided with a plurality of bearing groups, pre-supports a mandrel, and post-positions a motor, and is additionally provided with a set of permanent magnetic bearing auxiliary support between the front end of the motor and the bearing groups, so as to inhibit vibration during the operation of the spindle, and the heat generated by the motor of the spindle will not be conducted to the bearing groups at the front end of the mandrel, thereby ensuring normal operation of the electric spindle.

[0011] Further, the front end of the mandrel is provided with a second step surface, and the middle part is provided with a third step surface, and the third step surface is higher than the first step surface and the second step surface.

[0012] The third step surface is higher, and is used for distinguishing the first step surface and the second step surface.

[0013] Further, the end of the mandrel is fixed to the shell through the front locking nut, and the protrusion on the inner side of the front end cover is in abutment with the outer ring of the outer side bearing of the bearing group one.

[0014] The locking nut locks the front end cover, and the front end of the electric spindle is fixed and locked, and also plays a dustproof role.

[0015] Further, the inner side of the shell is provided with a limiting step surface which is equal in length to the second step surface, and the inner gasket and the outer gasket are in contact with the inner ring and the outer ring of the outer side bearing of the bearing group two respectively, and are in abutment with the protruding structure of the mandrel and the shell, and the bearing group one and the bearing group two are provided with an inner spacer ring which is in abutment with the mandrel and an outer spacer ring which is in abutment with the inner wall of the shell.

[0016] The inner gasket and the outer gasket facilitate positioning of the installation position of the mandrel, and ensure the installation progress of the mandrel, and the inner spacer ring and the outer spacer ring separate the bearing group one and the bearing group two, thereby increasing the span between the bearing groups and the rigidity of the bearings.

[0017] Further, the middle and rear section of the shell is provided with a mounting groove for mounting the permanent magnetic bearing group three, and the inner ring of the permanent magnetic bearing group is locked on the mandrel through interference fit at the rear end of the bearing group three.

[0018] Further, the stator seat is provided with a cooling jacket which is mounted through interference fit.

[0019] The cooling jacket assists the motor stator in heat dissipation.

[0020] Further, the tail end of the shell is provided with a rear end cover which is mounted through threads.

[0021] The rear end cover plays a role of dustproof and waterproof.

[0022] Further, the front end of the grinding disc is provided with a grinding wheel fixing disc which is mounted through threads.

[0023] The grinding wheel fixing disc is assembled through the mounting mode of threads, and can be quickly disassembled and assembled.

[0024] By the above scheme, the application has at least the following advantages: the application designs a motor-rear-mounted grinding electric spindle, adopts an arrangement that all bearing supports of the spindle are placed at the front end of the spindle, the motor is placed at the rear end of the spindle without support, in order to reduce the vibration of the spindle and increase the rigidity of the spindle, adopts a mixed support mode of permanent magnetic bearing and ceramic ball bearing, can reduce the vibration of the spindle, this configuration can effectively reduce the heat generated by the motor to be conducted to the bearing shaft system, the spindle has good thermal stability and good rigidity, can realize high-speed grinding, has small vibration, and can improve the surface quality and grinding efficiency of the ground parts.

[0025] The motor stator-rotor is built-in, there is no intermediate transmission link such as a belt and a gear, and high speed can be realized. Compared with a mechanical spindle, the electric spindle has large power torque and high speed, and for batch-produced parts, the grinding efficiency is high and the surface quality of the ground parts is high. The electric spindle is convenient to install and disassemble on a grinding machine. Compared with a traditional grinding electric spindle, the motor is arranged in a rear-mounted mode, the precision bearing group is placed at the front end of the spindle, and a group of permanent magnetic bearings is added in the middle to play a role in auxiliary support and vibration suppression, effectively avoids the heat generated by the motor from being transferred to the bearing support shaft system, the spindle runs more stably, has small vibration, high precision, and long service life.

[0026] The above description is only a summary of the technical scheme of the application, in order to more clearly understand the technical means of the application, and the content of the specification can be implemented, the following will be described in detail with the preferred embodiment of the application and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical scheme of the embodiment of the application, the following will briefly introduce the drawings needed to be used in the embodiment, it should be understood that the following drawings only show a certain embodiment of the application, therefore should not be regarded as a limitation to the scope, for those skilled in the art, without creative labor, other related drawings can also be obtained according to these drawings.

[0028] Figure 1 is a structural schematic view of the application;

[0029] Figure 2 is a sectional view of the application Figure 1

[0030] In the figure, 1 is a grinding wheel fixing disc, 2 is a grinding wheel disc, 3 is a mandrel, 4 is a front locking nut, 5 is a front end cover, 6 is a bearing group one, 7 is a shell, 8 is an outer spacer ring, 9 is an inner spacer ring, 10 is a bearing group two, 11 is an inner gasket, 12 is an outer gasket, 13 is a third step surface, 14 is a permanent magnetic bearing group three, 15 is a second step surface, 16 is a cooling jacket, 17 is a rotor, 18 is a stator, 19 is a rear end cover, and 20 is a first step surface.​ DETAILED DESCRIPTION

[0031] The specific embodiments of the utility model are described in further detail below in combination with the drawings and examples. The following examples are used to illustrate the utility model, but are not used to limit the scope of the utility model.

[0032] Referring to Figure 1 And Figure 2 The grinding motorized spindle adopts a hollow structure for the shell 7, and the bearing set one 6, the bearing set two 10 and the permanent magnetic bearing set three 14 are sequentially installed inside the shell 7 from front to back on the mandrel 3, so that the mandrel 3 can rotate, the rotor 17 is on the first step surface 15 at the tail end of the mandrel 3, the rotor 17 cooperates with the stator 18 at the rear end of the shell 7, the motor rear-mounted configuration of the spindle structure is convenient to install, and the heat dissipation efficiency can be ensured, the heat generated by the motor is avoided from being conducted to the bearing supported shaft system, and the spindle has good thermal stability.

[0033] The grinding wheel disc 2 is fixed in a mode of being attached to the conical surface of the mandrel 3, the installation positioning precision is high, installation is convenient, and the outer diameter of the grinding wheel disc can be changed according to the requirements of the inner diameter of the grinding wheel, so that different grinding requirements can be met.

[0034] The third step surface 13 protrudes in the middle of the mandrel 3, so that the mandrel 3 has a structure form of being high in the middle and low at both ends, and the bearing set is conveniently configured.

[0035] The front end of the mandrel 3 is fixed with the bearing set one 6 and the bearing set two 10 at the front end of the spindle by the front locking nut 4, the front end cover 5 is fixed on the shell 7, and the protruding structure on the inner side of the front end cover 5 is on the outer ring of the bearing on the outer side of the bearing set one 6, so that the front end of the bearing set one 2 is fixed and limited, and the front end cover 5 can also provide the functions of dustproof and waterproof.

[0036] The step-shaped structure on the inner side of the shell 7 is equal in length to the protruding structure at the tail end of the second step surface 20, the inner washer 11 and the outer washer 12 are attached to the inner side walls of the mandrel 3 and the shell 7 respectively, and are in contact with the inner and outer rings of the bearings on the outer side of the bearing set two 10, so as to position the stator in the rear end of the bearing set two 0, and the inner washer 11 and the outer washer 12 are placed at the innermost end of the mandrel 3, so as to facilitate the adjustment of the precision of the spindle.

[0037] The shell 7 has an installation groove for installing the permanent magnetic bearing set three 14.

[0038] The shell 7 has an installation groove for installing the permanent magnetic bearing set three 14, which is used for positioning the permanent magnetic bearing set three 14, the permanent magnetic bearing set three 14 is in interference fit with the mandrel 3, and the locking and positioning of the bearing set three 14 are completed,

[0039] The grinding wheel fixing disc 1 and the grinding wheel disc 2 are connected by screws to complete the fixation of the grinding wheel.

[0040] The cooling jacket 16 mounted on the shell 7 can assist the stator to dissipate heat.

[0041] The rear end cover 19 mounted at the tail end of the shell 7 seals the rear end of the main shaft, prevents water, dust and other foreign matters from entering the bearing, and increases the service life of the main shaft.

[0042] Finally, it should be noted that: first, in the description of the present application, it should be pointed out that unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, which can be mechanical connection or electrical connection, or the communication between two elements, or direct connection, "up", "down", "left", "right" and the like are only used to indicate the relative positional relationship, when the absolute position of the described object changes, the relative positional relationship may change;

[0043] Secondly: the utility model discloses the embodiment in the drawing, only relate to the structure involved in the embodiment of the present disclosure, other structures can refer to the usual design, under the condition of no conflict, the same embodiment and different embodiments of the utility model can be combined with each other.

[0044] Finally: the above is only the preferred embodiment of the utility model, and does not limit the utility model, it should be pointed out that for ordinary skilled in the art, on the premise of not departing from the technical principle of the present application, a number of improvements and modifications can be made, and these improvements and modifications should be regarded as the protection scope of the utility model.

Claims

1. A grinding electrospindle comprising a casing (7), characterized in that: The mandrel (3) is movably installed in the cavity in the shell (7) through bearing set one (6), bearing set two (10) and permanent magnetic bearing set three (14), the front end of the mandrel (3) is installed with the grinding disc (2) through the conical surface contact, the front end of the grinding disc is connected with the grinding wheel fixed disc (1), the tail end of the mandrel (3) has the first step surface (15), the first step surface (15) is installed with the rotor (17) through the thermal fit, the tail end of the shell (7) is fixed with the cooling jacket (16), the cooling jacket (16) is installed with the stator (18).

2. A grinding electrospindle according to claim 1, characterized in that: The front end of the mandrel (3) is the second step surface (20), the middle part is the third step surface (13), the third step surface (13) is higher than the first step surface (15) and the second step surface (20).

3. A grinding electrospindle according to claim 2, characterized in that: The front end cover (5) is fixed on the shell (7), the convex on the inner side of the front end cover (5) is on the outer ring of the outer bearing of bearing set one (6).

4. A grinding electrospindle according to claim 3, characterized in that: The inner side of the shell (7) has the limiting step surface with the same length as the second step surface (20), the inner gasket (11) and the outer gasket (12) are respectively in contact with the inner ring and the outer ring of the outer bearing of bearing set two (10), and are attached to the convex structure of the mandrel (3) and the shell (7), the bearing set one (6) and the bearing set two (10) have the inner spacer ring (9) attached to the mandrel and the outer spacer ring (8) attached to the inner wall of the shell (7).

5. A grinding electrospindle according to claim 4, characterized in that: The middle and rear section of the shell (7) has the installation groove for installing the permanent magnetic bearing set three (14), the permanent magnetic bearing set three (14) is fixed to the rear end of the mandrel (3) through the interference fit.

6. A grinding electrospindle according to claim 5, characterized in that: The cooling jacket (16) is installed on the shell (7).

7. A grinding electrospindle according to claim 6, characterized in that: The rear end cover (19) is installed on the tail end of the shell (7) through the thread.

8. A grinding electrospindle according to claim 1, characterized in that: The front end of the grinding disc (2) is installed with the grinding wheel fixed disc (1) through the thread. The front end of the grinding disc (2) is installed with the grinding wheel fixed disc (1) through the thread.

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