Features and Types LM Guide
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Features of the LM Guide Functions Required for Linear Guide Surface Large permissible load Smooth motion with no clearance Highly rigid in all directions Superbly high speed High positioning repeatability Easy maintenance Running accuracy can be obtained easily Can be used in various environments High accuracy can be maintained over a long period Features of the LM Guide Large permissible load and high rigidity Accuracy averaging effect by absorbing mounting surface error Ideal four raceway, circular-arc groove, two point contact structure Superb error-absorbing capability with the DF design Low friction coefficient Wide array of options (QZ lubricator, Laminated contact scraper LaCS, etc.) As a result, the following features are achieved. Easy maintenance Improved productivity of the machine Substantial energy savings Low total cost Higher accuracy of the machine Higher efficiency in machine design B

Features and Types Features of the LM Guide Large Permissible Load and High Rigidity Linear bushing Mounting base 165 LM block 34 LM rail Linear Bushing model LM80 OP Basic dynamic load rating: 14.7 kN Basic dynamic load rating: 7.35 kN Fig.1 Comparison between the LM Guide and the Linear Bushing Table1 Load Capacity per Ball (P and P1) Permissible contact surface pressure: 4,200 MPa R-groove (P) Flat surface (P1) Flat surface Fig.2 Load Capacity per Ball [Large Permissible Load] The LM Guide has raceway grooves with a radius almost equal to the ball radius, which is significantly different...

[High Rigidity] The LM Guide is capable of bearing vertical and horizontal loads. Additionally, due to the circular-arc groove design, it is capable of carrying a preload as necessary to increase its rigidity. When compared with a feed screw shaft system and a spindle in rigidity, the guide surface using an LM Guide has higher rigidity.  Example of comparing static rigidity between the LM Guide, a feed screw shaft system and a spindle (vertical machining center with the main shaft motor of 7.5 kW) Table2 Comparison of Static Rigidity Unit: N/m [Components] LM Guide: SVR45LC/C0 (C0...

Features and Types Features of the LM Guide High Precision of Motion [Small lost motion] The LM Guide is provided with an ideal rolling mechanism. Therefore, the difference between dynamic and static friction is minimal and lost motion hardly occurs. 10 20 30 Number of commands (pulse) 10 20 30 Number of commands (pulse) Square slide + Turcite (Measurements are taken with the single-axis table loaded with a 500-kg weight) Fig.4 Comparison of Lost Motion between the LM Guide and a Slide Guide Table3 Lost Motion Comparison Test method Type LM Guide (HSR45) Square slide + turcite C1 clearance...

[High running accuracy] Use of the LM Guide allows you to achieve high running accuracy. [Measurement method] 30 Pitching accuracy Fig.5 Dynamic Accuracy of a Single-axis Table

Features and Types Features of the LM Guide [High accuracy maintained over a long period] As the LM Guide employs an ideal rolling mechanism, wear is negligible and high precision is maintained for long periods of time. As shown in Fig.6, when the LM Guide operates under both a preload and a normal load, more than 90% of the preload remains even after running 2,000 km. 800 [Conditions] Model No. : HSR65LA3SSC0 + 2565LPRadial clearance : C0 (preload: 15.7 kN) Stroke : 1,050mm Speed : 15 m/min (stops 5 sec at both ends) Acceleration/decelelation time in rapid motion : 300 ms (acceleration: ...

Accuracy Averaging Effect by Absorbing Mounting Surface Error The LM Guide contains highly spherical balls and has a constrained structure with no clearance. In addition, it uses LM rails in parallel on multiple axes to form a guide system with multiple-axis configuration. Thus, the LM Guide is capable of absorbing misalignment in straightness, flatness or parallelism that would occur in the machining of the base to which the LM Guide is to be mounted or in the installation of the LM Guide by averaging these errors. The magnitude of the averaging effect varies according to the length or size...

Features and Types Features of the LM Guide Even on a roughly milled mounting surface, the LM Guide drastically increases running accuracy of the top face of the table. [Example of Installation] When comparing the mounting surface accuracy (a) and the table running accuracy (b), the results are : 92.5µm Mounting surface Bottom surface Side surface 105μ m Bottom surface B 80μm Side surface D Side surface C Fig.10 Surface Accuracy of the LM Guide Mounting Base (Milled Surface Only) Fig.11 Running Accuracy After the LM Guide Is Mounted Table5 Actual Measurement of Running Accuracy on the Table...

Easy Maintenance Unlike with sliding guides, the LM Guide does not incur abnormal wear. As a result, sliding surfaces do not need to be reconditioned, and precision needs not be altered. Regarding lubrication, sliding guides require forced circulation of a large amount of lubricant so as to maintain an oil film on the sliding surfaces, whereas the LM Guide only needs periodical replenishing of a small amount of grease or lubricant. Maintenance is that simple. This also helps keep the work environment clean.

Features and Types Features of the LM Guide Substantial Energy Savings As shown in Table6, the LM Guide has a substantial energy saving effect. Table6 Comparative Data on Sliding and Rolling Characteristics Machine Specifications Single-axis surface grinding machine (sliding guide) Overall length overall width Total mass Table mass Grinding area Table guide Rolling through V-V guide Rolling through LM Guide installation No. of grinding stone axes Three axes (5.5 kW + 3.7 kW x 2) Grinding capacity: 3 times greater Table Drive Specifications Motor used Drive hydraulic pressure Electric Power...

Low Total Cost Compared with a sliding guide, the LM Guide is easier to assemble and does not require highly skilled technicians to perform the adjustment work. Thus, the assembly man-hours for the LM Guide are reduced, and machines and systems incorporating the LM Guide can be produced at lower cost. The figure below shows an example of difference in the procedure of assembling a machining center between using siding guides and using LM Guides. Normally, with a sliding guide, the surface on which the guide is installed must be given a very smooth finish by grinding. However, the LM Guide can...